There have been many proposals for self-heating or self-cooling beverage containers. WO 96/29255, for example, discloses a can having the same external dimensions and shape as conventional beverage cans, but having an indented base to define an external cavity in which means to cool or heat the contents of the can are received.

Heating or cooling of the contents of the can can be achieved by using two chemical reactants which are stable when separated, but which produce an exothermic reaction or an endothermic reaction when mixed. US patent No.

5,626,022 shows just one example, from many, of an insert for a self-heating or self-cooling can which enables mixing of the reactants when required. This construction, as is common, utilises a breakable or pieceable barrier to separate the two reactants, and spikes or other piercing means to break the barrier when their reaction is required to heat or cool the can.

The present invention seeks to provide a new construction for a self- heating or a self-cooling container.

According to a first aspect of the present invention there is provided a self-heating or a self-cooling container comprising a sealed can containing contents to be heated or cooled, an outer container substantially enclosing said can, and heating or cooling means received within said outer container, wherein said outer container is divided into first and second chambers by way of a partition, a first chemical reactant being received within said first chamber and a second chemical reactant being received within said second chamber, and further comprising means incorporated within the container for removing said partition whereby said first and second chemical reactants can mix and cause a reaction to heat or cool the contents of the can, wherein said removing means is part of, or carried by, the container and is arranged such that movement thereof is operable to remove the partition.

Preferably, the sealed can contains a beverage to be heated or cooled.

In a preferred embodiment, the container is self-heating and the first reactant in the first chamber is quicklime, or includes quicklime, and the second reactant in the second chamber is water.

The outer container is generally an oversized container of substantially the same shape and configuration as the sealed can, but with inner dimensions which are substantially the same or just slightly larger than the outer dimensions of the can. After the can has been filled and sealed, and the can and its contents have been subjected to any required treatments, such as sterilisation or pasteurisation, the sealed can is placed within the outer container.

In one embodiment, the outer container is formed in two cooperating parts, the first part having the first chamber, and the second part having the second chamber. The first and second parts of the outer container are arranged to be appropriately fastened together to enclose the sealed can. In the fastened position of the outer container, the partition separates the first and second chambers.

The partition between the first and second chambers may be a mechanical partition which is mounted to be moved when mixing of the first and second chemical reactants is required. Presently, it is preferred, however, that the partition be a piercable or rupturable membrane, and that the removing means comprises piercing means arranged to come into contact with and pierce the membrane when mixing is required.

The first and second cooperating parts of the outer container may be screwed together, telescoped together, or otherwise assembled, to form the outer container. A tamper evident strip, or other barrier means, is preferably provided to prevent piercing of the membrane during closing or assembly of the two parts of the outer container. When it is required to heat or cool the contents of the sealed can, the tamper proof strip or other barrier is removed.

The two parts of the outer container may then be moved further towards one another. In one embodiment, such further movement of the two parts of the

outer container towards one another may be arranged to cause the membrane to be pierced or ruptured whereby the two chemical reactants mix, react, and thereby heat or cool the contents of the sealed can.

It is, of course, alternatively possible to arrange for movement of the two parts away from one another to cause rupture or piercing of the membrane.

It is possible, if required, to provide that opening of the sealed can to access the contents initiates the mixing of the reactants to initiate heating or cooling. However, it is generally preferred that heating or cooling be completed before the contents of the can are accessed.

In one embodiment, the second chamber is an inserted water container which has been mounted in, or forms one end, of the outer container. This water container may have a removable lid, for example as described in WO 00/35758.

Such a water container could be provided, for example, at either the base or the top of the outer container with a cylindrical first chamber, for receiving the quicklime, for example, provided around the exterior of the peripheral wall of the can.

In another embodiment, the outer container is divided by collapsible means which form or provide the partition between the first and second chambers, and wherein said removing means comprises a cap threaded onto, or telescoped with, the outer container, such that movement of the cap in a direction onto the outer container causes collapse and removable of the partition.

For example, the sealed can may have been inserted into the outer container such that the base of the sealed can contacts a base part of the outer container, and wherein the first chamber of the outer container comprises a substantially cylindrical chamber defined within a wall part of the outer container, and the second chamber is defined within the base part of the outer container.

