FieldThe present disclosure relates to an aerosol delivery system, an induction assembly for use in the aerosol delivery system, a cartridge comprising a susceptor, a device part for use with the induction assembly, and a method for operating the aerosol delivery system.
Many electronic vapour provision systems, such as e-cigarettes and other electronic nicotine delivery systems that deliver nicotine via vaporised liquids, are formed from two main components or sections, namely a cartridge or cartomiser section and a control unit (battery section). The cartomiser generally includes a reservoir of liquid and an atomiser for vaporising the liquid. These parts may collectively be designated as an aerosol source. The atomiser generally combines the functions of porosity or wicking and heating in order to transport liquid from the reservoir to a location where it is heated and vaporised. For example, it may be implemented as an electrical heater, which may be a resistive wire formed into a coil or other shape for resistive (Joule) heating or a susceptor for induction heating, and a porous element with capillary or wicking capability in proximity to the heater which absorbs liquid from the reservoir and carries it to the heater. The control unit generally includes a battery for supplying power to operate the system. Electrical power from the battery is delivered to activate the heater, which heats up to vaporise a small amount of liquid delivered from the reservoir. The vaporised liquid is then inhaled by the user.
The components of the cartomiser can be intended for short term use only, so that the cartomiser is a disposable component of the system, also referred to as a consumable. In contrast, the control unit is typically intended for multiple uses with a series of cartomisers, which the user replaces as each expires. Consumable cartomisers are supplied to the consumer with a reservoir pre-filled with liquid, and intended to be disposed of when the reservoir is empty. For convenience and safety, the reservoir is sealed and designed not to be easily refilled, since the liquid may be difficult to handle. It is simpler for the user to replace the entire cartomiser when a new supply of liquid is needed.
In this context, it is desirable that cartomisers are straightforward to manufacture and comprise few parts, whilst providing a suitable amount of vapour upon activation of the heater. They can hence be efficiently manufactured in large quantities at low cost with minimum waste without comprising the user's vaping experience. Cartomisers of a simple design which allow for efficient heating are hence of interest.
Various approaches are described which seek to help address some of these issues.
According to a first aspect of certain embodiments there is provided an aerosol delivery system for generating an aerosol from an aerosol generating substrate, the aerosol delivery system comprising: an induction assembly comprising an induction element disposed about a longitudinal axis, wherein the induction element is operable to induce current flow in a susceptor to inductively heat the susceptor to aerosolise a portion of the aerosol generating substrate in the vicinity of the susceptor; and a cartridge comprising a reservoir for the aerosol generating substrate and the susceptor, wherein the susceptor is disposed about the longitudinal axis and at least partly within the induction element.
In some examples in accordance with the first aspect, the susceptor is configured to extend around a circumference perpendicular to the longitudinal axis; and optionally wherein the susceptor is configured to extend around the entirety of the circumference perpendicular to the longitudinal axis.
In some examples in accordance with the first aspect, the susceptor comprises a tube element comprising a tube longitudinal axis extending between respective ends of the tube element, wherein the tube longitudinal axis is co-aligned with the longitudinal axis; optionally wherein the tube element comprises a circularly symmetric tube element.
In some examples in accordance with the first aspect, the susceptor comprises a first susceptor surface defining at least a part of an air pathway.
In some examples in accordance with the first aspect, the air pathway is co-aligned with the longitudinal axis.
In some examples in accordance with the first aspect, the air pathway is a peripheral air pathway, the first susceptor surface defining at least a part of the peripheral air pathway, the peripheral air pathway provided between the susceptor and the induction element.
In some examples in accordance with the first aspect, the susceptor is formed of a material having a capillary structure configured to wick a liquid aerosol generating substrate; wherein optionally the susceptor is formed of one of a wire wool, mesh or metal foam.
In some examples in accordance with the first aspect, the susceptor comprises a planar element, the planar element having a thickness in the range of one or more of 20 µm to 70 µm, 30 µm to 60 µm, and 40 µm to 55 µm.
In some examples in accordance with the first aspect, the susceptor is offset from the induction element by an offset distance, wherein the offset distance is one or more of a range of less than 3 mm, a range of less than 2 mm, a range of less than 1.5 mm, and a range of less than 1 mm.
In some examples in accordance with the first aspect, the reservoir is for a liquid aerosol generating substrate, wherein the cartridge is configured to supply liquid aerosol generating substrate from the reservoir to the susceptor; wherein optionally the cartridge comprises a liquid transport element configured to wick the liquid aerosol generating substrate towards the susceptor.
In some examples in accordance with the first aspect, the cartridge comprises one or more liquid flow channels for guiding liquid aerosol generating substrate from the reservoir; and / or the cartridge comprises a sub-reservoir provided at or towards an opposite end of the susceptor to the reservoir, the sub-reservoir configured to hold a smaller volume of liquid aerosol generating substrate than the reservoir, and wherein the cartridge is configured to supply liquid from the sub-reservoir to the susceptor.
In some examples in accordance with the first aspect, the aerosol delivery system comprises a mouthpiece for use in an aerosol delivery system, wherein the mouthpiece comprises an outlet and a cavity configured to accommodate at least a portion of the cartridge; wherein optionally the mouthpiece comprises an opening mechanism configured to allow the mouthpiece to be moved between a first configuration and a second configuration, wherein in the first configuration the cavity is at least partially exposed in order to allow a cartridge to be inserted and / or removed, and wherein the second configuration is configured to retain a cartridge provided within the cavity.
In some examples in accordance with the first aspect, the aerosol delivery system comprises control circuitry for controlling the supply of power to the induction element, wherein the control circuitry is configured to drive the induction element to induce current flow in the susceptor to inductively heat the susceptor to a first temperature so as to vaporise the portion of the aerosol generating substrate in the vicinity of the susceptor, and wherein the control circuitry is configured to drive the induction element to induce current flow in the susceptor to inductively heat the susceptor to a second temperature which is lower than the first temperature and lower than a temperature required to vaporise the portion of the aerosol generating substrate in the vicinity of the susceptor.
According to a second aspect of certain embodiments there is provided a cartridge for use in an aerosol delivery system for generating an aerosol from an aerosol generating substrate, the cartridge comprising: a reservoir for the aerosol generating substrate; and a susceptor disposed about a longitudinal axis, wherein the susceptor is configured to be at least partially inserted into an induction assembly comprising an induction element disposed about the longitudinal axis, wherein the induction element is operable to induce current flow in a susceptor to inductively heat the susceptor to aerosolise a portion of the aerosol generating substrate in the vicinity of the susceptor.
According to a third aspect of certain embodiments there is provided a method of generating an aerosol from an aerosol generating substrate in an aerosol delivery system, the aerosol delivery system comprising an induction assembly and a cartridge, wherein the induction assembly comprises an induction element disposed about a longitudinal axis and wherein the cartridge comprises a reservoir for the aerosol generating substrate and the susceptor, the method comprising: inserting the susceptor into a receiving cavity of the induction assembly, wherein the susceptor is disposed about the longitudinal axis and at least partly within the induction element when the susceptor is inserted into the receiving cavity; driving the induction element to induce current flow in the susceptor to inductively heat the susceptor and so vaporise a portion of the aerosol generating substrate in the vicinity of the susceptor.
These and further aspects of the certain embodiments are set out in the appended independent and dependent claims. It will be appreciated that features of the dependent claims may be combined with each other and features of the independent claims in combinations other than those explicitly set out in the claims. Furthermore, the approach described herein is not restricted to specific embodiments such as set out below, but includes and contemplates any appropriate combinations of features presented herein. For example, a heater for a vapour provision system or a vapour provision system comprising a heater may be provided in accordance with approaches described herein which includes any one or more of the various features described below as appropriate.
Various embodiments of the invention will now be described in detail by way of example only with reference to the following drawings in which:
- Figure 1 shows a schematic diagram of an example aerosol/vapour delivery system in accordance with aspects of the present disclosure;
- Figure 2 shows an exploded view of an example induction assembly in accordance with aspects of the present disclosure;
- Figure 3 shows an exploded view of an example cartridge in accordance with aspects of the present disclosure;
- Figure 4 shows a schematic diagram of an example cartridge and induction assembly in accordance with aspects of the present disclosure;
- Figure 5 shows a schematic diagram of a further example cartridge and induction assembly in accordance with aspects of the present disclosure;
- Figure 6 shows a schematic diagram of a still further example cartridge and induction assembly in accordance with aspects of the present disclosure; and
- Figure 7 shows a flow diagram depicting a method of generating an aerosol from an aerosol generating substrate in an aerosol delivery system in accordance with the present disclosure.
Detailed DescriptionAspects and features of certain examples and embodiments are discussed / described herein. Some aspects and features of certain examples and embodiments may be implemented conventionally and these are not discussed / described in detail in the interests of brevity. It will thus be appreciated that aspects and features of apparatus and methods discussed herein which are not described in detail may be implemented in accordance with any conventional techniques for implementing such aspects and features.
In accordance with the present disclosure there is described an aerosol delivery system for generating an aerosol from an aerosol generating substrate, the aerosol delivery system comprising an induction assembly comprising an induction element disposed about a longitudinal axis, wherein the induction element is operable to induce current flow in a susceptor to inductively heat the susceptor to aerosolise a portion of the aerosol generating substrate in the vicinity of the susceptor, and a cartridge comprising a reservoir for the aerosol generating substrate and the susceptor, wherein the susceptor is disposed about the longitudinal axis and at least partly within the induction element.
A system as described above, comprises a susceptor which can be efficiently heated due to the positioning of both the susceptor and the induction element around the same longitudinal axis. In particular, without being bound by theory, the magnetic field generated by the induction element in use is strongest towards the longitudinal axis around which it is disposed, and hence disposing a susceptor around the same longitudinal axis causes the susceptor to be exposed to a relatively strong magnetic field when a current is applied through the induction element.
As used herein, the term "delivery system" is intended to encompass systems that deliver at least one substance to a user, and includes non-combustible aerosol provision systems that release compounds from an aerosol-generating material without combusting the aerosol-generating material, such as electronic cigarettes, tobacco heating products, and hybrid systems to generate aerosol using a combination of aerosol-generating materials; and
According to the present disclosure, a "non-combustible" aerosol provision system is one where a constituent aerosol-generating material of the aerosol provision system (or component thereof) is not combusted or burned in order to facilitate delivery of at least one substance to a user.
In some embodiments, the delivery system is a non-combustible aerosol provision system, such as a powered non-combustible aerosol provision system.
In some embodiments, the non-combustible aerosol provision system is an electronic cigarette, also known as a vaping device or electronic nicotine delivery system (END), although it is noted that the presence of nicotine in the aerosol-generating material is not a requirement.
In some embodiments, the non-combustible aerosol provision system is an aerosol-generating material heating system, also known as a heat-not-burn system. An example of such a system is a tobacco heating system.
In some embodiments, the non-combustible aerosol provision system is a hybrid system to generate aerosol using a combination of aerosol-generating materials, one or a plurality of which may be heated. Each of the aerosol-generating materials may be, for example, in the form of a solid, liquid or gel and may or may not contain nicotine. In some embodiments, the hybrid system comprises a liquid or gel aerosol-generating material and a solid aerosol-generating material. The solid aerosol-generating material may comprise, for example, tobacco or a non-tobacco product.
Typically, the non-combustible aerosol provision system may comprise a non-combustible aerosol provision device and a consumable for use with the non-combustible aerosol provision device.
In some embodiments, the disclosure relates to consumables comprising aerosol-generating material and configured to be used with non-combustible aerosol provision devices. These consumables are sometimes referred to as articles throughout the disclosure.
In some embodiments, the non-combustible aerosol provision system, such as a non-combustible aerosol provision device thereof, may comprise a power source and a controller. The power source may, for example, be an electric power source.
In some embodiments, the non-combustible aerosol provision system may comprise an area for receiving the consumable, an aerosol generator, an aerosol generation area, a housing, a mouthpiece, a filter and/or an aerosol-modifying agent.
In some embodiments, the consumable for use with the non-combustible aerosol provision device may comprise aerosol-generating material, an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol generator, an aerosol generation area, a housing, a wrapper, a filter, a mouthpiece, and/or an aerosol-modifying agent.
In some embodiments, the substance to be delivered may be an aerosol-generating material or a material that is not intended to be aerosolised. As appropriate, either material may comprise one or more active constituents, one or more flavours, one or more aerosol-former materials, and/or one or more other functional materials.
In some embodiments, the substance to be delivered comprises an active substance.
The active substance as used herein may be a physiologically active material, which is a material intended to achieve or enhance a physiological response. The active substance may for example be selected from nutraceuticals, nootropics, psychoactives. The active substance may be naturally occurring or synthetically obtained. The active substance may comprise for example nicotine, caffeine, taurine, theine, vitamins such as B6 or B12 or C, melatonin, cannabinoids, or constituents, derivatives, or combinations thereof. The active substance may comprise one or more constituents, derivatives or extracts of tobacco, cannabis or another botanical.
In one embodiment the active substance is a legally permissible recreational drug.
In some embodiments, the active substance comprises nicotine. In some embodiments, the active substance comprises caffeine, melatonin or vitamin B12.
As noted herein, the active substance may comprise one or more constituents, derivatives or extracts of cannabis, such as one or more cannabinoids or terpenes.
The active substance may be CBD or a derivative thereof.
As noted herein, the active substance may comprise or be derived from one or more botanicals or constituents, derivatives or extracts thereof. As used herein, the term "botanical" includes any material derived from plants including, but not limited to, extracts, leaves, bark, fibres, stems, roots, seeds, flowers, fruits, pollen, husk, shells or the like. Alternatively, the material may comprise an active compound naturally existing in a botanical, obtained synthetically. The material may be in the form of liquid, gas, solid, powder, dust, crushed particles, granules, pellets, shreds, strips, sheets, or the like.
Example botanicals are tobacco, eucalyptus, star anise, hemp, cocoa, cannabis, fennel, lemongrass, peppermint, spearmint, rooibos, chamomile, flax, ginger, ginkgo biloba, hazel, hibiscus, laurel, licorice (liquorice), matcha, mate, orange skin, papaya, rose, sage, tea such as green tea or black tea, thyme, clove, cinnamon, coffee, aniseed (anise), basil, bay leaves, cardamom, coriander, cumin, nutmeg, oregano, paprika, rosemary, saffron, lavender, lemon peel, mint, juniper, elderflower, vanilla, wintergreen, beefsteak plant, curcuma, turmeric, sandalwood, cilantro, bergamot, orange blossom, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, geranium, mulberry, ginseng, theanine, theacrine, maca, ashwagandha, damiana, guarana, chlorophyll, baobab or any combination thereof. The mint may be chosen from the following mint varieties: Mentha Arventis, Mentha c.v.,Mentha niliaca, Mentha piperita, Mentha piperita citrata c.v.,Mentha piperita c.v, Mentha spicata crispa, Mentha cardifolia, Memtha longifolia, Mentha suaveolens variegata, Mentha pulegium, Mentha spicata c.v. and Mentha suaveolens
In some embodiments, the active substance comprises or is derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is tobacco.
In some embodiments, the active substance comprises or derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is selected from eucalyptus, star anise, cocoa and hemp.
In some embodiments, the active substance comprises or derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is selected from rooibos and fennel.
In some embodiments, the substance to be delivered comprises a flavour.
As used herein, the terms "flavour" and "flavourant" refer to materials which, where local regulations permit, may be used to create a desired taste, aroma or other somatosensorial sensation in a product for adult consumers. They may include naturally occurring flavour materials, botanicals, extracts of botanicals, synthetically obtained materials, or combinations thereof (e.g., tobacco, cannabis, licorice (liquorice), hydrangea, eugenol, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, maple, matcha, menthol, Japanese mint, aniseed (anise), cinnamon, turmeric, Indian spices, Asian spices, herb, wintergreen, cherry, berry, red berry, cranberry, peach, apple, orange, mango, clementine, lemon, lime, tropical fruit, papaya, rhubarb, grape, durian, dragon fruit, cucumber, blueberry, mulberry, citrus fruits, Drambuie, bourbon, scotch, whiskey, gin, tequila, rum, spearmint, peppermint, lavender, aloe vera, cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, khat, naswar, betel, shisha, pine, honey essence, rose oil, vanilla, lemon oil, orange oil, orange blossom, cherry blossom, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, wasabi, piment, ginger, coriander, coffee, hemp, a mint oil from any species of the genus Mentha, eucalyptus, star anise, cocoa, lemongrass, rooibos, flax, ginkgo biloba, hazel, hibiscus, laurel, mate, orange skin, rose, tea such as green tea or black tea, thyme, juniper, elderflower, basil, bay leaves, cumin, oregano, paprika, rosemary, saffron, lemon peel, mint, beefsteak plant, curcuma, cilantro, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, limonene, thymol, camphene), flavour enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and/or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example, liquid such as an oil, solid such as a powder, or gas.
In some embodiments, the flavour comprises menthol, spearmint and/or peppermint. In some embodiments, the flavour comprises flavour components of cucumber, blueberry, citrus fruits and/or redberry. In some embodiments, the flavour comprises eugenol. In some embodiments, the flavour comprises flavour components extracted from tobacco. In some embodiments, the flavour comprises flavour components extracted from cannabis.
In some embodiments, the flavour may comprise a sensate, which is intended to achieve a somatosensorial sensation which are usually chemically induced and perceived by the stimulation of the fifth cranial nerve (trigeminal nerve), in addition to or in place of aroma or taste nerves, and these may include agents providing heating, cooling, tingling, numbing effect. A suitable heat effect agent may be, but is not limited to, vanillyl ethyl ether and a suitable cooling agent may be, but not limited to eucolyptol, WS-3.
