U.S. patent application number 10/756954 was filed with the patent office on 2005-01-06 for self-contained temperature-change container assemblies.
Invention is credited to Rizzi, Massimillano, Schreft, H. Joshua.
Application Number | 20050000508 10/756954 |
Document ID | / |
Family ID | 34119197 |
Filed Date | 2005-01-06 |
United States Patent
Application |
20050000508 |
Kind Code |
A1 |
Schreft, H. Joshua ; et
al. |
January 6, 2005 |
Self-contained temperature-change container assemblies
Abstract
A container assembly heats or cools a product inside an inner
container. An outer jacket at least partially surrounds the inner
container, with a first internal volume and a second internal
volume in the space between the outer jacket and the inner
container. A first temperature-change reagent is contained inside
the first internal volume, and a second temperature-change reagent
is held in the second internal volume, with a reagent separator
between the two. Several penetrators are disposed to penetrate the
reagent separator to produce openings through the separator and
through which the two reagents can mix. Steel wool inside the first
internal volume acts as a steam condenser. The outer jacket
includes a jacket top ring secured around an upper surface of a
standard can, a jacket body secured to the jacket top, and a
flexible jacket bottom that carries several spikes molded onto the
jacket bottom.
Inventors: |
Schreft, H. Joshua; (Mercer
Island, WA) ; Rizzi, Massimillano; (Los Angeles,
CA) |
Correspondence
Address: |
HOGAN & HARTSON L.L.P.
500 S. GRAND AVENUE
SUITE 1900
LOS ANGELES
CA
90071-2611
US
|
Family ID: |
34119197 |
Appl. No.: |
10/756954 |
Filed: |
January 13, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10756954 |
Jan 13, 2004 |
|
|
|
10613322 |
Jul 3, 2003 |
|
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|
Current U.S.
Class: |
126/263.09 ;
206/219 |
Current CPC
Class: |
A47J 27/002 20130101;
A47J 27/022 20130101; F25D 5/02 20130101; F24V 30/00 20180501; A47J
36/28 20130101; F25D 2400/36 20130101 |
Class at
Publication: |
126/263.09 ;
206/219 |
International
Class: |
F24J 001/00 |
Claims
What is claimed is:
1. A self-contained, temperature-change container assembly
comprising: an inner container; an outer jacket at least partially
surrounding the inner container, wherein a first internal volume
and a second internal volume are defined between the inner
container and the outer jacket; a first temperature-change reagent
inside the first internal volume; a second temperature-change
reagent inside the second internal volume; a reagent separator
between the first internal volume and the second internal volume; a
movable member situated opposite the reagent separator, wherein
movement of the movable member opens the reagent separator to allow
mixing of the first and second temperature-change reagents in a
reagent mixing region inside the outer jacket; structure defining
an outlet in the outer jacket, wherein the outlet is configured to
release gas from the assembly; and an outlet barrier that
ordinarily obstructs the outlet, but which is configured to open
and thereby to release gas the assembly through the outlet in
response to positive pressure inside the outer jacket.
2. The assembly of claim 1, and further comprising a filter
material between the outlet and the reagent mixing region, wherein
the outlet is configured to vent gas from the assembly through the
filter material.
3. The assembly of claim 2, wherein the filter material is
cotton.
4. The assembly of claim 2, wherein the filter material is
felt.
5. A self-contained, temperature-change container assembly
comprising: an inner container; an outer jacket at least partially
surrounding the inner container, wherein a first internal volume
and a second internal volume are defined between the inner
container and the outer jacket; a first temperature-change reagent
inside the first internal volume; a second temperature-change
reagent inside the second internal volume; a reagent separator
between the first internal volume and the second internal volume; a
movable member situated opposite the reagent separator, wherein
movement of the movable member opens the reagent separator to allow
mixing of the first and second temperature-change reagents in a
reagent mixing region inside the outer jacket; structure defining
an outlet in the outer jacket, wherein the outlet is configured to
release gas from the assembly; and a filter material between the
outlet and the reagent mixing region, wherein the outlet is
configured to vent gas from the assembly through the filter
material.
6. The assembly of claim 5, wherein the filter material is
cotton.
7. The assembly of claim 5, wherein the filter material is
felt.
8. A self-contained, temperature-change container assembly
comprising: an inner container; an outer jacket at least partially
surrounding the inner container, wherein a first internal volume
and a second internal volume are defined between the inner
container and the outer jacket; a first temperature-change reagent
inside the first internal volume; a second temperature-change
reagent inside the second internal volume; a reagent separator
between the first internal volume and the second internal volume;
and a movable member situated opposite the reagent separator,
wherein movement of the movable member opens the reagent separator
to allow mixing of the first and second temperature-change reagents
in a reagent mixing region inside the outer jacket; wherein the
first-temperature change reagent includes a first portion that is
at least partially covered by an inert material that inhibits a
chemical reaction between the first and second temperature change
reagents, and a second portion that is not at least partially
covered by the inert material.
9. The assembly of claim 8, wherein the first temperature-change
reagent includes calcium oxide, the second temperature-change
reagent includes liquid water, and the inert material includes
mineral oil.
10. The assembly of claim 8, wherein the weight of the first
portion of the first temperature-change reagent is between 15% and
90% of the combined weight of the first temperature-change reagent,
each said weight measured exclusive of the weight of the inert
material.
11. The assembly of claim 8, wherein the weight of inert material
used with the first portion of the first temperature-change reagent
is between 1% and 20% of the total weight of the first and second
portions of the first temperature-change material measured
exclusive of the weight of the inert material.
12. A self-contained, temperature-change container assembly
comprising: an inner container; an outer jacket at least partially
surrounding the inner container, wherein a first internal volume
and a second internal volume are defined between the inner
container and the outer jacket; a first temperature-change reagent
inside the first internal volume; a second temperature-change
reagent inside the second internal volume; a reagent separator
between the first internal volume and the second internal volume; a
movable member situated opposite the reagent separator; wherein
movement of the movable member opens the reagent separator to allow
mixing of the first and second temperature-change reagents in a
reagent mixing region inside the outer jacket; and a heat insulator
inside the outer jacket between the outer jacket and the reagent
mixing region, wherein the heat insulator includes at least one
material selected from the group consisting of (a) a metallic foil,
and (b) a sprayable insulator applied to the interior of the outer
jacket.
13. The assembly of claim 12, wherein the heat insulator includes
an aluminum foil.
14. The assembly of claim 12, wherein heat insulator includes a
sprayable foam material.
15. The assembly of claim 12, wherein the heat insulator includes a
sprayable ceramic material.
16. A self-contained, temperature-change container assembly
comprising: an inner container; an outer jacket at least partially
surrounding the inner container, wherein a first internal volume
and a second internal volume are defined between the inner
container and the outer jacket; a first temperature-change reagent
inside the first internal volume; a second temperature-change
reagent inside the second internal volume; a reagent separator
between the first internal volume and the second internal volume;
and a movable member situated opposite the reagent separator;
wherein movement of the movable member opens the reagent separator
to allow mixing of the first and second temperature-change reagents
in a reagent mixing region inside the outer jacket; and wherein the
outer jacket includes an outer wall structure that inclines outward
in an upward direction.
17. A self-contained, temperature-change container assembly
comprising: an inner container; an outer jacket at least partially
surrounding the inner container, wherein a first internal volume
and a second internal volume are defined between the inner
container and the outer jacket; a first temperature-change reagent
inside the first internal volume; a second temperature-change
reagent inside the second internal volume; a reagent separator
between the first internal volume and the second internal volume; a
movable member situated opposite the reagent separator; and wherein
movement of the movable member opens the reagent separator to allow
mixing of the first and second temperature-change reagents in a
reagent mixing region inside the outer jacket; and wherein the
reagent separator is configured to maintain close contact between
the first temperature-change reagent and both a side surface and a
bottom surface of the inner container after the reagent separator
has been opened to allow mixing of the first and second
temperature-change reagents by supporting the first
temperature-change reagent on the opened reagent separator.
