BEVERAGE FROTHING DEVICE

Abstract: A method for creating a foamy dispersion of bubbles or "head" on a beverage, when dispensed from a sealed and pressurised package. The package has fitted therein a compressible secondary chamber. A small orifice (14) in the chamber releases a jet of fluid into the beverage to cause the formation of or assist in the formation of a "head" on the beverage, when the package is opened to dispense the beverage. The secondary chamber may be formed by means of a piston (10) and cylinder (12), or piston and rolling diaphragm (18), and valve means (20) may be provided to close off the orifice until sufficient gas pressure exists in the compressible chamber and a sufficient internal to external pressure gradient exists as will occur when the package is broken to dispense the beverage. Alternatively to open the orifice (14) a seal is provided which melts when the package is heated as during pasteurisation. Another alternative seal is mechanically broken as a result of the final movement of the piston into the position of maximum compression. A liquid/gas lock may be provided so as to minimise the ingress of beverage into the compressible chamber after the seal has been broken.

Description: Title: BEVERAGE FROTHING DEVICE h ielα of invention This invention concerns the packaging of beverages including alcoholic beverages such as beer, lager, ale ana stout which are sold in packaged form in sealed bottles and cans. The invention also lies in an improved package for such beverages particularly cans for alcoholic beverages as aforesaid and for devices for fitting in such packages particularly cans, to alter the characteristics of the beverage when it is dispensed from the package. This invention is of particular application to canned beers particularly of the type containing dissolved nitrogen and carbon dioxide. The expression beer is intended to include any alcoholic beverage such as ale, beer, porter, stout ana the like. Background to the invention It is characteristic of some alcoholic beverages especially stout and traditional ales and beers to generate a foamy head of gaseous bubbles during the dispensing of the beverage into a glass and to consume the drink with this head evident upon the liquid. The source of gas for the bubbles is the gases dissolved in the beverage which are caused to break out of solution through a nucleation process. When dispensing from the bar this nucleation process nas been stimulated by forcing the Deverage under very high pressure through small nozzles which create sufficient sheer force to stimulate gas nucleation. It is also known that if nitrogen is dissolved in such beverages, the bubbles are smaller, more stable and are perceived as creamier than when only carbon αioxiαe is present. It has therefore become common practice to aαd nitrogen to certain beers, ales ana stouts. To maintain the nitrogen in solution, nitrogen has been used in the gas over pressure dispensing systems for dispensing such' beverages so as to promote a stable and creamy heaα. It has also become commonplace to add nitrogen to canned alcoholic beverages as aforesaid and to pressurise the can with nitrogen to the extent of adding liquid nitrogen during filling, so that after the can is sealed the evaporating dose of liquid nitrogen will increase the internal pressure typically to two atmospheres or more. The can pressurisation has enabled thinner walled cans to be used and the use of non-oxidising gas tor the pressurisation (after purging the can and contents of all oxygen), has ensured that oxygen will be absent from the interior of the can. If nitrogen is used, it will be taken up by, and become dissolved in, the beverage, so that if the latter can be stimulated to give up the nitrogen on dispensing, a rich creamy head of nitrogen bubbles will be formed on the beverage. Various techniques have been adopted to stimulate the bubble formation on dispensing from such a pressurised can. Early attempts are describee in GB 1266351 particularly in relation to Figure 3 and 4, wherein a secondary chamber is defined within the can which is adapted to retain a charge of gas under pressure, which discharges into the beverage through a tine orifice, driven by the pressure difference arising immediately after the can is opened to atmospheric pressure by the consumer. A secondary chamber in the form of a capsule is disclosed in EP 227213A2 in which the secondary chamber is pressurised from the primary container and its contents discharged through a permanently open orifice in the side wall of the capsule into the beverage when the can is opened. Problems associated with the fitting and retention of such capsules resulted in other proposals such as described in GB 2211813A (Price) in which the secondary chamber is formed by an apertured diaphragm which divides the interior of the can into an upper larger part ano a smaller lower part. The quantity of beverage in the secondary compartment is clearly minimised by inverting the can as has been commonplace between filling and pasturisation since the introduction of the two-piece can following the published recommendation of the UK can manufacturer concerned as early as 1981. This inversion causes the orifice in the secondary compartment to communicate with the gaseous headspace, as described in GB 2211813A Price. PCT/GB90/01806 (tøhitbreao) propose a sealed gas-containing device into which beverage cannot ingress ano which only opens to communicate with the beverage after the can has been opened and depressurιsed, so that there should be no reverse transfer of beverage into the capsule as gas leaves it. however the cost of production of such devices is not inconsiderable and the complexity of the pressure sensitive mechanism of the device to release the gas only when the can is opened, means that in practice there has been a relatively high failure rate, resulting in poor or even no head formation