Aerosol-generating material is a material that is capable of generating aerosol, for example when heated, irradiated or energized in any other way. Aerosol-generating material may, for example, be in the form of a solid, liquid or gel which may or may not contain an active substance and/or flavourants. In some embodiments, the aerosol-generating material may comprise an "amorphous solid", which may alternatively be referred to as a "monolithic solid" (i.e. non-fibrous). In some embodiments, the amorphous solid may be a dried gel. The amorphous solid is a solid material that may retain some fluid, such as liquid, within it. In some embodiments, the aerosol-generating material may for example comprise from about 50wt%, 60wt% or 70wt% of amorphous solid, to about 90wt%, 95wt% or 100wt% of amorphous solid.
The aerosol-generating material may comprise one or more active substances and/or flavours, one or more aerosol-former materials, and optionally one or more other functional material.
The aerosol-former material may comprise one or more constituents capable of forming an aerosol. In some embodiments, the aerosol-former material may comprise one or more of glycerol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3-butylene glycol, erythritol, meso-Erythritol, ethyl vanillate, ethyl laurate, a diethyl suberate, triethyl citrate, triacetin, a diacetin mixture, benzyl benzoate, benzyl phenyl acetate, tributyrin, lauryl acetate, lauric acid, myristic acid, and propylene carbonate.
The one or more other functional materials may comprise one or more of pH regulators, colouring agents, preservatives, binders, fillers, stabilizers, and/or antioxidants.
A consumable is an article comprising or consisting of aerosol-generating material, part or all of which is intended to be consumed during use by a user. A consumable may comprise one or more other components, such as an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol generation area, a housing, a wrapper, a mouthpiece, a filter and/or an aerosol-modifying agent. A consumable may also comprise an aerosol generator, such as a heater, that emits heat to cause the aerosol-generating material to generate aerosol in use. The heater may comprise a susceptor.
A susceptor is a material that is heatable by penetration with a varying magnetic field, such as an alternating magnetic field. The susceptor may be an electrically-conductive material, so that penetration thereof with a varying magnetic field causes induction heating of the heating material. The heating material may be magnetic material, so that penetration thereof with a varying magnetic field causes magnetic hysteresis heating of the heating material. The susceptor may be both electrically-conductive and magnetic, so that the susceptor is heatable by both heating mechanisms. The device that is configured to generate the varying magnetic field is referred to as a magnetic field generator, herein.
An aerosol-modifying agent is a substance, typically located downstream of the aerosol generation area, that is configured to modify the aerosol generated, for example by changing the taste, flavour, acidity or another characteristic of the aerosol. The aerosol-modifying agent may be provided in an aerosol-modifying agent release component, that is operable to selectively release the aerosol-modifying agent
The aerosol-modifying agent may, for example, be an additive or a sorbent. The aerosol-modifying agent may, for example, comprise one or more of a flavourant, a colourant, water, and a carbon adsorbent. The aerosol-modifying agent may, for example, be a solid, a liquid, or a gel. The aerosol-modifying agent may be in powder, thread or granule form. The aerosol-modifying agent may be free from filtration material.
An aerosol generator is an apparatus configured to cause aerosol to be generated from the aerosol-generating material. In some embodiments, the aerosol generator is a heater configured to subject the aerosol-generating material to heat energy, so as to release one or more volatiles from the aerosol-generating material to form an aerosol.
Figure 1 is a highly schematic diagram (not to scale) of an example aerosol/vapour delivery system 10 in accordance with the present disclosure. The system 10 has a generally elongate shape in this example, extending along a longitudinal axis, and comprises two main components, namely a control or power component, section or unit 20 (sometimes also referred to as an aerosol/vapour delivery device), and a cartridge assembly or section 30 (sometimes referred to as a cartomiser or clearomiser) carrying aerosolisable substrate material and operating as a vapour-generating component.
The cartridge 30 includes a reservoir 33 containing a source liquid (sometimes called a liquid aerosol generating material) or other aerosolisable substrate material comprising a formulation such as liquid or gel from which an aerosol is to be generated, for example containing nicotine. As an example, the source liquid may comprise around 1 to 3% nicotine and 50% glycerol, with the remainder comprising roughly equal measures of water and propylene glycol, and possibly also comprising other components, such as flavourings. Nicotine-free source liquid may also be used, such as to deliver flavouring. A solid substrate (not illustrated), such as a portion of tobacco or other flavour element through which vapour generated from the liquid is passed, may also be included.
The reservoir 33 has the form of a storage tank, being a container or receptacle in which source liquid can be stored such that the liquid is free to move and flow within the confines of the tank. For a consumable cartridge, the reservoir 33 may be sealed after filling during manufacture so as to be disposable after the source liquid is consumed, otherwise, it may have an inlet port or other opening through which new source liquid can be added by the user. In some examples, the cartridge 30 also comprises a susceptor 34 (sometimes called a heater, a susceptor heater or a susceptor heating element) for generating the aerosol by vaporisation of the source liquid stored in the reservoir tank 33. The susceptor 34 is intended for heating via induction, which will be described further below.
A liquid transfer or delivery arrangement (sometimes called a liquid transport element or liquid delivery element) such as a wick or other porous element 35 may be provided to deliver source liquid from the reservoir 33 to the heater 34. A wick 5 may have one or more parts located inside the reservoir 33, or otherwise be in fluid communication with the liquid in the reservoir 33, so as to be able to absorb source liquid and transfer it by wicking or capillary action to other parts of the wick 35 that are adjacent or in contact with the heater 34. This liquid is thereby heated and vaporised, to be replaced by new source liquid from the reservoir for transfer to the heater 34 by the wick 35. The wick may be thought of as a bridge, path or conduit between the reservoir 33 and the heater 34 that delivers or transfers liquid from the reservoir to the heater. Terms including conduit, liquid conduit, liquid transfer path, liquid delivery path, liquid transfer mechanism or element, and liquid delivery mechanism or element may all be used interchangeably herein to refer to a wick or corresponding component or structure.
A heater and wick (or similar) combination is sometimes referred to as an atomiser or atomiser assembly, and the reservoir with its source liquid plus the atomiser may be collectively referred to as an aerosol source. Other terminology may include a liquid delivery assembly or a liquid transfer assembly, where in the present context these terms may be used interchangeably to refer to a vapour-generating element (vapour generator) plus a wicking or similar component or structure (liquid transport element) that delivers or transfers liquid obtained from a reservoir to the vapour generator for vapour / aerosol generation. Various designs are possible, in which the parts may be differently arranged compared with the highly schematic representation ofFigure 1.
In some examples, the wick 35 may be an entirely separate element from the heater 34. In some other examples, the heater 34 may be configured to be porous and able to perform at least part of the wicking function directly (a metallic mesh or foam, for example). For example, the susceptor 34 (sometimes called susceptor heating element or heater) may comprise a capillary structure configured to wick a liquid aerosol generating substrate.
The vapour generating element may be an inductively heated susceptor element 34 that operates by inductive heating to heat and vapourise an aerosol generating material. In general, therefore, an atomiser can be considered as one or more elements that implement the functionality of a vapour-generating or vaporising element able to generate vapour from source liquid delivered to it, and a liquid transport or delivery element able to deliver or transport liquid from a reservoir or similar liquid store to the vapour generator by a wicking action / capillary force. An atomiser is typically housed in a cartridge component of a vapour generating system. In some designs, liquid may be dispensed from a reservoir directly onto a vapour generator with no need for a distinct wicking or capillary element. Embodiments of the disclosure are applicable to all and any such configurations which are consistent with the examples and description herein.
The liquid delivery element 35 may comprise any suitable wicking material. For example, it may be made from fibres which are grouped, bunched, wadded, woven or non-woven into a fabric or a fibrous mass, where interstices are present between adjacent fibres to provide a capillary effect for absorbency and wicking. Examples of fibre materials include cotton (including organic cotton), ceramic fibres and silica fibres. Other suitable materials are not excluded and will be apparent to the skilled person. In some examples (as an alternative to fibre based materials) the liquid delivery element 35 comprises a solid porous element, such as a porous ceramic material or a porous foam. For example, a porous ceramic material comprises a network of tiny pores or interstices which is able to support capillary action and hence provide a wicking capability to absorb liquid from a reservoir and deliver it to the vicinity of the heater for vaporisation.
Returning toFigure 1, the cartridge 30 comprises a housing 36 defining a mouthpiece or mouthpiece portion having an opening or air outlet 12 through which a user may inhale the aerosol generated by the susceptor 34. In these examples, the outer surface of the housing 36 may be shaped to accommodate a user's lips to enable a user to more easily form a seal around the air outlet 12 with their mouth. In other examples (not shown), the cartridge 30 may not include or otherwise define a mouthpiece. Instead, in some examples, a mouthpiece may connect to the cartridge 30, or the cartridge 30 may be received within a cavity of the device part 20 (e.g. defined by the induction assembly 40) such that the cartridge 30 is entirely enclosed by the device part 20 which itself provides or is attached to a mouthpiece.
The power component or device part 20 (sometimes called a device or control part because it typically contains control circuitry) includes a power supply 25, such as a cell or battery, and which may be re-chargeable, to provide power for electrical components of the system 10, in particular to apply power to an induction element or work coil 42 (described in more detail below) to inductively heat the susceptor 34.
Additionally, there is a controller 28 such as a printed circuit board and/or other electronics or circuitry for generally controlling the aerosol delivery system 10. The control electronics / circuitry 28 operates the induction element 42 using power from the power supply 25 when vapour is required, for example in response to a signal indicative of a user pressing a button (not shown) or from an air pressure sensor or air flow sensor (not shown) that detects an inhalation on the system 10 during which air enters through one or more air inlets 14 (e.g. provided at a junction between the device part 20 and the cartridge 30).
When the induction element 42 is operated, the induction element 42 inductively heats the susceptor 34 to a suitable temperature in order to vaporise source liquid delivered from the reservoir 33 by the liquid delivery element 35 to generate the aerosol, and this is then inhaled by a user through the opening 12 in the mouthpiece of the cartridge housing 36. The aerosol is carried from the aerosol source to the mouthpiece outlet 12 along one or more air channels defining an air pathway 16 (for example, see the arrows depicted inFigure 1) that connect the air inlet 14 to the aerosol source to the air outlet when a user inhales on the air outlet 12.
In some examples, the device part 20 comprises a frame, or support structure 22 (sometimes called a device frame or support) which is configured to support, retain or position various components of the device part 20, including the power supply 25 and the control circuitry 28. The frame 22 may also support other components not shown such as a wired connection port and PCB for charging (and optionally, communication), user interface elements (e.g. buttons, LEDs, display screens, haptic feedback units), and / or wireless communication components. The frame 20 can be provided by a single component, or may comprise a number of frame components which are combined to form the frame 20.
In some examples, the device part 20 comprises an outer housing 24 and / or an end cap 26. For example, the outer housing 24 may be a tubular structure or wrap, which is configured to contain the components of the device part 20. For example, the frame 22 containing the power supply 25 and the control circuitry 28 can be inserted into the outer housing 24, or the outer housing 24 can be provided around the outside of the frame 22. In some examples, an end cap 26 is provided at one end of the outer housing 24 (e.g. after insertion of the frame 20 containing the power supply 25 and the control circuitry 28) to seal the outer housing 24 (e.g. to protect the components on the inside of the outer housing 24 from the ingress of water and dust).
The induction element or work coil 42 may be provided as part of an induction assembly 40 which comprises a support structure or housing 44 which is configured to position or contain the induction element or work coil 42 (i.e. the support structure 44 supports the induction element 42). In some examples, the induction assembly 40 is formed by integrally molding the support structure 44 around the inductive work element 42, whereas in other examples the support structure 44 provides a scaffolding to which the inductive work element is attached or fixed.
In some examples, the induction assembly 40 comprises a support 44 having a tube portion disposed about said longitudinal axis of the induction element 42, wherein the tube portion comprises an inner wall and an outer wall, wherein the induction element 42 is provided between the inner wall and the outer wall of the tube portion, and wherein the inner wall defines a receiving cavity 49 in which a susceptor 34 is at least partly located, when a portion of the cartridge 30 comprising the susceptor 34 (or a part of the susceptor 34) is inserted into the receiving cavity 49.
In some examples, the induction assembly 40 comprises a ferrite shield 48, such as a film, foil or sheet, which may be retained in position by the support structure 44. For example, the ferrite shield may be inserted or embedded into the support structure 44, or wrapped around an outer surface of the support structure 44. A ferrite shield can be used to inhibit magnetic flux in the direction of the shield from the induction element 42, when power is supplied to the induction element 42.
In some examples, the ferrite shield 48 is disposed about a circumference of the induction element 42. In some examples, the ferrite shield 48 comprises a film, foil or sheet. In some examples, the ferrite shield 48 is inserted or embedded into a support 44 for the induction element 42. In some examples, the ferrite shield 48 comprises a sleeve surrounding a support 44 for the induction element 42.
In some examples, the induction assembly 40 is a fixed or permanent component of the device part 20. For example, the support structure 44 can be integrally formed with the frame 22 of the device part 20. In other examples, the induction assembly 40 and the device part 20 are separate connectable parts detachable from one another by separation in a direction parallel to the longitudinal axis of aerosol delivery system 10. For example, the components 20, 40 are joined together when the system 10 is in use by cooperating engagement elements (for example, a screw or bayonet fitting) which provide mechanical and electrical connectivity between the power section 20 and the induction assembly 40.
The electrical connectivity can be required in order to provide electrical power to the induction element 42 when the control circuitry 28 determines that power should be supplied to the induction element 42. The control circuitry is at least for controlling the supply of power to the induction element, wherein the control circuitry is configured to drive the induction element to induce current flow in the susceptor to inductively heat the susceptor and so vaporise a portion of the aerosol generating substrate in the vicinity of the susceptor.
The use of an interchangeable induction assembly 40 improves the ease of replacing the induction assembly 40 in the case of damage or wear, as well as potentially also allowing for customisation of a system 10 by allowing a user to replace an induction assembly with a different induction assembly with an alternate configuration for operation with a different susceptor 34 arrangement (e.g. provided by a cartridge 30 having a different configuration).
In some examples, the induction assembly 40 may seal an end of the outer housing 24 (e.g. to protect the components on the inside of the outer housing 24 from the ingress of water and dust). For example, the induction assembly 40 may be provided at the opposite end of the outer housing 24 to the end having the end cap 26. The induction assembly 40 may connect to the frame 22 and / or the outer housing 24 in such a way that a liquid seal is formed preventing liquid from flowing into the cavity formed by the outer housing 24, end cap 26 and the induction assembly 40. Alternatively in some examples, the device part comprises a second end cap which is fixed to the outer housing 24 and / or frame 22 between the frame 22 and the induction assembly 40. In some of these examples, a second end cap may be configured to facilitate the attachment of the induction assembly 40 to the device part 20.
The device part (power section or control unit) 20 and the cartridge (cartridge assembly) 30 are separate connectable parts detachable from one another by separation in a direction parallel to the longitudinal axis of aerosol delivery system 10. In some examples, the components 20, 30 are joined together when the system 10 is in use by cooperating engagement elements (for example, a screw or bayonet fitting) which provide mechanical connectivity (and in some examples electrical connectivity) between the power section 20 and the cartridge assembly 30. For example, a portion of the outer housing 24 can be an engagement element (not shown) configured to engage with a corresponding engagement (not shown) of the cartridge 30 provided by a portion of the cartridge housing 36.
In some other examples, the induction assembly 40 may facilitate the connection between the device part 20 and the cartridge 30. For example the induction assembly 40 and the cartridge 30 may include cooperating engagement elements (for example, a screw or bayonet fitting) which provide mechanical (and optionally electrical) connectivity between the induction assembly 40 and the cartridge 30 to indirectly connect the cartridge 30 to the device part 20 (including electrical connectivity if necessary) via the induction assembly 40.
In systems that use inductive heating, electrical connectivity can be omitted from the connection between the cartridge 30 and the device part 20 if no parts requiring electrical power are located in the cartridge 30.
In some examples, the cartridge 30 and induction assembly 40 are shaped (e.g. the cartridge housing 36 and the induction support 44, respectively) so that when they are connected, there is an appropriate exposure of the susceptor 34 to flux generated by the induction element 42 for the purpose of generating current flow in the material of the heater. In examples, the induction element 42 is disposed about a longitudinal axis and the susceptor 34 is disposed about the same longitudinal axis and at least partly within the induction element 42, when the cartridge 30 and the induction assembly 40 are connected. Said longitudinal axis may be the same as a longitudinal axis of the system 10.
By disposed, it is meant that susceptor 34 is located or position with respect to the longitudinal axis. By about a longitudinal axis, it is meant that the susceptor 34 is positioned to with respect to an origin through which the longitudinal axis extends. In other words, the susceptor 34 may be disposed (or positioned or located) radially outward from the longitudinal axis (whilst still being within the induction element 42). Inductive heating arrangements are discussed further below. By at least partly within, it is meant that that the susceptor 34 is provided to be radially inwards of the longitudinal axis in comparison to the induction element 42 which is radially outwards from the susceptor 34. In some examples, the susceptor 34 and the induction element 42 are coaxial; for example, as shown infigure 1. Without being bound by theory, in this way the susceptor 34 can be closely aligned with the regions internal to the induction element 42 which have a high magnetic field when power is supplied to the induction element 42, and therefore a susceptor 34 provided within the induction element 42 and disposed about the same longitudinal axis is exposed to significant magnetic flux along the length of the susceptor 34.
In some examples, the susceptor 34 is configured to extend around a circumference perpendicular to the longitudinal axis (i.e. with respect to which the induction element 42 and susceptor 34 are positioned/disposed). In other words, the susceptor 34 extends around at least a portion of a periphery of a region or zone defined with respect to an origin through which the longitudinal axis extends.
