US3664548A - Aerosol containers and valves thereof - Google Patents

Abstract

THE DISCLOSURE ILLUSTRATES A VALVE WHICH MAY BE USED FOR THE AUTOMATIC OR MANUAL ACTUATION OF A DISPENSER FOR PRESSURIZED FLUIDS. THE VALVE INCORPORATES A PERMEABLE MEMBRANE, FOR EXAMPLE A LOW DENSITY POLYETHYLENE FILM, WHICH ALLOWS VAPOR FROM THE DISPENSER TO PERMEATE INTO THE VALVE AND GIVE RISE TO A PRESSURE BUILD-UP UNDER A SEALED DIAPHRAGM. THE PRESSURE BILD-UP EVENTUALLY CAUSES THE DIPHRAGM TO RELEASE A SPRING MECHANISM TO ACTUATE THE SPRAY OR AEROSOL DISCHARGE. ONCE DISCHARGE IS COMPLETE THE VAPOR UNDER THE DIAPHRAGM IS DISCHARGED AND THE MECHANISM AUTOMATICALLY RESET TO START THE CYCLE AGAIN.

Description

May 23, 1972 R. w. BRODERICK AEROSOL CONTAINERS AND VALVES THEREOF m S or a .3 Fl/ 04/ 8? Wm G i 2 m 4 0 J 6 i M N "III 0 7 \\N w 9, w M u J d 9 1 m y 23, 1972 R. w. BRODERICK 3,664,548

AEROSOL CONTAINERS AND VALVES THEREOF Filed July 9, 1970 r 5 Sheets-Sheet 3 lnvenlar Kw! wefionmu By I AGE/VT May 23, 1972 R. w. BRODERICK AEROSOL CONTAINERS AND VALVES THEREOF L5 Shoctu-l311eut 41 Filed July 9, 1970 mam Eur

lnoenlor R RY W. BRUDERICR v 6 a 6 4 ml 3 5 0 r 1/ 5 Z 8 4. 0/ 2 m m B A May 23, 1972 R. w. BRODERICK AEROSOL CONTAINERS AND VALVES THEREOF Filed July 9, 1970 IZE/I 56 United States Patent Oflice" 3,664,548 Patented May 23, 1972 3,664,548 AEROSOL CONTAINERS AND VALVES THEREOF Rory Wilson Broderick, Dalkey, Ireland, assignor to Institute for Industrial Research and Standards, and Norman John Thompson, both of Dublin, Ireland Filed July 9, 1970, Ser. No. 53,591

Claims priority, application Ireland, July 10, 1969,

941/69 Int. Cl. B67d 5 08 U.S. Cl. 22261 .24 Claims ABSTRACT OF THE DISCLOSURE The disclosure illustrates a valve which may be used for the automatic or manual actuation of a dispenser for pressurised fluids. The valve incorporates a permeable membrane, for example a low density polyethylene film, which allows vapour from the dispenser to permeate into the valve and give rise to a pressure build-up under a sealed diaphragm. The pressure build-up eventually causes the diaphragm to release a spring mechanism to actuate the spray or aerosol discharge. Once discharge is complete the vapour under the diaphragm is discharged and the mechanism automatically reset to start the cycle again.

The present invention relates to aerosol containers and particularly to valves for use in said containers. The term aerosol containers is intended to refer to enclosed containers charged with a fluid under pressure that is adapted to be expelled from the container by the pressure therein or more briefly a dispenser for pressurised fluids; A Conventional aerosol containers are normally provided with a valve operable by finger pressure to open the valve and thereby enable fluid in the container to issue to atmosphere. A demand exists, however, for aerosol contermittently operating the valve to permit periodic emission of fluid from the aerosol container.

With a view to avoiding the expense involved in providing mechanically or electro-mechanically operable means for dispensing fluid from aerosol containers, a primary object of the present invention is to provide, for use in such a dispenser for pressurised fluids, a valve which is manually operable and which is operable automatically to dispense at regular intervals of time, a quantity of fluid from the dispenser. 1

According to the invention, there is provided a valve for a dispenser for pressurised fluids, said valve comprising a valve housing incorporating a permeable membrane and pressure responsive means, the permeable membrane which allows vapour under pressure in the dispenser to penetrate into the valve housing to build-up pressure in the valve housing, the said built-up pressure actuating the pressure responsive means in the valve housing to open the valve, to discharge through thevalve, pressurised fluid from the dispenser.

