WO1996009507A2

WO1996009507A2 - Beverage container

Info

Publication number: WO1996009507A2
Application number: PCT/GB1995/002260
Authority: WO
Inventors: Robin Julian Fergusson; Peter John Houzego; Timothy Michael Wood; Philip Theaker; Frances Brindle; David Richard Stonehouse; Craig Harvey Nelson
Original assignee: Scottish & Newcastle Plc
Priority date: 1994-09-22
Filing date: 1995-09-21
Publication date: 1996-03-28
Also published as: WO1996009507A3; AU3529095A

Abstract

A device for chilling the contents of a beverage container (10) comprising a shell (12), the interior of which is adapted to accommodate the container and which defines an annular space (82, 84) therearound. A source of liquefied gas (98) under pressure is associated with the shell and means is openable to permit the liquefied gas to escape to create a cooling effect created by the change of phase from liquid to gas and expansion of the gas in the said annular space. An outer surface of the shell is formed from heat insulating material so that the cooling effect is preferentially directed towards the interior of the shell. Fins may be provided to increase the surface area. In a device for fitting around a can, ribs (80) on the inside of the shell centre the can in the shell. The escaping refrigerant is forced to change direction at the top of the annular space so that it has to move downwardly still within the shell, before it can escape through venting apertures at the base of the shell. A hollow base (100) of the sleeve houses the refrigerant and is rotatable relative to the sleeve to open the reservoir and release the refrigerant. Transfer valve means may be provided to control the transfer of refrigerant from a first compartment (into which the reservoir is vented when the device is first opened) into a second compartment, so that only when the first compartment has become fully pressurised can its contents transfer into the other compartment.

Description

BEVERAGE CONTAINER

Field of invention

This invention concerns the packaging of beverages, particularly devices for cooling cans and bottles containing alcoholic or non-alcoholic beverages before the beverage is to be consumed.

Background to the invention

Whilst it is possible to cool packaged beverages by placing them in the refrigerator and where appropriate if transportation is required, transporting the cooled beverage in a cold box or chilled compartment, there are many situations where it is not convenient to store or transport beverage containers in this way and it is virtually impossible for the consumer to enjoy a chilled drink. The warmer the weather, the greater is the likelihood that the consumer will wish the beverage to be chilled and in those conditions, unless a chilling cabinet or container is available, the drink will probably become warm as a result of the ambient temperature making it even less acceptable than would otherwise have been the case.

It is an object of the present invention to provide a portable device by which the contents of a container (can or bottle) can be chilled just before consumption.

It is a prerequisite that the wall of the container will permit the transfer of heap therethrough and to this end the invention is primarily of application to thin walled metal 2 and 3 piece beverage cans, such as are formed from aluminium or steel. Summary of the different aspects of the invention

1. Primary aspect of the invention

\r According the present invention, a device for chilling the contents of a beverage container comprises a shell, the interior of which is adapted to accommodate the container the contents of which are to be chilled, and which defines an annular space around the said container when the shell is fitted therearound, a source of liquified gas under pressure associated with the shell, and means which is openable to permit the liquified gas to escape to create a cooling effect created by the change of phase from liquid to gas and expansion of the gas in the said annular space.

Preferably an outer surface of the shell is formed with a heat insulating layer or sleeve so that the cooling effect is preferentially directed towards the interior of the shell and towards any container (and its contents) located therein.

Preferably the annular space around the container into which the escaping gas can pass, is vented at a point which is distant from the point of entry so that there is minimal pressure build-up in use and vaporisation can therefore continue until all of the liquified gas has been evaporated.

The venting may be provided at the upper or lower end of the shell.

2. Improved cooling efficiency

(1) Internal baffles

Since the cooling efficiency will be determined at least in part by surface area in contact with the cooling gas, according to a further feature of the invention, fins or other surface area increasing devices of good thermally conductive material may be incorporated into the hollow interior of the shell, and are adapted to make good thermal conductive contact with the wall of the beverage container so as to effectively increase the surface area of the container wall in contact with the escaping evaporating gas, thereby to assist in heat exchange therebetween.

Where the structure to which the fins are attached is also of good thermal conductivity, it may be desirable to include a thermal insulating member or so-called thermal break in the join between each fin and its support structure.

The annular space may be closed at its upper end and include baffle means which divides the annular space into inner and outer coaxial annular compartments which communicate over or through the baffle means at its upper end only, whereby the escaping refrigerant is caused to pass upwardly between the outer surface of the container and the baffle means, and then downwardly between the baffle means and the shell to exit through venting means near or at the base of the shell. The descending blanket of cold gas acts as a shield to reduce inward radial transfer of heat from outside the shell to the annular region immediately surrounding the container, thereby enhancing the cooling effect on the contents of the container located within the shell.

The baffle means may be in the form of a cylindrical wall intermediate the container and the inside surface of the shell.

The baffle means may be held in place by ribs between the shell and the baffle means, and the ribs may extend radially inwardly beyond the baffle means to form fins for making contact with, and increasing the effective surface area of the container wall. (2) Tortuous path

A tortuous path has the desirable effect of slowing down the escaping refrigerant, and increasing the length of the heat exchange path, both of which will enhance the cooling effect, and according therefore to a further aspect of the invention a tortuous path may be provided for the escaping refrigerant before it can vent to atmosphere.

Where the container is spaced from the inside of the shell by ribs or spacers these may create a tortuous path for refrigerant passing up the said annular passage.

A tortuous path may be formed by constructing the shell at least in part from a length of tube, wound into a spiral for close fitting around the container, so as to form a spiral package for the refrigerant to escape from.

An adjustable flow restriction means may be provided to further control the rate at which the evaporating refrigerant can vent, to allow the consumer to adjust the rate of cooling since it may be desirable to adjust the latter to take account of changes in ambient temperature and/or the temperature of the liquid to be cooled.

Where a distinct relationship between ambient temperature and flow rate is predictable or can be calculated, automatic means for adjusting the flow rate may be provided, operable for example by means of a temperature sensitive element such as a bi- etal strip or the like.

3. Separate liquified gas cannister-compartment

The source of liquified gas under pressure may comprise a separate compartment, normally sealed, to contain the refrigerant under pressure. The compartment may include valve means by which it is refillable with liquid refrigerant.

The compartment containing the liquified gas may be removable from the remainder of the shell. This allows a spent compartment to be removed from the shell, the empty beverage container removed, and a fresh compartment and container inserted.

The compartment containing the liquified gas may be movable, preferably rotatably relative to the shell, to effect the opening of the pressurised compartment.

The opening mechanism may include a piercing member by which a small hole can be punctured in the wall of the compartment to allow refrigerant to exit therethrough as the liquid changes state due to the sudden drop in pressure.

4. Double walled shell

The shell may include an internal thin wall radially spaced from the outside wall of the shell, and adapted to slidably receive the container. By ensuring that the thin wall makes good thermal conductive contact with the external surface of the container, the cooling effect of the expanding refrigerant is reliably transferred to the can through the thin internal wall.

The internal wall forms with the shell a hollow walled structure, which may contain one or more baffles, to ensure that the upwardly escaping refrigerant follows a tortuous path through the hollow wall of the shell, before it can vent to atmosphere, so as to enhance the cooling effect of the escaping refrigerant. 5. Can cooler with separable refrigerant compartment

In an embodiment of the invention which is adapted to be fitted around a can, an upper part of the shell may be made separable from the remainder and constructed in the form of an annular ring which can be fitted to the remainder of the shell as by screwing or by an adhesive, with sealing means located around the inside of the annular ring to seal against the outside surface of the can. Baffle means, ribs or flanges on the inside of the shell may be employed to centre the can in the shell and cause the escaping refrigerant to change direction in the upper reaches of the annular space within the shell so that it is thereby forced to move downwardly in the opposite direction from that in which it moved up the inside of the shell, before it can escape through one or more venting apertures at the base of the shell.

