U.S. patent application number 10/121838 was filed with the patent office on 2002-08-29 for self-heating of self-cooling containers.
This patent application is currently assigned to Thermotic Developments Limited. Invention is credited to Searle, Matthew J..
Application Number | 20020117163 10/121838 |
Document ID | / |
Family ID | 10862770 |
Filed Date | 2002-08-29 |
United States Patent
Application |
20020117163 |
Kind Code |
A1 |
Searle, Matthew J. |
August 29, 2002 |
Self-heating of self-cooling containers
Abstract
A self-heating container (10) has an internal cavity (22) for
its contents and an external cavity (20) for a heating mechanism,
for example, comprised of first and second chemically reactive
materials which are arranged to be mixed when heating is required.
A protective cover (52) is engaged on the can over the top end
member (14) to prevent access to a ring-pull opener (50). The
protective cover (52) has been shrunk onto the can such that it
cannot be removed normally. However, when the can and its contents
have been heated to the predetermined temperature by operation of
the heating mechanism, the protective cover (52) expands in size
relative to the can (10) and is removable. The ring-pull opener
(50) may then be opened to enable the contents to be dispensed.
After opening, the cover (52) may be reengaged on the can to
provide an insulated drinking lip which protects the consumer
against the heat of the can and provides a more pleasant surface to
drink from than the edge of the can itself.
Inventors: |
Searle, Matthew J.; (Bruton,
GB) |
Correspondence
Address: |
NIXON & VANDERHYE P.C.
8th Floor
1100 North Glebe Road
Arlington
VA
22201-4717
US
|
Assignee: |
Thermotic Developments
Limited
|
Family ID: |
10862770 |
Appl. No.: |
10/121838 |
Filed: |
April 15, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10121838 |
Apr 15, 2002 |
|
|
|
PCT/GB00/03968 |
Oct 16, 2000 |
|
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Current U.S.
Class: |
126/263.01 ;
220/201; 62/4 |
Current CPC
Class: |
F25D 2331/805 20130101;
F25D 5/02 20130101; B65D 81/3484 20130101; A47J 36/28 20130101;
F25D 31/007 20130101 |
Class at
Publication: |
126/263.01 ;
220/201; 62/4 |
International
Class: |
F25D 005/00; B65D
055/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 15, 1999 |
GB |
9924379.2 |
Claims
1. A method of protecting a self-heating or a self-cooling
container against premature opening, the container comprising a
heating or cooling mechanism for heating or cooling contents of the
container, and having opening means operable to enable access to
the container contents, wherein a protective cover is arranged on
the container so as to prevent operation of the opening means, and
wherein the method comprises the step of enabling the removal of
the protective cover only when the container and its contents have
attained a predetermined temperature.
2. A method of protecting a container as claimed in claim 1,
wherein the predetermined temperature is generally the steady state
temperature to which the container and its contents are brought a
predetermined time after the operation of the heating or cooling
mechanism.
3. A method of protecting a container as claimed in claim 1 or
claim 2, wherein the materials of the container and of the
protective cover are arranged to react differently to changes in
the temperatures to which they are subjected such that removal of
the protective cover is enabled by the reactions of the container
and of the protective cover to the predetermined temperature
attained by the container and its contents.
4. A method of protecting a container as claimed in any of claims 1
to 3, wherein the protective cover is retained in position to
prevent operation of the opening means by retaining means arranged
to change state with changes in temperature.
5. A method of protecting a container as claimed in claim 3, for a
self-heating container, wherein, upon heating, the protective cover
is arranged to expand relative to the container such that when the
container and its contents have reached the predetermined
temperature, the protective cover may be removed.
6. A method of protecting a container as claimed in claim 4, for a
self-heating container, wherein the protective cover is retained in
position to prevent operation of the opening means by retaining
means arranged to melt or soften when heated.
7. A method of protecting a container as claimed in claim 3, for a
self-cooling container, wherein, upon cooling, the protective cover
is arranged to contract less than the container to provide relative
expansion of the protective cover with respect to the container
when the container and its contents have reached the predetermined
temperature, whereby the protective cover may be removed.
8. A method of protecting a container as claimed in claim 4, for a
self-cooling container, wherein the protective cover is retained in
position to prevent operation of the opening means by retaining
means arranged to become frangible when cooled.