. Advantageously, the permeable membrane'which enables vapour to enter the valve housing from the interior of the dispenser, permits a build-up of pressurein the valve housing over a time period substantially in excess means serves to open the valve to enable a quantity of fluid to discharge from the dispenser. The process of penetrationof vapour through the permeable membrane is generally thought to be a solution or absorption of vapour on the surface of the membrane followed by diffusion of the vapour through the membrane. The vapour penetration rate is approximately inversely related to the thickness of membrane used and also approximately linearily related to the pressure difference across the membrane. Thus for example the time period of the automatic cycle may readily be controlled by merely varying the thickness of membrane used.

In a preferred construction according to the invention, the valve comprises:

(a) A bottom enclosure adapted to hold in sealed engagement a permeable membrane and to house a sealing cup within a metering chamber which is connected by a dip tube to the pressurised fluid in the dispenser.

(b) A mounting cup adapted at one end for fluid tight mounting on the dispenser the other end of the mounting cup engaging the bottom enclosure, housing a capillary stem seated, at one end thereof, in the sealing cup and pressure responsive means (c) An actuator which projects to atmosphere from the mounting cup and contains a spray button with an orifice open to atmosphere, the orifice being connected to the capillary stem at that end thereof remote from the metering chamber.

The pressure responsive means utilised may to advantage comprise a flexible diaphragm mounted above a core, a cradle member, a snap spring mounted on the cradle member, a collar fixedly mounted on the capillary stem and a cradle return spring, whereby a build-up of pressure due to the pressurised vapour penetrating into the valve housing causes the flexible diaphragm to move away from thecore above which his mounted and force the cradle to move in the same axial direction, until the snap spring isactuatedto depress the collar and hence the capillary stem and the sealing cup to open the valve to dispense the pressurisjed fiuid in the metering chamber to. atmosphere and allow dischargeof the pressurised fluid which has penetrated into the valve housing to atmosphere. I

Preferably the permeable membrane is a polyethylene film, though ethylene vinyl acetate film, polytetrafluorethylene and fluorosilicone rubber have also-been found to be most suitable.

The invention will be more clearly understood from the following description of preferred embodiments of the invention given by way of example only with reference to the accompanying drawings in which FIG. 1 isan elevation in section of a valve in the closed position thereof, with the valve set for automatic operation FIG. 2 is an elevation similar to FIG. 1 but showing the valve in the open or spray discharge position FIG. 3 is a plan view of the valve FIG. 4 is an elevation similar to FIG. 1 showing the valve in a closed position and set for manual actuation FIG. 5 is an elevation in section of a modified construction of valve, the valve beingvshown in the closed position 'and set for automatic operation.

of the time period during which the pressure responsive Referring to FIGS. 1-4 of the drawings, the constructionof the valve is described for the sake of clarity from its lower end, in its normal position of use, as shown in the drawings.

A-membrane sealingcap 10 having vertical slits in its sides 'to allow the sides to-fiex during the assembly operation, is snap fitted on to thebottom enclosure 11. The sealingcap 10 compresses a pair of Oring rubber seals 12 whichseal the periphery of apermeable membrane 13,

for example a low density polyethylene film, located .between the sealing cap and thebottom enclosure 11. Achannel 11a, allows the pressurised vapour in the dispenser access to thepermeable membrane 13. A disc ofporous paper 14 lies between thepermeable membrane 13 and the bottom of thebottom enclosure 11. Aclip tube 15 is push fitted into anopening 16 in the side of thebottom enclosure 11 and the opening 16 communicates via abore 17 and via aninlet port 21, with ametering chamber 18 within thebottom enclosure 11. Themetering chamber 18 is provided with a spring loadedsealing cup 19 which normally engages under the action of spring arubber seal 20 positioned at the top of themetering chamber 18. Thebore 17 from thedip tube 15 to thismetering chamber 18 terminates in the bottom of themetering chamber 18 in theinlet port 21 which is provided with a raisedridge 22. Thisridge 22 allows arubber ferrule seal 23 on thesealing cup 19 to seal olf thisinlet port 21 when thesealing cup 19 is pressed downwards against it.