A device as aforesaid may comprise a cylindrical shell adapted to be fitted around a can so that the upper can end protrudes beyond the upper end of the shell, leaving an annular space around the can, an annular member adapted to be secured to the upper end of the shell to close off the upper end of the annular space and to form a seal with the protruding can end, and a cylindrical compartment adapted to be secured, as by screwing, to the opposite end of the sleeve, so as to retain the can in place and close off the lower end of the shell and the lower end of the annular said space.

6. Preferred design of sleeve for use with cans

In an embodiment for use with a can, a device as aforesaid may comprise a generally cylindrical sleeve both ends of which are open but one end of which is formed with a reduced diameter lip which will form a gas tight seal against the external surface of a can pushed into the sleeve from the other end thereof, the can being spaced from the inside surface of the sleeve to create an annular passage through which refrigerant can pass, and the lower end of the cylindrical shell is adapted to receive and be closed off by a cylindrical cannister containing or comprising a pressurised compartment containing liquified refrigerant, means being provided to enable communication between the inside of the compartment and the said annular passage to allow expanding escaping refrigerant to chill the surface of the can. The sleeve wall may include exit passage means to permit refrigerant which has risen up and filled the annular passage to pass downwardly through the exit passage means in the sleeve wall, to vent through aperture means at the end thereof adjacent the said cylindrical member. The exit passage means may be formed by forming the sleeve with a hollow wall or by forming distinct passages in an otherwise solid sleeve wall.

This preferred design of sleeve is of advantage where replacement cannisters are to be provided for fitting to the lower end of the sleeve, each precharged with liquified refrigerant ready to be used as required. In this way the action of removing the spent cannister exposes the lower end of the now empty can which can thereby be removed by withdrawing it from the sleeve and a full can can be introduced into the sleeve and secured in place by fitting a replacement refrigerant cannister to the base of the sleeve.

7. Two stage cooling

Transfer valve means may be provided to control the transfer of refrigerant from a first compartment (into which the reservoir is vented when the device is first opened) into a second compartment, whereby only when the first compartment has become fully pressurised are its contents permitted to transfer into the other compartment, and thereafter exit to atmosphere.

Typically the two compartments are two radially separated annular compartments within the shell. If the volume of the first of the two annular compartments is small relative to the volume of the reservoir containing the pressurised liquified gas at the base of the device, the initial venting will not cause a substantial phase change to occur since the escape of fluid from the reservoir (containing liquified gas) will tend to rapidly pressurise the first annular compartment so that the latter will tend to become filled with the liquid phase rather than the gaseous phase of the gas, and only after the transfer valve means is opened, does the major phase change occur causing the liquid in the first compartment to change to the vapour/gas phase as it exits into the second compartment from which it vents to atmosphere.

The transfer valve means may comprise a pressure sensitive valve which opens when the pressure in the first of the two compartments exceeds the pressure in the other by a given amount.

Where the transfer valve means is pressure sensirive, the valve means is preferably of a bi-stable type such that having become opened, it remains open even if the pressure difference across the valve becomes less than that originally required to open it.

The transfer valve means may alternatively comprise a frangible membrane which punctures when the pressure difference thereacross exceeds a given pressure.

According to a further aspect of the present invention, the venting means for communicating the second of the two compartments to atmosphere may also comprise pressure relief valve means such that a significant pressure has to build up in the second of the two annular compartments before the contents of that compartment can vent to atmosphere. Again a pressure relief valve having a bi-stable characteristic is preferred, so that once communication to atmosphere has been established, little or no pressure differential is required to maintain the valve means venting to atmosphere in its open condition.

A frangible membrane which punctures at a given pressure differential thereacross, may be employed as a valve means for venting to atmosphere.

The transfer valve means between the two compartments may be under user control. Instructions may be provided on the outside of the unit to instruct the user. Preferably the user first vents the pressurised compartment (reservoir) into the first compartment (for example by rotating the base of the unit, to open the reservoir) and after a predetermined period of time to open the transfer valve means between the two compartments.

The mechanism for opening the transfer valve means may also be associated with the rotational base of the unit as aforesaid, so that whereas a first rotational movement opens the reservoir to the first compartment, and a second rotational movement beyond the first, opens the transfer valve to allow the first compartment to communicate with the second compartment.

Where such two stage rotational movement is provided for achieving the two venting and resistance means is provided marking the end of the first rotational movement and the beginning of the second, so that, in use, resistance will be felt to continued rotation of the base relative to the unit, at a point at which further rotation of the base beyond the point of resistance would achieve the second venting.

The stop means may comprise a ramp or inclined plane, a spring loaded plunger engaging a trough, or a frangible member which when extra force is applied, can be broken so as to permit the continued rotation of the rotatable base through the second part of the rotational movement required. Where valve means is provided for controlling the venting of the second annular compartment to atmosphere, this may also be under user control. Thus for example the rotatable member may be adapted to be rotated into a third rotational position to effect opening of a third valve means for venting the second annular compartment to atmosphere.

8. Expansion chamber achieves improved cooling

Since a maximum cooling effect occurs at a position in which the phase change from liquid to vapour/gas occurs, it is preferable for this to occur in close proximity to the wall of the can containing the liquid which is to be cooled, and by locating the transfer valve means at the base of an inner annular compartment, so the phase change which occurs when the transfer valve means is opened, will cause a cooling effect close to the wall of the can.

By making the expansion compartment of small volume relative to the volume of the reservoir containing the liquified gas at the base of the unit, when the reservoir is initially vented, the expansion (and therefore reduction in pressure which occurs) is minimal so that there is little tendency for any significant phase change to occur as a result of this primary expansion, and the expansion chamber will become filled with liquid rather than the gas.

9. Alternative venting arrangement

According to a still further aspect of the present invention a reservoir containing liquified gas and located at the base of the unit, may include an extension which leads to valves for venting the reservoir directly into the lower end of one of two annular compartments surrounding the can to be cooled, venting of the reservoir through the outlet causing a liquid to gas phase change cooling effect to occur within the lower end of the said first of the two annular compartments. Preferably in this arrangement, the said first annular compartment is that which is in intimate contact with the beverage container and is the inner of two annular regions defined by a baffle located within the shell, so that the liquid to gas phase change occurs in contact with the wall of the can.

10. Multiple expansion chambers and cooling points

According to a further preferred feature of the invention, in a device as aforesaid, a plurality of independent first compartments are provided supplying a corresponding plurality of independent valve means, for venting into a second compartment, at different heights up the beverage container, so that liquid to gas phase change cooling is available at a plurality of positions up the height of the beverage container when the independent valve means are opened.

According to a preferred arrangement, each of the independent first compartments may at least in part encircle the beverage container.

The first compartment may be formed by winding a tube into a spiral to encircle the container, over at least some of the length thereof.

Two or more such spiral tubes may encircle the container, interwound in the form of a multistart thread.

Each of the different spatial tubes may be independently valved for venting at different points up the height of the container.

Each of the spiral tubular windings may include one or more valved outlets so that cooling refrigerant can be vented at different points around the circumference of the can.

Valved outlets which are nearer to the reservoir, are preferably smaller in cross-section area than those further therefrom, the difference in size being selected so that a similar rate of flow of vaporising liquid will be achieved through each outlet, so that the liquid to vapour phase change cooling is distributed substantially evenly up and around the can.

Where it is intended that the phase change should occur over a period of time, it will be appreciated that the opening(s) forming the said second communication means must be relatively small so as to restrict the flow of vaporising liquid so that a controlled reduction in pressure of the liquified gas is obtained.