18. The assembly of claim 19, wherein the movement of the movable
member to open the reagent separator forms multiple openings
through the reagent separator, each of said openings being smaller
in size than an average grain size of the first temperature-change
reagent.
19. A self-contained, temperature-change container assembly
comprising: an inner container; an outer jacket at least partially
surrounding the inner container, wherein a first internal volume
and a second internal volume are defined between the inner
container and the outer jacket; a first temperature-change reagent
inside the first internal volume; a second temperature-change
reagent inside the second internal volume; a reagent separator
between the first internal volume and the second internal volume;
and a movable member situated opposite the reagent separator,
wherein movement of the movable member opens the reagent separator
to allow mixing of the first and second temperature-change reagents
in a reagent mixing region inside the outer jacket; wherein the
outer jacket includes a top ring snapped in place over a top rim of
the inner container.
20. The assembly of claim 19, and further comprising a jacket body
member and a jacket bottom member that carriers the movable member,
wherein the jacket body member is joined to the top ring and the
jacket bottom member is joined to the jacket body member to form
the outer jacket.
21. The assembly of claim 19, and further comprising a jacket body
member that carries the movable member, wherein the jacket body
member is joined to the top ring to form the outer jacket.
22. A self-contained, temperature-change container assembly
comprising: an inner container; an outer jacket at least partially
surrounding the inner container, wherein a first internal volume
and a second internal volume are defined between the inner
container and the outer jacket; a first temperature-change reagent
inside the first internal volume; a second temperature-change
reagent inside the second internal volume; a reagent separator
between the first internal volume and the second internal volume;
and a movable member situated opposite the reagent separator,
wherein movement of the movable member opens the reagent separator
to allow mixing of the first and second temperature-change reagents
in a reagent mixing region inside the outer jacket; wherein the
movable member comprises a pushbutton movable to bear against a
structure carrying at least one penetrator and thereby to urge that
penetrator through the reagent separator to open the reagent
separator.
23. The assembly of claim 22, wherein the pushbutton comprises a
material of greater flexibility than a material of the outer jacket
that carries the pushbutton.
24. A self-contained, temperature-change container assembly
comprising: an inner container; a removable and replaceable closure
member operable to close an opening in the inner container; wherein
the inner container is configured so that a user of the assembly
can place a substance inside the inner container through the inner
container's opening, and thereafter close the opening by replacing
the closure member; an outer jacket at least partially surrounding
the inner container, wherein a first internal volume and a second
internal volume are defined between the inner container and the
outer jacket; a first temperature-change reagent inside the first
internal volume; a second temperature-change reagent inside the
second internal volume; a reagent separator between the first
internal volume and the second internal volume; and a movable
member situated opposite the reagent separator, wherein movement of
the movable member opens the reagent separator to allow mixing of
the first and second temperature-change reagents in a reagent
mixing region inside the outer jacket.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of co-pending
U.S. patent application Ser. No. 10/613,322, which was filed on
Jul. 3, 2003.
BACKGROUND OF THE INVENTION
[0002] The invention relates generally to containers and apparatus
for heating or cooling materials held inside containers. More
particularly, the invention provides a can or a similar container
for holding a food product or another material, and a
self-contained assembly for heating or cooling the container and
the material within it to a temperature above or below the
material's storage temperature. In a preferred embodiment, a
standard metal can holds a quantity of a food or beverage. A jacket
or housing surrounds the can, with reagents for an exothermic or
endothermic temperature-change reaction inside the jacket in
proximity to the can. Activating the device initiates the reaction
to heat or cool the can and its contents.
[0003] Devices of this general type are known in the art. Some such
devices include a food container in proximity to a reagent storage
vessel. The reagent storage vessel holds a quantity of calcium
oxide and a quantity of water, with a barrier between them to keep
the two reagents separated. The devices include some mechanism for
breaching the barrier to allow the calcium oxide and water to mix.
When this occurs, the resulting exothermic reaction generates heat
that is transferred into the food container to raise the
temperature of a food product inside the container.
[0004] The prior art devices suffer from various deficiencies,
though. Some of the devices are prone to leak either steam or
heated reactants from the reagent mixture. These devices can be
hazardous in use. Concern over the possible injuries to users has
severely hindered the acceptability of these devices in the
marketplace. Other devices do not adequately control the rate of
the reaction after its initiation. The reaction may proceed either
too fast or too slow, and too much or too little heat may be
transferred to the food. Other devices are overly complex, and
difficult, expensive, or time-consuming to manufacture, assemble,
use and dispose of. For these reasons and others, there has never
been an acceptable mass-market, self-heating product until now.
[0005] A need exists, therefore, for self-contained
temperature-change container assemblies that are improved in
comparison with those of the prior art. Such an assembly should be
safe and reliable in use, and easy and inexpensive to manufacture.
Container assemblies of this type, and methods for manufacturing in
them, are described below in this document.
SUMMARY OF THE INVENTION
[0006] The invention is embodied in a self-contained,
temperature-change container assembly operable to heat or cool a
product packaged inside an inner container inside the assembly. The
product may be a food or beverage, or it may be another type of
product.
[0007] A preferred embodiment of the assembly includes an outer
jacket that at least partially surrounds the inner container, with
a first internal volume and a second internal volume in the space
between the outer jacket and the inner container. A first
temperature-change reagent is contained inside the first internal
volume, and a second temperature-change reagent is held in the
second internal volume, with a reagent separator between the
two.
[0008] The preferred embodiment includes a movable member with
several penetrators situated to penetrate the reagent separator to
produce openings through the separator and through which the two
reagents can mix. Mixing the reagents initiates a chemical
reaction--exothermic or endothermic--in order to heat or cool the
inner container and a product contained within it.
[0009] In the preferred embodiment, the first temperature-change
reagent is calcium oxide and the second temperature-change reagent
is liquid water. Mixing the two results in an exothermic reaction
that generates heat to raise the temperature of the product inside
the container.
[0010] In a particularly preferred embodiment, steel wool is
provided inside the first internal volume. The steel wool, which is
an efficient thermal conductor with a large surface area, acts as a
steam condenser to control the formation of steam generated by the
reaction.
[0011] The outer jacket can comprise a jacket top ring secured in
place around an upper surface of a standard can, a jacket body
secured to the jacket top, and a flexible jacket bottom that acts
as a movable member and which carries several penetrators in the
form of spikes molded onto the jacket bottom.
[0012] The assembly can be manufactured by fixing a jacket top ring
around a sealed inner container, fixing a jacket body onto the
jacket top ring, filling first and second reagents inside the
jacket body with a reagent separator between them, and then
installing a flexible jacket bottom onto the jacket body with
penetrators or spikes provided opposite the reagent separator.
[0013] Preferred embodiments will use standard size cans so that a
food or beverage manufacturer or canner may designate some units of
its output for sale to consumers as usual, and other units for
inclusion in temperature-change container assemblies according to
the invention, with minimal, if any, retooling or manufacturing
changes being required of the food manufacturer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of a self-contained
temperature-change container assembly that embodies the
invention.
[0015] FIG. 2 is a top view of the container assembly of FIG.
1.
[0016] FIG. 3 is a side section view of the container assembly of
FIGS. 1 and 2.
[0017] FIG. 4 is a schematic diagram illustrating the manufacture
of temperature-change container assemblies in combination with the
production of conventional packaged products.
[0018] FIG. 5 illustrates a safety feature useable with assemblies
of the type described in this document.
[0019] FIG. 5A is an enlarged view illustrating the safety feature
of FIG. 5.
[0020] FIG. 6 is an enlarged view of another embodiment of a safety
feature similar to the one of FIGS. 5 and 5A.
[0021] FIG. 7 depicts the attachment of an annular jacket top ring
to a container in the manufacturing of the container assembly of
FIGS. 1-3.
[0022] FIG. 8 illustrates the assembly of a jacket body around the
jacket top ring of FIG. 7.