on beer dispensed from faulty cans. EP 520646A1 describes a modified construction of the type of capsule described in EP 227213 which is also charged with gas from the heaάspace following heaospace transfer by means of can inversion, as described in UK 2211813 Price. Objects of the invention It is one object of the present invention to provide an improved gas jetting device which minimises the effects on gas jetting caused by the ingress of beverage, and which can be fitted into a standard spun aluminium beverage can of the type commonly used for packaging carbonated drinks and alcoholoic beverages, particularly nitrogenated beers, stouts and the like. It is another object of the present invention to provide an improved packaged beverage using a sealed container having a secondary compartment which communicates with the contents of the sealed container through a restricted orifice to jet gas when the container is oroached ahead of dispensing . It is another object ot the present invention to provide a simple, easily insertable, low cost αevice, by which gas can be trapped for jetting into a beverage when a can fitted therewith is opened. The Invention According to one aspect of the present invention, there is provided a method of creating a head on a beverage when dispensed from an individual package, according to which a compressible secondary chamber is situated in the package and pressurised with fluid by compression of the chamber either before insertion into, or on filling and pressurising the package or when the pressure in the package is temporarily increased by heating the package, the chamber having a small orifice open when the package is opened to release a jet of fluid into the beverage to cause the formation of, or assist in the formation of, a head thereon when the contents of the package are depressurised and dispensed. According to another aspect of the invention, there is provided an individually packaged beverage having within the package a secondary chamber which contains gas whicn has been pressurised by compression of the chamber, the chamber having an orifice which is open when the package is opened to release a jet of fluid into the beverage to cause the formation of, or assist in the formation of a head thereon, when the contents of the package are depressurised and dispensed. The present invention thus proposes the use of a compressible secondary chamber which will enable a desired volume of pressurised gas to be engineered within the package, essentially without either the need to pre- pressurise the secondary chamber before filling, nor the need to charge the secondary chamber from the primary chamber after filling. The advantages of this proposal are that the secondary chamber ooes not need to be manufacture to withstand ano maintain internal pressure for a prolonged period; its location inside the can is not critical to ensure charging it with gas; no special process is required on the beverage filling line either to remove oxidising gas or to ensure that gas rather than beverage is charged into the chamber; and the reduction of secondary chamber displacement volume in the beverage will facilitate the minimisation of oxygen in the proportionately small gaseous headspace remaining in the primary chamber after filling with the required amount of beverage. The compressible secondary chamber may be manufactured by various means such as a sliding piston within a cylindrical chamber or by movement of a diaphragm utilising a flexible membrane to substitute sliding seal mechanisms. Before inserting the uncompressed chamber into the package it is preferably filled with non-oxidising gas and has no means of communication between the contained volume and the exterior. The secondary chamber is preferably compressed by the normal pressure increase consequent from the filling process and addition of nitrogen when the package is charged ready for use. Alternatively it may be desirable to carry out the compression of the secondary chamber by a physical process or mechanism, prior to inserting it into the package . A number of variations in the design and subsequent operation of the compressible secondary chamber are possible. In one example, a movable member, piston or diapnragm, which acts to reduce the chamber volume under pressure, is prevented from returning or is prevented from moving back other than very slowly, when the package is opened and the pressure in the secondary chamber exceeds the primary chamber. This may be achieved by various means, for example allowing this member either to move in one direction only or otherwise to be retained in the chamber compresseα position. In another example, the movable member exhibits resistance to movement such that there is little expansion of the secondary chamber volume in the short period whilst the fluid jet is being emitted into the beverage upon opening of the package. In another example in which the package is heated up as during pasteurisation, the excess pressure which occurs within the package after such heating up may be employed to collapse the secondary chamber to an extent sufficient to leave the chamber in a collapsed condition with its contents now pressurised. The design of the chamber orifice from which gas or beverage will emerge when the package is opened is also subject to adaption for specific end requirements. In one example the orifice, which is closed during compression of the chamber, is opened to communicate with the primary chamber at or about the final stage of compression, this being achieved by means of the movement of the movable piston or diaphragm as it reaches its end position. For example, this movement may be caused to open any convenient type of valve or bursting disc which has prevented communication between the primary and secondary chambers through the orifice. In another example, the means of communication between primary and secondary chambers may be