11. Alternative construction of primary expansion chamber

Annular and/or spiral baffles may be provided to extend inwardly from the said intermediate cylindrical wall, towards the external wall of the container which is to be cooled, to make contact therewith and define a plurality of container encircling passages. Small apertures may be provided in the intermediate cylindrical wall, each communicating with one of the said encircling passages, and the reservoir is vented so as to supply escaping refrigerant to the outside of the said intermediate wall, so as to cause the refrigerant to pass through the small apertures therein into the said encircling passages.

A second cylindrical wall may be provided, the diameter of which is just greater than the external diameter of the said intermediate cylindrical wall, and which is sealed at its upper end to the said intermediate wall so as to form an annular chamber therebetween into which escaping refrigerant from the reservoir is directed.

Each of the said small apertures may be closed by a rupturable membrane so as normally to prevent communication therethrough, but which as soon as the pressure in the said annular chamber exceeds that required to rupture the membrane, refrigerant can flow therethrough.

Where second expansion chambers are formed by means of annular or spiral baffles protruding from the internal face of the main cylindrical baffle, the latter is preferably formed by injection moulding plastics material and the bursting apertures may be formed by means of locally weakened regions in the baffle wall which under excess pressure will burst open to perforate and create the desired openings.

12. Reusable cooling devices

Where devices are to be reused, the shell is preferably designed to be capable of receiving a can, as a snug fit, through an open end thereof. After the can has been cooled and the contents dispensed, the empty can may be removed and replaced with another full can. By arranging that the refrigerant reservoir can be refilled with liquified gas (or replaced by another refrigerant filled compartment), the replacement can may be chilled, when required, in the same way as the first.

13. Disposable cooling devices

Where there is no requirement to reuse the cooling device, the shell may be secured during manufacture to the outside surface of a can so as to leave an appropriate annular space between the shell and the can, and the cannister of pressurised liquified gas may be formed integrally with the shell, and the combination of the can, shell and cannister, is formed as a disposable commodity which once it has been used can be thrown away. In this event the component parts of the shell, can and cannister are preferably formed from materials which are compatible for recycling. Thus for example, where the container is formed from aluminium, the sleeve forming the outer shell for cooling and/or the container of liquified gas, may also be formed from aluminium, or from a suitable plastics material.

14. Methods of beverage packaging in cans to be fitted with a can-cooler

The invention also provides a method of packaging a beverage in a can comprising the steps of filling the can and sealing the latter in a conventional manner, subjecting the filled and sealed can to a pasteurisation process involving raising the temperature of the can and its contents to approximately 70°C, cooling the can, and thereafter affixing thereto a sleeve defining an annular cavity around the can.

In the above mentioned method, the sleeve may include an integral pressure vessel containing liquified refrigerant gas, which vessel is openable to permit its pressurised contents to exit therefrom and pass up through at least part of the annular cavity between the sleeve and the can so as to cool the can and its contents.

The invention also provides a packaging method in which a sleeve as aforesaid is attached to the can before pasteurisation but a pressure vessel containing liquified refrigerant is secured thereto only after pasteurisation and cooling.

The invention also provides a packaging method in which a sleeve and integral empty pressure vessel is attached to a can before pasteurisation, and the pressure vessel is charged with liquified gas after pasteurisation.

It will be seen that none of these methods involves a container filled with liquified gas, being subjected to pasteurisation temperatures, so that the vessel does not need to be as strong as it otherwise would have to be, if it was to be subjected to pasteurisation temperatures of 70°C and the attendant high pressure.

15. Dual purpose design

Where provided, the internal thin shell wall may serve two purposes. On the one hand it is adapted to receive a container as aforesaid and on the other it can serve as an open topped vessel into which liquid can be poured directly, so as to form a drinking vessel.

Thus if liquid is poured into the vessel, it can be cooled by venting the compartment containing the pressurised gas, so that the hollow wall of the drinking container becomes chilled by the escaping gas so as thereby to chill the liquid in the vessel.

A method of chilling a containerised beverage thus may comprise releasing the refrigerant from the source into the shell to cool the container, and thereafter removing the container from the shell after opening the latter, pouring the beverage into the interior of the shell to cause further cooling of the beverage before consumption.

If the apparatus is to be used in this way, it may be preferred to insert into the shell a plastics or glass insert which may be removable and which is constructed to intimately contact the internal thin wall of the shell, so that liquid contained within the plastics or glass insert will be cooled and can be drunk from the plastics or glass insert. After the insert has been used it can be removed and washed or replaced.

16. Refrigerant materials

Preferred refrigerants for cooling devices as aforesaid are liquid CFC HCFC and HFC gases, liquified Isobutane, liquified Carbon Dioxide and mixtures of liquified Carbon Dioxide and Isobutane or a CFC.

Environmental considerations dictate that the more preferred refrigerant is liquid Carbon Dioxide.

Another possible refrigerant is the refrigerant known as 22, such as is used for rapidly freezing water pipes to assist plumbers in mending leaks and changing fittings in water containing pipework.

The advantage of the refrigerant-22 over carbon dioxide is the pressure of refrigerant-22 at 70°C. Thus in the case of refrigerant-22 the pressure at 70°C is approximately 28bar whereas carbon dioxide has a pressure of 400bar at the same temperature. However whereas the ozone depletion potential of carbon dioxide is deemed to be zero, that of refrigerant-22 is 0.05 on a scale in which a CFC is 1.

For a typical popular can size of 340ml, the volume of refrigerant 22 required will be of the order of 100ml and since the heat capacity in joules per millilitre of both refrigerant- 22 and carbon dioxide is approximately the same, an equivalent volume of carbon dioxide would be required, albeit at a much higher pressure.

Another refrigerant which has a slightly lower heat capacity of 170 joules per millilitre is refrigerant 134A which at 70°C will exert a pressure of some 21bar.

Other refrigerants which are expected to become available on a commercial basis are KLEA61 and MP39 respectively, having heat capacities of 230 and 310 joules per millilitre at pressures (at 70°C) of 39 and 24bar respectively.

Whilst 134A and KLEA61 are deemed to have a zero ozone depletion potential, MP39 is somewhat similar to refrigerant- 22 which on a scale of CFC equal to 1 possesses an ozone depletion potential of 0.03.

The component blends of types 22 and 134A are known. The blends of KLEA61 and MP39 are as follows:

KLEA61 - 10% type 32, 70% type 125 and 20% type 134A MP39 - 53% type 22, 13% type 152A and 34% type 124.

Whilst carbon dioxide is attractive in principle, the very high pressure which has to be contained at temperatures much above 31°C means that a pressure vessel will be needed and this will inevitably increase the cost of the product if carbon dioxide is to be used for the refrigerant. Additionally the cooling effect of carbon dioxide tends to fall off as the temperature rises above 23°C.

It will be appreciated that if the can is left in the open exposed to bright sunlight, the contents of the can may well rise to temperatures considerably above 31^βC and in any case if the contents of the can are to be pasteurised it will be heated to 70°C or thereabouts.

It is envisaged that if carbon dioxide is to be used as a refrigerant, not only will a high pressure container be needed, but also a method of using the work energy which can be generated. It is also noted that carbon dioxide has similar toxicity to the HCFCs.

In order to obtain sufficient expansion and volume of cooling gas, it is almost inevitable that the vaporising liquid will have to exit to atmosphere. Criteria to be applied to the selection of refrigerant materials for the device are therefore as follows:

the vapour must be non-toxic and preferably non-anaesthetic, the vapour should not possess any pungent or unpleasant odour, the vapour should not be environmentally damaging, and the vapour should not be flammable.