[0023] FIG. 9 shows the filling of a steam condenser and a first
reagent between the jacket body and the container of FIGS. 7 and
8.
[0024] FIG. 10 illustrates the installation of a reagent separator
into the jacket body of FIGS. 7-9.
[0025] FIG. 11 depicts the placement of a second reagent into the
jacket body of FIGS. 7-9.
[0026] FIG. 12 illustrates the installation of a jacket bottom onto
the jacket body of FIGS. 7-11.
[0027] FIG. 13 is a plan view showing the arrangement of
penetrating spikes on the jacket bottom of FIG. 12.
[0028] FIG. 14 is a side view showing the arrangement of the
penetrating spikes of FIG. 13.
[0029] FIG. 15 illustrates a first layered configuration for the
outer wall of a container assembly that embodies the invention.
[0030] FIG. 16 shows a second layered configuration for the outer
wall of a container assembly that embodies the invention.
[0031] FIG. 17 depicts a third layered configuration for the outer
wall of a container assembly that embodies the invention.
[0032] FIG. 18 shows a jacket bottom member that forms a part of an
alternative preferred embodiment of the invention.
[0033] FIG. 19 shows a liquid reagent filled into the jacket bottom
member of FIG. 18.
[0034] FIG. 20 depicts a membrane applied to the jacket bottom
member of FIG. 18 over the liquid reagent shown in FIG. 19.
[0035] FIG. 21 illustrates the installation of a thin-profile
jacket top ring around the top of an inner container.
[0036] FIG. 22 shows the installation of a jacket body member to
the jacket top ring of FIG. 21.
[0037] FIG. 23 depicts the installation of a thermal insulator
inside the jacket body member of FIG. 22.
[0038] FIG. 24 illustrates the placement of a steam condenser
inside the jacket body member shown in FIGS. 22 and 23.
[0039] FIG. 25 illustrates a second reagent filled inside the
jacket body member of FIGS. 22-24.
[0040] FIG. 26 depicts the placement of a can support inside the
jacket body member of FIGS. 22-25.
[0041] FIG. 27 shows the installation of the subassembly of FIGS.
18-20 to the subassembly of FIGS. 21-26 to provide a self-contained
assembly embodying the invention.
[0042] FIG. 28 depicts an alternative construction in which a
jacket body member and jacket top ring are formed integral with one
another as a single piece.
[0043] FIG. 29 is an enlarged detail view showing a region of top
ring of FIG. 28.
[0044] FIG. 30 is a side section view of an alternative activation
assembly for use with a self-contained temperature-change assembly
according to the invention.
[0045] FIG. 31 is a side section view of a fixture and a
thin-walled plastic bag used in an alternative embodiment of the
invention.
[0046] FIG. 32 is a side section view showing a steam condenser
placed inside the thin-walled plastic bag of FIG. 31.
[0047] FIG. 33 is a side section view showing a first reagent filed
into the thin-walled plastic bag over the steam condenser shown in
FIG. 32.
[0048] FIG. 34 is a side section view illustrating a step of vacuum
sealing the thin-walled plastic bag of FIG. 33, with the first
reagent and the steam condenser sealed inside.
[0049] FIG. 35 shows a reagent subassembly constructed according to
the steps illustrated in FIGS. 31-34.
[0050] FIG. 36 shown the reagent subassembly of FIG. 35 placed
inside an outer jacket subassembly.
[0051] FIG. 37 illustrates the installation of an activation
subassembly onto the outer jacket subassembly of FIG. 36.
[0052] FIG. 38 shows a plastic bag placed inside a fixture during
the assembly of an alternative embodiment of the invention.
[0053] FIG. 39 shows the filling of a solid first reagent inside
the plastic bag of FIG. 38.
[0054] FIG. 40 shows a reagent subassembly created according to the
steps illustrated in FIGS. 38 and 39.
[0055] FIG. 41 illustrates an outer jacket subassembly with a steam
condenser filled inside it.
[0056] FIG. 42 shows the reagent subassembly of FIG. 40 installed
in the outer jacket subassembly of FIG. 41.
[0057] FIG. 43 illustrates the installation of an activation
subassembly onto the outer jacket subassembly of FIG. 42 to
complete an alternative embodiment of the invention.
[0058] FIG. 44 is a side section view illustrating an embodiment of
the invention including a relatively broad, shallow inner
container.
[0059] FIG. 45 is a side section view illustrating another
embodiment of the invention that features flared walls in a
bowl-like configuration.
[0060] FIG. 46 shows an embodiment of the invention that includes a
three-part outer jacket with two welds.
[0061] FIG. 47 illustrates another embodiment of the invention,
with a two-part jacket and a single weld.
[0062] FIG. 48 illustrates an alternative activation mechanism for
use with assemblies of the type described in this document.
[0063] FIG. 49 illustrates another embodiment, in which a user of
the assembly can place a product in the assembly's inner container
prior to activating the assembly to heat the product.
[0064] FIG. 50 illustrates an embodiment generally similar to that
shown in FIG. 49, with an inner wall insulator applied to the inner
wall of the assembly's inner container.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0065] An exemplary embodiment of the invention is a self-contained
temperature-change container assembly that is assembled around a
standard food can or a similar container that holds a food product
or another item that will be heated or cooled inside the
container.
[0066] FIG. 1 is a perspective view illustrating a container
assembly 3 embodying the invention. The container assembly is
assembled around an inner container 5 in this embodiment, a
cylindrical metal can that holds a quantity of a food or
beverage.
[0067] The inner container 5 is partially enclosed inside an outer
jacket 8, with the top 10 of the inner container exposed. A user
can remove or open the can's top using a pull-tab opener 12, a
mechanical can opener (not shown), or other conventional means.
[0068] A visual indicator 15 is provided on the top 10 of the can 5
or elsewhere in a suitable location. This indicator's color or
appearance changes to signal that the can's top 10 (and by
implication the food or beverage inside) has reached a desired
predetermined temperature, and that the can's contents are thus
ready to eat or drink. Before the assembly is activated, the visual
indicator serves as a guard against tampering and a confirmation
that the container assembly 3 remains undisturbed and ready for
use.
[0069] A disposable utensil 17--which might be a drinking straw, a
one-piece or two-piece plastic fork or spoon, or a combination
spoon/fork (a "spork")--can be attached by an adhesive or other
similar means to the outer wall 20 of the jacket 8. This utensil
can be packaged for security and cleanliness inside a plastic or
cellophane wrapper. A napkin or a moist disposable wipe (not shown)
might be provided as well. The entire assembly can be
shrink-wrapped or made to incorporate a tamper-evident plastic
lid.
[0070] The top 10 of the inner container 5 can be entirely
removable from the assembly, as is usually the case with a canned
soup or similar products. Means can also be provided for providing
a small opening in the top so that the contents of the container
can be sipped or poured conveniently and controllably without
spilling.
[0071] FIG. 2 is a top view of the container assembly 3 illustrated
in FIG. 1. The visual indicator 15 is an adhesive label pressed
onto the top 10 of the inner container 5. The label is printed with
a temperature sensitive ink that changes color (or otherwise
provides a change in appearance) at a given predetermined
temperature. When the container and its contents are heated to this
temperature, the ink changes color to show the user that the
contents of the can are ready for use. The color change is one time
only--the ink changes when the predetermined temperature is
reached, but does not change back to its original color when the
can cools back below its predetermined transition temperature. When
the user looks at the indicator and sees it in its original color
or appearance, the user can be confident that the assembly 3 has
not been activated--whether by accident or intentional
tampering--and that the assembly thus remains ready for use. When
the user activates the assembly, the user can watch the indicator
until it changes color, at which time the user will know that the
food or beverage is hot and ready for use.
[0072] Other indicators may be used in place of the color-change
label described here in connection with a preferred embodiment. An
alternative visual indicator might use a heat-sensitive ink that
would become visible (or change from visible to invisible) at the
predetermined temperature. Still other indicators might change
their shape or some other condition to indicate to the products
user that the product had been activated at some time in the past
or that the product is now ready for use.