In some examples, the susceptor 34 is configured to extend around the entirety of the circumference perpendicular to the longitudinal axis. For example, the susceptor 34 extends in an cross-section perpendicular to the longitudinal axis to surround an entire periphery tangential to the longitudinal axis in the perpendicular cross-section. In some examples, the susceptor 34 comprises a tube element (e.g. a sheet curved into a cylinder). In these examples, the tube element comprises a cross-section which surrounds an entire periphery tangential to the longitudinal axis in the perpendicular cross-section.
In some examples, the susceptor 34 formed from a tube element comprises a tube longitudinal axis extending between respective ends of the tube element, wherein the tube longitudinal axis is co-aligned with the longitudinal axis. In other words, the tube element is co-aligned or co-parallel with the longitudinal axis of the In some examples, the tube element comprises a circularly symmetric tube element (e.g. an annular cylinder). In some example, the tube element has an inner diameter in the range of 0.5 mm to 5 mm and / or an axial length (i.e. corresponding to the longitudinal axis of the tube element) in the range of 3 mm to 25 mm. In some example, the tube element has an inner diameter in the range of 1.5 mm to 3 mm and / or an axial length (i.e. corresponding to the longitudinal axis of the tube element) in the range of 5 mm to 25 mm.
In some examples, a portion of the cartridge 30 containing the susceptor 34 may be provided adjacent a portion of the induction assembly 40 proximal to the induction element 42.
As described above, aspects of the disclosure relate to inductive heating. This is a process by which an electrically conducting item, typically made from metal, is heated by electromagnetic induction via eddy currents flowing in the item which generates heat. An induction element 42 (e.g. work coil) operates as an electromagnet when a high-frequency alternating current from an oscillator is passed through it; this produces a magnetic field. When the conducting item (i.e. susceptor 34) is placed in the flux of the magnetic field, the field penetrates the item and induces electric eddy currents. These flow in the item, and generate heat according to current flow against the electrical resistance of the item via Joule heating, in the same manner as heat is produced in a resistive electrical heating element by the direct supply of current.
An attractive feature of induction heating is that no electrical connection to the conducting item is needed; the requirement instead is that a sufficient magnetic flux density is created in the region occupied by the item. In the context of vapour provision systems, where heat generation is required in the vicinity of liquid, this is beneficial since a more effective separation of liquid and electrical current can be effected. Assuming no other electrically powered items are placed in a cartomiser, there is no need for any electrical connection between a cartridge and its power section, and a more effective liquid barrier can be provided by the cartomiser wall, reducing the likelihood of leakage.
Induction heating is effective for the direct heating of an electrically conductive item, as described above, but can also be used to indirectly heat non-conducting items. In a vapour provision system, the need is to provide heat to liquid in the porous wicking part of the atomiser in order to cause vaporisation. For indirect heating via induction, the electrically conducting item is placed adjacent to or in contact with the item in which heating is required, and between the work coil and the item to be heated. The work coil heats the conducting item directly by induction heating, and heat is transferred by thermal radiation or thermal conduction to the non-conducting item. In this arrangement, the conducting item is termed a susceptor. Hence, in an atomiser, the heating component can be provided by an electrically conductive material (typically metal) which is used as an induction susceptor to transfer heat energy to a liquid proximal to the atomiser (e.g. held by a wick 35 and / or the susceptor 34 itself).
The susceptor 34 (sometimes called heater or susceptor heating element) may usefully be formed from a suitable material, which is electrically resistive/conductive, in other words able to carry an electrical current. This enables the heater to have its temperature increased by exposure to a magnetic field generated by a high frequency alternating current in a work coil, by induction effects as noted above, where the magnetic flux induces eddy currents in the heater material.
In some examples, the susceptor 34 comprises a sheet of an appropriate material, suitably dimensioned and shaped for making into a heater. In some examples, the susceptor 34 formed from a sheet may be curved or bent into a non-flat shape such as a tube shape (e.g. an open ended cylinder) or a portion of a tube defining an arc shape. The curving may be formed by rolling or folding.
A suitable element for a heater 34 (susceptor) is to be made from an electrically conductive material, with adequate resistance to enable heating by induction effects via induced eddy currents. In some examples, the susceptor 34 is provided by a planar element such as a sheet. For example, the susceptor 34 is a sheet or foil of a metallic material, where suitable metals include mild steel, ferritic stainless steel, aluminium, nickel, cupro-nickel, nichrome (nickel chrome alloy), and alloys of these materials. In some examples, the sheet may be laminate of layers of two or more materials. In some examples, the sheet thickness should be thin enough to allow a portion with a curved shape to be formed to make the heater without the requirement for excessive force, and thick enough to hold the curved shape once it has been formed without reversion of the sheet back towards its original configuration (e.g. a flat sheet).
It may be necessary to balance the thickness of the planar element that meets these requirements with the need to provide a sufficient volume of resistive material to provide sufficient heating (recalling that in some examples the amount of material is reduced by perforations). Accordingly in some examples, the susceptor comprises a planar element, the planar element having a thickness in the range of one or more of 20 µm to 70 µm, 30 µm to 60 µm, and 40 µm to 55 µm.
In some examples, the thickness of a sheet providing the susceptor 34 may be in the range of about 20 µm to about 70 µm, for example about 30 µm to about 60 µm, or about 40 µm to about 55 µm. These values may be the total thickness of the sheet including any supporting elements or coatings. If the thickness is insufficient, the heater may lack adequate structural integrity, although this may be compensated by additional components (e.g. support components).
In some examples, a susceptor for a heater 34 has a simple rectangular shape, which can be manipulated into a particular configuration (e.g. by curving the surface of the shape) such as tube. In other examples, an element providing a susceptor may have an alternative shape such as a non-rectangular, polygonal shape or a circular or elliptical shape . This may be particularly useful where heating is intended to be focussed at particular zones or portions within the cartridge 30. In some of these examples, the susceptor can be provided with a shape that corresponds to zones which are incident with relatively large magnetic flux from the induction element.
In some other examples, the susceptor 34 is not provided by a sheet (i.e. defined by two dimensions and a thickness of a relatively small order of magnitude in comparison to the two dimensions) and may, for example, be instead provided by a block element having a thickness of a similar order of magnitude to the two dimensions defining the planar surface of the susceptor 34; the element or block formed of a suitable electrically conductive material, with adequate resistance to enable heating by induction effects via induced eddy currents. For example, the susceptor 34 may comprise an inductively heatable material such as wire wool or mesh (e.g. a (ferritic) stainless steel mesh) or a metal foam (e.g. nickel foam or cupro-nickel foam) formed into an appropriate shape. In contrast to a sheet providing the susceptor 34, a block (e.g. provided by stainless steel mesh or nickel foam) may have a thickness in the range of 0.1 to 3 mm. In some examples, the stainless steel mesh or nickel foam may have a thickness in the range of 0.2 to 1 mm. In some examples, the stainless steel mesh or nickel foam may have a thickness in the range of 0.25 to 0.6 mm.
In some examples, a block element for a heater 34 has a tubular or annular shape. In some examples, a block can be formed into a particular configuration (e.g. by curving the surface of the shape). In other examples, a block element may have an alternative shape such as a flat or curved slab, with a thickness as described above. In some examples, a suitable block element may be formed by pressing a steel mesh into a required shape or by forming a nickel foam within a mould having a required shape.
In some examples, the susceptor heating element 34 (sometimes called the susceptor 34 or heater 34) comprises a plurality of apertures extending through the susceptor heating element 34. Said apertures may be called perforations or holes. In some examples, the plurality of perforations may be holes cut or punched through the material of a susceptor 34 formed from a planar element (e.g. a sheet of material). Each hole is small compared to the total external surface area of the susceptor 34 (e.g. the plane of a sheet). In some examples, the holes are relatively closely packed and evenly distributed over the surface of the susceptor 34 so that many holes are included. The holes may be circular, for example, or may be elongated or slot-shaped. The purpose of the holes is to enable the generated vapour to more easily escape from the atomiser (e.g. wick and susceptor) into the aerosol chamber to be collected by the airflow through the aerosol chamber. For example, when liquid in the wick 35 within the atomiser is vaporised by the heat from the heater 34, the generated vapour can flow through the perforations into the free space of the air pathway 16 adjacent to the heater 34.
When designing the heater 34, it may be necessary to balance the increased ease of vapour flow afforded by additional perforations with the decreased amount of heater material available for heating. Accordingly, one can consider an optimum total area for the perforations compared to the area of the heater material which generates heat and provides it for vaporisation. If we define the total heater material area without any holes, a range for the total area then taken up the perforations may be in the range of about 5% to 30%, for example about 20% of the total heater material area, for example. In any case, it is useful that the total area of the perforations does not exceed about 50%, due to manufacturing restrictions. Also, too large an open area (total area of the perforations) may lead to poor inductive coupling in the event that induction heating is used, while too small an open area makes it difficult for generated vapour to escape from the wick 35.
In some examples, the number density of the plurality of apertures varies from an end of the susceptor (e.g. an end portion of a tube providing the susceptor) towards a centre of the susceptor (e.g. the middle portion of a tube between the end portions). In other words, in some examples, the density of the plurality of apertures varies from a peripheral edge of the surface of the susceptor 34 (e.g. at one end of a tube providing the susceptor 34) towards a centre of the surface of the susceptor 34 (e.g. towards the centre of a tube providing the susceptor 34).
In some examples, the density of the plurality of apertures increases from the end of the susceptor towards the centre of the susceptor 34. In other words, in some examples, the density of the plurality of apertures increases from the peripheral edge of the surface of the susceptor 34 towards a centre of the surface of the susceptor 34.
In some examples, the plurality of apertures or perforations are arranged in a pattern. In some examples, the plurality of apertures or perforations are randomly positioned.
In some examples, the wick 35 comprises an inductively heatable material such as a stainless steel mesh or a nickel foam. Said wick 35 formed of an inductively heatable material may also provide the heater 34 component (e.g. a combined wick-heater atomiser) or may be in addition to the heater 34 (e.g. the wick part of an atomiser formed of a wick 35 and heater 34). When the wick 35 is placed in the flux of the magnetic field, the field penetrates the item and induces electric eddy currents. These flow in the item, and generate heat according to current flow against the electrical resistance of the item via Joule heating, in the same manner as heat is produced in a resistive electrical heating element by the direct supply of current. In some examples, particularly where the wick 35 is used in conjunction with a separate susceptor 34, the wick 35 is able to contribute to the heating of the liquid and may also retain residual or latent heat between puffs, which can act to reduce the amount of energy or time required to heat the susceptor 34 to a vaporisation temperature on a subsequent puff. In particular, the wick 35 may have a large mass, in comparison to the susceptor 34, which acts to store latent heat, while the relatively low mass of the susceptor 34 allows for rapid heating of the susceptor 34.
In some examples, a stainless steel mesh or nickel foam providing a wick 35 has a shape corresponding to the susceptor 34. For example, a wick 35 and a susceptor 34 may both comprise annular or tubular shapes, where the wick 35 has an inner diameter which is slightly larger than an outer diameter of the susceptor 34, if the susceptor 34 is provided within the wick 35; or where the wick 35 has an outer diameter which is slightly smaller than an inner diameter of the susceptor 34, if the susceptor 34 is provided outside of the wick 35. It will be appreciated that susceptor 34 formed of a thin sheet like material (e.g. 50µm metal sheet) can be defined by a single diameter (i.e. because the diameter is significantly larger that the thickness). Hence, in examples where the susceptor 34 comprises a sheet-like material, the susceptor 34 can comprise a layer on an external surface of the wick 35, such as an inner surface or an outer surface of an annular wick 35.
Returning toFigure 1 in more detail, in the example shown, the cartridge 30 and induction assembly 40 are shaped so that a portion of the cartridge 30 is received within a cavity or void 46 of the induction assembly 40 when the cartridge 30 and induction assembly 40 are connected. Said cavity or void 46 may be termed a receiving cavity 46. In some examples, the receiving cavity 46 is defined by a housing or support 44 of the induction assembly 40. For example, the support 44 may comprise an inner surface defining the shape of the receiving cavity 46. A portion of the support 44 defining part of the receiving cavity 46 may be a tubular support.
In examples, such as those in accordance withFigure 1, the induction element 42 is provided in the form of a spiral or helical induction element 42. In these examples, the induction element 42 is formed substantially in a coil surrounding and extending along an axis. In examples such as those in accordance withFigure 1, the axis around which the induction element 42 is formed is parallel with the longitudinal axis of the system 10.
In some examples, the induction element 42 is formed by of a conductive element or component embedded within or provided on a surface of the support 44 defining the receiving cavity 46 (e.g. within a tubular part of the support 44). The induction element 42 is provided such that a portion of the cartridge 30 inserted into the receiving cavity 46 is within the coil of the induction element 42. In particular, a portion of the cartridge 30 comprising the susceptor 34 is provided within the coil of the induction element 32 when the cartridge 30 is received in the receiving cavity. In use an AC electric current is passed through the helical induction coil 42 which results in the generation of a varying magnetic field which generates eddy currents within a susceptor 34 of a cartridge 30 thereby rapidly heating the susceptor 34, which may result in aerosol being generated.
As such, in some examples, a support 44 comprises a substantially tubular or annular body having a size that corresponds to the induction element 42. For example, the inner diameter of a tubular support 44 may be equivalent to the required diameter of an induction element 42 which is received on the inner surface of the tubular portion of the support 44, or the outer diameter of a tubular support 44 may be equivalent to the required diameter of an induction element 42 received outer surface of the tubular portion of the support 44 (e.g. an induction element 42 deposited on a surface or embedded into grooves provided in the surface, as discussed below).
In some examples, the coil of the induction element 42 may have a constant number of turns per unit length (i.e. along the axis) or the number of turns per unit length may be different at different sections of the coil of the induction element 42. In some examples a coil can be considered to have a total length which can be subdivided into two or more sections. In some examples, a coil comprises two equal sections (i.e. the length of the first section is the same as the length of the first section, and the number of turns per unit length in the first section is the same as the number of turns per unit length in the second section). However, in some other examples, the number of turns per unit length may be greater in the first section than the number of turns per unit length in the second section, or vice versa.
In some examples, a coil may comprise a plurality of sections and wherein at least some of the sections may have a different or the same number of turns per unit length. Similarly, in some examples, the induction element 42 comprises two or more separate and distinct coils, each of which may have a same or different number turns per unit length and / or total length. The variation in the number of turns can increase or decrease the rate at which the susceptor 34 is heated (e.g. the rate at which the susceptor can reach a maximum operating temperature). Such an arrangement may provide asymmetrical heating of susceptor materials within a cartridge 30 along the length of the cartridge which is received within the receiving cavity 46, if desired.
In some examples, the induction assembly 40 comprises a first induction element 42 and a second induction element both of which are disposed about the same longitudinal axis. In these examples, a first portion of the susceptor 34 is located at least partly within the first induction element and a second portion of the susceptor 34 is located at least partly within the second induction element. The first and second induction elements are operable to induce current flow in the second portion of the susceptor to inductively heat the first and second portions of susceptor 34, respectively.
As above, in some examples, the first and second induction elements may have a same length, diameter and number of turns per unit length (including any variation in the number of turns per unit length), or alternatively one or more of the length, diameter, number of turns per unit lengths (including variation in the number of turns per unit length) may differ between the different induction elements. Furthermore, in some systems having additional induction elements, each additional induction element may be the same as, or differ from, one or more other induction elements.
In some examples, the first portion of the susceptor 34 and the second portion of the susceptor 34 are portions of a single susceptor. For example the susceptor 34 may be a tube component extending into both the first and second induction elements.
In some examples, the first portion of the susceptor 34 is distinct and separate from the second portion of the susceptor 34. For example, each portion of the susceptor 34 may be a separate component such as a separate tube component.
In some examples, the induction element 42 is formed by a resistive wire, such as a nickel or cupronickel wire, which is configured or arranged into a shape such as a spiral or helix (e.g. a spiral coil or a helical coil). In some examples, the induction element is a litz coil. In some examples, a resistive wire providing the induction element 42 is provided in a support 44 which acts to retain the resistive wire in a particular shape (e.g. a three-dimensional spiral). In some of these examples, the resistive wire may be embedded in the support. In other examples, a resistive wire providing the induction element 42 is substantially free-standing in that the resistive wire is able to support an orientation and configuration with respect to an anchor location (i.e. where the resistive wire engages a support 44). For example, the resistive wire may be a suitably rigid material (e.g. a suitably thick wire) that it is able to maintain a configuration throughout continued use. In some examples, an induction element 42 formed by a spiral coil (or helical coil) has a diameter in the range of 3 mm to 10 mm and/ or an axial length of 2 mm to 15 mm. In some examples, an induction element 42 formed by a spiral coil (or helical coil) has a diameter in the range of 5 mm to 10 mm and/ or an axial length of 3 mm to 10 mm.
In some examples, the induction element 42 may be printed or deposited on a portion of a substrate or support 44. In some examples, a laser is used to activate the surface of the support 44, which may comprises a thermoplastic material such as polyetheretherketone (PEEK) which may have been doped with a metallic inorganic compound. The laser creates one or more laser activated regions upon the support 42 which can then be further metallised using e.g. an electroless plating process to build up one or more conductive layers of e.g. copper. For example, an induction element 42may be deposited upon a tubular portion of a support 44 so as to form a spiral induction coil or a helical induction coil (i.e. a spiral coil or a helical coil). In some examples, the induction element has a diameter in the range of 5 mm to 10mm and/ or an axial length of 2 mm to 15 mm. In some examples, the induction element has a diameter in the range of 5 mm to 10mm and/ or an axial length of 3 mm to 10 mm.