9. A method of protecting a container as claimed in any preceding
claim, wherein the container has a first end closed by an end
member in which the opening means is formed, and wherein the
protective cover is a removable cover arranged to engage on the
container to enclose the first end member and thereby prevent
access to the opening means.
10. A method of protecting a container as claimed in any of claims
1 to 8, wherein the container has a first end closed by an end
member in which the opening means is formed, and wherein the
protective cover is engaged over the opening means to prevent
access thereto.
11. A self-heating or a self-cooling container having a heating or
cooling mechanism for heating or cooling contents of the container,
and opening means operable to enable access to the container
contents, said container further comprising a protective cover
arranged on the container so as to prevent operation of the opening
means, the arrangement being such that the removal of the
protective cover is enabled only when the container and its
contents have attained a predetermined temperature whereby the
container is protected against premature opening.
12. A container as claimed in claim 11, wherein the materials of
the container and of the protective cover are arranged to react
differently to changes in the temperatures to which they are
subjected such that removal of the protective cover is enabled by
the reactions of the container and of the protective cover to the
predetermined temperature attained by the container and its
contents.
13. A container as claimed in claim 11 or claim 12, further
comprising retaining means to retain the protective cover in
position to prevent operation of the opening means, wherein the
retaining means are arranged to change state with changes in
temperature.
14. A self-heating container as claimed in claim 12, wherein the
protective cover is arranged, upon heating, to expand relative to
the container such that, when the container and its contents have
reached the predetermined temperature, the protective cover is
removable.
15. A self-heating container as claimed in claim 13, wherein said
retaining means are arranged to melt or soften when heated.
16. A self-cooling container as claimed in claim 12, wherein the
protective cover is arranged, upon cooling, to contract less than
the container such that, when the container and its contents have
reached the predetermined temperature, the protective cover has
expanded relative to the container and is removable therefrom.
17. A self-cooling container as claimed in claim 13, wherein said
retaining means are arranged to become frangible when cooled.
18. A container as claimed in any of claims 11 to 17, further
comprising a first end closed by an end member in which the opening
means is formed, and wherein the protective cover is a removable
cover arranged to engage on the container to enclose the first end
member and thereby prevent access to the opening means.
19. A container as claimed in any of claims 11 to 17, further
comprising a first end closed by an end member in which the opening
means is formed, the protective cover being engaged over the
opening means to prevent access thereto.
20. A self-heating or self-cooling container comprising a tubular
peripheral wall within which first and second separated cavities
extend, the first cavity receiving the contents of the container,
and the second cavity housing a heating or cooling mechanism, a
first end member closing the first cavity, and a second end member
closing the second cavity, and opening means operable to enable
access to the contents of the container formed in, or associated
with, said first end member, said container further comprising a
protective cover for protecting against premature opening of the
container, said protective cover being arranged on the container so
as to prevent operation of the opening means, the arrangement being
such that removal of the protective cover is enabled only when the
container and its contents have attained a predetermined
temperature.
21. A self-heating or self-cooling container as claimed in claim
20, wherein the container and the protective cover react
differently to changes in the temperatures to which they are
subjected such that their relative sizes alter and removal of the
protective cover is enabled when the container and it contents
attain the predetermined temperature.
22. A self-heating or self-cooling container as claimed in claim 20
or claim 21, further comprising retaining means to retain the
protective cover in position to prevent operation of the opening
means, the retaining means being arranged to change state with
changes in temperature.
23. A self-heating container as claimed in claim 21, wherein the
protective cover is arranged, when heated, to expand relative to
the container such that, when the container and its contents have
reached the predetermined temperature, the protective cover is
removable.
24. A self-heating container as claimed in claim 22, wherein the
retaining means are arranged to melt or soften when heated.
25. A self-cooling container as claimed in claim 21, wherein the
protective cover is arranged, upon cooling, to contract less than
the container such that, when the container and its contents have
reached the predetermined temperature the protective cover has
expanded relative to the container and is removable therefrom.
26. A self-cooling container as claimed in claim 22, wherein the
retaining means are arranged to become frangible when cooled.
27. A container as claimed in any of claims 20 to 26, wherein said
opening means are formed in said first end member, and the
protective cover is engaged over the opening means to prevent
access thereto.
28. A container as claimed in any of claims 20 to 26, wherein said
opening means are formed in said first end member, and the
protective cover is engaged on the container to enclose the first
end member and thereby prevent access to the opening means.