Aplastic core 26 is located in thebottom enclosure 11, above themetering chamber 18. Thecore 26 is held in thebottom enclosure 11 byscrew threads 27 or alternatively, it may be ultrasonically welded into place. With either assembly method, thecore 26 compresses the periphery of therubber seal 20 above themetering chamber 18 and ensures that therubber seal 20 prevents the leakage of fluid (vapour or liquid) from themetering chamber 18 into atiming chamber 28, which is substantiallyfilled by theplastic core 26, and is beneath aflexible rubber diaphragm 29. Anannular valve seat 30 projects down from a recess provided in the bottom face of thecore 26. Therubber seal 20 above themetering chamber 18 is normally pressed against this seat by an upwards spring influenced thrust of thesealing cup 19 in themetering chamber 18. During the automatic cycle of the valve, the pressure of the contents of themetering chamber 18 also press therubber seal 20 against thisvalve seat 30, as the pressure in themetering chamber 18 is the same as the dispenser contents pressure (except when the chamber is emptied and the valve is resetting) and the pressure above therubber seal 20 is considerably lower.

Theflexible rubber diaphragm 29 is fastened above the top of thecore 26 by ahollow rivet 31. Therivet 31 passes through a hole in the centre of thediaphragm 29 and is a tight fit in a hole in thecore 26. Thehead 31a of therivet 31 compresses abead 32, which is around the edge of the hole in the diaphragm29 against aridge 33 formed in thecore 26 and thereby creates a permanent seal here. The outer edge of thediaphragm 29 also contains a thickenedbead 34 and this bead is compressed against aledge 35 in avalve mounting cup 36, by a raisededge 37 on the top of thebottom enclosure 11. Thebottom edge 39 of thevalve mounting cup 36, a deep drawn metal component, is crimped in during assembly, under astep 38 in the outside wall of thebottom enclosure 11, to hold thebottom enclosure 11 in this position. This creates a permanent seal at the peripheral edge of thediaphragm 29 which serves two purposes, namely:

(a) To prevent the container contents fromleaking upwards past the ledge in the valve mounting cup and (b) To contain vapour, which has permeated into the,

space under the diaphragm.

From the foregoing, it may be seen that thetimingchamber 28 is normally sealed from the atmosphere and also always sealed from the dispenser contents, except for the slow permeation of vapour through themembrane 13.

Within thistiming chamber 28 vapour flow paths or channels are provided on the bottom and sides of thecore 26 to ensure that permeated vapour, rising through avertical hole 40 from themembrane 13, may readily flow to thetiming chamber 28 which is on the underside of thediaphragm 29. These channels also allow the flow of this vapour to thecore recess 26a where theannular valve seat 30 is located. 1

Ahollow capillary stem 41 extends from the top of the valve, down through the pressure responsive means and thetiming chamber 28 into the metering chamber 18.,Aspray button 42 is located on the top of thisstem 41 and thespray button 42 is provided with anexit orifice 43 for the discharge spray. Thestem 41 is free to slide in the parts through which it runs and the bottom of the stern rests in awell 19a provided with anorifice groove 45, in the sealingcup 19. Acollar 46, which is a tight fit, is located around portion of thestem 41.

In the top half of thevalve mounting cup 36 above thediaphragm 29 there is located a pressure responsive mechanism. The pressure responsive means consists of asnap spring 48, acradle 49, acradle ring 50, ahelical return spring 51, an automatic-manual actuator 53 and acover 54. Thesnap spring 48 is a flat strip of spring steel which bows up when inserted into thecradle 49. The cradle contains locating slots to orient thesnap spring 48 and theslots 55 are tapered to allow flexing of the ends of thesnap spring 48. Theslots 55 run around portion of opposite sides of thecradle 49 and are slightly wider than thesnap spring 48. The narrowest part of theslots 55 open to the outside wall of thecradle 49 and thus ensure that the end-thrust of thesnap spring 48 is taken by asteel cradle ring 50 which is pressed over thecradle 49. The bottom of thecradle 49 rests on thediaphragm 29 and it is pressed against thediaphragm 29 by thehelical return spring 51. Two opposite portions of the bottom coil of thisreturn spring 51 rest on twoopposite ledges 56 formed on the inside face of thecradle 49.