In a preferred implementation, at least a top wall of the base part of the outer chamber is formed by a collapsible partition wall, and wherein said cap is movable along the wall part of the outer container to collapse and rupture said collapsible partition wall.

This alternative embodiment may also be provided with tamper evident means. For example, a tamper evident barrier may be positioned on the outer container to prevent movement of said cap in a direction to collapse the partition.

In this embodiment, the cap is screwed, or otherwise moved, along the wall of the outer container to collapse the collapsible partition. The second chamber is used to contain a fluid, such as water, so that if the container is also inverted, the fluid will assist in causing the collapse of the partition and will then run into the first chamber whereby the volume taken up by the second chamber is reduced, facilitating further movement of the cap.

It will be appreciated that the configuration of the two chambers within the outer container can be chosen as required. It is, of course, desirable that the configuration is such that when the first and second chemical reactants are mixed the resultant heating or cooling effect takes place in intimate contact with a large area of the peripheral wall of the can. For example, the second chamber can be arranged to substantially surround the can.

It is required that the separation between the first and second chambers is reliable during transportation and storage, for example, but is readily removable without there being any necessity to use tools when the contents of the can are to be heated or cooled.

The present invention also extends to a method of providing a self- heating or self-cooling container, the method comprising the steps of filling a can with a beverage, sterilising, pasteurising, or otherwise treating the beverage in the can, and sealing the can before or after the treatment steps, assembling the sealed can into an outer container enclosing the sealed can, the outer container defining first and second separate chambers divided by a

partition, and the container incorporating removing means operable to remove the partition.

Preferably, said partition is a rupturable or breakable membrane.

Embodiments of the present invention will hereinafter be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows schematically a self-heating or self-cooling container of an embodiment of the present invention, Figure 2 shows an alternative embodiment of the invention, the embodiment being shown in its initial condition, and Figure 3 shows the embodiment of Figure 2 after actuation of the self- heating means.

The invention is described hereinafter with reference to a self-heating beverage container having a particular design of heating mechanism.

However, the invention is applicable to both self-heating and self-cooling containers and finds application irrespective of the proposed contents of the container.

The self-heating container shown in Figure 1 includes a can 10 in which a beverage 2 is contained. The can 10 has a substantially cylindrical peripheral wall 12 which is closed at one end by a base member 14 and at its top end by a top member 16.

The can 10 may be made of any material able to conduct heat.

Preferably, the can 10 is metal. In a preferred embodiment, the can 10 is a substantially conventional beverage can of substantially conventional size and configuration, and is made of aluminium. The can 10 has its base member 14 seamed to the base of the cylindrical wall 12 and its top member 16, which incorporates opening means (not shown), seamed to the top end of the cylindrical wall 12. The opening means may, in conventional fashion, be arranged to pull away all of the top member 16 of the can on opening or may comprise any appropriate design of ring pull arranged, on opening, to form a dispensing hole in the top member 16 of the can 10.

In use, the can 10 is filled with a beverage 2 and is sealed. In this respect, as the can 10 has the same shape and configuration as conventional cans, it can be filled, and subjected to any required treatments, on conventional filling lines. Often it is required to pasteurise and/or sterilise the contents of the can, and such treatments may be performed before or after the top member 16 is sealed onto the can 10 to seal the can.

After the beverage has been fitted into the can, after suitable treatments have been performed, and with the can sealed by the top member 16, the sealed can 10 is assembled in an outer container generally referenced 20.

This outer container 20 has an inner surface or shell 21 which closely follows the outer surface of the can 10, and a spaced outer surface or shell 23. The inner and outer spaced shells 21,23 define between them a generally cylindrical space enclosing the cylindrical wall 12 of the can 10, and a space beneath the base member 14 of the can 10. Initially, the spaces defined between the inner and outer shells 21,23 are divided into two separate chambers 22 and 24, as described below. These first and second chambers 22,24 receive first and second chemical reactants which are held apart by any appropriate means. When the contents of the can 10 are to be heated, the contents of the two chambers are caused to mix whereby the resultant exothermic reaction generates heat to heat the contents of the can 10. In a preferred embodiment, the first chemical reactant in a lower chamber 22 of the outer container 20 is quicklime, or includes quicklime, whilst the second chemical reactant in a second upper chamber 24 of the container 20 is water.