Forming an induction element 42 by printing or depositing a conductive layer on a support 44, such as by utilising a laser direct structuring process as described above, results in a induction element 42 being formed which is integrated with or into the support 44. This advantageously can reduce the size of the support 42 required compared to a support 42 which is suitable for retaining a resistive wire providing an induction element 42 and can therefore enable the induction assembly 40 to be provided in a more compact arrangement.
In the example ofFigure 1, the portion of the induction assembly 40 containing the induction element 42 is part of the support structure 44 or housing (sometimes called the support 44 as above) of the induction assembly 40. In some examples, the support structure 44 may surround the induction element 42 thereby providing a protective housing for the induction element and / or to support or maintain the position of the induction element 42 within the induction assembly 40. In some other examples, not shown, at least a portion of the induction element 42 may not be covered by the support structure 44. In such examples, the induction element 42 may be exposed to ambient air. Additionally, the support 44 can provide other functionality such as facilitating the attachment of the induction assembly 40 to the control part 20.
As stated above, the susceptor 34 which may comprise a tube shape, is received within the spiral or helical shape of the induction element 42. By providing the susceptor 34 within the induction element 42 there is an appropriate exposure of the susceptor 34 to flux generated by the induction element 42 for the purpose of generating current flow in the material of the susceptor 34. In this way, the susceptor 34 is responsive to the magnetic field generated by the induction element 42.
The distance separating the susceptor 34 (e.g. the outer surface of the susceptor 34) from the induction element 42 (e.g. the inner diameter of the spiral shape of the induction element 42) is sometimes called the coupling distance. Without being bound by theory, the susceptor 34 and the induction element 42 effectively form a pair in which the induction element 42 is inductively coupled to the susceptor and is able to transmit or transfer energy to the susceptor 34 when a current is applied to the induction element 42. The coupling distance relates to the distance across which energy is transferred from the induction element 42 to the susceptor. The further away the susceptor 34 is (i.e. the larger the coupling distance), the greater the loss in energy. In some examples, (for example, in order to reduce energy losses to a suitable proportion), the coupling distance is in the range of less than 3 mm. In some examples, the coupling distance is in the range of less than 3 mm. In some examples, the coupling distance is in the range of less than 1.5 mm. In some examples, the coupling distance is in the range of less than 1 mm.
The coupling distance can be described by the offset distance relating to the distance separating the susceptor 34 from the induction element 42. In some examples, the offset distance is the distance separating a closest surface of the susceptor 34 from the induction element 42. In some examples, the offset distance is the average distance separating the outer surface of the susceptor 34 from the induction element 42, where the outer surface is a surface facing towards a portion of the induction element 42 (e.g. not a surface which is facing towards the central axis). In some examples, the susceptor is offset from the induction element by an offset distance in a range of less than 3 mm. In some examples, the susceptor is offset from the induction element by an offset distance in a range of less than 2 mm. In some examples, the susceptor is offset from the induction element by an offset distance in a range of less than 1.5 mm. In some examples, the susceptor is offset from the induction element by an offset distance in a range of less than 1 mm.
It will be appreciated that the relationship of different portions of the susceptor 34 to the induction element can be defined by their own coupling distance. For example, where the susceptor 34 and the induction element 42 are both defined by a fixed diameter from a same origin point (e.g. the axis around which the induction element 42 is formed), then the coupling distance is substantially constant. However, in examples, where the shape of the susceptor 34 does not match the shape of the induction element 42 (e.g. the susceptor 34 and / or the induction element 42 are not circularly symmetric), then different portions of the susceptor 34 may have different coupling distances and therefore heated differently by the magnetic field.
As shown inFigure 1, in some examples, the aerosol delivery system 10 comprises an air pathway 16 defined in part by a volume between a portion of the cartridge 30 received in the receiving cavity 46 and a surface of the induction assembly 40 defined by the support 44. Said portion of the air pathway 16 is provided between the inlet 14 and a vapour/aerosol generation portion of the air pathway provided within the cartridge 30. The separation (e.g. coupling distance) of the susceptor 34 and the induction assembly 40 is set at least in part by the width or size of the portion of the air pathway 16 formed between the cartridge 30 and induction assembly 40, with the air pathway 16 in this region of the system 10 needing to be sized to allow adequate air flow. In some examples, the separation of the cartridge 30 and the induction assembly 40 is in the range of 0.2 mm to 1 mm.
Where a portion of the air pathway 16 is defined in part by a volume existing between a portion of the cartridge 30 received in the receiving cavity 46 and a surface of the induction assembly 40 defined by the support 44, the requirements of the aerosol pathway and the coupling distance need to be balanced against one another when determining the sizing and positioning of the various items. In some examples, the coupling distance is in the range of 1 mm to 3 mm, and the separation of the cartridge 30 and the induction assembly 40 (thickness of the air pathway 16) is in the range of 0.2 mm to 1 mm, where the separation of the susceptor 34 and the induction assembly 40 is less than or equal to the coupling distance.
In some other examples, where an air pathway 16 does not extend between longitudinally extending portions of the cartridge 30 and the support 44, and the separation of the separation of the cartridge 30 and the induction assembly 40 is in the range of up to 0.5 mm, and preferably less than 0.2mm. A small separation of the cartridge 30 and the induction assembly 40 may cause an interference fit to be formed which aids in retaining the cartridge 30 with the induction assembly 40.
In some examples, such as shown in the example ofFigure 1, the cartridge 30 is configured to provide a portion of the air pathway 16 on an opposing side of the susceptor 34 to the side closest to the induction element 42. In other words, the air pathway 16 is not provided between the susceptor 34 and the induction element 42 but is instead further from the induction element 42 than the susceptor 34.
In these examples, the susceptor 34 may be considered to comprise a first susceptor surface defining at least a part of an air pathway 16. By defining an air pathway it is meant that the first susceptor surface defines a void or space through which air (or aerosol/vapour) can flow. In some examples, the air pathway is co-aligned with the longitudinal axis about which the susceptor 34 and the induction element 42 are disposed. For example as shown inFigure 1, the air pathway 16 is provided in the susceptor 34, central to cartridge 30. In some examples, the susceptor 34 comprises a hollow body, wherein the air pathway extends through the hollow body. For example, the portion of the air path 16 may be provided within a channel defined by a tubular susceptor 34.
By providing the air pathway 16 on the opposing side of the susceptor 34 to the induction element 42, the width of the air pathway 16 can be increased without increasing the coupling distance. For example, when the air pathway 16 is provided between the susceptor 34 and induction element 42, the width of the air pathway is limited in order to prevent the susceptor 34 from being spaced too far from the induction element 42 thereby increasing the coupling distance (e.g. the width may be less than 1.5mm, preferably less than 1.2 mm, and more preferably less than 1.1mm). However, by providing the air pathway 16 on the other side of the susceptor 34 (e.g. internally to a tubular susceptor), the air pathway 16 can be larger because the air pathway 16 constrained primarily by the dimensions of the induction element 42 (e.g. diameter of a spiral coil) and the susceptor 34 (e.g. diameter of a tube), both of which could be increased to accommodate a wider air path; thereby allowing a reduced resistance to draw during an inhalation.
In some examples, the susceptor 34 defines a portion of an air pathway 16 (e.g. central to a tubular or annular susceptor 34) having a width in the range of 1 mm to 3 mm. In some examples, the susceptor 34 defines a portion of an air pathway 16 (e.g. central to a tubular or annular susceptor 34) having a width in the range of 1.4 mm to 2 mm. It will be appreciated that for a susceptor 34 provided in the form of a circularly symmetric tube, the width of the air pathway 16 within the susceptor 34 is equivalent to the diameter of the inner channel of the tube.
In some examples, the induction element 42 comprises a spiral induction coil having a diameter in the range of 3 mm to 10 mm (or 5 to 10 mm) and/ or an axial length (i.e. height defined by an axis around which the spiral is wound) of 2 mm to 15 mm (or 3 to 10 mm). In some examples, the susceptor 34 comprises a tubular shape having an inner diameter of 0.5 mm to 5 mm and / or an axial length (i.e. a height defined by an axis of a longitudinal extension of the tube) of 3 mm to 25 mm. In some examples, the susceptor 34 comprises a tubular shape having an inner diameter of 1.5 mm to 3 mm and / or an axial length (i.e. a height defined by an axis of a longitudinal extension of the tube) of 5 mm to 25 mm. In some examples, the susceptor 34 is formed by a tubular shape having a longer axial length than the induction element 42 formed by the spiral induction coil. The diameter of the induction element 42 formed by the spiral induction coil is greater than the diameter of the tubular susceptor 34, to allow the susceptor 34 to be received within the induction element 42 (and in some examples, to allow a portion of an air pathway 16, and /or other elements of the system 10 to be provided between the induction element 42 and the susceptor 34).
In some examples, a liquid transport element 35 provides liquid to a second susceptor surface on an opposing side of the susceptor 34 to the first susceptor surface. In some examples, liquid can be supplied to the susceptor 34 via the liquid transport element 35 and then when the liquid is vaporised and the liquid is able to pass through the susceptor 34 (e.g. by one or more apertures extending through the susceptor 34) from the second susceptor surface to the first susceptor surface.
TheFigure 1 design is merely an example arrangement, and the various parts and features may be differently distributed between the power section 20 and the cartridge assembly section 30, and other components and elements may be included. The two sections may connect together end-to-end in a longitudinal configuration as inFigure 1, or in a different configuration such as a parallel, side-by-side arrangement. The system may or may not be generally cylindrical and/or have a generally longitudinal shape. Either or both sections or components may be intended to be disposed of and replaced when exhausted (the reservoir is empty or the battery is flat, for example), or be intended for multiple uses enabled by actions such as refilling the reservoir and recharging the battery. In other examples, the system 10 may be unitary, in that the parts of the device part 20 (including the induction assembly 40) and the cartridge 30 are comprised in a single housing and cannot be separated. Embodiments and examples of the present disclosure are applicable to any of these configurations and other configurations of which the skilled person will be aware.
Figure 2 is an exploded view of an example induction assembly 40 in accordance with the present disclosure. The exploded view of the induction assembly 40 depicts an example support structure or housing 44 (sometimes called support), an induction coil 42 (e.g. an example of an induction element 42), and a ferrite shield 48. The example housing 44 comprises a (tubular) receiving portion 46 and a base portion 45. Aspects of the induction assembly 40 may be as described in relation toFigure 1.
The receiving portion 46 is configured to define the receiving cavity 49 into which a portion of the cartridge 30, containing a susceptor 34, is received when the cartridge 30 and the induction assembly 40 are joined. The receiving portion 46 may have a tubular or annular shape where an inner void is configured to define the receiving cavity 49.
In some examples, the configuration of the receiving portion 46 corresponds to the configuration of the portion of a cartridge 30 received in cavity 49 of the receiving portion 46. For example, if the portion of the cartridge 30 is cylindrical, then the receiving portion 46 may be in the shape of a circularly symmetric tube. Alternatively, if the portion of the cartridge 30 is not cylindrical and has for example, a elliptical cross-section, then the receiving portion 46 may be configured to provide a cavity 49 having a cross-section of the same shape. In some examples, the cross-section of the receiving portion 46 may be slightly larger than that of the portion of the cartridge 30, in order to allow airflow between the receiving portion 46 and the cartridge 30.
The receiving portion 46 ofFigure 2 additionally comprises a spiral recess 47 for receiving a spiral coil. In the example shown, the induction assembly 40 is formed by providing an suitable induction element 42 (i.e. a spiral coil in this example) in the spiral recess 47 (and optionally surrounding or sleeving with a ferrite shield 48). The spiral recess 47 of receiving portion 46 may extend between the first and second opposing faces as shown, or the spiral recess 47 may be internal to the housing 44 (i.e. to encapsulate an induction element 42). It will be appreciated that in other examples, where the induction element 42 does not comprise a spiral coil, the receiving portion 46 will not comprise the spiral recess 47, and may instead comprise a recess of a different configuration or a surface upon the induction element 42 can be formed.
In some examples, the thickness of the receiving portion 46 (e.g. thickness of tubular walls) is selected to be equal or to approximately equal the width of the induction element 42 received in the spiral recess 47 (e.g. the diameter of a wire providing a spiral coil). By approximately equal it is meant that the thickness may be slightly less than the width of the induction element 42 (no less than 95% of the width), or slightly more than the support the width of the induction element 42 (no more than 105% of the width). In some examples, the thickness of the receiving portion 46 is selected to provide structural rigidity to the induction assembly 40 and / or support for the induction element 42.
The base portion 45 comprises attachment features 43 configured to facilitate the connection of the housing 44 to a control part 20 having corresponding attachment features (i.e. the control part 20 ofFigure 1). In some examples, the attachment features 473 allow an induction assembly 40 to be reversibly connected to a control part, such that the induction assembly 40 can be removed and replaced without damaging the control part or the induction assembly 40. In some other examples, where the induction assembly 40 is an integral component of a control part, the attachment features 43 may be omitted (e.g. the housing 44 may be integrally formed with a housing of the control part), or the attachment features 43 may be configured to provide a permanent attachment which is not intended to be reversed (i.e. disconnected).
The base portion 45 may also facilitate the electronic connection of the induction element 40 to the control part 20. In some examples the base portion 45 comprise through holes 41 for respective ends of a wire coil providing the induction element 42, or for electrodes connecting to the induction element 42. In some examples, said through holes 41 extend from a top surface of the base portion 45 to a bottom surface in order to allow the wire ends or electrodes to pass through the base portion 45 towards the interface with the device part 20.
In some examples, the base portion 45 further comprises one or more channels providing a portion of the air pathway 16. The channel may for example direct, or facilitate, air flow through the base portion 45 and into the receiving cavity 49 defined by the receiving portion 46. A suitable channel may align with a corresponding channel provided by the cartridge 30 (i.e. a channel defined by the susceptor 34), such that air may flow from the induction assembly 40 into the channel of the cartridge 30. In some examples, the channel may extend into a recessed void on the lower side of the base portion (opposite the receiving portion 46) which is configured to allow airflow between the base portion 45 and the device part (e.g. a surface of a housing of a device part as shown inFigure 1).
In accordance with some examples,Figure 2 depicts an induction element 42 comprising a wire coil. The wire coil is a length of wire which has been configured or shaped into a spiral coil. In practice, the wire coil may be manipulated into the required shape by winding the wire of the coil onto the outer surface of the receiving portion 46 (e.g. by winding the wire into the spiral recess 47). The wire coil further comprises two respective ends 421 which are configured to allow the formation of a circuit for the transmission of power through the wire coil providing the induction element 42. The respective ends 421 may be inserted into through holes 41 of the base portion 45 when the wire coil is combined with the support 44.
In accordance with some examples,Figure 2 depicts a ferrite shield 48. In the example ofFigure 2, the ferrite shield 48 comprises a sleeve which is provided over the receiving portion 46 and induction element 42 (in other words the receiving portion 46 and induction element 42 are inserted into the sleeve of the ferrite shield 48), or the ferrite shield 48 is wrapped around the receiving portion 46 and induction element 42. The ferrite shield 48 acts to block or inhibit magnetic flux in an outward direction from the induction element 42 when a current is applied through the induction element 42.
Figure 3 is a exploded perspective drawing of an example cartridge 30 in accordance with the present disclosure. The cartridge 30 may be for use with an induction assembly 40 comprising the support 44 ofFigure 2. The cartridge 30 comprises an upper housing 361, a lower housing 362, a seal 363, a susceptor 34, and a liquid transport element 35 (sometimes called a wick). Various aspects of the cartridge 30 may be as described in relation toFigure 1.
In some examples, the susceptor 34 comprises a plurality of apertures extending through the susceptor. For example, the susceptor 34 ofFigure 3 comprises a tube formed of a metal sheet in which a plurality of apertures 345 have been provided. The susceptor 34 ofFigure 3 may be formed by a sheet of material (e.g. nickel, cupronickel, aluminium) which is folded to form the tubular shape.
The liquid transport element or wick 35 of Figure similarly comprises a tube formed of a suitable wicking material (e.g. cotton or a synthetic material). The susceptor 34 ofFigure 3 is received within the wick 35 ofFigure 3 such that the wick 35 is able to supply liquid to an outer surface of the susceptor 34. The inner surface of the susceptor 34 defines a portion of the air pathway 16 passing through the cartridge 30.
The susceptor 34 ofFigure 3 comprises a plurality of apertures, holes or perforations 345 extending through the material of the susceptor 34. The plurality of perforations 345 may be provided by cutting holes or piercing through the material of the susceptor 34. Each hole is small compared to the area of the susceptor. The purpose of the holes 345 is to enable the generated vapour to more easily escape through the susceptor 34 into the air pathway 16 within the susceptor 34 (i.e. the aerosol chamber) to be collected by the airflow through the air pathway 16. For example, when liquid in the wick 35 adjacent to the susceptor 34 is vaporised by the heat from the susceptor 34, the generated vapour can flow inwardly through the perforations 345 into the free space of the air pathway 16 defined by the surface of the susceptor 34.
As discussed in relation toFigure 1, in some examples, the liquid transport element 35 is formed from a magnetically heatable material, such as a steel mesh or a nickel foam. In these examples, the liquid transport element 35 can additionally heat up in response to the generation of a magnetic field by the induction element 42. In other words, the liquid transport element can be formed from a susceptor material. In comparison to the susceptor 34, the volume and mass of the liquid transport element 35 is significantly greater (for example, the liquid transport element 35 has a width of 0.5 to 2mm, in contrast to a width of 20µm to 70 µm for the susceptor 34). The liquid transport element 35 takes longer to heat up (e.g. requires more energy) in comparison to the susceptor 34 due to the mass of the liquid transport element 35, but may be able to retain greater thermal energy (e.g. due to its larger mass). This may advantageously raise the temperature of liquid in the vicinity of the liquid transport element 35, thereby reducing the difference between the liquid temperature at the start of a next activation of the induction element 42 and the target temperature of the susceptor 34 during the next activation of the induction element 42 (assuming that the time between activations is not excessively long such that the system 10 cools to ambient condition).