The top of thehelical return spring 51 presses the automatic-manual actuator 53 upwards against thecover 54 of the valve. Two raisedribs 57 are provided on the face of theactuator 53 which is close to the top inside face of thevalve cover 54. When the actuator is in the automatic position, these ribs rest in twoshallow grooves 58 provided in the top inside face of thevalve cover 54. When theactuator 53 is in the manual position, the raisedribs 57 nest inside twoslots 59 provided in the top of thevalve cover 54. Theslots 59 are shown in the plan view of the valve FIG. 3. The rotation of the actuator 53 from the automatic to the manual position thus has the eflect of retracting upwards by a predetermined amount, afinger 60 which has projected downwards from theactuator 56 into close proximity with the centre of thesnap spring 48 for automatic operation of the valve.

The sides of thevalve mounting cup 36 are crimped in at 61 to hold thevalve cover 54 in place. Thebottom edge 62 of thevalve cover 54 acts as a cradle stop to limit upwards movement of thecradle 49. I

The valve may be operated manually by finger tip pres sure to give either:

(l) A continuous spray which is obtained by exerting slight finger pressure on the spray button or (2) A metered spray which is obtained by exerting a greater finger pressure on the spray button.

Both of these modes of manual spraying may be obtained with the automatic-manual actuator set in either the automatic or manual position. Detailed working is as follows:

(1) Continuous spray-Downward movement of thespray button 42 causes thecapillary stem 41 to push the sealingcup 19 away from therubber seal 20, against which the sealingcup 19 has been pressed by the action of thespring 25. The seal formed between the lip on the top of the sealingcup 19 and therubber seal 20 is thus opened and this allows the product propellant mixture to flow from themetering chamber 18 into the well 1901 in the sealingcup 19 and from there, via theorifice groove 45 in the well 190, into thecapillary stem 41 to emanate as a spray from thespray button orifice 43. If no further downward motion of thespray button 42 takes place, there will be a continuous flow of fluid into themetering chamber 18 from thedip tube 15, to maintain it full, so,

long as some pressurised contents remain in the disis applied initially to thespray button 42 and this causes the sealingcup 19 to open as before but also ensures that theferrule seal 23 closes off theinlet port 21 into Automatic operation FIG. 1 shows the valve parts in their position at the start of the automatic cycle. Thebottom enclosure 11 of the valve, which houses thepermeable membrane 13 may be below the liquid level of the product/propellant mixture in the dispenser if the container is relatively full, or alternatively if the dispenser contents have been partially used, themembrane 13 may be above the liquid level and in the vapour phase alone. The liquid level in the dispenser dose not alfect the functioning of the valve. It may be assumed that the vapour pressure under thediaphragm 29, atvthe commencement of the-cycleis at atmospheric. The pressure of the propellant in the dispenser is above atmospheric pressure and typically will be about 4 to atmospheres. Because of this pressure difference, propellant vapour, from either the liquid or vapour phase, gradually permeates through thepermeable membrane 13. Theporous paper backing 14 under themembrane 13 allows sideways transmission of this vapour to thevertical hole 40 in thebottom enclosure 11 which communicates with the timingchamber 28 under thediaphragm 29. The timingchamber 28 is partially occupied by thecore 26 and since thetiming chamber 28 is sealed from the atmosphere, the pressure will gradually rise in thechamber 28 with a consequent extension upwards of thediaphragm 29. This causes thecradle 49 to move gradually upwards against the restrainingaction of thereturn spring 51 and thesnap spring 48. Thefinger 60 projecting down from the automatic-manual actuator 53 limits the upward movement of the centre of thesnap spring 48. When the edges of thesnap spring 48, held in thecradle 49, reach a point level with or slightly above the bottom of thefinger 60 thesnap spring 48 snaps over-centre. As thebottom edge 62 of .thecover 54 acts as a cradle stop further upward movement of thecradle 49 is only possible to a marginal extenL Thus thesnap spring 48 reacts downwards on thecollar 46 of thecapillary stem 41 and depresses thecapillarystem 41 and sealingcup 19.

FIG. 2 shows the position of the valve parts during this discharge portion of the automatic cycle;- -As theinlet port 21 in the bottom of themetering chamber 18 has been closed by theferrule seal 23, the product/propellant mixture, isolated in the meteringchamber' 18, will issue as a spray from thespraybutton orifice 43.