[0073] FIG. 3 is a side section view showing internal details of
the container assembly 3. The food, drink, or other contents 23 are
held inside the sealed inner container 5. The inner container can
be a custom container or a conventional standard-sized can. The
food, drink, or other contents can, if desired, be placed inside
the can as usual at a canning factory and delivered to another
location for assembly of the other elements around the can, or the
food can be packaged and the entire assembly assembled at one
location. Preferred embodiments use standard cans, which is
advantageous because it allows for a great variety of canned foods
and drinks to be assembled into a self-heating assembly without any
special tooling or manufacturing on the part of the food
manufacturers. Voluntary can size standards are developed and
published, for example, by the Can Manufacturers Institute Can
Standards Working Group.
[0074] A food producer may produce many individual cans of a
product sealed inside standard size cans. Some of these units may
be designated for conventional labeling and delivery for sale to
consumers. Other identical units can be designated for
incorporation in a temperature-change assembly of the type
described here. Those assemblies might be constructed at the
canning facility or another location where a food or beverage is
packaged inside the containers, or delivered to another location
for further assembly and later delivery for sale to consumers. Use
of standard containers in these assemblies means that no
significant retooling or other manufacturing changes are required
of a food producer in order to have their canned products
incorporated in assemblies like those described in this
document.
[0075] FIG. 4 illustrates schematically the manufacture of
temperature-change container assemblies according to the invention
in combination with the production of conventional packaged
products. Process step 150 indicates the packaging of products into
closed containers. In a preferred embodiment, this step might
represent the canning and sealing of a soup product or another food
product inside standard metal cans or similar sealed metal
containers.
[0076] Process step 152 represents the designation or diversion of
the products inside their containers into first and second
portions. A first portion 155 of the containers is sent for
conventional labeling 158 and shipment 160 for sale to consumers or
other users. In preferred embodiments, cans of soup or another food
product may be labeled in the usual way, and sent to markets and
other points of sale for purchase and use by consumers.
[0077] A second portion 163 of the containers is sent for further
manufacturing 165, in which the other elements of a self-contained
temperature-change container assembly according to the invention
are assembled around the containers. The finished assemblies are
then sent for shipment 167 for sale to consumers or other users. In
a preferred embodiment, self-heating canned food products are
placed on sale at markets and other points of sale for purchase and
use by consumers.
[0078] Process step 152 may represent a physical process on a
manufacturing line, or it may represent the mere designation of a
certain portion of the packaged products for special handling. On a
manufacturing line, for example, a splitter may divide the line
into two portions and select some cans for direct labeling and
shipment, and others for further assembly into self-contained
temperature change assemblies. Process step 152 might also
represent, for example, the manual designation and division of cans
waiting for shipment inside a warehouse, where some of the cans are
designated and labeled for sale as usual, and others are designated
for inclusion inside assemblies of the type described in this
document.
[0079] A standard cylindrical food can 5 like that shown in FIG. 3
comprises a top 10 and a bottom 25 with a cylindrical container
wall 28 between them. Conventional cans are usually steel,
aluminum, or similar materials that are--conveniently for this
invention--very effective heat conductors. The container's contents
23 can be a food, a drink, or another item intended for use at a
temperature above its usual storage temperature.
[0080] The outer jacket 8 surrounds the inner can 5. The jacket in
this embodiment (for a cylindrical can) comprises an annular jacket
top ring 30, a cylindrical jacket body 32, and a jacket bottom 35.
The jacket parts can be formed of an inexpensive ordinary plastic
material. There is no direct contact between the plastic and the
food 23 inside the can 5 so special food-grade plastics are not
required. The material that forms the jacket parts should
preferably have a relatively low thermal conductivity--lower in
particular than the thermal conductivity of the material of the
inner can 5.
[0081] A space is defined inside the jacket 8 between the inside of
the jacket and the outside of the can 5. This space includes a
first internal volume 38 and a second internal volume 40, with an
intermediary barrier 42 between them.
[0082] The first internal volume 38 holds a first reagent 45, the
second internal volume 40 holds a second reagent 50, and the
barrier 42 separates the two. In a preferred embodiment the first
reagent is granular calcium oxide and the second reagent is
ordinary liquid water. The barrier can be a thin, breakable
membrane such as a metal foil or a plastic film. Spikes or
penetrators 53 are provided on the jacket bottom 35, with the
spikes pointing inward toward the barrier membrane reagent
separator 42.
[0083] To heat the contents 23 of the can 5, the user inverts the
assembly 3 so that it rests on the can's top 10 and the jacket top
ring 30. The jacket bottom 35 is flexible enough so that the user
can force the spikes 53 through the membrane 42 by pressing down on
the middle of the flexible jacket bottom. When the user removes the
pressure, the flexible jacket bottom returns to its original
position, withdrawing the spikes and leaving several spaced-apart
holes in the membrane. One such hole is produced by each spike, and
the holes are spaced-apart in a pattern corresponding to the
spikes' configuration.
[0084] The liquid water second reagent 50 runs or drips out of the
second internal volume 40 and into the calcium oxide first reagent
45 in the first internal volume 38. An exothermic reaction ensues
as the water percolates downward through the granular calcium
oxide. The heat of this reaction is conducted preferentially
through the bottom 25 and the wall 28 of the can, which--being
metal--conduct heat much better than the plastic of the outer
jacket 8.
[0085] After a short time--after the liquid water second reagent 50
has permeated sufficiently through the calcium oxide first reagent
40--the user may flip the assembly 3 back into the upright
configuration shown in FIG. 3. The reagent mixture will continue to
produce heat and warm the food for a considerable time until the
reaction is complete. During this time, convection currents
(indicated by the arrows in FIG. 3) are generated in the food or
drink 23, which helps to distribute the heat within the product so
that the product is heated in a controlled manner with the food or
drink brought to a relatively uniform temperature throughout the
volume of the can 5.
[0086] In this embodiment, the penetrators are spaced apart from
one another and configured so that each penetrator creates its own
opening or hole through the barrier film. This results in a
spaced-apart pattern of relatively small holes. Such a pattern is
advantageous in that the flow rate of the liquid water second
reagent into the solid first reagent is limited by the limited area
of the openings through the barrier. This helps to guard against a
too vigorous reaction occurring at a localized area, as might be
the case, for example, if the penetrators were configured to tear
through and create a large breach through the barrier.
[0087] The configuration of this embodiment is also advantageous in
that the holes created by the penetrators are generally smaller
than the typical grain size of the calcium oxide first reagent. The
barrier film can thus support the weight of the calcium oxide and
maintain the calcium oxide in close contact with the sides and
bottom of the inner container, even after the barrier has been
penetrated to mix the first and second reagents and initiate the
reaction. Such a configuration allows for more efficient heating in
comparison with other embodiments that create a larger breach
through the intermediate barrier, and in which the solid reagent
can thus fall through the breach and out of close contact with the
inner container.
[0088] The exothermic reaction between the calcium oxide 45 and the
liquid water 50 is a fairly strong one. Temperatures within the
mixture can reach 400 degrees Fahrenheit (200 degrees Celsius) or
more, and a significant quantity of steam is generated.
[0089] A steam condenser 55 is provided in the first internal
volume 38 around the can 5 near the top of the jacket 8. In a
preferred embodiment, the steam condenser is a quantity of fairly
loosely packed steel wool. Steel wool is an efficient conductor of
heat, with a high surface area relative to its volume. Hot steam
that moves upward from the reagent mixture is cooled rapidly as it
comes into contact with and condenses onto the steel wool.
Significant heat is released, especially in changing the steam from
vapor to liquid water. This heat is transferred efficiently from
the highly conductive steel wool into the also highly conductive
metal wall 28 of the can 5. The high surface area of the steel wool
provides a large effective surface area for condensation of the
steam. The liquid water condensate is then available to drip back
down into the calcium oxide 45 to further the ongoing exothermic
reaction. The reaction can continue for a considerable time,
maintaining the product at an appropriate temperature long after
the initial heating.