29. A container as claimed in any of claims 20 to 28, wherein said
second cavity extends within the first cavity, and the first cavity
opens at one end of the peripheral wall and the second cavity opens
at the other, opposite, end of the peripheral wall.
30. A container as claimed in any of claims 11 to 29, wherein said
protective cover is reengageable on the container and has a
drinking hole such that the contents of the container can be drunk
through the protective cover.
31. A container as claimed in claim 30, wherein said protective
cover is made of an insulating material.
32. A container as claimed in claim 30 or claim 31, wherein the
drinking hole in the protective cover is closed by a breakable
seal.
33. A container as claimed in any of claims 30 to 32, wherein the
protective cover is shaped to provide a drinking rim within which
the drinking hole is formed, and wherein a recess is provided in
the protective cover adjacent the drinking hole.
34. A container as claimed in any of claims 11 to 33, wherein the
protective cover comprises an end wall from the periphery of which
a peripheral rim depends, the peripheral rim being appropriately
shaped to engage on the peripheral wall of the container.
35. A method of protecting a self-heating or a self-cooling
container against premature opening substantially as hereinbefore
described with reference to the accompanying drawings.
36. A self-heating or a self-cooling container substantially as
hereinbefore described with reference to the accompanying drawings.
Description
[0001] The present invention relates to a self-heating or a
self-cooling container.
[0002] 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.
[0003] 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. U.S. Pat. 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
pierceable 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.
[0004] Increasingly, consumers will drink direct from a can rather
than pouring out the contents. However, self-heating or
self-cooling containers as shown, for example, in WO 96/29255 or in
PCT/GB00/01865 are very effective at heating or cooling their
contents, such that the can, particularly where it is made of
metal, will be relatively hot or cold. This can be unpleasant to
drink from and can also be hazardous in that the temperature of the
can can injure the lips.
[0005] There is also a potential danger with self-heating or
self-cooling containers. The containers described in the
International specifications referred to above are designed such
that they effectively heat the contents of the can. It is, of
course, possible for a consumer to start the heating process, for
example, and then to open the can and dispense some of the
contents. If this happens, or if the contents are dispensed before
the heating process is initiated, overheating of the can with
potentially hazardous effects can occur.
[0006] It is an object of the present invention to reduce the
problems identified above.
[0007] According to the present invention there is provided a
method of protecting a self-heating or a self-cooling container
against premature opening, the container comprising a heating or
cooling mechanism for heating or cooling contents of the container,
and having opening means operable to enable access to the container
contents, wherein a protective cover is arranged on the container
so as to prevent operation of the opening means, and wherein the
method comprises the step of enabling the removal of the protective
cover only when the container and its contents have attained a
predetermined temperature.
[0008] A method of an embodiment of the invention prevents
premature opening of the container in that the protective cover
cannot be removed before the heating or cooling mechanism has been
operated, or before the container and its contents have attained
the predetermined temperature. This obviates the problem of
overheating arising because some or all of the contents have been
dispensed before or during the heating process.
[0009] To make self-heating or self-cooling containers operate most
effectively, it is generally necessary that the consumer wait until
the heating or cooling mechanism has performed its function.
Preferably, therefore, the predetermined temperature is chosen to
be the steady state temperature to which the container and its
contents are brought a predetermined time after the operation of
the heating or cooling mechanism.
[0010] In one embodiment, the materials of the container and of the
protective cover are arranged to react differently to changes in
the temperatures to which they are subjected such that removal of
the protective cover is enabled by the reactions of the container
and of the protective cover to the predetermined temperature
attained by the container and its contents.
[0011] For example, the container and the protective cover are
arranged such that their relative sizes alter when they are
subjected to changes in temperature. This change in relative sizes
is used to enable removal of the protective cover. Thus, where the
protective cover is received within an area of the container,
expansion of that container area relative to the cover will enable
release of the protective cover. In an alternative construction,
where the protective cover is arranged to engage around an area of
the container, expansion of the cover will enable its release.
[0012] Additionally, and/or alternatively the protective cover is
retained in position to prevent operation of the opening means by
retaining means arranged to change state with changes in
temperature.