In view of the above, the susceptor 34 can provide rapid heating to a vaporisation temperature due to its lower mass and preferential position, whilst a magnetically heatable liquid transport element 35 can absorb energy which would otherwise be lost, and latent heat, which may raise the ambient temperature of the aerosol generating material between vaporisations leading to a decrease in the amount of heating required for the susceptor 34 to reach a vaporisation temperature for a suitable aerosol generating material.
The cartridge 30 ofFigure 3 further includes a housing 36 formed of an upper housing 361, a lower housing 362, and a seal 363. The upper housing 361 may instead be called a downstream or mouth-end housing in that it provides the portion of the housing that is towards the mouthpiece outlet 12. In particular, the upper housing 361 is configured to have a mouthpiece shape comprising the outlet 12 for a user to inhale through. The lower housing 362 may instead be called an upstream or device-end housing in that it provides the portion of the housing that is towards the inlet 14 of the system 10, and towards the position of the device or control part 20 when the cartridge 30 is connected to a control part 20.
The upper housing 361 defines an internal volume which is configured to retain a liquid aerosol generating material. In other words, the upper housing 361 provides a reservoir. The lower housing 362 defines a volume (or void) which is configured to receive the susceptor 34 and liquid transport element 35. The lower housing 362 is additionally configured to be inserted into the upper housing to seal the reservoir, to inhibit movement of liquid from the reservoir except via the liquid transport element 35. For examples, the lower housing 362 may comprise the seal 363 (e.g. an o-ring) which is configured to inhibit movement of liquid between a wall of the upper housing 361 and the lower housing 362. The upper and lower housings 361,362 may be formed from, for example, plastic materials using conventional materials and manufacturing methods (e.g. injection moulding). It will be appreciated thatFigure 3 is just one example of a cartridge 30, and that in other examples a suitable housing 36 may be provided by different components in different configurations (e.g. reservoir provided in a lower housing 362, or the housing 36 not requiring a seal).
The lower housing 362 is configured to define a portion of the cartridge 30 (e.g. a protrusion) which is received into the receiving cavity 49 of the induction assembly 40. The susceptor 34 (and optionally the liquid transport element 35) is provided in the lower housing 362 such that when the cartridge 30 is connected to the induction assembly 40, at least a portion of the susceptor 34 is provided within the induction element 42 (e.g. within a spiral coil of the induction element 42). An induction element 42, as discussed above in relation toFigure 1 andFigure 2, is configured to generate a magnetic field that primarily (or dominantly) extends within the coil of the induction element 42. As a result, the inductive heating is strongest for a susceptor which is placed within the induction element 42.
At the same time, portions of the susceptor 34 which are not directly adjacent to the induction element 42 will receive a relatively lower amount of flux and therefore generate less heat than portions of the susceptor adjacent to, or overlapping with, the induction element 42. In some examples, the induction element 42 may have a first length parallel to an axis (e.g. the axis central to the spiral coil), and the susceptor 34 may have a second length also parallel to the axis (e.g. axis central to the spiral coil may be co-aligned with the axis of a tube defining the susceptor 34). The first length may be shorter than the second length and hence a portion of the susceptor 34 may not be received within the induction element 42, and therefore the heating will be substantially less for the portion of the susceptor 34 which is not received the induction element 42 because the magnetic flux is weaker outside of the induction element 42. Instead the heating may be primarily by conduction from the portion of the susceptor 34 which is within the induction element 42, and aerosol generation may therefore be reduced in the portions of the susceptor 34 which are not within the induction element 42.
Figure 4 is a schematic diagram (not to scale) of an example of a cartridge 30 and induction assembly 40 for use in an aerosol/vapour delivery system 10 in accordance with the present disclosure. In addition to the features described in relation toFigures 1 to 3, the cartridge ofFigure 4 comprises one or more liquid flow channels 37 and a sub-reservoir 331. The one or more liquid flow channels 37 and sub-reservoir 331, as described herein, may be implemented with any of the cartridge 30 embodiments described in relation toFigures 1 and3. The remaining aspects of the example cartridge 30 and induction assembly 40 ofFigure 4 are as described in relation toFigures 1 to 3 and will not be described again in detail.
The one or more liquid flow channels 37, which may be called liquid pathways or conduits, are provided adjacent to the liquid transport element 35 (or the susceptor 34 where the susceptor 34 is configured to provide the function of a liquid transport element). The one or more liquid flow channels 37 extend from the reservoir 33 along a surface of the liquid transport element 35 and act to facilitate the ingress of liquid aerosol generating material into the liquid transport element 35. Advantageously this may improve the supply of liquid to the entirety of the liquid transport element 35 by increasing the surface area into which the liquid aerosol generating material can enter the liquid transport element 35. In other words, while in some examples where a liquid flow channel 37 is not present, the liquid can only enter the liquid transport element 35 via the portion of the liquid transport element 35 in contact with the reservoir 33, on examples, where a liquid flow channel 37 (or multiple channels) is present, the liquid can additionally enter the liquid transport element 35 along the surface of the liquid transport element 35 adjacent to the channel 37.
Each liquid flow channel 37 acts to provide a pathway suitable for the conduction of liquid. For example, a liquid flow channel 37 may comprise a cavity or void in which liquid can reside. As an example, liquid may flow into the liquid flow channel 37 from the reservoir 33 to fill the channel 37; the susceptor 34 is heated via inductive heating and liquid in the in the liquid transport element 35 in the vicinity of the susceptor 34 is vaporised; liquid in the liquid flow channel 37 and the reservoir 33 is drawn into the liquid transport element 35 along the entire surface of the liquid transport element 35 in contact with either the reservoir 33 or liquid flow channel 37. The increased surface area allows the liquid transport element 35 to return to a saturated liquid state quicker.
In some examples, one or more of the liquid flow channels 37 are elongated channels (e.g. cavities or voids having a length which is significantly greater that a width). In some examples, the liquid flow channels 37 are elongated channels extending from the reservoir 33 towards the end of the cartridge 30 which is adjacent the control part 20 in use. In some examples, the liquid flow channels 37 are elongated channels extending from the reservoir 33 along the entire length of the liquid transport element 35, or to a furthest extremity of the liquid transport element 35 from the reservoir 33. In some examples, one or more of the liquid flow channels 37 are linear channels (i.e. extending in a straight line). In some examples, one or more of the liquid flow channels 37 include curves and bends (e.g. winding channels).
In some examples, each liquid flow channel 37 is configured to cause a capillary effect on the liquid aerosol generating material to draw liquid into the liquid flow channel 37. For example, a liquid flow channel 37 may have a width in the range of 0.1 mm to 1 mm (the width being perpendicular to an direction of elongation of the channel 37). Without being bound by theory, the capillary effect of a channel 37 on the liquid aerosol generating material may be defined by capillary drive force of the channel 37 which relates to the ability of the liquid flow channel 37 to draw liquid aerosol generating material into by the capillary effect. In some examples, in order to ensure that liquid is drawn into the liquid transport element 35, the liquid transport element 35 is configured to cause a capillary effect having a capillary drive force that is stronger than the capillary drive force of the liquid flow channel 37. For examples, the liquid transport element 35 may be formed of a material having channels or pores of a porous network which are smaller in dimension (e.g. width) than the width of the one or more liquid flow channels 37.
The sub-reservoir 331, sometimes called a secondary reservoir or supplementary reservoir, comprises a cavity or void which is configured to retain an amount of liquid aerosol generating material. In some examples, the sub-reservoir 331 is provided at an opposing end of the liquid transport element 35 (or susceptor 34 where the susceptor 34 is configured to provide the function of the liquid transport element 35) to the reservoir 33. The sub-reservoir 331 is positioned such that after vaporisation of aerosol generating material, the liquid transport element 35 is able to absorb, or receive, liquid from both the reservoir 33 and the sub-reservoir 331. This may improve the distribution of liquid aerosol generating material along the length of liquid transport element 35 (e.g. in contact with the susceptor 34). In particular, this may prevent a portion of the liquid transport element 35 which is distal from the reservoir 33 from being under-saturated (e.g. sub-optimally saturated) during a subsequent activation of the induction element 42, particularly where there is only a relatively short duration between puffs by a user (e.g. activations of the induction element 42).
As such, in some examples, the cartridge 30 comprises a sub-reservoir 331 provided at or towards an opposite end of the susceptor 34 to the reservoir 33, the sub-reservoir 331 configured to hold a smaller volume of liquid aerosol generating substrate than the reservoir 33, and wherein the cartridge 331 is configured to supply liquid from the sub-reservoir 331 to the susceptor 34. For example, the cartridge 30 is configured such that the sub-reservoir 331 can supply liquid to a distal end of the susceptor 34 in comparison to the end of the susceptor closest to the reservoir 33.
The sub-reservoir 331 may be provided by the housing 36 of the cartridge 30 or a different structural component of the cartridge 30. For example, the sub-reservoir 331 can be provided by injection moulding the housing 36 to have a shape defining the sub-reservoir 331. In some examples, the sub-reservoir 331 may be an annular reservoir extending around the air pathway 16, similarly to the reservoir 33. In some examples, there may be more than one sub-reservoir 331 (e.g. two sub-reservoirs on opposing sides of the cartridge 30).
In some examples, the sub-reservoir 331 is configured to hold a volume of liquid in the range of 0.005 ml to 0.1 ml (e.g. the total volume of the sub-reservoir 331). In some examples, the sub-reservoir 331 is configured to hold a volume of liquid in the range of 0.01 ml to 0.05 ml. In some examples, the sub-reservoir 331 is configured to hold a volume of liquid in the range of 0.015 ml to 0.02 ml.
In some examples, the sub-reservoir 331 is configured to hold a volume of liquid corresponding to an amount of liquid aerosol generating material vaporised in a number of puffs (or fractions of a puff). For example, an example system could vaporise approximately 0.09ml of liquid aerosol generating material during an average puff (e.g. over a 3 second period in which the induction element 42 is activated to heat the susceptor 34). As such a sub-reservoir 331 configured to hold a volume of liquid in the range of 0.015 ml to 0.02 ml can hold enough liquid for approximately 2 puffs. In some examples, the sub-reservoir 331 is configured to hold a volume of liquid corresponding to the amount of liquid aerosol generating material vaporised, on average, in 0.5 to 5 puffs. In some examples, the sub-reservoir 331 is configured to hold a volume of liquid corresponding to the amount of liquid aerosol generating material vaporised, on average, in 1 to 3 puffs.
In some examples, the reservoir 33 is configured to hold around 2 ml of liquid (e.g. the total volume of the reservoir 33). For example, the reservoir 33 may be configured to hold a volume of liquid in the range of 1 ml to 4 ml. In some examples, the sub-reservoir 331 is configured to hold a volume of liquid corresponding to a fraction of the total volume of the reservoir 33. In some examples, the sub-reservoir 331 is configured to hold a volume of liquid in the range of 0.2 % to 2.5 % of the total volume of the reservoir 33. In some examples, the sub-reservoir 331 is configured to hold a volume of liquid in the range of 0.5 % to 1.5% of the total volume of the reservoir 33.
In some examples, one or more liquid flow channels 37 fluidly connect the reservoir 33 to the sub-reservoir 331. In these examples, liquid aerosol generating material can flow between the reservoir 33 and the sub-reservoir 331 via the one or more liquid flow channels 37.
In some examples, the sub-reservoir 331 comprises or is formed of a capillary material. For example, the sub-reservoir 331 may comprise a structure having capillary channels or a capillary material may be inserted into the sub-reservoir 331. Similarly to as described in relation to the liquid flow channels 37, a capillary material of the sub-reservoir 331 may exert a lower capillary driving force to a capillary driving force exerted by the liquid transport element 35 to enable liquid to be drawn into liquid transport element 35 from the sub-reservoir 331.
In some examples, not shown, the cartridge 30 comprises one or more liquid flow channels 37 for guiding liquid aerosol generating substrate from the reservoir 33, and does not comprise a sub-reservoir 331. In some examples, the cartridge 30 comprises a sub-reservoir 331 configured to hold a smaller volume of liquid aerosol generating substrate than the reservoir, where the cartridge is configured to supply liquid from the sub-reservoir to the susceptor; and does not comprise liquid flow channels 37 (e.g. liquid can be transported from the reservoir 33 to the sub-reservoir 331 via a liquid transport element 35).
In some examples such as those in accordance withFigure 4, the cartridge 30 comprises one or more liquid flow channels 37 and a sub-reservoir 331. In some of these examples, the one or more liquid flow channels 37 are configured to guide liquid aerosol generating substrate from the reservoir 33 to the sub-reservoir 331.
Figure 5 is a schematic diagram (not to scale) of an example of a mouthpiece 50, cartridge 30 and induction assembly 40 for use in an aerosol/vapour delivery system 10 in accordance with the present disclosure. The cartridge 30 differs from the cartridges 30 shown inFigures 1,3 and4, in that the cartridge 30 is configured to be received in a separate mouthpiece component 50 (called a mouthpiece 50 herein). The susceptor 34, the liquid transport element 35, the reservoir 33 of the cartridge 30, as well as the induction assembly 40 ofFigure 5 are as described in relation toFigure 1 and will not be described again in detail. Alternate embodiments of a cartridge 30, which are suitable for use with a mouthpiece 50 as disclosed inFigure 5, may include aspects described in relation toFigures 3 and4 (e.g. liquid flow channels 37, a sub-reservoir 331).
The cartridge 30 ofFigure 5 may be termed a pod or capsule and is configured to be received inside a cavity or void of the mouthpiece 50. For example, the housing 36 of the cartridge 30 is not configured to define a mouthpiece shape, but is instead configured to define a structure which can be received within a component providing mouthpiece 50, and which can accommodate components such as the reservoir 33, a susceptor 34, and a liquid transport element 35.
As depicted inFigure 5, the housing 36 may be a body having a central passage extending between two openings in opposing end faces of the body. The central passage provides a portion of the air pathway 16 of the system 10. The susceptor 34 provides one or more surfaces of the central passage. For example, the susceptor 34 can comprise a tube with the air pathway 16 extending through the centre of the tube. The openings in the opposing end faces of the body may be circular or elliptical apertures or may be any other shape (e.g. polygonal, or a combination of curved and straight edges), and the outer surface of the central passageway may be defined by walls (including walls defined by the susceptor 34) which extend between the periphery of each of the openings. In this way the cartridge 30 may be an annular structure. In some examples, not shown, the passageway is not a central passageway (i.e. not disposed centrally in the cartridge 30) and is instead displaced to one side of the cartridge 30
The cartridge 30 includes a liquid transport element 35 which is provided between the susceptor 34 and the reservoir 33. The reservoir 33 is provided by cavities defined by the housing 36 and optionally the liquid transport element 35 and /or susceptor 34. For example, the reservoir 33 may be an annular cavity extending downstream or towards a mouth-end of the housing 36 from the liquid transport element 35.
The mouthpiece 50 for use with a separate cartridge 30 comprises a cavity 51 (e.g. void or volume) which is suitable for receiving a cartridge 30. In the example ofFigure 5, the cavity 51 is an internal space or volume defined by a housing which also defines the external shape of the mouthpiece 50. For example, the mouthpiece defines an outlet 12 of the air pathway 16 through which a user can inhale. In some examples, the housing is formed from a metal or plastic material (for example, the housing may be formed by plastic injection moulding process).
In some examples, the cavity 51 has a shape and size which corresponds to the outer shape defined by the cartridge 30 but which is larger, (e.g. slightly larger such as 1 % larger) than the outer shape defined by the cartridge 30. This allows the cartridge 30 to be inserted or placed into cavity 51, such that the cartridge 30 is retained in the cavity 51. In some examples, the size of the cartridge 30 and the size of the cavity 51 may be substantially similar such that an interference fit is formed between the housing defining the cavity and the housing 36 defining the cartridge 30.
In some examples, such as those in accordance withFigure 5, the housing comprises two portions. A first, upper, downstream or mouth-end portion 52 (which also defines the external shape of the mouthpiece which is configured for a user to form a seal with when the user is inhaling) and a second, lower, upstream or device-end portion 54 (which is configured to be inserted at least partially into the receiving cavity 49 of the induction assembly 40). The cavity 51 may be formed by one or both of the upper and lower portions 52,54. In these examples, the mouthpiece 50 may comprise an opening mechanism 56 and a connection mechanism 58.
The opening mechanism 56 is configured to allow for movement of the first portion 52 with respect to the second portion 54, or vice versa. In some examples, the opening mechanism 56 is a hinge or flexible connector. Where the opening mechanism 56 is a hinge, the opening mechanism 56 can allow for rotation of the first portion 54 with respect to the second portion 52. In some examples, the rotation can be with respect to an axis which is perpendicular to the longitudinal axis of the system 1, while in some other examples the rotation with respect to an axis which is parallel to the longitudinal axis of the system 1.
The opening mechanism 56 allows the mouthpiece 50 to be moved between a first configuration in which the cavity 51 is at least partially exposed in order to allow a cartridge 30 to be inserted and / or removed, and a second configuration in which the cavity 51 is substantially closed (except for via openings for the air pathway 16) in order to retain and / or protect a cartridge 30 provided within the cavity 51. The first configuration may be termed an open or accessible configuration because the cavity 51 is open and accessible to a user, and the second configuration may be termed a closed or inaccessible configuration because the cavity 51 is closed and inaccessible to a user.
As such, in some examples, a mouthpiece comprises an opening mechanism configured to allow the mouthpiece to be moved between a first configuration and a second configuration, wherein in the first configuration the cavity is at least partially exposed in order to allow a cartridge to be inserted and / or removed, and wherein the second configuration is configured to retain a cartridge provided within the cavity.