A further advantage of the proposed design for liquid to vapour phase cooling is that the vessel containing the liquified gas is separate from and external to the beverage container. Whilst the latter is designed to withstand pressures typically of the order of 7 or 8 bar which will arise during pasteurisation at temperatures of the order of 70°C, the former may need to contain pressures considerably in excess of that level and if the device containing the liquified gas were within the beverage container, then for safety, the latter would also have to be capable of withstanding the much higher pressure contained within the liquified gas cannister. This would be a clear disadvantage which would necessitate an increase in the wall thickness and operational strength of what has been developed as a relatively low cost packaging device, namely the two piece thin walled aluminium can.

On the other hand, since the cooling is applied to the outside of the can or bottle, the transfer of heat from the liquid contents to the vapour cannot occur instantaneously and as the outer layers of liquid within the can or bottle become cooled, it is necessary for them to be replaced by warmer liquid from the central regions of the can or bottle before complete cooling is effected. It is therefore a desirable feature of the invention that the escaping gas, effecting the cooling, leaks past the can or bottle surface in a controlled and relatively slow manner, and in any case for a sufficient period of time, to permit thorough cooling of the contents of the can or bottle.

In the case of a beer can having nominal 340ml volume, the volume of liquid, in the case of beer will be typically 280ml and the can height will be approximately 140mm and the can diameter will be of the order of 72mm. Using that size of can and volume of liquid, the time required to cool the contents of the can has been found to be of the order of 1 to 3 minutes, and for effective cooling, the gaseous passage over the exterior of the can has to occur during a roughly similar period.

17. Advantage of cooling devices constructed in accordance with the invention

It is an advantage of the present invention that the cooling devices described herein can be fitted around the outside of a pre-packaged can or bottle of beverage either by the manufacturer or by the consumer.

It is a particular advantage of devices embodying the invention that they do not have to be fitted within the can or bottle during manufacture as is the case with other cooling systems which have been proposed. In this way existing canning or bottling lines do not need to be altered. This is of particular advantage in countries where the need for the invention may only exist during some weeks or months during the year and in which the precise period is of indeterminate and unpredictable duration and will not necessarily occur at the same point in time each year.

18. Combination of packaged beverages and chilling devices

The invention also envisages chilling devices as aforesaid when packaged with a commensurate number of filled beverage containers, which latter are adapted to fit therein for cooling.

The invention further envisages the packaging of portable chilling compartments for use with standard cans or bottles for sale alongside pre-packs of the latter, typically sold in fours or sixes or eights, to enable the consumer to purchase a commensurate number of each, so that in use and when required the prepacked cans or bottles can be separated and inserted into chilling compartments, and before consumption the gas cannister is opened so as to initiate cooling of the contents of each can or bottle fitted therein.

Where chilling compartments as aforesaid are packaged for use by the consumer, they are preferably of the re-usable variety and comprise sleeves on the one hand adapted to receive and surround a can or bottle and appropriately packaged plural replaceable gas-filled compartments containing liquified gas as aforesaid, adapted to be fitted individually to the different sleeves, with a can or bottle therein. The advantage of this arrangement is that the consumer need only purchase the sleeves once and thereafter only needs to purchase liquified gas cannisters and according to a further aspect of the invention, separate pre-packs of N cans or bottles and N cannisters of liquified gas are packaged, typically in groups of four or six or eight.

Since the contents of a can or a bottle are for human consumption, the packaging will normally include a date by which the product should be consumed. By separating the chilling sleeve and pressurised liquid gas cannister from the beverage packaging, items such as the sleeve and liquified gas cannister (which do not have to be sold or used before a certain date), can be sold separately from the cans or bottles of beverage (which have to be sold before a certain date) so that the stock items of unlimited life (such as sleeves and liquified gas cannisters) will not be linked to stock items of limited life.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a side elevation of a first embodiment of the invention as applied to a drinks can;

Figure 2 is a view of the base of the embodiment shown in Figure 1; Figure 3 is an enlarged view of the section marked A in Figure 2;

Figure 4 is a plan view of a sleeving station;

Figure 5 is a cross-section through a device of the type shown in Figures 1 to 3 indicating the different component parts which make up the cooling jacket and coolant reservoir which fits around a standard drinks can;

Figure 6 is a cut-away perspective view of another embodiment of the invention;

Figure 7 is an enlarged cross-sectional detail of the lower rim of the arrangement of Figure 5;

Figure 8 is a cross-section through a hollow walled vessel adapted for cooling liquid contained in cans or poured directly therein.

Detailed description of the drawings

In Figure 1 the top of a standard drinks can is shown at 10, the remainder of the can being shown in hidden detail.

The can fits within a sleeve 12 which is sealed at the upper end 14 to the can and is open at its lower end to receive a cylindrical reservoir shown in dotted outline at 16. The reservoir includes an enlarged base 18 the surface of which is grooved as at 20 to facilitate its rotation relative to the sleeve 12 as and when required.

The enlarged diameter section 18 is generally flat on its underside.

Stability is increased by forming the underside of the section 18 with a circular rebate 22 visible in Figure 2. This leaves a shallow circular shoulder 24 between the annulus 26 and a generally flat circular area 22. It is the annulus 26 which comes into contact with the surface on which the unit stands and the surface 22 is thereby kept away from the surface by the shoulder 24.

Figure 3 shows the detail of the grooving and the annulus 26.

The arrangement is such that liquid gas is contained under pressure within the unit 16 and when it is desired to cool the can 10 and any liquid in of the can, the base 18 is rotated relative to the sleeve 12 so as to fracture a seal (not shown) to enable the container 16 to vent to atmosphere thereby allowing the liquid gas to boil off and in so doing cool the can and its contents.

To this end the escaping gas is constrained to flow past the can between the external cylindrical surface of the can and the internal cylindrical surface of the sleeve 12 for which purpose a small gap is provided between the can and the sleeve. Apertures may be provided at the top of the sleeve but more preferably a return path is provided within the thickness of the sleeve so that after the escaping gas has passed upwardly to the top of the annular space between the can and the sleeve, it is forced to traverse in the opposite direction via a passage or passages in the thickness of the sleeve to vent finally through apertures near the base of the sleeve.

The sleeve 12 may be secured to the can during the canning process and preferably is secured to the can after the can has been filled and sealed with the beverage.

Where the beverage has to be pasteurised by subjecting the filled can to an elevated temperature for a short period of time, the application of the sleeve to the can is preferably left until after the pasteurisation has been completed and the can and its contents have been cooled and the level checked so that a sleeve is only applied to cans which have been pasteurised and which have passed the leak test implicit in the level detection post-pasteurisation.

The cans may be inserted into sleeves automatically or by hand.

An automatic insertion process is shown diagrammatically in Figure 4. A conveyor 28 conveys filled and where appropriate, pasteurised cans such as 10 from the pasteuriser (not shown) towards a sleeving station, generally designated 30. The station is located at the intersection of the conveyor 28 with a transverse conveyor 32. The direction of movement of conveyor 28 is shown by arrow 34 and that of conveyor 32 by arrow 36.

The conveyor 34 is elevated relative to conveyor 32 by the height of the sleeve 12 and since the can must be inserted into the sleeve through the larger opening at the base of the sleeve into which the unit 16 is subsequently to be fitted, the cans 10 are inverted on the conveyor 28 and the sleeves 12 are likewise inverted on the conveyor 32.

Empty inverted sleeves such as 38 are shown lined up on the conveyor 32 and inverted filled cans can be seen lined up on the conveyor 28 as at 40.

Guides 42 and 44 prevent the cans such as 40 from toppling. Similar guides 46 and 48 prevent the inverted sleeves from toppling.