[0013] For example, the retaining means may be a structural member
joining the protective cover to the container and arranged to
degrade or change state in some manner which enables at least part
of the structural member to be broken as its temperature is
changed. Where the container is heated, the structural member may
melt or soften, and where the container is cooled, the structural
member may become frangible.
[0014] In an embodiment of a self-heating container, the protective
cover is arranged to expand upon heating relative to the container
such that when the container and its contents have reached the
predetermined temperature, the protective cover may be removed. For
a self-cooling container, the protective cover may also be released
by arranging for it to expand relative to the container. In this
case, the protective cover would be arranged to contract less than
the container upon cooling, for example.
[0015] Additionally and/or alternatively, the retaining means may
be in the form of a glue, adhesive or other bonding material, for
example, holding the protective cover on the container and arranged
to degrade upon change of temperature whereby the hold or bond is
released.
[0016] The present invention also extends to a self-heating or a
self-cooling container having a heating or cooling mechanism for
heating or cooling contents of the container, and opening means
operable to enable access to the container contents, said container
further comprising a protective cover arranged on the container so
as to prevent operation of the opening means, the arrangement being
such that the removal of the protective cover is enabled only when
the container and its contents have attained a predetermined
temperature whereby the container is protected against premature
opening.
[0017] According to a further aspect of the present invention,
there is provided a self-heating or self-cooling container
comprising a tubular peripheral wall within which first and second
separated cavities extend, the first cavity receiving the contents
of the container, and the second cavity housing a heating or
cooling mechanism, a first end member closing the first cavity, and
a second end member closing the second cavity, and opening means
operable to enable access to the contents of the container formed
in, or associated with, said first end member, said container
further comprising a protective cover for protecting against
premature opening of the container, said protective cover being
arranged on the container so as to prevent operation of the opening
means, the arrangement being such that removal of the protective
cover is enabled only when the container and its contents have
attained a predetermined temperature.
[0018] With a self-heating or self-cooling container of an
embodiment of the invention, the protective cover is not removable
until the container and its contents attain the predetermined
temperature. As the protective cover prevents operation of the
opening means until it has been removed, dispensing of the contents
of the container before the operation of the heating or cooling
mechanism, or during that process, is prevented.
[0019] Preferably, the materials of the container and of the
protective cover are arranged to react differently to changes in
the temperatures to which they are subjected such that removal of
the protective cover is enabled by the reactions of the container
and of the protective cover to the predetermined temperature
attained by the container and its contents.
[0020] For example, the container and the protective cover are
arranged such that their relative sizes alter when they are
subjected to changes in temperature. This change in relative sizes
is used to enable removal of the protective cover. Thus, where the
protective cover is received within an area of the container,
expansion of that container area relative to the cover will enable
release of the protective cover. In an alternative construction,
where the protective cover is arranged to engage around an area of
the container, expansion of the cover will enable its release.
[0021] Additionally, and/or alternatively the protective cover is
retained in position to prevent operation of the opening means by
retaining means arranged to change state with changes in
temperature.
[0022] For example, the retaining means may be a structural member
joining the protective cover to the container and arranged to
degrade or change state in some manner which enables at least part
of the structural member to be broken as its temperature is
changed. Where the container is heated, the structural member may
melt or soften, and where the container is cooled, the structural
member may become frangible.
[0023] In an embodiment of a self-heating container, the protective
cover is arranged to expand upon heating relative to the container
such that when the container and its contents have reached the
predetermined temperature, the protective cover may be removed. For
a self-cooling container, the protective cover may also be released
by arranging for it to expand relative to the container. In this
case, the protective cover would be arranged to contract less than
the container upon cooling, for example.
[0024] Additionally and/or alternatively, the retaining means may
be in the form of a glue, adhesive or other bonding material, for
example, holding the protective cover on the container and arranged
to degrade upon change of temperature whereby the hold or bond is
released.
[0025] A self-heating or a self-cooling container of an embodiment
of the invention may incorporate any heating or cooling mechanism.
Various arrangements are described, for example, in WO 96/29255. In
a preferred embodiment, the heating or cooling mechanism comprises
a first chemical reactant and a second chemical reactant received
within the second cavity of the container. The chemical reactants
are kept apart until heating or cooling of the contents of the
container is required.
[0026] In one embodiment of a container of the invention, said
opening means are formed in said first end member, and the
protective cover is engaged over the opening means to prevent
access thereto.