Advantageously, the opening mechanism 56 allows a user to open the cavity 51 without a full disconnection of the first portion 52 from the second portion 54, thereby improving user accessibility because a user does not have to hold each portion 52,54 separately whilst inserting or removing a cartridge 30 from the cavity 51. However, it will be appreciated that in some other examples, an opening mechanism 56 may not be included and instead the first portion 52 and the second portion 54 may fully detach from each other when changing the mouthpiece configuration from the second configuration to the first configuration.
The connection mechanism 58 acts to retain the first portion 52 in contact with the second portion 54 of the housing. For example, the connection mechanism 58 may be a latch or lock which prevents or inhibits the first portion 52 from moving relative to the second portion 54, or vice versa. The connection mechanism 58 is configured to prevent or inhibit the mouthpiece 50 from moving from the closed configuration to the open configuration in order to prevent a cartridge 30 from inadvertently being leaving the cavity 51 prior to a user intending to remove the cartridge 30.
In some examples, the connection mechanism 58 is provided in one or both of the first portion 52 and the second portion 54. For example, the connection mechanism 58 can comprise a corresponding component in each of the first and second portions 52,54 which are configured to engage with each other to prevent or inhibit movement of the first and second portion 52,54 with respect to each other. In some examples, the connection mechanism 58 comprises a mechanical mechanism including a latch or clip in one of the first portion 52 and the second portion 54, and a corresponding component (e.g. a second clip or a ridge) in the other of the first portion 52 and the second portion 54 for retaining the latch or clip. In some examples, the connection mechanism 58 comprises a first magnet in the first portion 52, and a second magnet (attractive to the first magnet) in the second portion 54, the two magnets generating a force that needs to be overcome to move the first portion 52 relative to the second portion 54.
In some examples, the connection mechanism 58 is user actuatable such that a user can interact directly with the connection mechanism 58 to inhibit the connection mechanism 58 from retaining the mouthpiece in the second configuration. In other words, the connection mechanism 58 is user actuatable such that a user can interact directly with the connection mechanism 58 to allow the first portion 52 to move relative to the second portion 54 (e.g. the user may move or bend a latch out of a position with respect to a corresponding clip, or may apply force to overcome the attraction between two magnets).
In some examples, the connection mechanism 58 is electronically controlled (e.g. electrically operated by the control circuitry 28). For example, while not shown, at least a part of the connection mechanism 58 may be electrically connected to the control circuitry 28 and may be operable (e.g. in response to electrical signals) by the control circuitry 28 to activate or deactivate the connection mechanism 58. In some examples, the connection mechanism 58 may comprise an electromagnet and a permanent magnet, where the electromagnet is configured to generate a magnetic field when a current is supplied through the electromagnet, which causes an attractive force to be generated between the permanent magnet and electromagnet. In some examples, the connection mechanism 58 comprises an actuator which is movable in response to an electric signal to engage a latch or similar (such a latch and actuator may be positioned to not be visible to a user when the mouthpiece 50 is in the second configuration).
Advantageously, the connection mechanism 58 can be used to slow down a user, when a user is seeking to change a cartridge 30. For example, when a susceptor 34 is heated by induction the susceptor 34 may heat up to high temperature. Particularly in cases where a user activates the induction element a number of times in a short period (e.g. 10 puffs in 1 minute), elements of the cartridge 30 can become hot (particularly, the susceptor and those close to the susceptor). If the user were to remove the cartridge 30 immediately after puffing the user (or their clothing or nearby item such as a table) could be burned.
The provision of connection mechanism 58 delays the user from accessing the cartridge 30 immediately, and instead allows heat (thermal energy) to dissipate throughout the cartridge 30 and surrounding elements of the system 10. It will be appreciated that even where the connection mechanism 58 is a simple mechanical mechanism such as a latch, this may still delay the user from accessing the cartridge by a few seconds (e.g. at least 2 to 3 seconds). In some examples, where the connection mechanism 58 is electronically controlled, the control circuitry 28 may implement a timer preventing the connection mechanism 58 from being disengaged for a period of time after a most recent activation of the induction element 42 (e.g. the period of time is in a range of greater than 3 seconds, and preferably greater than 5 seconds). In some examples the period of time may be fixed, whereas in other examples the period of time may be calculated based on the usage of the system up to the last puff (e.g. increased usage prior to the last activation causing the period of time to be greater).
In some examples, not shown, the lower portion 54 may not be a component of the mouthpiece 50. Instead in these examples, the induction assembly 40 or the device 20 define or otherwise provide at least a portion of the cavity 51 for the cartridge 50 (for example, at a minimum the induction assembly 40 or the device 20 may define an end surface of the cavity with the remaining surfaces defined by a single mouthpiece housing component). In these examples, the connection mechanism 58 and / or the opening mechanism 56, as described above, can be provided by the induction assembly 40 or device 20. For example, the mouthpiece 50 may be connected by a hinge (opening mechanism 56) to the induction assembly 40 or to the device 20. As such, in some examples, the mouthpiece 50 comprises at least a component of an connection mechanism, wherein the connection mechanism is configured to retain the mouthpiece in the second configuration.
Furthermore, in some examples, a connection mechanism 58 as described above is provided to connect a cartridge 30 directly to the device part 20 and/or the induction assembly 40 without the presence of a separate mouthpiece 50. For example, the connection mechanism 58 may engage or lock the cartridge 30 on to the device part 20 and/or the induction assembly 40 to prevent the cartridge from inadvertently disconnecting.
Figure 6 is a schematic diagram (not to scale) of an example of a cartridge 30 and induction assembly 40 for use in an aerosol/vapour delivery system 10 in accordance with the present disclosure. In contrast to the example cartridge 30 shown infigure 1, a portion of the air pathway 16 adjacent to the susceptor 34 (i.e. the aerosol generation region) is provided between the susceptor 34 and the induction element 42. Various aspects of the example cartridge 30 and induction assembly 40 ofFigure 6 are as described in relation toFigures 1 to 3 and will not be described again in detail.
As discussed above, the a portion of the air pathway 16 adjacent to the susceptor 34 is provided between the susceptor 34 and the induction element 42. In these examples, the susceptor 34 may be considered to comprise a first susceptor surface defining at least a part of an air pathway. In particular, the air pathway may be a peripheral air pathway, with the first susceptor surface defining at least a part of the peripheral air pathway, the peripheral air pathway provided between the susceptor 34 and the induction element 42. By defining, it is meant that the air pathway 16 is bounded or bordered by the first susceptor surface.
In some examples, such as those in accordance withFigure 6, a portion of the housing 36 of the cartridge 30 is additionally provided between the susceptor 34 and the induction element 42, and the air pathway 16 is defined (bounded or bordered) by the portion of the housing 36 (e.g. an engagement portion 364 as discussed below) in combination with the first susceptor surface (e.g. they define different sides of the peripheral air pathway 16 adjacent to the first susceptor surface).
In some examples, the susceptor 34 is a tubular or annular component 34 which may be formed as described in relation tofigure 1. For example, the susceptor 34 may be formed from a sheet of a suitable inductively heatable metal which is rolled or curved into a tube shape, or the susceptor 34 may be formed from a mesh or foam of a suitable inductively heatable material. As such, in some examples, a susceptor 34 is formed of a planar element which is curved or rolled to provide a cylindrical body.
In some examples, such as those in accordance withFigure 6, a liquid transport element 35 (sometimes called a wick 35) is provided internally to the susceptor 34 (e.g. within the tube). In some examples, the liquid transport element 35 extends from a reservoir 33 and along the entire length of the susceptor 34, such that the liquid transport element 35 is able to deliver or supply liquid aerosol generating material to the entire inner surface of the susceptor 34.
In use, the susceptor 34 may be heated inductively when a current is supplied to the induction element 42. Liquid aerosol generating material adjacent or within the susceptor 34 is aerosolised or vaporised when the susceptor 34 reaches a suitable temperature, and may flow through perforations in the surface of the susceptor 34 (e.g. as described in relation toFigure 3), and into the air pathway 16. Once in the air pathway 16, the aerosol/vapour can flow towards an outlet 12 of the system 10 for inhalation by a user.
In some examples, the air pathway 16 adjacent to the susceptor 34 is defined by a surface of the susceptor 34 and a surface of an engagement portion 364 of the cartridge 30 which is configured to be inserted into the receiving cavity 49 of the induction assembly 40. In some examples, the engagement portion 364 is configured to form an interference fit with a wall of the induction assembly defining the receiving cavity 49. The engagement portion 364 may, in some examples, protect and / or conceal the susceptor 34 when the cartridge 30 is not engaged with the induction assembly 40.
In some examples, not shown, the air pathway 16 adjacent to the susceptor 34 is defined by a surface of the susceptor 34 and a surface of the induction assembly 40. In these examples, the engagement portion 364 is omitted or is present only around one or more portions of the circumference of the susceptor 34. In these examples a smaller coupling distance may be achievable without increasing the resistance to draw of the air pathway 16 because the coupling distance is not increased by the width of the engagement portion 364 (at least for the regions or zones where the engagement portion 364 is not present).
In some examples, the coupling distance between the susceptor 34 and the induction element 42 (or the offset distance relating to the distance separating the surface of the susceptor 34 from the induction element 42) is in the range of less than 3 mm. In some examples, the coupling distance between the susceptor 34 and the induction element 42 is in the range of less than 2 mm. In some examples, the coupling distance between the susceptor 34 and the induction element 42 is in the range of less than 1.5 mm. In some examples, the coupling distance between the susceptor 34 and the induction element 42 is in the range of less than 1 mm.
In some examples, the air pathway 16 adjacent to the susceptor 34 has a width in the range of 0.3 to 2 mm. By a width it is meant the distance separating a surface of the susceptor 34 from the opposing surface of the engagement portion 364 or the induction assembly 40 which defines the other side of the air pathway 16. In examples, where the susceptor 34 and the induction element 42 are aligned with a longitudinal axis of the system 10, the width is perpendicular to the longitudinal axis of the system 10. In some examples, the air pathway 16 adjacent to the susceptor 34 has a width in the range of 0.5 to 1.5 mm.
In some examples, the support 44 of the induction assembly 40 comprises an airflow channel or passage 441. The airflow channel 441 is configured to allow airflow to flow through the support 44 towards the cartridge 30. In other words, the airflow channel 441 is configured to allow flow from an upstream or device side of the induction assembly 40 towards a downstream or cartridge side of the induction assembly 40. In these examples, the airflow channel 441 provides a portion of the air pathway 16 (shown by the arrows). While not shown, the air pathway 16 can extend to an inlet provided, for example, by the control part 20. In some examples, not shown, the support 44 may comprise multiple airflow channels 441 rather than a single airflow channel 441.
In some examples, in accordance withFigure 6, the liquid transport element 35 is formed of a single cylinder of material which is configured to provide liquid around an inner circumference of the susceptor 34. In some other examples, the liquid transport element 35 is formed of a annular structure. In some of these other examples, one or more liquid flow channels 37 (as described in relation toFigure 4) may be provided internally to the liquid transport element 35 (i.e. within the annulus). The one or more liquid flow channels 37 may be provided by a portion of the housing 36 (e.g. particularly where the one or more liquid flow channels 37 are formed by a capillary channels in a structure), or may simply be provided as a result of the absence of the liquid transport element 35 in the centre of the annulus. The presence of one or more liquid flow channels 37 aid in supplying liquid along the length of the liquid transport element 35, and hence improve the supply of liquid to the susceptor 34 via the liquid transport element 35 (in particular the supply of liquid to the upstream end of the susceptor 34).
In some examples, not shown, a cartridge 30 having an air pathway 16 in accordance withFigure 6, may further comprise a sub-reservoir 331 as described in accordance withFigure 4.
The presence of a sub-reservoir 331 functions to improve the supply of liquid to the upstream end of the susceptor 34 (distal to the main reservoir 33).
Figure 7 is a flow diagram depicting a method 100 of generating an aerosol from an aerosol generating substrate in an aerosol delivery system 10 in accordance with the present disclosure. The aerosol delivery system 10 comprises a cartridge 30 and a device part 20 (sometimes called device, control unit or control part), wherein the cartridge 30 comprises a susceptor 34, and the control part 20 comprises an induction element 42, a power supply 25 and control circuitry 28. The system 10 and its components (e.g. induction assembly 40, cartridge 30 and control part 20) may be as described in relation to any ofFigures 1 to 6 and will not be described again in detail.
The method 100 starts with a first step 110 of inserting the susceptor 34 into the receiving cavity 49. The cartridge 30 is connected with the induction assembly 40 (or device part 20) to position the susceptor 34 within the induction element 42 (e.g. within a volume defined by a spiral coil forming the induction element 42). At least a portion of the susceptor 34 is provided in a portion of the cartridge 30 which will be inserted into the receiving cavity 49 of an induction assembly when the cartridge 30 is connected to the induction assembly 40; for example, as described in relation toFigures 1 to 6. In some examples, inserting a susceptor 34 into the receiving cavity 49 comprises inserting the whole of the susceptor 34 into the receiving cavity 49. In some examples, inserting a susceptor 34 into the receiving cavity 49 comprises a portion of the susceptor 34 into the receiving cavity 49.
The first step 110 may alternatively be termed as engaging the receiving cavity 49 of the induction assembly with the cartridge 30 to surround at least a portion of the susceptor 34. In other words, it will be appreciated that the relative movement (i.e. insertion) of the susceptor 34 into the receiving cavity 49 can also be described as the relative movement of the receiving cavity 49 with respect to the susceptor 34. Furthermore, the first step 110 may further be termed as providing (at least a portion of) the susceptor 34 within the receiving cavity 49.
In some examples, the method 100 continues with a step 120 of driving the induction element 42 to induce current flow in the susceptor 34 to inductively heat the susceptor 34 to inductively heat the susceptor to a first temperature, and so vaporise a portion of the aerosol generating substrate in the vicinity of the susceptor 34. For example, the induction element 42 may be driven to heat the susceptor 34 to at least a vaporisation temperature of an aerosol forming component of the aerosol generating substrate (e.g. a liquid from a reservoir 33). The temperature to which the susceptor is driven to vaporise a portion of the aerosol generating substrate in the vicinity of the susceptor 34 can be considered a first temperature or a vaporisation or aerosolisation temperature. In some examples, the first temperature is in the range of between 150°C and 300°C. In some examples, the first temperature is in the range of between 190°C and 220°C.
In some examples, step 120 is triggered by a user input. For example, the user may engage a user input element. For example, the user may interact with a user actuatable element, such as a button, or the user may inhale on the system (e.g. via the outlet 12) to trigger a puff sensor. In addition to the user input element being a user actuatable element such as a button, or a puff sensor, the user input element could also be any sensor capable of identifying a user interaction (e.g. a capacitance sensor, a motion sensor, or an optical sensor). The user input element can be configured to send a signal to the control circuitry 28 indicating that a user input has occurred, and the control circuitry 28 can trigger step 120 (i.e. drive the induction element 42). For example, a user inhales on the outlet 12, a puff sensor sends a signal to the control circuitry identifying a user input corresponding to an inhalation (e.g. a signal identifying a pressure drop), and the control circuitry 28 triggers the driving of the induction element 42 to induce current flow in the susceptor 34 to inductively heat the susceptor 34 to inductively heat the susceptor to a first temperature.
In some examples, the system 10 comprises a temperature sensor for measuring a temperature of the susceptor 34. The temperature sensor may be configured to measure a value indicative of the temperature of the susceptor 34 rather than directly measuring the susceptor 34 directly. For example, a suitable temperature sensor may be able to determine the temperature of the susceptor 34 based on resistance of an element close to the susceptor 34 (e.g. a thermocouple in the vicinity of the susceptor 34). In some examples, the induction element 42 may be used to measure the temperature of the susceptor 34 based on a strength and frequency of the inductive coupling between the susceptor and the induction element 42. Measurements or signals relating (directly or indirectly) to the temperature of the susceptor 34 can be sent to the control circuitry 28, and used to control how the induction element 42 is driven (i.e. to achieve or maintain a temperature).
In some examples, the method ends after driving the induction element 42 to induce current flow in the susceptor to inductively heat the susceptor to a first temperature. For example, the control circuitry 120 can cease to drive the induction element 42 to induce current flow in the susceptor 34 to inductively heat the susceptor 34 to a first temperature after a period of time corresponding to a user's puff, and / or corresponding to a predicted amount of aerosol generation (e.g. based on knowledge of the energy input to the system and energy required to vaporise the aerosol generating substrate, and either actively calculated during use or based on predetermined data, such as a look-up table, for a particular system 10 configuration).
In some examples, the method ends after driving the induction element 42 to induce current flow in the susceptor to inductively heat the susceptor to a first temperature for a fixed period of time. In some examples, the fixed period of time may be a period of time in the range of 1.5 to 5 seconds. In some examples, the fixed period of time may be a period of time in the range of 2.5 to 4 seconds.
In some examples, the method ends after driving the induction element 42 to induce current flow in the susceptor to inductively heat the susceptor to a first temperature when a user input (e.g. inhalation, button press, or similar as described above) ceases to be provided. For example, a user ceases to inhale of the system 10, the puff sensor sends a signal indicating that air pressure has increased, and the control circuitry 28 stops driving the induction element 42. Alternatively, a user ceases to press a button of the system 10, the button sends a signal indicating that the button is not being pressed, and the control circuitry 28 stops driving the induction element 42. In some examples, the control circuitry 28 implements a maximum activation period even where the user continues to trigger a user input mechanism. This may prevent overheating of the system 10, if for example the user input element has malfunctioned. In some examples, the maximum activation period is a period in the range of 6 to 15 seconds. In some examples, the maximum activation period is a period in the range of 7 to 12 seconds. The method 100 may, in some examples, end after step 120.
