Title: APPARATUS FOR PREPARING AN INFUSIONThis invention is concerned with an apparatus for preparing an infusion from a liquid and an infusible ingredient. For example, the apparatus may be used for preparing coffee or tea in a drinks dispensing machine, in which case the apparatus is known as "a brewer.
Existing brewers are complex and bulky so that they occupy a considerable volume in a drinks dispensing machine. Such brewers comprise an infusion chamber in which liquid, e.g. hot water, and an infusible ingredient, e.g. ground coffee, are mixed to create an infusion. Much of the complexity and bulk is caused by the arrangements for disposal of spent ingredient from the infusion chamber. The chamber defines filtration means through which liquid but not the ingredient can leave the chamber and after the liquid has left it is necessary to remove spent ingredient from the filtration means both on the grounds of hygiene and in order to maintain the quality of successive infusions.
In one existing design of brewer, the filtration means is provided in the form of a cup and means is provided for removing the cup from the infusion chamber and inverting it to remove spent ingredients. This arrangement, however, requires a complex and bulky mechanism to achieve the movement of the cup and the inversion thereof. In another brewer design, a disposable filter is utilised which is replaced after each infusion.
This, however, requires mechanism for feeding filters to and from the infusion chamber. It has also been proposed to design a spinning infusion chamber which removes the spent ingredients by centrifugal force. In all these designs, however, it is necessary to arrange for linear movement of parts of the infusion chamber relative to one another so that an opening is created forming an exit through which spent ingredients and/or disposable filters can pass. Such openings cannot be left open permanently as the liquid and ingredients would leave the infusion chamber therethrough.
Thus, there has to be mechanism for creating this relative linear movement.
It is an object of the present invention to provide an apparatus for preparing an infusion which is simpler and less bulky than the designs mentioned above.
The invention provides apparatus for preparing an infusion from a liquid and an infusible ingredient comprisingan infusion chamber arranged to receive the infusible ingredient and the liquid, the infusion chamber defining filtration means through which the liquid but not the ingredient can leave the chamber;wherein the filtration means comprises a cylindrical filter extending around an axis which is inclined to the vertical,and means for rotating the infusion chamber about said axis, the chamber having an exit for spent ingredients at a lower end thereof and closer to said axis than the filter, the inclination of the chamber being such that liquid and ingredients introduced into the chamber fall on to the filter.
In an apparatus according to the last preceding paragraph, the exit of the chamber can be permanently open since the centrifugal effect of rotating the chamber prevents the liquid and ingredients from falling through the exit. This avoids the necessity for an opening and closing mechanism for the exit.
Suitably, the axis is inclined at approximately 45 degrees to the vertical.
Preferably, the apparatus also comprises scraping means operable to scrape spent ingredients off the filter so that the spent ingredients fall through the exit. The scraping means may comprise a spiral spring engaging the filter and means for causing relative rotation between the scraping means and the filter. The means for causing relative rotation may be arranged to hold the scraping means against rotation while the infusion chamber rotates.
Preferably, the apparatus also comprises an annular chamber extending around the filter and arranged to catch liquid passing through the filter and direct it to a dispensing pipe.
There now follows a detailed description, to be read with reference to the accompanying drawing, of an apparatus for preparing an infusion which is illustrative of the invention. It is to be understood that the illustrative apparatus has been selected for description by way of example and not of limitation.
The drawing is a cross-section view through the illustrative apparatus.
The illustrative apparatus is for preparing an infusion from a liquid and an infusible ingredient and comprises a base 10. The base 10 is supported on framework of the apparatus (not shown) and has a support surface 12 which is inclined at 45 degrees to the vertical. An electric motor 14 of the apparatus is mounted on the surface 12 and has an output shaft 16 projecting into a passage 18 through the base 10. Within the passage 18, a coupling 20 couples the output shaft 16 to a spindle 22 which is thus rotatable about its longitudinal axis 24 by the operation of the motor 14. The longitudinal axis 24 extends at 45 degrees to the vertical. The motor 14 provides means for rotating an infusion chamber of the apparatus, to be described, about the axis 24.
The spindle 22 is rotatable on a bearing 26 supported in a central passage 28 through a generally cylindrical lid 30. The lid 30 is supported on a cylindrical water-tight cover 32 which is mounted on the base 10 and extends parallel to the axis 24, the cover 32 being symmetrical about the axis 24. A sealing ring 34 makes a water-tight seal between the lid 30 and the cover 32 and a sealing ring 36 makes a water-tight seal between the cover 32 and the base 10. There is, thus, a generally cylindrical chamber 38 defined by the lid 30, the cover 32 and the base 10.