A shutter mechanism is provided to separate inverted cans and inverted sleeves so as to present an inverted can and inverted sleeve in synchronism to the sleeving position 30. This is achieved by moving the gate 50 from the position shown in the direction of arrow 52 for a sufficient length of time to allow the conveyor 28 to transfer the next awaiting can to the position shown at 54. As it arrives at the position 54, a pair of jaws 56 moves into the position shown in Figure 4 so as to embrace the can and hold the can until it is to be released.

Shutters 58 and 60 operate in a similar manner to gate 52 and first one and then the other is moved in the direction of the arrows 62 and 64 to allow an inverted sleeve to occupy the position shown by the sleeve 12 and another sleeve to be held waiting at 66.

Sensors located at 68, 70 and 72 provide position signals to control the operation of the jaws 56 and the gates 58 and 60.

When a can is in position at 54 and a sleeve is in position at 12, the jaws 56 are withdrawn from the position shown in Figure 4 to allow the conveyor 28 to move the can until it reaches the position immediately above the empty awaiting sleeve 12 at which stage it can drop into the sleeve to occupy the position 10 shown in the sleeving station. A further gate 74 may be provided to arrest the movement of the sleeve which has been released into the position 12 until it is filled by a can but thereafter the gate 74 can be slid sideways so as to release the now filled sleeve to move downstream of the sleeving station to occupy the positions such as shown at 76.

Guide means in the region of the actual sleeving station which ensure that the can 54 remains vertical and drops in a correct manner have been omitted for clarity.

The various gates and the jaws 56 therefore provide an escapement mechanism for holding up waiting cans and waiting sleeves to release the cans to the sleeves in synchronism to allow the sleeving to be performed.

The mechanism can be operated at high speeds so that many cans per minute can be sleeved in this way.

By sleeving the cans after processing, the cans can be marshalled and released onto the second conveyor 32 either with or without sleeves depending on whether or not empty sleeves are positioned at 38. Thus if cans do not need to be sleeved because for example of a lack of demand due to cold weather, the cans can be processed through the sleeving station without sleeves being applied.

The inverted sleeved cans (such as at 76) are now in a position to receive the cannister containing the liquid gas 16, 18 and a similar arrangement to that shown in Figure 4 may be provided for inserting the closure devices into the upper open ends of the sleeves.

The seal between the neck of the can 10 and the upper end of the sleeve 14 may be provided by means of an appropriate resiliently deformable member formed around the internal periphery of the open end 14 of the sleeve or a liquid sealing agent may be applied to the sleeves before they arrive at the sleeving station 30 of Figure 4 so that when the cans are dropped into the sleeves, the liquid seal adheres to the can and bonds the can to the sleeve. The sealing material may be in the form of a jelly or paste and may be such as to dry into a generally solid form or may be arranged to remain in the form of a jelly or paste so as to effect the sealing between the can and the sleeve.

Although not shown, conveyor 32 supplies the cans to a marshalling arrangement whereby the sleeved or unsleeved cans are arranged in groups of four or six or eight as required for packing into prepacks.

Figure 5 illustrates a preferred arrangement of the combined unit shown in Figures 1 to 3. In Figure 5 the can is shown contained within the sleeve and held away from the inside surface thereof by means of studs or pips such as 78 and 80 which may be formed at regular intervals around and up and down the interior of the sleeve. Alternatively the pips 78, 80 may be replaced by a helical profile on the inside surface of the sleeve so as to provide a helical path for the escaping gases which they have to traverse before they can reach the top of the inside of the sleeve.

Alternatively elongate ribs which may be axially parallel or may follow parallel curved paths around the interior of the sleeve may be formed on the inside surface thereof to form a plurality of parallel gas paths from the base to the top of the interior of the sleeve around the can 10.

The sleeve 12 includes at least one gas return paths one of which is shown at 82. Another is shown at 84. These communicate with apertures 86 and 88 respectively at the upper end of the sleeve, the apertures 86 and 88 communicating with the interior of the sleeve near the seal 90 between the upper end 14 of the sleeve and the can 10. Further apertures 92 and 94 near the lower end of the sleeve 12 allow gas to escape from the gas paths 82 and 84 to the atmosphere.

Although two paths are shown in Figure 5, it is to be understood that only one such path such as 82 needs to be provided and if preferred, a larger number than two such paths may be provided. Where the sleeve includes a number of such paths, they are preferably equally circularly spaced around the sleeve.

The rate at which the gas can pass up between the can and the sleeve and out through the passages such as 82 and 84 will be dictated inter alia by the size of the openings such as at 86 and 88, 92 and 94. A degree of flow control is achievable by fitting an endless band which is at least in part formed from gas porous material 96 around the lower end of the sleeve 12 so as to cover the apertures 92 and 94 etc. Depending on the porosity of the band 96, so the passage of gas therethrough will be impeded to a greater or lesser extent. Gas to produce the cooling is stored under high pressure in liquid form as shown at 98 in the container 100. The latter includes one or more gas outlets denoted by reference numeral 102 and 104 respectively and until required, these outlets are sealed externally of the housing 100 typically by means of foil which can be pierced, severed, peeled or otherwise removed from the opening such as 102 and 104 to allow the pressure within the container 100 to be released and allow the liquid gas 98 to boil and produce the supply of cooling gas required to effect the cooling of the can 10 and its contents. Further flow control can be achieved by flow restriction means 106 and 108 covering the apertures 102 and 104 internally of the container 100 or fitted within the apertures 102, 104 or partly therewithin. In their simplest form, the flow restrictors may comprise segments of porous material which simply reduce the area available for the gas to escape through.

The container 100 includes at least one seal to prevent the gases escaping from apertures 102, 104 etc venting to atmosphere directly. To this end a first ring seal 110 may be provided between the cylindrical side wall of the container 100 and the internal cylindrical surface of the sleeve 12. A second ring seal 112 may be provided between the annular shoulder in the container 100 and the end of the sleeve 12.

Although not shown, means is provided for axially retaining the unit 100 within the end of the sleeve 12 whilst permitting relative rotation between the unit 100 and sleeve 12.

Preferably the degree of rotation is limited to for example 20° and as already indicated, the act of rotating the unit 100 relative to the sleeve 12 ideally provides the mechanism for severing, breaking, peeling or otherwise removing a closure to the apertures 102, 104 etc and to this end a seal of some form is provided which will indicate if the device has been tampered with and if the unit 100 has been rotated even by a small amount relative to the sleeve 12. The consumer can therefore have confidence in the product if the seal has not been broken.

A further degree of security can be provided by shrink wrapping plastics film at least over the lower end of the sleeve and unit 100 so that the wrapping has to be removed before the unit 100 can be rotated relative to the sleeve.

A degree of variation of flow rate can be achieved if the band 96 is formed from a tape wound two, three or more times around the region of the sleeve containing the apertures, one layer above the other. By peeling the tape away so as to leave less layers or no layers of tape, so the resistance to flow can be reduced.

Alternatively the apertures 92 and 94 etc may be selectively uncovered by peeling back a foil tape or the like, so as to expose more of the apertures and allow increased venting to occur.

Alternatively the band 96 may be rotatable or slidable relative to the sleeve 12 with means for retaining the band around the sleeve and the act of rotating or axially sliding the band is arranged to cause different regions of the band to overlie the apertures, the different regions of the band having greater or lesser resistance to gas flow therethrough.

Where adjustment of flow rate is provided for, the movable or peelable member may be calibrated so as to enable the consumer to adjust the flow rate to what is desired.

A temperature sensing element may be incorporated into the surface of the sleeve 12 or the outside surface of the container 100 so as to indicate the ambient temperature and the calibration of the flow rate determining device may be linked to the temperature reading so as to enable the consumer to adjust the flow rate to compensate for elevated ambient temperatures. The material from which the sleeve 12 is formed may be metal or plastics or a composite thereof and the outer surface may incorporate a paper or cardboard sleeve which may bear printing or the like.