The emptying of themetering chamber 18 causes a resultant drop in pressure in it. The propellant'vapour under thediaphragm 29 is in communication with thecore recess 26a abovethe'rubber seal 20 which is above themetering chamber 18 The resultant pressure dilference across this seal ,29 causes it to deflect downwards slightly into themetering chamber 18 and thereby move away from theannular valve seat 30 in the core'26. The deformation of thisseal 20, as shown in FIG. 2, allows the vapour, trapped under thediaphragm 29 to escape to atmosphere. Its path in doing so follows a small channelv the capillary stem "41 and the holes of the parts throughwhich'the' stem slides. Thecradle 49, presseddown by the return spring 5, forces thediaphragm 29 to deflate and expel the vapour. As thecradle 49 moves down during this deflation of thediaphragm 29, thesnap spring 48 reacts against thecollar 46 on thecapillary stem 41 which forcesthesnap spring 48 to subsequently snap back .over centre? into its original position. This allows the sealing 'cup 19 to move up in themetering chamber 18 again to its original position of sealing against therubber seal 20 abovemetering chamber 18. The automatic cycle will now commence again.

The automatic-manual actuator 53 projects upwards through thecover 54 of the valve and partially surrounds thespray button 42. Anopening 47 in the side of theactuator 53 provides clearance for the spray from theexit orifice 43 of thespray button 42. Thespray button 42 projects above the top of theactuator 53 to allow finger pressure to be applied to thebutton 42 for manual spraymg.

As previously mentioned afinger 60 projects down into the valve from theactuator 53 and thisfinger 60, in the automatic mode of the valve, serves to compress thesnap spring 48 during upward movement of thecradle 49, and thus causes thesnap spring 48 to snap over to the down position. Retraction upwards of theactuator 53 and finger '60 to the position shown in FIG. 4 switches the valve from the automatic to the manual mode. Upwards movement of thecradle 49 with theactuator 53 in this position does not now impose compression on thesnap spring 48 and hence it will remain in the up position.

From the users point of view, the valve is switched from the automatic to the manual mode as follows: A metered spray is first dispensed by manual pressure on thespray button 42. The auto-manual actuator 53 is then grasped between the fingers, pressed down slightly and rotated a quarter turn to the manual position where it is released as it clicks into position. The same procedure is followed to revert to the automatic position.

The. initial manual spraying of a metered burst is necessary before turning the auto-manual actuator 53 as this serves to reset thecradle 49 to the position it normally has at the start of the automatic cycle. In this position thesnap spring 48 is not reacting against the finger 60.of theactuator 53 .and the upwards force of the cradle return spring. 51 against theactuator 53 is at a minimum. Thus theactuator 53 can be easily depressed 1 y and rotated.

The switching of the actuator 53 from the automatic to-the manual position does not immediately stop penetration of vapour through thepermeable membrane 13. Penetration of vapour continues for some time and will cease only when'the vapour pressure under thedisphragm 29 hasreached equilibrium with the pressure in the dispenser. FIG. 4 shows thevalve in this manual position and this would normally be the position of the parts during storage of the dispenser (aerosol container) prior- 1 to sale or use.

A second embodiment of the invention is illustrated in- FIG. 5 of the accompanying drawings. In FIG. 5 like valve parts to those shown in FIGS. 1-4 illustrating the first embodiment, are given the same reference numeral, proceeded by the digit one, for the sake of clarity. In

this second embodiment the permeable membrane geometry has been altered and the form of the cradle return spring varied. The valve operates however in substantially the same manner as described in relation to the first embodiment.

The disc type of permeable membrane as illustrated in FIGS. 1, 2 and 4 of the accompanying drawings must be limited in area, if the valve is to fit into the standard one lIlCh opening of dispensers for pressurised fluids (aerosols). Accordingly, in applications of the valve where a fairly frequent intermittent spray is required, a different geometry of permeable membrane may be adopted to allow a larger effective area of permeable membrane for vapour penetration. The cylindrical type of permeable membrane shown in FIG. covers this requirement. Here the cylindricalpermeable membrane 113, in the form of a length of tubular low density polyethylene film, is heat shrunk or slipped as a tight fit over the exterior surface of thebottom enclosure 111. If thebottom enclosure 111 has been manufactured from a compatible plastic material, the two ends of the cylindricalpermeable membrane 113 may be heat sealed or bonded with an adhesive to the exterior cylindrical surface of thisbottom enclosure 111 to form hermetic joints in these areas. A sleeve ofporous paper 114 is interposed between the cylindricalpermeable membrane 113 and thebottom enclosure 111, except in the area at the ends where the sealing takes place. This sleeve of.porous paper 114 lies in a shallow groove formed on the exterior cylindrical surface of thebottom closure 111. Theporous paper 114 allows transmission of vapour, which has penetrated through themembrane 113, to a hole which communicates with thetiming chamber 128.