In an alternative arrangement, able to enhance the heating effect, the inner surface or shell 21 of the outer container is not provided by a separate wall, but is, in fact defined by the cylindrical wall 12 of the can 10. This means, of course, that the quicklime and water cannot be reloaded. Instead, the quicklime and the water are loaded into the chambers 22 and 24 after these chambers have been formed by assembling the outer shell 23 on the filled and sealed can 10.

It is required to keep the quicklime and the water separated until the beverage in the sealed can 10 is to be heated and this is achieved, in the embodiment illustrated, by the provision of a rupturable membrane 26. The

membrane is an annular disc of foil 26 which is secured to the outer container 20 to define the upper chamber 24 and to retain the water within that upper chamber.

In the embodiment illustrated, the outer container 20 is formed in two cooperating parts, namely, a lower part 32, which contains the first chamber 22 and the quicklime, and an upper part 34 which contains the second chamber 24 in which water is sealed therein by way of the foil 26. It will be appreciated that, in use, the sealed and filled can 10 can be inserted into the lower part 32 of the outer container 20 and then the upper part 34 may be fastened on to the lower part whereby the outer container 20 is formed and encloses the sealed can 10. In the illustrated embodiment, the sealed can 10 is substantially completely enclosed except for its top surface 16.

In the embodiment illustrated, the two parts 32 and 34 of the outer container 20 are either arranged to be screwed together, or to be telescoped together, or to be otherwise assembled. However, it would also be possible to clip or otherwise assemble each part 32,34 onto the can 10 individually so that they are in close abutment. Of course, actuation of the heating means by mixing of the reactants contained in the two parts needs to occur only when required. To this end, a tamper proof band 36 is provided to keep the two parts 32,34 of the outer container 20 from interacting. In this respect, it will be seen that an upwardly pointed annular rim 38 is provided within the lower chamber 22.

When heating of the contents of the can 10 is required, the tamper proof band 36 is removed. This enables the two parts 32 and 34 to be brought together whereby the pointed edge of the rim 38 is caused to pierce the foil 26.

This causes the water in the upper chamber 24 to flow over the quicklime in the lower chamber 22 whereby an exothermic reaction is caused. The heat so generated will thereby heat the contents of the can 10.

It will be appreciated that the method of assembling the outer container on the can, and the method of removing or rupturing the membrane 26, may be chosen as is required.

It would be possible, for example, for the upper part 34 of the outer container 20 to completely enclose the top member 16 of the can 10. However, in the embodiment illustrated, the top panel is uncovered providing access to the opening means on the top member 16. Furthermore, the top of the outer container is provided with a smooth drinking rim 4.

The shape and configuration of the outer container 20, its materials and its manner of manufacture, may all be chosen as is required. However, in a preferred embodiment, the spacing of the two shells 21,23 of the container 20 is kept as small as possible so that the self-heating container assembled from the filled can 10 and the outer container 20 does not take up excessive space.

Preferably, the inner shell 21 of the outer container is formed of metal to provide good heat transmission of the heat generated into the contents of the can 10. The outer shell 23 may be made of a plastics material, for example, to safeguard the user against the heat which is generated.

In the embodiment described above, the means separating the two chambers 22 and 24 is a rupturable or breakable membrane 26. Of course, a mechanically removable partition may alternatively or additionally be provided.

The outer container 20 needs to be reliably closed or secured to the sealed can 10 for ease of storage and transport. In addition, an operating mechanism for causing the two chemical reactants to mix when required has to be provided. This operating mechanism comprises a partition and removing means operable to remove the partition. These two requirements may be met by any appropriate means and the operating mechanism may be completely separate from the mechanism securing the outer container on the can.