[0027] For example, the protective cover may be attached to the
first end member to extend over the opening means and deny access
thereto. Alternatively, the protective cover may be a retaining
device arranged to engage the opening means in a manner to prevent
its operation. Where, for example, the opening means is a
substantially traditional ring-pull, a retaining device may be a
staple which is threaded through the user part of the ring-pull to
prevent pivoting thereof relative to the first end member.
[0028] In an alternative embodiment, said opening means are formed
in said first end member, and the protective cover is engaged on
the container to enclose the first end member and thereby prevent
access to the opening means.
[0029] Where the protective cover encloses the first end member, it
is preferably reengageable on the container and provided with a
drinking hole such that the contents of the container can be drunk
through the protective cover. For example, the reengageable
protective cover may be made of an insulating material such that
the protective cover can act to protect the consumer from the
temperature of the container. The cover also provides a more
pleasant surface to drink from than the edge of a can, for
example.
[0030] The protective cover may be of any appropriate shape. In one
embodiment, the cover may be of the type increasingly supplied on
beverage containers at takeaway outlets, for example, as described
in U.S. Pat. No. 4,589,569.
[0031] For hygienic reasons, the drinking hole in the protective
cover may be closed by a breakable seal. The seal will be opened to
reveal the drinking hole when the protective cover is reengaged on
the container.
[0032] In an embodiment, the protective cover is shaped to provide
a drinking rim within which the drinking hole is formed.
Furthermore, a recess is provided in the protective cover adjacent
the drinking hole.
[0033] In WO 96/29255, the second cavity of the container, which
supports the heating or cooling mechanism, extends within the first
cavity in which the container contents are received. It will be
appreciated that the invention is not limited to any particular
form or structure of self-heating or self-cooling container and is
applicable, for example, to a container in which the second cavity
surrounds the first cavity which houses the contents.
Alternatively, the first and second cavities may extend side by
side.
[0034] Although it is generally preferred that the end member for
the first cavity is at the opposite end of the peripheral wall to
that for the second cavity, this is not essential. The first and
second end members may, if required, both be arranged at the same
end of the peripheral wall.
[0035] A self-heating or self-cooling container of the invention
may be used to contain any contents which may require cooling or
heating. Thus, not only is the container suitable for beverages, it
may alternatively be used for foodstuffs or medicines.
[0036] Embodiments of the present invention will hereinafter be
described, by way of example, with reference to the accompanying
drawings, in which:
[0037] FIG. 1 shows, partly in section, a self-heating or a
self-cooling container illustrating an external reactant cavity
thereof and a closure for the cavity,
[0038] FIG. 2 shows a section through a protective cover to be
provided on a top end member of a container of FIG. 1,
[0039] FIG. 3 shows a top plan view of the cover of FIG. 2,
[0040] FIG. 4 shows a plan view of a top end member of a container
as in FIG. 1, and
[0041] FIG. 5 shows schematically the use of a protective cover
after opening of a container to aid drinking from the
container.
[0042] 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. As
described, the container has an external cavity in which heating or
cooling means is received, the external cavity being closed by a
closure. The invention is not limited to such an arrangement and
can be used with other constructions of self-heating or
self-cooling mechanisms.
[0043] The container shown in FIG. 1 may be a metal or plastics
material beverage container 10 having a substantially cylindrical
peripheral wall 12 which is closed at one end by a top end member
14. As described in WO 96/29255, a base end member 16 of the
container is indented to define an elongate external cavity 20
which extends within the peripheral wall 12. It will is be
appreciated that the peripheral wall 12 and the top and base
members 14 and 16 of the container together define an internal
cavity 22 in which the beverage is received. It will be seen that
the external cavity 20 extends within this internal cavity 22, but
is separated therefrom by the wall of the base member 16.
[0044] The container 10 illustrated in FIG. 1 is configured to have
the same external dimensions and shape as a conventional beverage
can. This means that the can can be filled and treated on existing
filling lines. The can 10 may be made of aluminium, as is
conventional, and have a ring-pull opening means 50 (FIG. 4) in the
top end member 14 as is also usual.
[0045] The external cavity 20 of the can 10 is to be utilised to
contain a heating mechanism. In the embodiment shown, the heating
mechanism comprises a first reactant material, which, for example,
may be quicklime (calcium oxide). The cavity 20, incorporating the
quicklime, is closed by a closure 30. For the self-heating can this
closure 30 may contain water.