The chamber 38 is divided into an outer generally annular chamber 40 and an inner generally cylindrical chamber 42 by a cylindrical filter 44. The chambers 40 and 42 and the filter 44 are all symmetrical about the axis 24. The outer chamber 40 is a liquid-catching chamber arranged to catch liquid passing through the filter 44 from the chamber 42 which is an infusion chamber of the apparatus arranged to receive infusible ingredient and liquid. The filter 44 forms filtration means defined by the infusion chamber 42 through which the liquid but not the ingredient can leave the chamber 42. The liquid-catching chamber 40 is arranged to direct liquid to a dispensing pipe 46 which passes through the cover 32 at the lowermost point of the chamber 40.
The filter 44 is supported by a cage member 48 which is symmetrical about the axis 24. The cage member 48 has an end portion 50 which is pinned to the spindle 22 so that the cage number 48 rotates about the axis 24 when the motor 14 is operated. The end portion 50 presents a conical surface 52 towards the base 10 which extends parallel to a conical surface 54 of the base 10, the surfaces 52 and 54 tapering towards the motor 14.
A downwardly-extending cylindrical passage 56 extends through the base 10 and has an entrance in the surface 54. The passage 56 provides an exit from the chamber 42 for spent ingredients located at a lower end of the chamber 42 and closer to the axis 24 than the filter 44. Six uniformly distributed passages 58 pass through the portion 50 of the cage member 48 and have exits in the surface 52 so arranged that, as the cage member rotates about the axis 24, the exits of the passages 58 overlie in turn the entrance of the passages 56 through the base 10. The passages 56 and 58 provide an exit route for spent ingredients to leave the infusion chamber 42.
The cage member 48 has an opposite end portion 60 in the form of an annular flange 60 which is symmetrical about the axis 24.
The opposite end portions 50 and 60 of the cage member 48 are joined by twelve ribs 62 which are uniformly distributed about the axis 24 and each extend parallel to the axis 24. The filter 44 extends along the inner surfaces of the ribs 62 (the surfaces facing towards the axis 24) and is clamped between the portions 50 and 60 of the cage member 48. The entrances of the passages 58 through the portion 50 of the cage member 48 open into the infusion chamber 42 within the filter 44. Between these entrances and the filter 44, the portion 50 presents a frusto-conical surface 64 to the chamber 42. The end portion 60 has a cap member 66 screwed thereto which presents a frusto-conical surface 68 to the chamber 42. The cap member 66 extends into an annular groove 70 in the lid 30. The surfaces 64 and 68 taper towards the axis 24.
The illustrative apparatus also comprises a filter scraper 71 in the form of a coil spring mounted within the cage member 48 so that it engages the interior surface of the filter 44. The scraper 71 is operated (as described below) by a catching device (not shown) in the form of a pivoting stop mounted in a bore 72 through the lid 30. The lid 30 has two further bores (not shown) therethrough at the level of the bearing 26, one bore being to introduce ingredients into the chamber and the other being to introduce boiling water. The inclination of the chamber 42 (at 45 degrees to the vertical) is such that liquid and ingredients introduced into the chamber 42 through said bores fall on to the filter 44 rather than on to the end portion 50 of the cage member 48.
In the operation of the illustrative apparatus, the motor 14 is operated to set the cage member 48 and hence the filter 44 rotating about the axis 24. Then, infusible ingredient is introduced through the aforementioned bore in the lid 30 so that it falls in the direction of the arrow 74. The ingredient lands on the filter 44 and is distributed thereon by the centrifugal effect, the inwardly inclined surfaces 64 and 68 assisting in retaining the ingredient on the filter. Next, water is introduced through the aforementioned bore in the lid 30 and also falls in the direction of the arrow 74. The water is also distributed around the filter 44 by the centrifugal effect and is thereby mixed with the ingredient.
Centrifugal force and gravity force the infusion formed by the water and the ingredient through the filter 44 where it is caught by the chamber 40 and directed to the dispensing pipe 46.
Only sufficient boiling water is introduced into the infusion chamber 42 to provide one cup of drink, the cup being positioned beneath the dispensing pipe 46. When all the liquid has passed through the filter 44, the continued rotation of the filter 44 dries the spent ingredient which remains on the filter 44. The scraper 71 is then operated by using the catching device to engage the scraper 71 which has previously been rotating with the filter 44. This prevents the scraper 71 from rotating so that as the filter 44 rotates, the coils of the scraper 71 scrape across the filter and force the spent ingredients to fall into the passages 58 from which they exit from the apparatus through the passage 56.
In the illustrative apparatus, the axis 24 is at 45 degrees to the vertical but, in variations of the illustrative aparatus, this angle may be more or less than 45 degrees. The ingredients and water must fall on to the filter and not straight out through the passages 58.
The illustrative apparatus is compact and simple in construction and operation.
The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.