In some examples, the method 100 comprises a further step 115 of driving the induction element 42 to induce current flow in the susceptor 34 to inductively heat the susceptor 34 to a second temperature that is a lower temperature than the first temperature, and which is not sufficient to vaporise a portion of the aerosol generating substrate in the vicinity of the susceptor 34. In other words, the second temperature is lower than a temperature required to vaporise the portion of the aerosol generating substrate in the vicinity of the susceptor. The second temperature may be considered a preheat temperature. In some examples, the second temperature is in the range of 80°C to 200°C. In some examples, the second temperature is in the range of 120°C to 170°C.
As such, in some examples, in accordance with step 115 the method 100 comprises driving the induction element to induce current flow in the susceptor to inductively heat the susceptor to a first temperature so as to vaporise the portion of the aerosol generating substrate in the vicinity of the susceptor, and wherein the method further comprises driving the induction element to induce current flow in a susceptor to inductively heat the susceptor to a second temperature which is lower than the first temperature and lower than a temperature required to vaporise the portion of the aerosol generating substrate in the vicinity of the susceptor.
It will be appreciated that the control circuitry 28 is able to drive the induction element 42 to induce current flow in the susceptor 34 to inductively heat the susceptor 34 to a particular temperature by modifying the power supplied through the induction element. For example, the control circuitry 28 can monitor the temperature of the susceptor by a suitable sensor (e.g. thermocouple or based on a shift in resonant frequency detectable by the induction element 42), and can turn alter the power supplied through the induction element. As an example, the control circuitry 28 can supply power in a periodic pulses at a set frequency (e.g. 500-50Hz) until a required temperature is reached. As long as the susceptor 34 is at or above the required temperature the control circuitry 28 can prevent the supply of power during the next scheduled pulse. When the susceptor falls below the required temperature, the control circuitry 28 can resume supplying pulses to drive the induction element 42.
The provision of a preheat temperature may be particular advantageous for use with a susceptor 34 formed from a high mass element such as a block element formed from steel mesh or nickel foam, and / or when a susceptor 34 such as a sheet is used with a wick 35 formed from an inductively heatable material (such as steel mesh or nickel foam). Such a susceptor 34 and / or wick 35 may take a relatively long time to heat due to the high mass, but is able to store latent heat between activations. Hence, by maintaining the susceptor 34 and / or wick at a higher than ambient temperature, the time taken to heat the susceptor 34 to a first temperature so at to vaporise a portion of the aerosol generating substrate in the vicinity of the susceptor 34 is reduced. Furthermore, the high mass of the susceptor 34 and / or wick 35 increases the time taken for the temperature of the susceptor 34 to return to ambient conditions because the susceptor 34 and / or wick 35 has an increased bulk heat capacity which is less easily dissipated into the surrounding system 10 because of the reduced ratio of external surface area to volume ratio in comparison to a planar element such as a thin sheet of metal.
In some examples, the induction element 42 is driven to induce current flow in the susceptor 34 to inductively heat the susceptor 34 to the second temperature in response to a stimulus. In some examples, the control circuitry 28 is configured to drive the induction element to induce current flow in a susceptor to inductively heat the susceptor to a second temperature in response to a stimulus, wherein the stimulus comprises one or more of a signal indicative of the insertion of at least a part of the susceptor into the induction element, and a signal indicative of a user's intention to begin a session of usage.
In some examples, a signal indicative of the insertion of at least a part of the susceptor 34 into the induction element 42 is based on a detection that an inductively heatable element has been moved towards the induction element 42. In other examples, a signal indicative of the insertion of at least a part of the susceptor 34 into the induction element 42, is indirectly based on the detection of the connection of a cartridge 30 to the induction assembly 40 and / or device 20.
In some examples, a stimulus may be the detection of the connection of a cartridge 30 to the induction assembly 40 and / or device 20. In some examples, the control circuitry 28 may be able to determine that a cartridge 30 has already been attached (i.e. is currently attached) based on a measurement or sensor reading (e.g. from a sensor for detecting attachment of a cartridge 30 such as an optical sensor or resistive sensor, or based on a signal from the induction element 42 indicating that a inductively heatable element has been moved towards the induction element). In some examples, a stimulus may be the user pressing a button of the device 20, or the user taking a first puff on the device 20 (triggering a puff sensor, if present).
A stimulus may be indicative of a user's intention to begin a session of usage (e.g. a user's intention to take a series of puffs on the system 10 (by puff it is meant a user will inhale on the outlet 12 of the system 10). In some examples, the method 100 comprises (the control circuitry 28) driving the induction element to induce current flow in the susceptor to inductively heat the susceptor to a second temperature in response to a stimulus, wherein the stimulus comprises one or more of a signal indicative of the insertion of at least a part of the susceptor into the induction element, and a signal indicative of a user's intention to begin a session of usage.
In some examples, the control circuitry 28 is configured to maintain the susceptor 34 at the second temperature prior to raising the temperature to the first temperature during an activation of the device 20 by a user (e.g. a puff), and / or the control circuitry 28 is configured to maintain the susceptor 35 at the second temperature between activations of the device 20 by a user. In other words, the control circuitry is configured to maintain the susceptor at the second temperature prior to raising the temperature to the first temperature in response to a signal indicating that a user is interacting with a user input element, and / or the control circuitry is configured to maintain the susceptor at the second temperature between signals indicating that a user is interacting with a user input element. By maintaining the temperature of the susceptor 34 at the second temperature, the time taken to ramp the temperature up to the first temperature can be decreased, thereby leading to the quicker production of a vapor (if an aerosol generating substrate is present). As discussed above, a user input element may comprise one or more of a button, a capacitance sensor, a motion sensor, an optical sensor and a pressure sensor, or any other suitable input mechanism.
As such, in some examples, the method 100 comprises driving the induction element 42 to induce current flow in the susceptor 34 to inductively heat the susceptor 34 from the second temperature to the first temperature in response to a signal indicating that a user is interacting with a user input element. For example, while the control circuitry 28 is driving the induction element 42 to induce current flow in the susceptor 34 to inductively heat the susceptor 34 from the second temperature, a user may press a button or inhale on the system 10, and the control circuitry 28 may switch to driving the induction element to induce current flow in the susceptor 34 to inductively heat the susceptor from the second temperature.
In some examples, the control circuitry 28 is configured to perform step 115 (i.e. driving the induction element 42 to induce current flow in the susceptor 34 to inductively heat the susceptor 34 to a second temperature that is a lower temperature than the first temperature), after performing step 120 (driving the induction element 42 to induce current flow in the susceptor 34 to inductively heat the susceptor 34 to inductively heat the susceptor to a first temperature). In some examples, this is in addition to driving the induction element 42 to induce current flow in the susceptor 34 to inductively heat the susceptor 34 to a second temperature that is a lower temperature than the first temperature prior to a first puff (e.g. in response to a stimulus such as the detection of the insertion of the susceptor 34 into the receiving cavity 49 and / or induction element 42).
In some examples, the control circuitry 28 is further configured to alternate between driving the induction element 42 to heat the susceptor 34 to the first temperature and the driving the induction element 42 to heat the susceptor 34 to the second temperature, in response to receiving a user input and not receiving a user input, respectively. For example, when the user inhales, or indicates they are inhaling (e.g. button press), the susceptor 34 is heated to the first temperature, and when the user ceases to inhale, or ceases to indicate they are inhaling (e.g. stops pressing a button), the susceptor 34 is heated to the second temperature (it will be appreciated that this may involve ceasing to drive the induction element 42 until the susceptor 34 cools from the first temperature to the second temperature, and then periodically driving the induction element 42 to maintain the susceptor 34 at the second temperature).
As such, in some examples the method comprises maintaining the susceptor at the second temperature after a signal indicating that a user is interacting with the user input element has stopped, and / or between signals indicating that a user is interacting with the user input element.
In some examples, where the method comprises step 115, the method 100 additionally comprises a step 125 of ceasing to drive the induction element 42 after a period of inactivity. The control circuitry 28 may be configured to maintain the susceptor at the second temperature for a period of time in response to a stimulus, and to cease driving the induction element 42 if an input from the user is not received before the end of the period of time. In other words, in some examples, the control circuitry is configured to cease driving the induction element to induce current flow in the susceptor to maintain the susceptor at the second temperature after a period of inactivity. As above, the input (i.e. action indicating activity) may be a button press or a puff (measured by a puff sensor) indicating that the user is inhaling, or intends to inhale) on the system 10. In some examples, the period of inactivity is in the range of 10 seconds to 120 seconds. In some examples, the period of inactivity is in the range of between 20 seconds to 60 seconds. The method 100 may, in some examples, end after step 125.
When the method 100 ends, the system 10 may enter a standby mode or a low power sleep mode. For example, after step 120 or after step 125, the control circuitry 28 may enter a standby mode where the control circuitry 28 periodically interrogates any user input elements for indications that the user is inhaling or intending to inhale on the device (or for other interactions relation to control of the system such as checking battery levels, changing heater temperature and turning off or resetting the device). In some examples, if no user inputs are received for a period of time (e.g. 5 to 10 minutes), the control circuitry 28 may turn the system 10 off or place the system 10 in a low power sleep mode.
In some examples, there is a connection mechanism 58 (e.g. as described in relation toFigure 5) configured to retain a cartridge 30 as part of the aerosol delivery system 10. The method can additionally comprise engaging and disengaging the connection mechanism 58, wherein the connection mechanism 58 is electronically operable (e.g. by the control circuitry 28). In some examples, the connection mechanism 58 connects different portions of a mouthpiece 50 which define a cavity 51, the connection mechanism 58 connects a mouthpiece 50 to the device part 20 and/or the induction assembly 40 (a cavity 51 for the cartridge 30 being provided by one or more of the mouthpiece 50, device part 20 and induction assembly 40), or the connection mechanism 58 connects the cartridge directly to the device part 20 and/or the induction assembly 40 (e.g. there is no separate mouthpiece 50).
In some examples, the method 100 further comprises (not shown) engaging a connection mechanism 58 configured to retain a cartridge as part of an aerosol delivery system, and disengaging the connection mechanism. By disengaging the connection mechanism, a user is able to remove and / or attach a cartridge 30 (e.g. by inserting a cartridge 30 into a cavity 51 as described in relation toFigure 5). By implementing such a connection mechanism 58 a risk to a user of injury or a risk of damage to the surroundings can be reduced, because disabling or disengaging the connection mechanism can delay the user from removing the cartridge for a few seconds; in which time the susceptor 34 can cool to a lower temperature.
In some examples, the method comprises engages the connection mechanism 58 in response to the control circuitry 28 determining that a cartridge has been attached to the system. In some examples, the method comprises engages the connection mechanism 58 in response to the control circuitry 28 receiving an input from a user indicating the connection mechanism 58 should be engaged. For example the connection mechanism 58 may be engaged in response to a first activation of the aerosol delivery system 10.
In some examples, the method comprises disengaging the connection mechanism 58 in response to the control circuitry 28 receiving an input from a user indicating the connection mechanism 58 should be disengaged (e.g. a button press or combination of button presses). In some examples, the method comprises disengaging the connection mechanism 58 in response to the control circuitry 28 entering a standby mode or a low power sleep mode. In some examples, the method comprises disengaging the connection mechanism 58 in response to the control circuitry 28 ceasing to drive the induction element 42 after a period of inactivity. In some examples, the method comprises disengaging the connection mechanism 58 in response to the control circuitry 28 determining that an amount of time has passed since a last activation (e.g. the time since the control circuitry 28 caused the susceptor to be heated to the first temperature). In some of these examples, the amount of time since a last activation may be in the range of 2 to 10 seconds or 3 to 5 seconds. In some examples, the method comprises disengaging the connection mechanism 58 in response to the control circuitry 28 determining that the susceptor 34 is below a threshold temperature.
Thus, there has been described an aerosol delivery system generating an aerosol from an aerosol-generating substrate is described. The aerosol delivery system includes an induction assembly comprising an induction element disposed about a longitudinal axis. The induction element is operable to induce current flow in a susceptor to inductively heat the susceptor to aerosolise a portion of the aerosol generating substrate in the vicinity of the susceptor. The aerosol delivery system also includes a cartridge comprising a reservoir for the aerosol generating substrate and the susceptor. The susceptor is disposed about the longitudinal axis and at least partly within the induction element.
Thus, there has also been described a cartridge for use in an aerosol delivery system for generating an aerosol from an aerosol generating substrate. The cartridge comprises a reservoir for the aerosol generating substrate. The cartridge also includes a susceptor disposed about a longitudinal axis. The susceptor is configured to be at least partially inserted into an induction assembly comprising an induction element disposed about the longitudinal axis. The induction element is operable to induce current flow in a susceptor to inductively heat the susceptor to aerosolise a portion of the aerosol generating substrate in the vicinity of the susceptor.
Thus, there has further been described a method of generating an aerosol from an aerosol generating substrate in an aerosol delivery system. The aerosol delivery system comprising an induction assembly and a cartridge. The induction assembly comprises an induction element disposed about a longitudinal axis and the cartridge comprises a reservoir for the aerosol generating substrate and the susceptor. The method comprises inserting the susceptor into a receiving cavity of the induction assembly. The susceptor is disposed about the longitudinal axis and at least partly within the induction element when the susceptor is inserted into the receiving cavity. The method further comprises driving the induction element to induce current flow in the susceptor to inductively heat the susceptor and so vaporise a portion of the aerosol generating substrate in the vicinity of the susceptor.
As noted, a heater in accordance with the disclosure is a susceptor for induction heating of a liquid aerosol generating material, as described with regard to cartridges shown inFigures 1 and3 to 6. In some other examples, a heater in accordance with the disclosure may be used for induction heating of an alternate aerosol generating material such as a gel aerosol generating material (e.g. a thermo-reversible gel).
In conclusion, in order to address various issues and advance the art, this disclosure shows by way of illustration various embodiments in which the claimed invention(s) may be practiced. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are presented only to assist in understanding and to teach the claimed invention(s). It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope of the claims. Various embodiments may suitably comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. other than those specifically described herein, and it will thus be appreciated that features of the dependent claims may be combined with features of the independent claims in combinations other than those explicitly set out in the claims. The disclosure may include other inventions not presently claimed, but which may be claimed in future.
Furthermore, there is a great degree of flexibility in the design/configuration of the aerosol provision system as a whole, as is exemplified at least by the various possibilities of features as outlined in the set of clauses following this paragraph. For the avoidance of any doubt, it will be commensurately appreciated that any features from these clauses may be combined as required in any combination beyond those as expressly set out in these clauses, noting the great flexibility and interchangeability in the usage of such features which the present disclosure clearly provides for.
- 1. An aerosol delivery system for generating an aerosol from an aerosol generating substrate, the aerosol delivery system comprising:
- an induction assembly comprising an induction element disposed about a longitudinal axis, wherein the induction element is operable to induce current flow in a susceptor to inductively heat the susceptor to aerosolise a portion of the aerosol generating substrate in the vicinity of the susceptor; and
- a cartridge comprising a reservoir for the aerosol generating substrate and the susceptor, wherein the susceptor is disposed about the longitudinal axis and at least partly within the induction element.
- 2. The aerosol delivery system of clause 1, wherein the induction assembly comprises a support having a tube portion disposed about said longitudinal axis, wherein the tube portion comprises an inner wall and an outer wall, wherein the induction element is provided between the inner wall and the outer wall of the tube portion, and wherein the inner wall defines a receiving cavity in which the susceptor is at least partly located.
- 3. The aerosol delivery system of clause 1 or 2, wherein the susceptor is configured to extend around a circumference perpendicular to the longitudinal axis.
- 4. The aerosol delivery system of clause 3, wherein the susceptor is configured to extend around the entirety of the circumference perpendicular to the longitudinal axis.
- 5. The aerosol delivery system of any preceding clause, wherein the susceptor comprises a tube element.
- 6. The aerosol delivery system of clause 5, wherein the tube element comprises a tube longitudinal axis extending between respective ends of the tube element, wherein the tube longitudinal axis is co-aligned with the longitudinal axis.
- 7. The aerosol delivery system of clause 5 or 6, wherein the tube element comprises a circularly symmetric tube element, and optionally wherein the tube element has an inner diameter in the range of 1.5 mm to 3 mm and / or an axial length in the range of 5 mm to 25 mm.
- 8. The aerosol delivery system of any preceding clause, wherein the susceptor comprises a first susceptor surface defining at least a part of an air pathway.
- 9. The aerosol delivery system of clause 8, wherein the air pathway is co-aligned with the longitudinal axis.
- 10. The aerosol delivery system of clause 9, wherein the susceptor comprises a hollow body, wherein the air pathway extends through the hollow body.
- 11. The aerosol delivery system of clause 8, wherein the air pathway is a peripheral air pathway, the first susceptor surface defining at least a part of the peripheral air pathway, the peripheral air pathway provided between the susceptor and the induction element.
- 12. The aerosol delivery system of any preceding clause, wherein the susceptor comprises a plurality of apertures extending through the susceptor.
- 13. The aerosol delivery system of clause 12, wherein the number density of the plurality of apertures varies from an end of the susceptor towards a centre of the susceptor.
- 14. The aerosol delivery system of clause 13, wherein the density of the plurality of apertures increases from the end of the susceptor towards the centre of the susceptor.
- 15. The aerosol delivery system of any of clauses 12 to 14, wherein the plurality of apertures are arranged in a pattern.
- 16. The aerosol delivery system of any preceding clause, wherein the susceptor is formed of a material having a capillary structure configured to wick a liquid aerosol generating substrate.
- 17. The aerosol delivery system of clause 16, wherein the susceptor is formed of one of a wire wool, mesh or metal foam.
- 18. The aerosol delivery system of clause 17, wherein the susceptor comprises a nickel foam or a cupro-nickel foam.
- 19. The aerosol delivery system of clause 17, wherein the susceptor comprises a stainless steel mesh.