With this form of construction, a very large area ofpermeable membrane 113 can be obtained readily. It also allows the more conventional bottom entry of thedip tube 115 into the valve.

FIG. 5 also illustrates an alternative geometry for thecradle return spring 151. Here a stack of disc springs have been substituted for the helical spring shown in the FIGS. 1, 2 and 4 of the accompanying drawings. These disc springs 151 may be full discs or alternatively may have radial cut outs so that each disc has a number of fingers projecting either radially inwards from a solid periphery or radially outwards from the centre portion of the disc. Thesprings 151 may be manufactured from conventional spring materials such as stainless steel or spring steel or alternatively may be manufactured from a bimetal spring material.

In some applications of the valve, the use of a bimetal material here may be necessary, in order to reduce the variation in frequency with temperature of the automatic intermittent operation. The pressure in a dispenser container normally increases with a rise in the ambient temperature, because of the properties of the propellant fluid. This results in a more rapid penetration of vapour through themembrane 113 and, with the valve construction shown previously, a faster automatic cycle. This m'ay be an advantage in both insecticidal and air freshe'ning applications, where higher temperatures normally result in more insects or more odours. In other applications, however, such as the automatic lubrication of machinery, a dispensing frequency which is relatively independent of ambient temperature may be required. In such an application, the disc springs 151 may be made of bimetal spring material, so arranged that the thrust of thesprings 151 against thesnap spring cradle 149 increases with temperature. A higher pressure under thediaphragm 129 is thus required to operate the valve and this, compensating for the higher pressure in the can, results in a relatively uniform automatic dispensing frequency.

What we claim is:

1. A valve for a dispenser for pressurized fluid, said valve comprising a valve housing incorporating a permeable membrane, a timing chamber in communication with the permeable membrane, pressure responsive means, an exit orifice, a fluid supply under pressure, and

a valve disposed intermittent the exit orifice and fluid supply, said permeable membrane allowing vapor under pressure in the dispenser to penetrate by diffusion into the valve housing along one path to build-up pressure in the timing chamber, said timing chamber being enclosed at least 'in part by a flexible diaphragm which can move in response to the build-up of pressure to actuate the pressure responsive means to open the valve and discharge fluid under pressure through a second path by way of the valve and exit orifice.

2. The valve of claim 1 wherein the pressure responsive means includes a snap spring which in response to 8 the build-up of pressure in the timing chamber can snap over from a first position to a second position to open the valve.

3. The valve of claim 1 includes a metering chamber within said second path, a closable inlet thereto in communication with the interior of the dispenser, a closable outlet therefrom in communication with atmosphere, and means for holding said inlet closed while said outlet is open, and vice versa. V

4. The valve of claim 1 wherein there is included:

(a) a bottom enclosure adapted to hold in sealed engagement the permeable membrane and to house a sealing cup within a metering chamber which is connected by a dip tube to the pressurized fluid in the dispenser;-

(b) a mounting cup adapted at one end for fluid tight mounting on the dispenser, the other end of the mounting cup engaging the bottom enclosure '(a), housing a capillary stem seated, at one end thereof, in the sealing cup and pressure responsive means; and

'(c) an actuator which projects to atmosphere from the mounting cup and contains a spray button with the orifice exit to the atmosphere, the orifice exit being connected to the capillary stem at that end thereof remote from the metering chamber.

5. A valve for a dispenser for pressurized fluids, said valve comprising:

(a) a bottom enclosure adapted to hold in sealed engagement a permeable membrane and to house a sealing cup within a metering chamber which is connected by a dip tube to the pressurized fluid in the dispenser;

(b) a seal member located between the sealing cup and the core, said seal member in co-operation with the sealing cup and the core being adapted to prevent vapor passing along the exterior and/ or interior of the capillary stem between the metering chamber and atmosphere and along the exterior of the capillary stem between the timing chamber and atmosphere when the valve is closed, the said sealmember being adapted to deform following discharge of the contents of the metering chamber to allow the vapor in the timing chamber, which has built up a pressure under the flexible diaphragm, to discharge to atmosphere, closing of the valve serving to allow the seal member reverse to its undeformed sealing position;

(c) a mounting cup adapted at one end for fluid tight mounting on the dispenser, the other' end of the mounting cup engaging the bottom enclosure, housing a capillary stem seated, at one end thereof, in

, the sealing cup and pressure responsive means; and

(d) an actuator which projectsto atmosphere from the mounting cup and contains a spray button with an orifice open to atmosphere, the orifice being connected .to the capillary stem at that end thereof remote from the metering chamber.