partially or wholly prevented until at or about the moment of opening the packages if it is desireo to ensure that only gas is emitted to form the jet. This can be achieved by means of any convenient valve design which allows gas flow to emit from the orifice but prevents beverage flow into the secondary chamber. In yet another example, communication between primary and secondary chambers is established after the filling process by the use of a dissolving or heat sensitive material or mechanism triggered by subjecting the sealed packages to a further process such as a thermal cycle or an electrical or magnetic field. Description of Drawings Several exemplary embodiments of secondary chamber for insertion into a beverage containing package in accordance with the invention are shown in the accompanying drawings, in which Figures 1 to 4 respectively show four possible arrangements diagrammatically. Description of the Embodiments Figure 1 shows an example of secondary chamber in the form of a piston 10 slidable with substantial resistance to movement in a cylinder 12. The end face of the cylinder has a small orifice 14. This secondary chamber is inserted into a package, ie a Dottle or can, prior to loading the can with beverage and pressurising it with nitrogen. When the package is pressurised and then sealed, any fluid (nitrogen or beverage), in the secondary chamber is pressurised. When subsequently the package is opened, the stiff piston 10 resists return movement ano is slow to respond, so that pressure in the cylinder is substantially maintained and the compressed fluid in the cylinder 12 is emitted through the orifice 14 as a jet, thus producing a rich head on the beverage, eg beer, as it is dispensed. Instead of relying on stiff movement of the piston 10, a non-return device 16 may be incorporated, as exemplified by Figure 2. The device 16 comprise a bevelled washer which slides freely on the central guioe 17 in one direction but ams and prevents movement in the opposite direction thereaiong. In the embodiment of Figure 3, a diaphragm device 18 is employed instead of a piston and a valve mechanism 20 is incorporated, actuated by the diaphragm device to open the orifice 14 only when the package is filled and pressurised. A similar valve mechanism 20 may of course be fitted to the piston/cylinder arrangement of Figures 1 and 2. Figure 4 shows another modification in which the orifice 22 is provided through the piston 10, and a non-return mechanism 24 is also incorporated, preventing the exit of gas from the cylindrical region 23 through the orifice 22 unless there is a pressure differential across the valve member 24 as will occur when the package is opened to atmosphere. In all embodiments, a preferred volume for the secondary chamber is from 5 to 50 cc, preferably 10 to 30 cc, and the orifice diameter is in the range 0.1 to 0.6 mm, preferably 0.1 to 0.4 mm. Although the secondary chamber is most preferably automatically pressurised when the package is filled and pressurised, it is alternatively possible to pressurise the secondary chamber by subjecting the sealed package for example to a thermal cycle or a mechanical squeezing before it is inserted in the can. A device (not shown) for fitting the device 12 into a can may be adapted to squeeze the piston 10 into the cylinder 12 (or 19 into 12 - Figure 3) or (10 into 12 - Figure 4). Where the package is to be pressurised on filling a small quantity of liquid nitrogen may be dropped into the package just before the package is sealed in manner known per se. The expansion produced as the liquid nitrogen is warmed up to ambient temperature and converted to gas, pressurizes the interior of the package typically in the range 2 to 4 atmospheres although higher pressures of up to 6 atmospheres are possible. Although not shown a liquid or air lock may be provided in association with the orifice so tnat after it has been opened by whatever means or mechanism the tendancy for gas/beverage exchange to occur is reduced. Although not shown the device may be fitted within a squeezable ring or have fitted thereto petals or other fixing devices such as are shown associated with the alternative gas jetting capsules of Figures 10-19 of our copending PCT Patent Application No (case reference C700.1/C) filed concurrently herewith and claiming priority inter alia from GB9305726.3 filed 1 th March 1993, the teaching of which is imported herein by reference.

Claims: Claims 1. A method of creating a head on a beverage when dispensed from an individual package according to which a compressible secondary chamber is situated in the package and pressuriseα with fluid by compression of the chamber either before insertion into, or on filling and pressurising the package, or when the pressure in the package is temporarily increased by heating the package, the chamber having a small orifice open when the package is opened to release a jet of fluid into the beverage to cause the formation of, or assist in the formation of, a head thereon when it is dispensed from the package. 2. A method as claimed in claim 1 where the uncompressed secondary chamber is filled with non-oxidising gas and has no means of communication between the contained volume and the exterior. 3. A method as claimed in claim 1 wherein the individual package comprises a two part can which is partially filled with nitrogenated beer and a compressible secondary chamber is added to the can before during or after filling with beer and a quantity of liquid nitrogen is added to the contents of the can before the lid is sealed in position so that as the liquid nitrogen evaporates the pressure in the gaseous head space above the beer increases thereby increasing the internal can pressure ano exerts sufficient pressure on the compressible secondary chamber to cause the latter to compress to a fraction of its original uncompressed volume thereby compressing the contents of the secondary chamber so that the latter becomes pressurised to substantially the same pressure as the internal pressure of the can. 4. A method as claimed in claim 1 wherein the secondary chamber is compressed prior to insertion into the package. 