[0090] The steam condenser might also be placed inside the second
internal volume, when the product is activated steam fills the
entire interior space comprising the first and second internal
volumes, so that a steam condenser in the second internal volume
might also be effective in condensing excess steam generated by the
reaction.
[0091] FIG. 5 illustrates a further safety feature that may be
included in some embodiments of assemblies of the type described in
this document. This figure illustrates the jacket bottom 35 that
holds the penetrators 53 and which contains liquid reagent 50
inside it. As with other embodiments, pressing the jacket bottom
inward urges the penetrators through a barrier 42 which allows the
liquid reagent to mix with a solid reagent inside the first
internal volume 38.
[0092] This embodiment, though, includes an outlet 165 that vents
steam in case to prevent a condition of overpressure inside the
assembly's jacket. In this embodiment, the outlet 165 is in the
form of a normally closed hole, notch, or gap in the lower surface
of the jacket bottom 35, in communication with the first internal
volume 38, which contains the first reagent, and in which the
reaction and steam generation primarily occur.
[0093] The outlet 165 in this embodiment is normally closed by a
relatively thin outlet barrier 168, which may simply be a thin
plastic structure left in place when the outlet is formed in the
jacket bottom 35. (The outlet and outlet barrier can be seen best
in the partial enlargement at the bottom of FIG. 5A.) If the
reaction occurs too quickly so that excess steam and high pressure
are present inside the jacket, the outlet barrier ruptures to allow
the overpressure to vent itself to the outside of the jacket.
[0094] This embodiment includes a steam filter 170 inside the
jacket between the outlet 165 and the first internal volume 38. The
steam filter controls the release of pressure and the passage of
steam through the outlet. Much or all of the steam that would
otherwise pass through the outlet will condense onto the steam
filter, which enhances the safety of the device while still
allowing release of excess pressure inside the jacket when
required. The steam filter may be a small amount of ordinary
cotton, felt, or some other porous or fibrous material that allows
gas or vapor to pass through the outlet in a measured, controlled
manner. The steam filter might also be some form of more elaborate
mechanical valve constructed to allow venting of high pressure,
although a simple, inexpensive material like cotton will usually be
preferred for its low cost, reliability, and ease of assembly.
[0095] FIG. 6 is an enlarged view that depicts another embodiment,
in which the outlet is in the form of a simple through-hole without
a barrier between the first internal volume 38 and the outside of
the assembly. Such an embodiment is easy to make, and reliable,
because its operation does not rely on the controlled rupture or
opening of an outlet barrier in response to overpressure inside the
jacket.
[0096] Although the outlet is shown in these figures as being
formed through the jacket bottom, such outlets could be formed in
the top or side of the jacket, or at any suitable location in
communication with the internal space in which the reaction takes
place.
[0097] In some cases, it may be desirable to mix an inert material
(one that does not contribute to the temperature-change reaction)
with the first reagent 45 in the first internal volume 38. This can
be done to moderate the reaction to control the rate of the
reaction and the rate and amount of heat generation.
[0098] The reaction rate may also be moderated by providing a
second quantity of the liquid reagent inside the first internal
volume inside a plastic bag with an appropriate melting point. When
the liquid reagent mixes with the solid reagent, the temperature
will rise inside the jacket body. At some point, the temperature
will exceed the melting point of the bag that contains the second
quantity of the liquid reagent, which will then be released into
the first reagent to contribute further to the reaction.
[0099] If desired, an appropriate substance may be added to the
liquid reagent to lower its freezing point to protect the liquid
reagent against freezing as the assembly is transported or stored.
Common sodium chloride salt is an inexpensive substance that can
lower the freezing temperature of liquid water substantially.
[0100] A variety of different reagent combinations might be used in
different embodiments. The first reagent may be a combination of an
acidic anhydride or salt and a basic anhydrade or salt. Adding
water as a second reagent to such a first reagent mixture will
produce heat and an acid/base mixture. The neutralization reaction
between the acid and the base produces additional heat, and a safe,
neutral, easily disposable end product.
[0101] Possible reagent mixtures include calcium oxide (CaO) in
combination with phosphorous pentoxide (P.sub.2O.sub.5); calcium
oxide in combination with aluminum chloride (AlCl.sub.3), calcium
oxide in combination with oxalic acid (H.sub.2C.sub.2O.sub.4), and
calcium oxide in combination with magnesium chloride (MgCl.sub.2).
Other reagent mixes are possible as well, and an inert material
might be added to such a first reagent mix, if desired, to control
the rate and degree of heat produced in the reaction. Mixture
proportions might include, for example, between 100-125 grams of
calcium oxide, between 0-30 grams of oxalic acid, and between 0-15
grams of inert mineral oil.
[0102] A "two-stage" reagent mix can be achieved by using an inert
material in combination with less than the entire amount of one of
the reagents. Such a mix might include, for example, calcium oxide,
a portion of which is coated with an inert mineral oil, and a
portion of which is uncoated.
[0103] When water enters such a mixture, the uncoated portion is
quickly exposed to the water and begins producing heat rapidly and
immediately through the resulting exothermic reaction. The coated
portion is initially shielded from contact with the water, and does
not at first contribute much to the reaction.
[0104] As the reaction continues, though, the mineral oil coating
begins to break down and be penetrated by the water. As this
happens, more and more of the coated portion of the calcium oxide
begins contributing to the reaction, effectively replacing to some
extent the calcium oxide consumed previously in the reaction. Such
a "two-stage" mixture thus provides quick initiation of heat
generation from the reaction (primarily from initially contact
between the water and the uncoated portion of the calcium oxide),
followed by a longer, sustained heat generation as more and more of
the coated portion begins contributing to the overall reaction.
[0105] The goal, of course, is to devise a reagent mix that
combines quick initiation and rapid heating of the food product,
followed by a sustained heat generation that will keep the food
inside the inner container warm for a considerable time, all while
economizing on the amounts of reagents used and seeking to avoid a
too vigorous reaction that might, for example, create an
overpressure inside the reagent container or scorch or burn the
food inside the inner container.
[0106] Any of a considerable variety of reagent mixes might be
found optimal for a particular application. Generally speaking, a
two-stage reagent mix might have only 15-90% of its calcium oxide
(by weight) coated with mineral oil as an inert material. The
weight of the mineral oil used in the coated portion might be
between 1% and 20% of the total weight of the calcium oxide (the
coated and non-coated portions, weighed before any is coated) used
in the overall mix.
[0107] In one particular reagent mix used in a presently preferred
embodiment, the calcium oxide is divided into two portions--70% by
weight is coated with mineral oil and 30% is not. The weight of the
mineral oil used to coat the coated portion in this embodiment is
7% of the weight of that portion of the calcium oxide to be used in
the coated portion (weighed before coating). A mix of this
composition might thus include 100 grams of calcium oxide, with 70
grams of that being coated with about 5 grams of mineral oil, and
the two portions then being mixed back together as a combined first
reagent for use in combination with water as a second reagent.
[0108] Although the preferred embodiment described here is intended
primarily for heating a food or beverage, other applications are
also contemplated. There are, for example, certain cosmetic,
medical, pharmaceutical, therapeutic, or sports
appliances--bandages, wraps, treatments for soreness or stiffness,
and the like--that are intended to be applied to a user's body at
temperatures above room temperature. Such products could be
enclosed inside a container in an assembly like that described
here, for activation and application at the desired elevated
temperatures, even at locations where more conventional heating
equipment is not available. Food products can include foods and
beverages, in single servings or multiple-portions, including
platoon-size meals for military or similar use in the field. Foods
may obviously include entrees, side dishes, baby foods or formulas,
pet foods, or any other food or beverage for which heating or
cooling might be desired.