- 20. The aerosol delivery system of any of clauses 1 to 15, wherein the susceptor comprises a planar element, the planar element having a thickness in the range of one or more of 20 µm to 70 µm, 30 µm to 60 µm, and 40 µm to 55 µm.
- 21. The aerosol delivery system of clause 20, wherein the planar element comprises a sheet or foil.
- 22. The aerosol delivery system of clause 20 or clause 21, wherein the planar element comprises one or more of mild steel, ferritic stainless steel, aluminium, nickel, cupro-nickel, and nichrome.
- 23. The aerosol delivery system of any of clauses 20 to 22, wherein the planar element is curved or rolled to provide a cylindrical body.
- 24. The aerosol delivery system of any preceding clause, the susceptor is offset from the induction element by an offset distance, wherein the offset distance is one or more of a range of less than 3 mm, a range of less than 2 mm, a range of less than 1.5 mm, and a range of less than 1 mm.
- 25. The aerosol delivery system of clause 24, wherein the offset distance comprises a smallest separation distance between the susceptor and the induction element.
- 26. The aerosol delivery system of clause 24 or 25, wherein the offset distance comprises an average separation distance between the susceptor and the induction element.
- 27. The aerosol delivery system of any preceding clause, wherein the reservoir is for a liquid aerosol generating substrate, wherein the cartridge is configured to supply liquid aerosol generating substrate from the reservoir to the susceptor.
- 28. The aerosol delivery system of clause 27, wherein the cartridge comprises a liquid transport element configured to wick the liquid aerosol generating substrate towards the susceptor.
- 29. The aerosol delivery system of clause 28, wherein the liquid transport element is formed of a susceptor material.
- 30. The aerosol delivery system of clause 28 or 29, wherein the liquid transport element provides liquid to a second susceptor surface on an opposing side of the susceptor to the first susceptor surface.
- 31. The aerosol delivery system of any of clauses 27 to 30, wherein the cartridge comprises one or more liquid flow channels for guiding liquid aerosol generating substrate from the reservoir.
- 32. The aerosol delivery system of clause 31, as dependent on any of clauses 28 to 30, wherein the one or more liquid flow channels are configured to guide liquid aerosol generating substrate from the reservoir to the liquid transport element.
- 33. The aerosol delivery system of clause 31 or 32, wherein the one or more liquid flow channels comprise a capillary channel.
- 34. The aerosol delivery system of any of clauses 27 to 33, wherein the cartridge comprises a sub-reservoir provided at or towards an opposite end of the susceptor to the reservoir, the sub-reservoir configured to hold a smaller volume of liquid aerosol generating substrate than the reservoir, and wherein the cartridge is configured to supply liquid from the sub-reservoir to the susceptor.
- 35. The aerosol delivery system of clause 34, wherein the sub-reservoir is configured to hold a volume of liquid in the range of 0.2 % to 2.5 % of a volume of the reservoir.
- 36. The aerosol delivery system of clause 35, wherein the sub-reservoir is configured to hold a volume of liquid in the range of 0.5 % to 1.5% of the volume of the reservoir.
- 37. The aerosol delivery system of any of clauses 34 to 36, wherein the sub-reservoir is configured to hold a volume of liquid in the range of 0.005 ml to 0.1 ml.
- 38. The aerosol delivery system of any of clauses 34 to 36, as dependent on any of clauses 31 to 33, wherein the one or more liquid flow channels are configured to guide liquid aerosol generating substrate from the reservoir to the sub-reservoir.
- 39. The aerosol delivery system of any preceding clause, wherein the induction element is formed from a resistive wire.
- 40. The aerosol delivery system of any of clauses 1 to 38, wherein the induction element comprises one or more conductive layers deposited upon a support.
- 41. The aerosol delivery system of clause 40, wherein the one or more conductive layers comprise a metal or a metal alloy.
- 42. The aerosol delivery system of clause 40 or 41, wherein the one or more conductive layers comprise copper, nickel, silver, gold, chromium, palladium, tin, aluminium, platinum, tungsten or zinc.
- 43. The aerosol delivery system of any of clauses 39 to 42, wherein the induction element comprises a helical coil or a spiral coil, and optionally wherein the induction element has a diameter in the range of 5 mm to 10mm and/ or an axial length of 3 mm to 10 mm.
- 44. The aerosol delivery system of any preceding clause, wherein the induction element is a first induction element and wherein the induction assembly comprises a second induction element disposed about said longitudinal axis, wherein a first portion of the susceptor is located at least partly within the first induction element and a second portion of the susceptor is located at least partly within the second induction element, the second induction element operable to induce current flow in the second portion of the susceptor to inductively heat the second portion of susceptor.
- 45. The aerosol delivery system of clause 44, wherein the first portion of the susceptor and the second portion of the susceptor are portions of a single susceptor.
- 46. The aerosol delivery system of clause 44, wherein the first portion of the susceptor is distinct and separate from the second portion of the susceptor.
- 47. The aerosol delivery system of any preceding clause, wherein the induction assembly comprises a ferrite shield disposed about a circumference of the induction element.
- 48. The aerosol delivery system of clause 47, wherein the ferrite shield comprises a film, foil or sheet.
- 49. The aerosol delivery system of clause 47 or 48, wherein the ferrite shield is inserted or embedded into a support for the induction element.
- 50. The aerosol delivery system of clause 47 or 48, wherein the ferrite shield comprises a sleeve surrounding a support for the induction element.
- 51. The aerosol delivery system of any preceding clause, wherein the cartridge is configured to provide a mouthpiece for a user to inhale an aerosol generated from an aerosol-generating substrate.
- 52. The aerosol delivery system of any of clauses 1 to 50, wherein the aerosol delivery system comprises a mouthpiece for use in an aerosol delivery system, wherein the mouthpiece comprises an outlet and a cavity configured to accommodate at least a portion of the cartridge.
- 53. The aerosol delivery system of clause 52, wherein the mouthpiece comprises an opening mechanism configured to allow the mouthpiece to be moved between a first configuration and a second configuration, wherein in the first configuration the cavity is at least partially exposed in order to allow a cartridge to be inserted and / or removed, and wherein the second configuration is configured to retain a cartridge provided within the cavity.
- 54. The aerosol delivery system of clause 53, wherein the mouthpiece comprises at least a component of a connection mechanism, wherein the connection mechanism is configured to retain the mouthpiece in the second configuration.
- 55. The aerosol delivery system of clause 54, wherein the connection mechanism is user actuatable such that a user can interact directly with the connection mechanism to inhibit the connection mechanism from retaining the mouthpiece in the second configuration.
- 56. The aerosol delivery system of any preceding clause, wherein the aerosol delivery system comprises control circuitry for controlling the supply of power to the induction element, wherein the control circuitry is configured to drive the induction element to induce current flow in the susceptor to inductively heat the susceptor and so vaporise a portion of the aerosol generating substrate in the vicinity of the susceptor.
- 57. The aerosol delivery system of clause 56, wherein the aerosol delivery system comprises a device part comprising the control circuitry.
- 58. The aerosol delivery system of clause 57, wherein the device part comprises a power supply for supplying power to the induction element, the control circuitry configured to control the supply of power from the power supply to the induction element.
- 59. The aerosol delivery system of clause 57 or 58, wherein the induction assembly is releasably attached to the device part.
- 60. The aerosol delivery system of any of clauses 56 to 59, wherein the control circuitry is configured to drive the induction element to induce current flow in the susceptor to inductively heat the susceptor to a first temperature so as to vaporise the portion of the aerosol generating substrate in the vicinity of the susceptor, and wherein the control circuitry is configured to drive the induction element to induce current flow in the susceptor to inductively heat the susceptor to a second temperature which is lower than the first temperature and lower than a temperature required to vaporise the portion of the aerosol generating substrate in the vicinity of the susceptor.
- 61. The aerosol delivery system of clause 60, wherein the second temperature is a temperature in the range of 80°C to 200°C.
- 62. The aerosol delivery system of clauses 60 or 61, wherein the control circuitry is configured to drive the induction element to induce current flow in the susceptor to inductively heat the susceptor to the second temperature in response to a stimulus, wherein the stimulus comprises one or more of a signal indicative of the insertion of at least a part of the susceptor into the induction element, and a signal indicative of a user's intention to begin a session of usage.
- 63. The aerosol delivery system of any of clauses 60 to 62, wherein the control circuitry is configured to drive the induction element to induce current flow in the susceptor to inductively heat the susceptor from the second temperature to the first temperature in response to a signal indicating that a user is interacting with a user input element.
- 64. The aerosol delivery system of clause 63, wherein the control circuitry is configured to maintain the susceptor at the second temperature after a signal indicating that a user is interacting with the user input element has stopped, and / or between signals indicating that a user is interacting with the user input element.
- 65. The aerosol delivery system of clause 63 or 64, wherein the device part comprises the user input element, the user input element comprising one or more of a button, a capacitance sensor, a motion sensor, an optical sensor and a pressure sensor.
- 66. The aerosol delivery system of any of clauses 60 to 65, wherein the control circuitry is configured to cease driving the induction element to induce current flow in the susceptor to maintain the susceptor at the second temperature after a period of inactivity.
- 67. The aerosol delivery system of clause 66, wherein the period of inactivity is in the range of 10 seconds to 120 seconds.
- 68. A method of generating an aerosol from an aerosol generating substrate in an aerosol delivery system, the aerosol delivery system comprising an induction assembly and a cartridge, wherein the induction assembly comprises an induction element disposed about a longitudinal axis and wherein the cartridge comprises a reservoir for the aerosol generating substrate and the susceptor, the method comprising:
- inserting the susceptor into a receiving cavity of the induction assembly, wherein the susceptor is disposed about the longitudinal axis and at least partly within the induction element when the susceptor is inserted into the receiving cavity;
- driving the induction element to induce current flow in the susceptor to inductively heat the susceptor and so vaporise a portion of the aerosol generating substrate in the vicinity of the susceptor.
- 69. The method of clause 68, wherein the method comprises driving the induction element to induce current flow in the susceptor to inductively heat the susceptor to a first temperature so as to vaporise the portion of the aerosol generating substrate in the vicinity of the susceptor, and wherein the method further comprises driving the induction element to induce current flow in a susceptor to inductively heat the susceptor to a second temperature which is lower than the first temperature and lower than a temperature required to vaporise the portion of the aerosol generating substrate in the vicinity of the susceptor.
- 70. The method of clause 69, wherein the second temperature is a temperature in the range of 80°C to 200°C.
- 71. The method of clause 68 or 69, wherein the method comprises driving the induction element to induce current flow in the susceptor to inductively heat the susceptor to a second temperature in response to a stimulus, wherein the stimulus comprises one or more of a signal indicative of the insertion of at least a part of the susceptor into the induction element, and a signal indicative of a user's intention to begin a session of usage.
- 72. The method of any of clauses 69 to 71, wherein the method comprises driving the induction element to induce current flow in the susceptor to inductively heat the susceptor from the second temperature to the first temperature in response to a signal indicating that a user is interacting with a user input element.
- 73. The method of clause 72, wherein the method comprises maintaining the susceptor at the second temperature after a signal indicating that a user is interacting with the user input element has stopped, and / or between signals indicating that a user is interacting with the user input element.
- 74. The method of any of clauses 68 to 73, wherein the method comprises ceasing to drive the induction element to induce current flow in the susceptor to maintain the susceptor at the second temperature after a period of inactivity.
- 75. The method of clause 74, wherein the period of inactivity is in the range of 10 seconds to 120 seconds.
- 76. The method of any of clauses 68 to 75, wherein the method comprises engaging a connection mechanism configured to retain a cartridge as part of the aerosol delivery system, and disengaging the connection mechanism, wherein the connection mechanism is electronically operable.
- 77. A cartridge for use in an aerosol delivery system for generating an aerosol from an aerosol generating substrate, the cartridge comprising:
- a reservoir for the aerosol generating substrate; and
- a susceptor disposed about a longitudinal axis, wherein the susceptor is configured to be at least partially inserted into an induction assembly comprising an induction element disposed about the longitudinal axis, wherein the induction element is operable to induce current flow in a susceptor to inductively heat the susceptor to aerosolise a portion of the aerosol generating substrate in the vicinity of the susceptor.
- 78. The cartridge of clause 77, wherein the susceptor is configured to extend around a circumference perpendicular to the longitudinal axis.
- 79. The cartridge of clause 78, wherein the susceptor is configured to extend around the entirety of the circumference perpendicular to the longitudinal axis.
- 80. cartridge of any of clauses 77 to 79, wherein the susceptor comprises a tube element.
- 81. The cartridge of clause 80, wherein the tube element comprises a tube longitudinal axis extending between respective ends of the tube element, wherein the tube longitudinal axis is co-aligned with the longitudinal axis.
- 82. The cartridge of clause 80 or 81, wherein the tube element comprises a circularly symmetric tube element, optionally wherein the tube element comprises a circularly symmetric tube element, and optionally wherein the tube element has an inner diameter in the range of 1.5 mm to 3 mm and / or an axial length in the range of 5 mm to 25 mm.
- 83. The cartridge of any of clauses 77 to 82, wherein the susceptor comprises a first susceptor surface defining at least a part of an air pathway.
- 84. The cartridge of clause 83, wherein the air pathway is co-aligned with the longitudinal axis.
- 85. The cartridge of clause 84, wherein the susceptor comprises a hollow body, wherein the air pathway extends through the hollow body.
- 86. The cartridge of clause 83, wherein the air pathway is a peripheral air pathway, the first susceptor surface defining at least a part of the peripheral air pathway, the peripheral air pathway provided between the susceptor and the induction element.
- 87. The cartridge of any of clauses 77 to 86, wherein the susceptor comprises a plurality of apertures extending through the susceptor.
- 88. The cartridge of clause 87, wherein the number density of the plurality of apertures varies from an end of the susceptor towards a centre of the susceptor.
- 89. The cartridge of clause 88, wherein the density of the plurality of apertures increases from the end of the susceptor towards the centre of the susceptor.
- 90. The cartridge of any of clauses 87 to 89, wherein the plurality of apertures are arranged in a pattern.
- 91. The cartridge of any of clauses 77 to 90, wherein the susceptor is formed of a material having a capillary structure configured to wick a liquid aerosol generating substrate.
- 92. The cartridge of clause 91, wherein the susceptor is formed of one of a wire wool, mesh or metal foam.
- 93. The cartridge of clause 92, wherein the susceptor comprises a nickel foam or a cupro-nickel foam.
- 94. The cartridge of clause 92, wherein the susceptor comprises a stainless steel mesh.
- 95. The cartridge of any of clauses 77 to 90, wherein the susceptor comprises a planar element, the planar element having a thickness in the range of one or more of 20 µm to 70 µm, 30 µm to 60 µm, and 40 µm to 55 µm.
- 96. The cartridge of clause 95, wherein the planar element comprises a sheet or foil.
- 97. The cartridge of clause 95 or 96, wherein the planar element comprises one or more of mild steel, ferritic stainless steel, aluminium, nickel, cupro-nickel, and nichrome.
- 98. The cartridge of any of clauses 95 to 97, wherein the planar element is curved or rolled to provide a cylindrical body.
- 99. The cartridge em of any of clauses 77 to 98, the susceptor is offset from the induction element by an offset distance, wherein the offset distance is one or more of a range of less than 3 mm, a range of less than 2 mm, a range of less than 1.5 mm, and a range of less than 1 mm.
- 100. The cartridge of clause 99, wherein the offset distance comprises a smallest separation distance between the susceptor and the induction element.
- 101. The cartridge of clause 99 or 100, wherein the offset distance comprises an average separation distance between the susceptor and the induction element.
- 102. The cartridge of any of clauses 77 to 101, wherein the reservoir is for a liquid aerosol generating substrate, wherein the cartridge is configured to supply liquid aerosol generating substrate from the reservoir to the susceptor.
- 103. The cartridge of clause 102, wherein the cartridge comprises a liquid transport element configured to wick the liquid aerosol generating substrate towards the susceptor.
- 104. The cartridge of clause 103, wherein the liquid transport element is formed of a susceptor material.
- 105. The cartridge of clause 103 or 104, wherein the liquid transport element provides liquid to a second susceptor surface on an opposing side of the susceptor to the first susceptor surface.
- 106. The cartridge of any of clauses 102 to 105, wherein the cartridge comprises one or more liquid flow channels for guiding liquid aerosol generating substrate from the reservoir.
- 107. The cartridge of clause 106, as dependent on any of clauses 103 to 105, wherein the one or more liquid flow channels are configured to guide liquid aerosol generating substrate from the reservoir to the liquid transport element.
- 108. The cartridge of clause 106 or 107, wherein the one or more liquid flow channels comprise a capillary channel.
- 109. The cartridge of any of clauses 106 to 108, wherein the cartridge comprises a sub-reservoir provided at or towards an opposite end of the susceptor to the reservoir, the sub-reservoir configured to hold a smaller volume of liquid aerosol generating substrate than the reservoir, and wherein the cartridge is configured to supply liquid from the sub-reservoir to the susceptor.
- 110. The cartridge of clause 109, wherein the sub-reservoir is configured to hold a volume of liquid in the range of 0.2 % to 2.5 % of a volume of the reservoir.
- 111. The cartridge of clause 110, wherein the sub-reservoir is configured to hold a volume of liquid in the range of 0.5 % to 1.5% of the volume of the reservoir.
- 112. The cartridge of any of clauses 109 to 111, wherein the sub-reservoir is configured to hold a volume of liquid in the range of 0.005 ml to 0.1 ml.
- 113. The cartridge of any of clauses 109 to 112, as dependent on any of clauses 106 to 108, wherein the one or more liquid flow channels are configured to guide liquid aerosol generating substrate from the reservoir to the sub-reservoir.