At the least the section of the wall radially beyond the passages 82, 84 etc is formed from thermally insulating material and in the embodiment shown in Figure 5, it will be seen that the entire cross-section of the sleeve is shown as formed from thermally insulating material.

The unit 100 may be formed from metal or plastics but must have a wall strength sufficient to contain the high internal pressure associated with maintaining the gas in liquid form.

Where the can 10 has a nominal volume of 340ml and a preferred refrigerant such as refrigerant 22 is used, the volume of the liquified gas 98 in the container 100 will need to be of the order of 100ml. For a can of that size, the time during which the can should be exposed to the escaping gas will preferably lie in the range 1 to 3 minutes and the size and number of the apertures and/or the degree of porosity of flow rate restriction means such as 106, 108 and 96 and 94 should be such as to ensure that a back pressure between the final outlets and the contents of the container 100 is such as to ensure that the liquified gas will boil off over a period of 1 to 3 minutes.

Although not shown, the passages such as 82, 84 may in fact be replaced by a labyrinth or by a helical path or a combination of both so that the path length between the aperture 86 and the aperture 92 (and if provided 88 to 94), is much greater than the axial length of the sleeve 12 such as shown in Figure 5. The cross-section of the passage and the length of the passage will determine the resistance to flow and this factor can be used to control the rate of boiling of the liquified gas in the container 100 provided a good seal exists between the container 100 and the sleeve 12 such as is provided by the seals 110, 112 already described.

The means provided for retaining the container 100 within the end of the sleeve must be such that even when vented, the increased pressure within the sleeve will not force the container 100 out of the sleeve in an axial direction, or break the sealing between the container and sleeve.

Preferably the mechanism for holding the container within the sleeve includes a positive interlock as between abutting axial shoulders and where the overall unit of sleeve, can and container is intended to be disposable and thrown away after use, the interconnection of the container and the sleeve may for example include a so-called fir tree connection which allows the container to be pushed into the sleeve but prevents the container from being pulled out of the sleeve.

Where the container 100 is to be detachable from the sleeve to allow the container 100 to be recharged and/or a freshly charged replacement container fitted to a sleeve after the spent can has been replaced with a filled can, the mechanism for retaining the container within the sleeve will need to be such as to allow the consumer to withdraw the container without the need for tools and the like as would be the case if a fir tree connection were incorporated. To this end a bayonet type approach may be employed or a cam may be provided to ensure that the container cannot be rotated relative to the sleeve into the position in which the container can be removed axially from the sleeve without the user realising that the unit is being rotated beyond a point at which the user will realise that disengagement can occur.

Figures 6 and 7 illustrate an alternative form of construction of sleeve and cannister for fixing to a can.

Figure 6 shows a standard 207/211 two piece can generally designated 114 has fitted immediately below its curved base a domed gas cannister 116 and the two cylindrical units are retained in position and alignment by means of a two part cylindrical sleeve comprising an inner packaging layer 118 and an outer skin 120. The latter is typically formed from cardboard, plastics or metal and may comprise a metal foil. At the upper end it can either be stuck to the neck of the can at 122 or as shown trapped beneath the folded over periphery 124 of the closure cap. The flange cap before folding can be seen at 126.

The packing layer 118 includes a radially inwardly directed annular flange 128 which is adapted to engage the underside of a domed dish 130 and trap the latter at its periphery between the flange 128 and the peripheral edge of the domed gas cannister 116.

By sticking or otherwise bonding the outer sheath 120 to the packing layer 118, so the configuration will be maintained.

As shown in Figure 7, the capsule 116 is spaced from the flange of the disc 130 and from the packing member 118 by means of dimples or protrusions 132 and 134 respectively so as to permit gas to pass from the region between the plate and the underside of the domed capsule denoted by reference numeral 136 in Figure 7 and to pass upwardly around the outside of the capsule.

In a similar manner the packing layer 118 is stood off from the wall of the can by bridges or dimples or protrusions or the like so that gas can pass up the assembly between the surface of the can and the interior surface of the packing member 118. The external surface of the packing member is grooved for example as shown at 138 so that gas which has reached the top of the packing member can pass down through the grooves to exit the base of the can.

Whilst the grooves may be straight and parallel such as at 138, alternatively a more tortuous type of groove path may be provided such as shown at 140 in the cut-away view in the centre of the can. A helical path or the like may be substituted.

The outer sheath 120 needs to be bonded to the packing layer between the grooves as by means of an adhesive or by heat welding or the like depending on the materials used.

The cap 142 includes a conventional ring pull 144 so that the can can be opened to dispense the liquid contents.

The latter are cooled by gas escaping from the capsule 116 so as to permeate up through the can and to this end a puncturing pin is shown at 144 operated by means of a spring 146 which can be released by pulling the draw wire 148. The latter includes an upturned end which can be secured against the side of the sheath 120 by means of a strip of adhesive tape or the like to prevent the drawn wire 148 being pulled outwardly until the consumer is ready to puncture the capsule 116 and release the gas to cool the can.

The resistance to gas flow between the can and the packing sleeve and between the packing sleeve and the outer sheath is arranged to be such that the boiling of the liquid gas in the capsule 116 will occur for approximately 1 to 3 minutes.

Where the can 114 is a standard 340ml can, the capsule 116 will need to contain approximately 100ml of liquid refrigerant 22.

Figure 8 shows an alternative embodiment in which gas from a liquid gas cannister generally designated 150 can permeate around a tortuous path within a hollow walled beaker 152. The hollow wall is divided internally by means of a cylindrical sleeve baffle 154 supported by stand-offs or ribs such as 156, 158, 160 etc which whilst joining the baffle to the inner and outer skins of the beaker, nevertheless allow gas to pass upwardly and downwardly.

At the upper end of the baffle, gases passing in an upward sense within the radially inner annular region can pass over the top of the baffle as denoted by reference numeral 162 so as to be capable of descending in the radially outer annular region of the arrangement between the baffle and the outer wall of the beaker.

At the base of the beaker which is closed, apertures are formed as at 164 and 166 and a band or sleeve 168 may be provided to cover the aperture and to allow more or less of the apertures to be opened and exposed to allow gas to exit. The band or sleeve 168 may be formed at least in part from porous material through which the gas can leak albeit with resistance to flow.

The mechanism for puncturing the cannister 150 is not shown but typically involves rotating the lower end 170 relative to the beaker 152.

Seals are provided as at 172 and 174 to prevent gas from leaking down past the cannister 150 and thereby forcing the gas to move upwardly around the interior of the beaker.

In one arrangement the beaker interior is designed so as to accommodate a standard metal beverage can such as a 340ml can. Alternatively the beaker may be formed from a material which can be kept clean as by washing and which allows the contents of a can such as a beer can to be emptied into the container and chilled before it is drunk.

The inside wall of the container is preferably formed from a material having a good thermal conductivity such as a thin metal sleeve and the outside wall of the beaker may be coated, covered with, or formed from a thermally insulating material or at least a material having a much poorer thermal conductivity than that from which the inner skin 176 is formed. As shown, a layer of insulating material 178 is shown secured to the outside surface of the beaker.

By making the unit 150 separable from the beaker, and supplying items such as 150 separately, or providing a device for recharging the devices 150, so the beaker can be made re¬ usable.

Claims

1. A device for chilling the contents of a beverage container comprising a shell, the interior of which is adapted to accommodate the container the contents of which are to be chilled, and which defines an annular space around the said container when the shell is fitted therearound, a source of liquified refrigerant gas under pressure associated with the shell, and means which is openable to permit the liquified gas to escape to create a cooling effect created by the change of phase from liquid to gas and expansion of the gas in the said annular space.