[0109] Moreover, although such an assembly will commonly be used to
heat a product from room temperature to well above room
temperature, the use of the invention is not so limited. Some
products may best be stored, even in a sealed container, in a
refrigerator or freezer at a temperature well below room
temperature. In that case, an assembly of this type might be used
to quickly bring the product up to room temperature for use, or in
any event up to a temperature above the product's normal storage
temperature.
[0110] Finally, although the invention is embodied here in a
self-heating assembly that uses an exothermic reaction to deliver
heat to the product, other reagents could be used that would, upon
mixing, initiate an endothermic reaction to extract heat from the
container and thereby cool a product contained inside it. Cold beer
or wine, water, juices, or soft drinks could be delivered at
locations away from conventional refrigeration and without the need
for heavy and space-consuming ice or freezer appliances. There are
also sports wraps and similar therapies--such as those intended to
treat minor sprains and reduce swelling--that are best applied at
temperatures well below normal temperature. These products and
others--including but by no means limited to food entrees and side
dishes including baby food or formulas, and beverages such as beer,
wine, coffee, tea, cocoa, or hot apple cider, and non-food products
including hair dyes, hot oil hair treatments, self-heating beauty
wax treatments, surgical tools, and other products--might be
delivered for convenient use inside a self-contained
temperature-change container according to the invention.
[0111] FIGS. 4-9 illustrate process steps in the manufacturing of a
container assembly that embodies the invention. FIG. 4 illustrates
the attachment of the annular jacket top ring 30 around the edge of
the top 10 of the inner container metal can 5. The top ring is
placed generally flush with the top edge of the can, and secured to
the can by an adhesive or by any other suitable method. If desired,
the food, drink or other contents can be put into the can and the
can sealed at an ordinary canning facility, which may be at a
location other than that at which the finished product is
assembled. Standard sealed cans identical to those usually sold to
consumers can be delivered to the assembly location for inclusion
in the final product.
[0112] FIG. 5 illustrates the attachment of the outer jacket body
32 to the top ring 30. After the top ring is fixed at the top 10 of
the can 5, the can and the top ring are turned top down so that the
outer jacket body can be fixed around the top ring. The jacket body
can be secured to the top ring by any suitable method, including
adhesive fixing, or heat, sonic, or spin welding.
[0113] FIG. 6 depicts a filling of the steel wool 55 and the
calcium oxide 45 (in that order) into the interior of the jacket
body 32 around the outside of the can 5. The calcium oxide is
filled as shown in FIG. 6 to a depth sufficient to cover the
inverted body 25 of the can.
[0114] FIG. 7 shows the attachment of the aluminum metal foil or
plastic film membrane 42 over the top of the calcium oxide first
reagent 45. As the partial enlargement portion of FIG. 7
illustrates, the inner wall of the jacket body 32 has a stepped
profile at the location where the membrane 42 is to be anchored.
The calcium oxide is filed into the jacket body to a height near
the step 57, so that the membrane is installed close to the calcium
oxide reagent. The membrane can be attached to the inner jacket
body wall by any suitable method, including thermal or press
welding.
[0115] After the membrane barrier 42 is in place over the calcium
oxide first reagent 45, the liquid water second reagent 50 is
placed into the jacket body 32 over the membrane, as FIG. 8
indicates.
[0116] FIG. 9 depicts the installation of the jacket bottom 35
inside the jacket body 32. The jacket bottom is positioned so that
the spikes 53 do not pierce the membrane 42, but close enough so
that they will pierce the membrane when the user presses the jacket
bottom inward toward the membrane. The jacket bottom can be fixed
to the jacket body by any suitable method, including adhesive
fixation, or thermal-, sonic-, or spin-welding.
[0117] Fixation of the jacket bottom 35 to the jacket body 32
completes this stage of the assembly. Further steps may involve
applying labels to the jacket body. If desired, one or more
insulating layers can be applied between the jacket body and an
outer layer, to further inhibit transfer of heat to the outside of
the assembly.
[0118] Several characteristics are desired for a self-heating
assembly of the type described above. First, it is desirable that
the quantity of heat generated in the exothermic reaction be
sufficient to heat the food to the desired temperature, and to hold
the food at an appropriate temperature for an appreciable period of
time. Second, the reaction should be vigorous enough to heat the
food quickly to the desired temperature, so that the user does not
have to wait too long between his activation of the assembly and
the time when the food is heated and ready for consumption. Third,
it is vital that the product be safe. There should be no danger of
any overpressure that might rupture the jacket; nor should the
outer surfaces of the jacket become too hot to touch or for the
user to hold comfortably in his or her bare hands. Finally, the
product should not be prone to accidental activation, and the user
should be assured that no such premature activation has occurred.
The preferred embodiment described above includes several features
that contribute to the achievement of these goals.
[0119] FIG. 10 is a plan view illustrating a configuration of the
spikes or membrane penetrators 53 on the jacket bottom 35. FIG. 11
is a corresponding side section view of the spikes on the jacket
body, and a lower portion of the jacket body 32. Multiple spikes
are arrayed across the surface of the jacket bottom. In this
embodiment, nine spikes cover substantially the entire surface of
the jacket bottom, opposite substantially the entire surface of the
membrane.
[0120] When the jacket bottom 35 is flexed toward the membrane, the
spikes 53 form a pattern of relatively small holes distributed over
the substantially the entire area of the membrane, one hole at the
location of each spike. This allows the liquid water first reagent
to drip in a controlled way into the calcium oxide second reagent.
The water flow is distributed across the surface of the calcium
oxide rather than localized at a single point, and the water drips
onto the calcium oxide through multiple small holes rather than
simply flooding into it through a single, large rupture in the
membrane. This allows the reaction to proceed fairly rapidly while
avoiding local overheating or overpressure at any single place
within the calcium oxide reagent. It will generally be desirable to
provide at least three spaced-apart spikes to penetrate the
membrane, and five or more spikes will often be preferred.
[0121] The steel wool steam condenser 55 at the top of the volume
38 that contains the calcium oxide 45 helps to moderate
overproduction of steam in the reaction. Steam generated in the
reaction can condense efficiently on the large surface area of the
steel wool filaments. Heat released by this condensation is
transmitted efficiently from the highly conductive steel wool into
the (also highly conductive) outer surface of the metal can 5.
[0122] To heat the food efficiently while maintaining the outside
of the assembly 3 at a comfortable temperature, it is desirable
that the heat generated in the reaction be transmitted highly
preferentially into the can 5, rather than through the material of
the jacket 8 to the outside of the assembly. This is achieved to a
significant extent due to the different thermal conductivities of
the different materials. The metal of the can conducts heat much
more readily than either the plastic of the jacket or any thermal
insulator that might be used between the jacket and the steel
wool.
[0123] If desired, heat flow to the exterior of the assembly 3 can
be further limited by applying appropriate insulators to the
interior or exterior of the plastic jacket 8, or within the
material of the jacket itself. FIG. 15 shows one such application.
In this embodiment, a first insulator paper layer 60 is applied to
the inner side of the jacket body 32, between the calcium oxide and
the jacket body. In this embodiment, moreover, air pockets 61 are
present between multiple layers that jointly comprise the jacket
body. These air pockets are maintained by ribs, corrugations, or
similar structure (not shown) between the multiple layers of the
jacket body. The internal paper layer provides a first degree of
insulation, and closed pockets of trapped air such as those within
the jacket body are highly effective insulators.
[0124] The inner insulator layer 60 shown in FIG. 15 could also
comprise a metallic foil such as an aluminum foil between the first
reagent 45 and the plastic outer jacket body material 20. Such a
foil would protect the plastic from heat to prevent its melting
under the heat of the exothermic reaction.
[0125] Another configuration of layered insulators is shown in FIG.
16. This embodiment includes an inner layer 63 of molded or pressed
fiber such as that commonly used in pressed egg containers. This
inner layer is applied to the inside of the jacket body 32. A thin
(3 millimeter) layer 65 of expanded polystyrene foam (e.g.,
Styrofoam.RTM.) is applied over the jacket body. The Styrofoame
layer is an effective insulator with a surface that is easily and
comfortably gripped and held by a user of the product. The
Styrofoam.RTM. layer is also appropriate for the printing of
permanent, colorful, and attractive visual designs, and is thus
well-suited for use as the product's identifying label.