However, it is required that there is no necessity to provide a separate tool, and the operating mechanism is incorporated within the container, either as part thereof, or carried thereby. It is presently preferred that the operating mechanism be intimately related to the mechanism for securing the outer container on the can.

As described above, the outer container may be in two parts, which are assembled or fastened together to enclose the sealed can, whereby the securing of the outer container on the sealed can is assured. Where the outer

container is formed of two assembled parts, the removing means may be activated, for example, by causing the two parts to move towards one another by relative rotation or by pushing them together. A mechanical lever action may alternatively be provided with, for example, an actuating handle.

Figures 2 and 3 show an alternative embodiment of a self-heating container in accordance with the invention. In the embodiments of Figures 2 and 3, the can 10 has substantially the same configuration as that of Figure 1.

As previously, the sealed can is assembled within an outer container 20 which has inner and outer spaced shells 21,23. Also as previously, a first chamber 22 and a second chamber 24 are defined within the spaces between the shells 21,23. The first chamber 22, which is to contain the quicklime, for example, is a substantially cylindrical chamber defined within an upstanding wall part of the outer container 20. The second chamber 24, which contains water in this example, is defined in the base part of the outer container 20. In the assembled condition shown in Figure 2, the base of the can 10 contacts a top wall 26 of the second chamber 24.

All of the walls within which the second chamber 24 is defined may be made of the same material, such as a plastics material. Preferably, however, the walls defined by the outer shell 23 are of the same material as the rest of the outer container, for example, of a metal, whilst the partition wall 26 is of a collapsible and rupturable plastics material or foil.

The embodiment shown in Figures 2 and 3 also has a cap 44 as described below. Otherwise, the embodiment shown in Figures 2 and 3 is substantially the same as described above with reference to the embodiment illustrated in Figure 1. In particular the variations and modifications set out above in connection with Figure 1, may be made to the embodiment of Figures 2 and 3.

It will be seen that the sealed can 10 is fitted into the outer container 20 so that the base of the can 10 contacts the partition wall 26 of the second chamber 24. This can be done, where the outer container 20 has an inner wall defined by the inner shell 21, by sliding the can into position. Where there is no

inner shell, the can is supported on the base part whilst quicklime is charged into the chamber 22.

Operation of the can to effect heating requires that the partition wall 26 be collapsed and/or ruptured and to achieve this removing means in the form of a cap 44 are provided.

As can be seen, for example in Figure 2, the cap 44 has a generally circular base 42 from which a peripheral wall 46 depends. This peripheral wall 46 is provided with an internal screw thread indicated at 48. The wall part of the outer container 20 has a reduced diameter, neck portion 50 which extends upwardly from an annular shoulder 54 of the outer container. An external screw thread 52 is provided on the neck portion 50.

In the initial position of the container shown in Figure 2, the cap 44 is engaged on the neck portion 50 of the outer container 20 and on the top member of the can 10. In this condition, there is a gap between the shoulder 54 on the outer container 20 and the free outer end 56 of the depending wall 46 of the cap 44. In use, the cap 44 is screwed downwardly to close this gap.

However, such movement can only be achieved if the volume of the second chamber 24 is reduced so that the container can achieve the condition illustrated in Figure 3.

In this respect, initial movement of the cap 44 towards the base of the container will tend to collapse the partition wall increasing the pressure within the chamber 24 from the water. Continued movement, and increasing pressure will cause the partition wall 26 to rupture, releasing the water from the second chamber 24 into the first chamber 22. This process is assisted by inverting the container. Accordingly, and as will be appreciated, generation of heat by mixing of the water and quicklime will occur.

Of course, and as previously, a tamper proof band, not shown, may be provided around the neck portion 50 of the outer container 20 between the free end 56 of the depending wall 46 and the shoulder 54 to prevent movement of the cap 44, and hence operation of the self-heating can, until required. In addition, the further variations indicated above may be made to this

embodiment. Thus, for example, the screw means illustrated may be replaced by a telescopic fitting of the cap 44 onto the container.

It will be appreciated that further modifications or variations to the embodiments as described and illustrated may be made within the scope of the present application as defined in the appended claims.