2. A device as claimed in claim 1, wherein an outer surface of the shell is formed with a heat insulating layer or sleeve so that the cooling effect is preferentially directed towards the interior of the shell and towards any container (and its contents) located therein.

3. A device as claimed in claim 1 or claim 3, wherein the annular space around the container into which the escaping refrigerant can pass, is vented at a point which is distant from the point of entry, so that there is minimal pressure build-up in use, and vaporisation can continue until all of the liquified gas has escaped.

4. A device as claimed in any of claims 1 to 3, wherein fins or other surface area increasing devices of good thermally conductive material are incorporated into the hollow interior of the shell, and are adapted to make good thermal conductive contact with the wall of the beverage container so as to effectively increase the surface area of the container wall in contact with the escaping refrigerant, thereby to assist in heat exchange therebetween.

5. A device as claimed in claim 4, wherein a thermal insulating member (a so-called thermal break) is provided in the join between each fin and its support structure.

6. A device as claimed in any of claims 1 to 5, wherein the annular space is closed at its upper end and includes baffle means which divides the annular space into inner and outer coaxial annular compartments which communicate over or through the baffle at its upper end only, whereby the escaping refrigerant is caused to pass upwardly between the outer surface of the container and the baffle, and then downwardly between the baffles and the shell to exit through venting means near or at the base of the shell, so that the descending blanket of cold refrigerant acts as a shield to reduce inward radial transfer of heat from outside the shell to the annular region immediately surrounding the container, thereby enhancing the cooling effect on the contents of the container located within the shell.

7. A device as claimed in claim 6, wherein the baffle is in the form of a cylindrical wall intermediate the container and the inside surface of the shell.

8. A device as claimed in claim 6 or 7, wherein the baffle is held in place by ribs between the shell and the baffle, and the ribs extend radially inwardly beyond the baffle to form fins for making contact with, and increasing the effective surface area of the container wall.

9. A device as claimed in any of claims 1 to 8, wherein the annular space up, or down (or both) which the refrigerant passes is constructed in the form of a tortuous path which has the effect of slowing down the escaping refrigerant and increasing the length of the heat exchange path, both of which will enhance the cooling effect.

10. A device as claimed in claim 9, wherein the container is spaced from the inside of the shell by ribs or spacers, and these are arranged to create the tortuous path.

11. A device as claimed in any of claims 1 to 10, wherein the shell is formed at least in part from a length of tube, wound into a spiral for close fitting around the container, so as to form a spiral package through which the refrigerant can escape.

12. A device as claimed in any of claims 1 to 11, wherein an adjustable flow restriction means is provided to further control the rate at which the escaping refrigerant can vent, to allow the consumer to adjust the rate of cooling, to adjust the latter to take account of changes in ambient temperature and/or temperature of the liquid to be cooled.

13. A device as claimed in claim 12, containing automatic means for adjusting the refrigerant flow rate operable by a temperature sensitive element.

14. A device as claimed in any of claims 1 to 13, wherein the source of liquified gas refrigerant under pressure comprises a separate compartment, normally sealed, to contain the refrigerant under pressure.

15. A device as claimed in claim 14, wherein the compartment includes valve means by which it is refillable with liquid gas.

16. A device as claimed in claim 14 or 15, wherein the compartment containing the liquified gas is removable from the remainder of the shell, to allow a spent compartment to be removed from the shell, the empty beverage container removed, and a fresh compartment and container inserted.

17. A device as claimed in any of claims 14 to 16, wherein the compartment containing the liquified gas refrigerant is movable, relative to the shell, to effect the opening of the pressurised compartment.

18. A device as claimed in claim 17, wherein the compartment is rotatable relative to the shell.

19. A device as claimed in claim 17 or 18, wherein the opening mechanism includes a piercing member by which a small hole is punctured in the wall of the compartment to allow refrigerant to exit therethrough, the movement of the piercing member being effected by the movement of the compartment relative to the shell.

20. A device as claimed in any of claims 1 to 19, wherein the shell includes an internal thin wall radially spaced from the outside wall of the shell, and adapted to slidably receive the container, its internal dimensions being chosen so that the thin wall makes good thermal conductive contact with the external surface of the container, whereby the cooling effect of the escaping refrigerant will be reliably transferred to the container through the thin internal wall.

21. A device as claimed in claim 20, wherein the internal wall forms with the shell a hollow walled structure, containing one or more baffles, to ensure that the upwardly escaping refrigerant follows a tortuous path through the hollow wall of the shell, before it can vent to atmosphere, so as to enhance the cooling effect.

22. A device as claimed in claim 1, which is adapted to be fitted around a can, wherein an upper part of the shell is made separable from the remainder and constructed in the form of an annular ring which can be fitted to the remainder of the shell as by screwing or by an adhesive, with sealing means located around the inside of the annular ring to seal against the outside surface of the can.

23. A device as claimed in claim 22, wherein baffle means, ribs or flanges on the inside of the shell are employed to centre the can in the shell and cause the escaping refrigerant to change direction at least once within the shell so that it is thereby forced to move in an opposite direction from that in which it moved initially inside the shell, before it can escape to atmosphere through one or more venting apertures in the shell.

24. A device as claimed in any of claims 1 to 23, which comprises a cylindrical shell adapted to be fitted around a can so that the upper can end protrudes beyond the upper end of the shell, leaving an annular space around the can, an annular member adapted to be secured to the upper end of the shell to close off the upper end of the annular space and to form a seal with the protruding can end, and a cylindrical compartment adapted to be secured, as by screwing, to the opposite end of the sleeve, so as to retain the can in place and close off the lower end of the shell and the lower end of the annular space.

25. A device for use with a can, as claimed in claim 1, which comprises a generally cylindrical sleeve both ends of which are open but one end of which is formed with a reduced diameter lip which will form a gas tight seal against the external surface of a can pushed into the sleeve from the other end thereof, the can being spaced from the inside surface of the sleeve to create an annular passage through which refrigerant can pass, and the lower end of the cylindrical shell is adapted to receive and be closed off by a cylindrical member containing or comprising a pressurised compartment containing liquified refrigerant, means being provided to enable communication between the inside of the compartment and the said annular passage to allow escaping refrigerant to chill the surface of the can.

26. A device as claimed in claim 25, wherein the sleeve wall includes exit passage means to permit refrigerant which has risen up and filled the annular passage to pass downwardly through the exit passage means in the sleeve wall, to vent through aperture means at the end thereof adjacent the said cylindrical member.

27. A device as claimed in claim 26, wherein the exit passage means is formed by forming the sleeve with a hollow wall defining one or more distinct passages.

28. A device as claimed in any of claims 1 to 27, wherein transfer valve means is provided to control the transfer of refrigerant from a first compartment (into which the reservoir is vented when the device is first opened) into a second compartment, whereby only when the first compartment has become fully pressurised are its contents permitted to transfer into the other compartment, and thereafter exit to atmosphere.

29. A device as claimed in claim 28, wherein the two compartments are two radially separated annular compartments within the shell.

30. A device as claimed in either of claims 28 or 29, wherein the communication controlling valve means comprises a pressure sensitive valve which opens when the pressure in the first of the two compartments exceeds the pressure in the other by a given amount.

31. A device as claimed in claim 30, wherein the valve means is of a bi-stable type such that having become opened, it remains open even if the pressure difference across the valve becomes less than that originally required to open it.

32. A device as claimed in any of claims 28 to 31, wherein the valve means comprises a frangible membrane which punctures when the pressure difference thereacross exceeds a given pressure.