[0126] Still another layered configuration is shown in FIG. 17.
This embodiment includes a molded or pressed fiber layer 63 applied
to the inside of the jacket body 32 as in the prior configuration,
and a Styrofoam.RTM. layer 65 applied to the outside of the
assembly. This embodiment includes an additional layer of
corrugated cardboard 67 between the plastic of the jacket body and
the Styrofoam.RTM.. The corrugated cardboard defines channels or
voids in which air pockets are held--and these air pockets are of
course highly effective insulators.
[0127] Particular embodiments may use alternate insulation
materials. In particular, a sprayable foam or ceramic insulator can
be used in place of or in addition to any of the insulative layers
described in this document. Such materials can be applied by
spraying through multi-head nozzles and are thus suitable in high
speed industrial production. In a preferred embodiment, a multiple
layer outer jacket 20 (see FIG. 15) is produced by, e.g., injection
molding or blow molding to produce an outer jacket with ribs or
corrugations separating the individual layers and air spaces 61
trapped between them. A sprayable foam or ceramic layer 60 is then
applied to the inner surface of the outer jacket.
[0128] An alternative preferred construction is illustrated in
FIGS. 18-24. FIG. 18 shows a cup-shaped jacket bottom member 35
that carries a number of pointed penetrators or spikes 53. Water or
another liquid reagent 50 is filled into the internal volume 40 in
the bottom member's upward-facing cup as shown in FIG. 19. The film
or foil membrane barrier 42 is then fastened over the spikes and
the internal volume as shown in FIG. 20 to hold the liquid reagent
inside the cup. The membrane is secured to the bottom member by an
adhesive, heat-sealing, ultrasonic welding or any other suitable
means. Sealing the membrane over the liquid reagent packages the
reagent inside a self-contained activation subassembly 80.
[0129] FIG. 21 illustrates the installation of a thin-profile
jacket top ring 30 around the top 10 of the inner container 5. The
top ring is slipped from the bottom of the can upward into
engagement with the lower edge of the rim 83 near the top of the
can. The normal, unstressed inner diameter of this top ring is
slightly less than the outer diameter of the can. A watertight,
airtight seal is thus formed between the top ring and the can wall
28 when the ring is slipped onto the can.
[0130] As the detail view in FIG. 21 illustrates, this top ring 30
includes a notch 85 around the upper surface of the top ring. FIG.
22 shows the installation of a jacket body member 32 to the top
ring. This jacket body member includes a notch engaging ring,
configured to engage with the top ring's notch, and a can rim
engaging ring 90, configured to engage the inside of the rim 83 at
the top of the can 5. The jacket body member is fixed to the top
ring by ultrasonic welding, spin welding, or any other suitable
method.
[0131] After the jacket body member 32 is fixed to the top ring 30,
the resulting can/jacket body subassembly is inverted as shown in
FIG. 23. A thermal insulator 92 is then placed inside the internal
volume 38 between the can 5 and the jacket body member 32, near the
inner wall of the jacket body member. The thermal insulator can be
a corrugated cardboard or pressed paper material, a reflective
foil, a reflective paint applied to the jacket body's inner wall,
or any other suitable thermal insulator.
[0132] FIG. 24 illustrates the placement of the steel wool steam
condenser 55 inside the internal volume 38 around the top 10 (shown
inverted in this figure) of the can 5. As FIG. 25 shows, calcium
oxide 50 or another suitable reagent is then filled into the
internal volume over the steam condenser to a depth that covers the
inverted bottom 25 of the can.
[0133] Then, as indicated in FIG. 26, a can support 95 can be
placed inside the jacket body member 32 to support the can. The can
support includes a lip 98, which engages with the bottom 25 of the
can 5, a can support base 100, and a support column 95 to support
the lip over the base. The exact configuration of the can support
can vary considerably. It may include multiple support columns, for
example, and the base can be a simple, thin bar, a circular member
running around the circumference of the outer jacket, or any other
suitable shape so long as sufficient open space is left to allow
the liquid reagent to drip down into the first reagent inside the
jacket body member. The can support is in fact optional, and may
not be included at all in some preferred embodiments.
[0134] The assembly is completed as illustrated in FIG. 27 by
installing the activation subassembly 80--comprising the flexible
bottom member 35, the barrier membrane 42, and the liquid water
second reagent 50--to the bottom of the jacket body member 38 to
seal the calcium oxide first reagent 45 inside the jacket.
Additional insulation layers or product packaging can be applied
over the outside of the jacket body if desired. This is assembly is
used in the same way as the previous one, by flexing the jacket
bottom to force the spikes 53 through the barrier. This leaves a
pattern of holes through the barrier--one hole corresponding to
each penetrator, and the liquid second reagent 50 can then move
through the holes and into contact with the first reagent 45 to
initiate the temperature change reaction.
[0135] FIGS. 28 and 29 illustrate yet another preferred embodiment.
FIG. 28 shows a jacket configuration in which the jacket body 32 is
formed integral with the jacket top ring 30, rather than as
separate pieces joined together as in the previous figures. FIG. 29
is a detail view showing the region where the top ring of the
integral jacket embodiment contacts the upper edge of the can
5.
[0136] In this embodiment, as in the previous one, the jacket top
ring 30 is slipped over the outside of the can 5. Referring
particularly to the detail view of FIG. 29, the top ring includes
lower seal retainer 105 and an upper seal retainer 107. A seal 110
is retained in contact with the side of the can between these two
seal retainers. The seal may be an elastomeric or otherwise
flexible O-ring, a hardening liquid seal such as a hot liquid glue
or a liquid elastomer that hardens upon cooling, or any other
suitable material. The rim 83 of the can is gripped between the
upper seal retainer 105 and an upper can rim retainer 113. This
embodiment and its assembly are otherwise generally similar to the
other embodiments described previously. The reagents, principles of
operation, and applications are generally the same.
[0137] FIG. 30 is a side section view of an alternative actuator
115 for use in temperature-change assemblies of the type described
here. This actuator, like those described above, can be
incorporated as a jacket bottom 35 in a jacket assembly surrounding
an inner container. As in the other jacket bottoms, this one
includes several spikes, or penetrators 53 on a movable member
disposed opposite a foil, film, or other membrane-like barrier.
Each of the spikes in this embodiment includes two penetrating
spike tips 117 with a notch 120 between them. The spike tips
penetrate and tear the membrane. The notches provide open flow
paths through the resulting holes for the liquid second reagent to
flow through the membrane into contact with the solid first
reagent.
[0138] The embodiment of FIG. 30 differs slightly from the
embodiments described above. This embodiment includes a flexible
"hinge" 123 around the rim of the jacket bottom 35. To operate an
assembly that includes this actuator 115, the user presses the
jacket bottom on the side opposite the spikes 53. The hinged rim
123 is flexible enough to allow the spike tips 117 through the
membrane. In this case, though, when the jacket bottom has moved on
the hinge, it does not move back into the original configuration
shown in the drawing when the pressure is removed. The jacket
bottom, in other words, does not flip back outward across the rim
hinge. This provides the user with a way of knowing whether or not
a given assembly has been activated previously. If the hinge rim is
flipped inward, the jacket bottom has been pressed. If not, the
assembly remains ready for use.
[0139] This embodiment further includes an outer rim surface 125,
which provides a convenient location for anchoring a membrane to
the actuator 115, or for securing the actuator to other elements of
the overall assembly.
[0140] Reagents used in prior temperature-change assemblies have
been subject to degradation over time. Calcium oxide, for example,
is very hygroscopic and its absorption of water from the atmosphere
might limit the shelf life of the product. In the embodiments
described below, the solid first reagent is packaged inside a
vacuum-sealed plastic bag having a virtually zero water vapor
transmission rate.