[0046] When it is required to heat the contents of the can 10, the
can is inverted and stood on its top member 14 so that the base of
the closure 30 is accessible. A button on the bottom of the base is
depressed whereby a water chamber 42 within the closure 30 is
opened so that water from the closure 30 flows over the quicklime
in the reactant cavity 20 to cause the exothermic reaction. The
user retains the can in its inverted position until the contents of
the can have been heated to a satisfactory temperature.
[0047] The size of the external cavity 20 and the amount of
quicklime charged therein are chosen to ensure that the contents of
the container can be heated within an appropriate time period of,
for example, two to five minutes. However, if the contents of the
container were dispensed before or during operation of the heating
mechanism there would be no contents to absorb the heat generated
and excessive heating of the can would result. The invention
proposes that such premature opening of the can be prevented and a
protective cover to be fixed to the can to enclose the top end
member 14 is shown in FIGS. 2 and 3.
[0048] As indicated above, the top end member 14 of the can 10 may
be provided with opening means in the form of a ring-pull
arrangement indicated generally at 50. The protective cover 52
shown in FIGS. 2 and 3 is attached to the can 10 such that it
extends over the ring-pull 50 and fully encloses the top end member
14. Whilst the protective cover 52, therefore, is fixed onto the
can 10, access to the ring-pull 50 is not possible.
[0049] The protective cover 52, as illustrated in FIGS. 2 and 3,
has a top end member 54 from whose periphery a peripheral rim 56
depends. The top end member 54 is also configured to define an
annular rim 58 in which a drinking hole 60 is defined. A recess 62
is provided adjacent the drinking hole 60.
[0050] The protective cover 52 may be made, for example, of a
material which expands upon heating at a greater rate than the
material of the can 10. For example, the protective cover may be
made of an appropriate thermoplastics material. Accordingly, after
the can 10 has been filled and sealed, the protective cover 52 may
be applied thereto, whilst hot, to enclose the top end member 14.
The cover 52 is then allowed to cool and shrink to contract onto
the can. Additionally, and/or alternatively, the protective cover
may be welded, bonded or glued in place by a heat meltable or heat
softenable substance.
[0051] The self-heating can 10 with the protective cover 52 applied
cannot be opened because the ring-pull 50 is not accessible.
Opening is only possible by removal of the protective cover and
this, in its turn, requires that the contents be properly heated by
operation of the heating mechanism. When the container and its
contents have been heated such that they attain the predetermined
temperature, the cover 52 expands and/or the glue or other bonding
material melts or softens to enable removal of the cover. The
ring-pull 50 may then be operated to open the can whereby the
contents can be dispensed.
[0052] The protective cover can be disposed of once it has been
removed. However, in the embodiment illustrated, the protective
cover 52 has been designed to make drinking from the can safer and
more pleasant. Accordingly the user may push the protective cover
52 to reengage it onto the can 10. The user can then drink the
contents of the can through the drinking hole 60.
[0053] If required, the drinking hole 60 may be provided with a
breakable seal or cover (not shown), which can be broken to reveal
the drinking hole when the contents are to be drunk from the can.
This mechanism keeps contaminants from entering through the
drinking hole into the cover whilst this is fixed on the can
initially.
[0054] FIG. 5 shows the reengagement of a protective cover, as 52,
onto a can 10 and shows the use of the cover 52 when drinking from
the can 10. In the embodiment of the cover 52 shown in FIG. 5, a
further depending rim 64 extends the first depending rim 56. Such
an additional rim 64 could be used, if required, as the means to
retain the protective cover 52 on the can either through
contraction and expansion and/or by being bonded or otherwise
joined to the can.
[0055] In the embodiments described so far, it has been assumed
that the can 10 is a substantially conventional can with a
ring-pull. Of course, other opening and closing means might be
utilised. For example, the top end member, as 14, may be engaged on
the container by screw threads or other means at its periphery. In
that case, the protective cover may be in the form of an annular
rim engaged around the peripheral edge of the container 10. This
annular rim would be removable, as described above, in response to
heating of the container to enable opening of the container. The
annular rim would be reengageable to provide an insulating rim for
drinking from the container as described above.
[0056] It will be appreciated that other variations or
modifications to the embodiments as described and illustrated may
be made within the scope of the appended claims.
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