33. A device as claimed in any of claims 28 to 32, wherein the venting means for communicating the second of the two compartments to atmosphere also comprises pressure relief valve means such that a significant pressure has to build up in the second of the two compartments before the contents of that compartment can vent to atmosphere.

34. A device as claimed in claim 33, wherein a pressure relief valve having a bi-stable characteristic is employed, so that once communication to atmosphere has been established, no pressure differential is required to maintain the valve means venting to atmosphere in its open condition.

35. A device as claimed in claim 34, wherein a frangible membrane which punctures at a given pressure differential thereacross, is employed as the valve means for venting to atmosohere.

36. A device as claimed in claim 28, 29 or 30, wherein the said valve means between the two compartments is under user control to vent the reservoir to the first compartment and, after a predetermined period of time, to open the transfer valve means to vent the first compartment into the second compartment.

37. A device as claimed in claim 36, wherein the venting of the reservoir into the first compartment is achieved by rotating a rotatable base relative to the remainder of the unit.

38. A device as claimed in claim 37, wherein the mechanism for venting the first compartment into the second is also associated with the rotational base, so that a first rotational movement achieves the first venting (of the reservoir) and a second rotational movement, beyond the first, achieves the second venting (between the first and second compartments).

39. A device as claimed in claim 38, wherein two stage rotational movement is provided for achieving the two ventings and resistance means is provided marking the end of the first rotational movement and the beginning of the second, so that. in use, resistance will be felt to continued rotation of the base relative to the unit, at a point at which further rotation of the base beyond the point of resistance would achieve the second venting.

40. A device as claimed in claim 41, wherein the stop means comprises a ramp or inclined plane, or a spring loaded plunger which engages a trough, or a frangible member which when extra force is applied, can be broken so as to permit the continued rotation of the rotatable base through the second part of the rotational movement required.

41. A device as claimed in claim 34, wherein the valve means for controlling the venting of the second compartment to atmosphere is also under user control.

42. A device as claimed in claim 41, wherein the rotatable member is adapted to be rotated into a third rotational position to effect opening of a third valve means for venting the second annular compartment to atmosphere, the end of the second and beginning of the third rotational movement may be defined by a resistance stop, similar to that marking the transition between the first and second rotational movements.

43. A device as claimed in any of claims 28 to 42 wherein the first and second compartments are separate annular regions within the annular space around the container defined by the shell.

44. A device as claimed in any of claims 28 to 43, wherein the volume of the first compartment is small relative to the volume of the reservoir of liguid refrigerant so that when the first valve means is opened, the expansion (and therefore reduction in pressure which occurs) is minimal, so that there is little tendency for a phase change to occur as a result of the venting of the reservoir, and the first compartment will become filled with liquid rather than gas, so that when the second valve means is opened, liquid is available within the first compartment to exit through the second valve means (when opened), whereby a liquid to gas phase change will occur as the liquid leaves the first compartment.

45. A device as claimed in claim 45, wherein a plurality of independent first compartments are provided supplying a corresponding plurality of independent valve means, for venting into a second compartment, at different heights up the beverage container, so that liquid to gas phase change cooling is available at a plurality of positions up the height of the beverage container when the independent valve means are opened.

46. A device as claimed in claim 45, wherein each of the independent first compartments at least in part encircles the beverage container.

47. A device as claimed in any of claims 28 to 46, wherein the first compartment is formed by winding a tube into a spiral to encircle the container, over at least some of the length thereof.

48. A device as claimed in claim 47, wherein there are two or more such spiral tubes around the container, interwound in the form of a multistart thread.

49. A device as claimed in claim 48 wherein each of the different spiral tubes is independently valved for venting at different points up the height of the container.

50. A device as claimed in claim 49, wherein each spiral tubular winding includes one or more valved outlets so that cooling refrigerant is also vented at different points around the circumference of the can.

51. A device as claimed in claim 50, wherein valved outlets which are nearer to the reservoir, are smaller in cross-section area than those further therefrom, the difference in size being selected so that a similar rate of flow of vaporising liquid will be achieved through each outlet, so that the liquid to vapour phase change cooling is distributed substantially evenly up and around the can.

52. A device as claimed in any of claims 1 to 27, wherein the reservoir contains liquified gas and is located at the base of the unit, and the reservoir includes an extension which leads to valves for venting the reservoir directly into the lower end of one of two annular compartments surrounding the can to be cooled, venting of the reservoir through the outlet causing a liquid to gas phase change cooling effect to occur within the lower end of the said first of the two annular compartments.

53. A device as claimed in claim 52, wherein the said first annular compartment is that which is in intimate contact with the beverage container and is the inner of two annular regions defined by a baffle located within the shell, so that the liquid to gas phase change occurs in contact with the wall of the can.

54. A device as claimed in any of claims 28 to 53, insofar as they are dependent from claim 7, wherein annular and/or spiral baffles extend inwardly from the said intermediate cylindrical wall, towards the external wall of the container which is to be cooled, to make contact therewith and define a plurality of container encircling passages, and small apertures are provided in the intermediate cylindrical wall, each communicating with one of the said encircling passages, and the reservoir is vented so as to supply escaping refrigerant to the outside of the said intermediate wall, so as to cause the refrigerant to pass through the small apertures therein into the said encircling passages.

55. A device as claimed in claim 54, wherein a second cylindrical wall is provided, the diameter of which is just greater than the external diameter of the said intermediate cylindrical wall, and which is sealed at its upper end to the said intermediate wall so as to form an annular chamber therebetween into which escaping refrigerant from the reservoir is directed.

56. A device as claimed in claim 54 or 55, wherein each of the said small apertures is closed by a rupturable membrane so as normally to prevent communication therethrough, but which as soon as the pressure in the said annular chamber exceeds that required to rupture the membrane, refrigerant can flow therethrough.

57. A method of packaging a beverage in a can comprising the steps of filling the can and sealing the latter in a conventional manner, subjecting the filled and sealed can to a pasteurisation process involving raising the temperature of the can and its contents to approximately 70°C, cooling the can, and thereafter affixing thereto a sleeve defining an annular cavity around the can.

58. A method as claimed in claim 56, wherein the sleeve includes an integral pressure vessel containing liquified refrigerant gas, which vessel is openable to permit its pressurised contents to exit therefrom and pass up through at least part of the annular cavity between the sleeve and the can so as to cool the can and its contents.

59. A method as claimed in claim 57, wherein a pressure vessel containing liquified refrigerant gas is subsequently secured to the sleeve.

60. A method as claimed in claim 57, in which the sleeve includes an integral empty pressure vessel, and the pressure vessel is subsequently charged with liquified refrigerant gas.

61. A method of chilling a containerised beverage using a device as claimed in claim 20, releasing the refrigerant from the source to cool the container but thereafter removing the container from the shell and after opening the latter, pouring the beverage into the interior of the shell to cause further cooling of the beverage before consumption.

62. Devices and methods as claimed in any of claims 1 to 62, wherein the refrigerant is a liquified CFC, HCFC or HFC gas; liquified Isobutane; liquified Carbon Dioxide; or a mixture of liquified Carbon Dioxide and either Isobutane or a CFC, HCFC, or HFC gas; liquified refrigerant known as 22, or 134A or KLE461 or MP39.

63. Devices as claimed in any of claims 1 to 56, when packaged with a commensurate number of filled beverage containers, which latter are adapted to fit therein for cooling.

64. A portable beverage chilling package comprising a plurality of beverage containing containers, and at least one device as claimed in any one of claims 1 to 56 adapted to receive a full container, and plural reservoirs containing liquified refrigerant gas adapted to be fitted individually to the said device, with a beverage container therein for chilling same.

65. Devices for chilling containerised beverages constructed and arranged to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.