[0141] FIG. 31 illustrates a fixture 128 for filling the first
reagent into an open plastic bag 130. The fixture includes a
cylindrical central support 132 of a size corresponding at least
generally to the size of the inner container of the final assembly.
The fixture also includes an outer wall 135 around the central
support; the outer wall is sized to correspond to the size of the
outer jacket in the final assembly. An open bag is placed inside
the outer wall and over the central support as shown in FIG.
31.
[0142] The steel wool steam condenser 55 is then filled into the
plastic bag 130 to a desired depth appropriate for the final
assembly, as illustrated in FIG. 32. The first reagent is filled
into the bag over the steam condenser, as shown in FIG. 33. The
open top of the bag is then vacuum-sealed as shown in FIG. 34.
Sealing the bag provides a completely vapor tight reagent
subassembly 137, which is shown removed from the support figure in
FIG. 35.
[0143] FIG. 36 illustrates the placement of the filled solid
reagent subassembly 137 (carrying the steam condenser 55) into an
insulated outer jacket subassembly 140. The outer jacket
subassembly and its construction may be substantially identical to
that of the assembly described above in connection with FIGS.
21-23. The solid reagent subassembly is slipped into the outer
jacket body 32 between a layer of thermal insulation 92 and the
outer wall 28 of the filled inner container 5.
[0144] The assembly is completed, as shown in FIG. 37, by
installing a water-filled activation subassembly 80 to close the
bottom of the outer jacket. The activation subassembly may be
configured and assembled in substantially the same way as that
described above in connection with FIGS. 18-20, or it may use the
alternate actuator described above in connection with FIG. 30.
[0145] The solid first reagent 45 is thus packaged inside a
vapor-barrier in the form of the thin-walled plastic bag 130. The
material of the bag should be thin (perhaps on the order of 1-2
one-thousandths of an inch(0.004-0.008 millimeters)), and may
advantageously be of a plastic with a low melting temperature. When
the activation device 80 is depressed, its spikes 53 penetrate the
foil or plastic membrane 42 to release the liquid second reagent
50. The spikes then penetrate further through the bag 130 to allow
the liquid reagent to reach the solid reagent 45 inside the bag.
This initiates the exothermic reaction in a relatively controlled
way as the liquid percolates into the solid reagent through the
openings in the membrane and the holes in the bag. As the
temperature rises, the low melting temperature bag material melts
away, thereby allowing more and more of the liquid to reach the
solid reagent. The reaction accelerates, but without the initial
steep temperature spike that might occur if the liquid reagent were
simply dumped all at once into the solid.
[0146] The bag configuration 130 shown in these figures is also
advantageous in corresponding generally to the space between the
jacket body 32 and the inner container 5. If the solid reagent 45
is packed reasonably tight inside the bag, the solid reagent and
the bag can provide structural support for the inner container
inside the jacket. This may allow for the omission of the can
support 95 (see FIG. 24), and the elimination of the assembly step
required to place such a can support inside the jacket.
[0147] Still another configuration is illustrated in FIGS. 38-43.
This variant packages the first reagent 45 inside a plastic bag 130
as before, but the steam condenser in this variant is outside the
bag. FIG. 38 shows the placement of the open plastic bag inside a
supporting fixture 128. FIG. 39 illustrates the filling of the
first reagent 45 into the bag. After the bag is filled and
vacuum-sealed, it is lifted off the fixture as shown in FIG. 40.
The steam condenser 55 is provided inside the outer jacket
subassembly 140 as shown in FIG. 41 (and not inside the bag, as in
the previous embodiment). The reagent filled bag 130 is then placed
around the inner container 5 and over the steam condenser 55 inside
the outer jacket body 32 as shown in FIG. 42. Finally, the
activation subassembly 80 carrying the liquid reagent 50 is then
sealed over the open end of the jacket body as shown in FIG.
43.
[0148] Other possible configurations are illustrated in FIGS.
44-47. FIG. 44 is a side-section view illustrating a configuration
in which the inner container 5 is a can that is relatively shallow
in compared to the can shown, e.g., in FIGS. 1-3.
[0149] FIG. 45 depicts an embodiment in which the inner container 5
and the outer jacket 8 each have sides that flare outward and
upward in a bowl-like configuration that can be held securely and
conveniently by a user consuming the product. The embodiment shown
in FIG. 45 also features vent outlets 165 and steam filters 170 of
the type described above in connection with FIG. 3A.
[0150] FIG. 46 illustrates an embodiment that features a
three-piece outer jacket 8 that includes two spin weld joints. This
embodiment is assembled by first snapping an annular top ring 30
over the top rim of the inner container 5. A jacket body member 32
is then spin welded to the top ring at a first spin weld site 173.
A lower activation subassembly 80 is then spin welded to the jacket
body member 32 at a second spin weld site 175. If desired, the
order in which the spin welds are formed could be changed, or
alternative weld-forming methods could be used instead of spin
welding as described here.
[0151] FIG. 47 shows another embodiment the features a relatively
long top ring 30 that extends downward to the lower activation
subassembly 80. This embodiment requires only a single spin weld,
at a first spin weld site 173.
[0152] FIG. 48 depicts an alternative activation device 178. In
this configuration, several penetrators 53 fixed to a mounting
structure in the form of a central shaft 180. The device includes a
flexible member in the form of a pushbutton 183 formed, for
example, of a relatively soft polymeric material that is
substantially more flexible than the relatively rigid material of
the outer jacket that surrounds the inner container. When a user
presses the pushbutton, the central shaft 180 is urged upward
(relative to the figure), which in turn forces the penetrators 53
upward and through the barrier.
[0153] FIG. 49 is a side-section view of an alternative embodiment
that can be shipped and sold with the inner container 5 empty. This
embodiment includes a removable and replaceable lid 185. The
removable lid may be a relatively thin and somewhat flexible
plastic, for example, with a ridge or lip 187 that fits into place
over a rim 190 around the outside of the upper edge of the wall 28
of the inner container 5.
[0154] To use this assembly, the user removes the lid 185 from the
inner container 5. The user can then place his own food or another
item or substance that he would like to have heated inside the
inner container. The user then replaces the lid onto the inner
container, and activates the assembly in the same way as the
assemblies described above. The reaction between the solid first
reagent 45 and the liquid second reagent 50 generates heat, which
is transferred through the walls of the inner container and into
user's own product.
[0155] The lid 185 includes a vent 193 in the form of an opening or
hole through the lid, in this case in the lid's center. This vent
allows pressure to escape from the inner container 5 as the product
is heated. A steam filter 195, which may be felt or another porous
or permeable material, covers the vent 193 to prevent or moderate
the ejection of hot steam from the container.
[0156] FIG. 50 depicts another embodiment generally similar to that
of FIG. 49. This embodiment, though, includes an inner wall
insulator 197. The inner wall insulator may be a, e.g., a layer of
cardboard, plastic, or a layer of plastic over a layer of
cardboard. The inner wall insulator might also be in the form of a
plastic cup or the like inserted into the inner container. The
inner wall insulator should be configured to allow heat to flow
fairly readily from the wall of the inner container into the
substance placed into it, but the inner wall insulator should
provide just enough thermal insulation so that a user will not burn
himself, for example, if he activates the product and places his
hand inside the inner container 5 in contact with its inner wall
28. The inner wall insulator should thus be in fairly close contact
with the inner container, and selected and dimensioned to provide
only the necessary degree of thermal insulation.
[0157] Though it is generally contemplated that all parts of the
assemblies described in this document will be disposable, for
convenience, at least parts of the assembly could be re-used and
recycled by refilling the assembly with new temperature change
chemicals and reinstalling a newly-filled inner container into the
assembly.
[0158] Several self-contained temperature-change assemblies have
been described to as examples of how the invention might be
configured. The invention is not limited to these exemplary
assemblies, though, and various modifications or additions will no
doubt occur to those of skill in the art. The true scope of the
invention should thus be determined primarily by reference to the
appended claims, along with the full scope of equivalents to which
those claims are legally entitled.
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