6. A valve as claimed in claim 3 which includes means 0 responsive to the evacuation of pressurised fluid from the metering chamber for releasing the pressure in the' timingvchamber and means responsive to the release of pressure from the timing chamber for closing the valve:

7. A valve as claimed in claim 6 wherein the means for closing the valve serve to close the outlet from the meable membrane is fiurosilicon rubber.

12. A valve as claimed in claim in which the bottom enclosure is provided with a membrane sealing cap which is snap fitted to the bottom enclosure to compress sealing members to seal in position a permeable membrane mounted upon the bottom enclosure, the membrane sealing cap having a channel therein to provide an access for the pressurised vapour in the dispenser to the permeable membrane.

13. A valve as claimed in claim 5 in which the permeable membrane is mounted upon a portion of the exterior surface of the bottom enclosure and heat sealed at its edges to the bottom enclosure.

14. A valve as claimed inclaim 12 in which a layer of porous paper is provided between the permeable membrane and the bottom enclosure, the bottom enclosure having a communicating passage therein to allow the pressurised vapour penetrating the permeable membrane to pass to a timing chamber immediately adjacent a flexible diaphragm on a core side thereof.

15. A valve as claimed in claim 5 in which the bottom enclosure is provided with a metering chamber which houses a spring mounted sealing cup, the bottom of the metering chamber being provided with an inlet port connected to the dip tube, the sealing cup having mounted thereon a seal member which closes the inlet port when the sealing cup is depressed upon the opening of the valve.

16. A valve as claimed in claim 5 in which the sealing cup is provided with a well having an orifice groove which communicates with the end of the capillary stem within the well for discharge to atmosphere of the contents of the metering chamber when the valve is open.

17. A valve -for a dispenser for pressurised fluids as claimed in claim 5 in which the pressure responsive means comprises a flexible diaphragm mounted above the core, a cradle member, a snap spring mounted on the cradle member, a collar fixedly mounted on the capillary stem and a cradle return spring, whereby a build-up of pressure due to the pressurised vapour penetrating into the valve housing causes the flexible diaphragm to move away from the core above which it is mounted and "force the cradle to move in the same axial direction, until the snap spring is actuated to depress the collar and hence the capillary stem and the sealing cup to open the valve to dispense the pressurised fluid in the metering chamber to atmosphere and allow discharge of the pressurised 10 vapour which has penetrated into the valve housing to atmosphere.

18. A valve as claimed inclaim 17 in which the flexible diaphragm is of rubber and is sealed on the bottom enclosure at its outer edge portions by the mounting cup and at its centre by a rivet mounted about the capillary stem.

19. A valve as claimed inclaim 17 in which the snap spring of the pressure responsive means is a strip spring which bows when mounted in locating slots provided in the cradle said slots being adapted to locate and accommodate the end edge portions of the snap spring and to allow complete flexin g of the snap spring.

20. A valve as claimed inclaim 17 in which the cradle of the pressure responsive means is provided with a cradle ring to provide a suitable bearing surface for the end edges of the snap spring.

21. A valve as claimed inclaim 17 in which the cradle return spring is a helical spring mounted around the capillary stem and between the cradle and the actuator.

22. A valve as claimed inclaim 17 in which the cradle return spring is a stack of disc springs of bimetal material responsive to a variation in temperature.

23.'A valve as claimed inclaim 17 in which the actuator is provided with a finger which embraces the capillary stem and which is constrained for limited axial movement relative to the capillary stem for setting of the valve for automatic or manual operation, the flnger almost abutting against the snap spring when the valve is set for automatic operation and in an axially retracted position from the snap spring when the valve is set for manual operation.

24. A valve as claimed inclaim 23 in which the actuator is provided with a cover fixedly mounted on the mounting cup and adapted to co-operate, by means of a complimentary rib and groove arrangement, with the actuator for setting of the valve for automatic or manual operation.

References Cited UNITED STATES PATENTS 3,115,277 12/1963 Montague, 1a., 222- UX 3,497,108 2/ 1970 Mason 222-499 ROBERT B. REEVES, Primary Examiner J. M. SLATIERY, Assistant Examiner

Images