5. A method as claimed in claim 1 wherein the secondary chamber is compressed by mechanical means prior to inserting it into the package. 6. A method as claimed in either claims 4 or 5 wherein means is provided for automatically inserting the compressed package into the can. 7. A method as claimed in claim 6 wherein the insertion means additionally serves as a compression mechanism to compress the secondary chamber as it is inserted. 8. An individually packaged beverage having within the package a compressible secondary chamber the contents of which are pressurised by compression of the chamber, the chamber having an orifice which is open when the package is opened, to release a jet of fluid into the beverage to cause the formation of, or assist in the formation of, a head thereon when it is dispensed from the package. 9. A package as claimed in claim 8 wherein the compressible secondary chamber comprises a cylindrical chamber and a piston slidable therein which is moved inward as the pressure builds up in the package to compress the contents of the cylinder ahead of the piston. 10. A package as claimed in claim 8 wherein the compressible secondary chamber comprises a diaphragm utilising a flexible membrane which is displaceable into a chamber to compress the contents thereof with increasing pressure in the package. 11. A compressible secondary chamber for use in the method of claims 4, 5 or 6 wherein latching means is provided to retain the compressible secondary chamber in its compressed state after the physical or mechanical process of compression has been completed. 12. A compressible chamber as claimed in claim 11 wherein latching means blocks the return movement of a piston or diaphragm the forward movement of which has allowed the chamber volume to be decreased under pressure. 13. A compressible secondary chamber as claimed in claim 11 wherein the latching means acts to prevent the return movement of a displaced piston or diaphragm other than very slowly when the package is opened and the pressure in the secondary chamber exceeds that of the primary chamber. 14. A compressible secondary chamber as claimed in claim 13 in which the movable piston or diaphragm exhibits resistance to movement such that there is little expansion of the secondary chamber volume during the short period whilst the jet of fluid is being emitted into the beverage upon opening the package. 15. A compressible secondary chamber as claimed in claim 8 or claim 11 wherein the chamber includes an orifice through which fluid under pressure within the compressed chamber will jet when the package into which the chamber has been fitted, is opened and depressurised, and closure means is provided to prevent the exit of fluid therethrough while the chamber volume is decreased by compression thereof and opening means is provided responsive to the compression of the chamber, to open the orifice at or about the final stage of compression. 16. A compressible secondary chamber as claimed in claim 15 wherein the opening of the orifice is linked to the movement of a movable piston or diaphragm as it reaches its end position. 17. A compressible secondary chamber as claimed in claim 16 wherein the final movement of the movable member opens a valve or bursting disk which has previously prevented communication between the primary and secondary chambers through the orifice. 18. A compressible secondary chamber as claimed in claim 17 wherein the means of communication between primary and secondary chambers is partially or wholly prevented until at or about the moment of opening the package by means of a valve which allows gas flow to exit from the orifice but prevents beverage flow in the reverse direction. 19. A compressible secondary chamber as claimed in claim 15 wherein the communication between the primary and secondary chambers is established after the filling process by the use of a dissolving or heat sensitive material, or a mechanism triggered by subjecting the sealed package to heat as occurs during pasteurisation. 20. A compressible secondary chamber as claimed in any proceeding claim wherein the orifice communicates internally or externally with a liquid lock to inhibit the unwanted transfer of liquid into the secondary chamber or the exit of gas from the secondary chamber. 21. Methods of pressurising a secondary chamber within a pressurised package containing beverage and gas whereby a jet of gas is available for head formation into the beverage when it is dispensed after the package is broken substantially as herein described and with reference to the accompanying drawings. 22. A compressible capsule for fitting within a package which is to be filled with beverage and gas and sealed and pressurised so as to compress the contents of the capsule to provide a source of a high pressure gas within the package for jetting into the beverage when the package is opened to dispense the beverage, constructed arranged and adapted to operate substantially as herein described and with reference to the accompanying drawings.

Inventors: CONWAY JOHN KELSHAW, COX PETER ERICH, FRESHWATER STEPHEN MICHAEL, POLEY JOHN, REYNOLDS ANDREW JOHN, SKINGSLEY JOHN DAVID, CONWAY, JOHN, KELSHAW, COX, PETER, ERICH, FRESHWATER, STEPHEN, MICHAEL, POLEY, JOHN, REYNOLDS, ANDREW, JOHN, SKINGSLEY, JOHN, DAVID
Applicants: CONWAY JOHN KELSHAW, COX PETER ERICH, FRESHWATER STEPHEN MICHAEL, PA CONSULTING SERVICES, POLEY JOHN, REYNOLDS ANDREW JOHN, SKINGSLEY JOHN DAVID, CONWAY, JOHN, KELSHAW, COX, PETER, ERICH, FRESHWATER, STEPHEN, MICHAEL, PA CONSULTING SERVICES LIMITED, POLEY, JOHN, REYNOLDS, ANDREW, JOHN, SKINGSLEY, JOHN, DAVID
Application year: 1993
Main classification: B65D79
IPC codes: B65D79, B65D85