Note: Descriptions are shown in the official language in which they were submitted.
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INVERTIBLE FOOD CONTAINER
FIELD OF THE INVENTION
This invention relates to food containers and, more particularly a food
container, which at
the point of use and dependent upon user preference, can assume two geometries
-- a first
geometry and a second geometry concavely opposite the first. In the two
different geometries,
the food container may have two different volumetric capacities and/or depths.
BACKGROUND OF THE INVENTION
Disposable food containers are well known in the art. Disposable food
containers include
plates, bowls, clam shells, trays, etc.
The art has paid considerable attention to malcing, molding, and deforming
these food
containers out of a single plane. In this latter process a flat blank is
provided. The blank may
have radial grooves at its peripheral region. The blank is inserted between
mating dyes and
pressed. The radial grooves provide for accumulation of the material deformed
by the dies.
Exemplary art includes U.S. Patents 3,033,434, issued May 8, 1962 to Carson;
4,026,458, issued
May 31, 1977 to Morris et al.;
4,606,496, issued August 19, 1986 to Marx et al.; 4,609,140, issued September
2, 1986 to van
Handel et al.; 4,721,500, issued Jan. 26, 1988 to van Handel et al.;
5,230,939, issued July 27,
1993 to Baum; 5,326,020, issued July 5, 1994 to Cheshire et al. However, none
of these attempts
in the art provide a way to use the articles described therein in a
configuration other than that
originally provided. Typically the articles, such as food containers, are
provided in a generally
open configuration with sloped side walls. The side walls reduce the
occurrences of food spilling
from the food container.
One example of a food container that may be used in two distinct forms is
disclosed in
commonly assigned WO 99/47424A1, published Sept. 23, 1999 in the names of
Toussant et al.
Toussant et al. teaches a dontainer which assumes a first
geometry which is open for receiving food and, by folding, assumes a second
geometry which
encloses the food contents.
At picnics and other occasions where disposable food containers are utilized,
many
different types of food are often served. Some foods are amenable to eating
from a plate, while
others are amenable to eating from a bowl. Often the user of disposable food
containers would
enjoy the convenience of a food container which can receive food as a plate
and can also
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separately receive food as a bowl. Existing containers which purport to be
usable as a bowl and a
plate operate in one and only one geometry and are compromised in one or both
capacities.
The art shows a need for a container transformable between plate and bowl
geometries.
One such transformation is inversion of the food container. Inversion refers
to the transposition
of the convex/concave surface relationship of the food container. An
invertible food container
would allow one to buy and store only one package of containers. No longer
would one have to
buy separate packages of plates and bowls to acconunodate different types of
culinary items.
Additionally, waste of containers would be reduced. When separate packages are
purchased,
only half of the plates and half of the bowls may be used. Many times unused
containers are
discarded. Clearly, in such a situation, one package of invertible containers
could be exhausted,
leaving no containers to discard. Also, an invertible container can be stored
in a plate
configuration. The height of plates is less than the height of an equal number
of bowls.
Therefore, one can store more invertible containers than bowls in a particular
space which is
vertically constrained. Additionally, the efficiency and convenience of
storing the invertible
containers in their plate form is preferred compared to storing bowls. For
example bowls require
more vertical lift height to clear the stack than plates.
Accordingly, this invention provides a food container which can be used in two
different
geometries. The first geometry resembles plate-like geometry for receiving
food as a plate. The
second geometry resembles bowl-like geometry for receiving food as a bowl.
This invention also
provides a dual-volume food container.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of a food container according to the present
invention and
used in Example 1.
Figure 2 is the food container of Fig. 1 being inverted from its first, plate-
like geometry to
its second, bowl-like geometry with the application of force as shown by the
arrow.
Figure 3 is a perspective view of the food container of Fig. 1 after inversion
to the second
geometry.
Figure 4 is a broken top plan view of an alternative food container according
to the present
invention, the left half having a single polygonally shaped circumferential
hinge line, the right
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half additionally having a circular circumferential hinge line and radial
hinge lines internal to the
circumferential hinge lines.
Figure 5 is a top plan view of an alternative food container according to the
present
invention having a continuous circular circumferential hinge line and
discontinuous polygonal
circumferential hinge lines intercepting the continuous circular
circumferential hinge line, the
food container of Fig. 5 further having continuous radial hinge lines between
the circumferential
hinge lines and exhibiting a high degree of stability.
Figure 6 is a top plan view of an alteinative food container according to the
present
invention having spirally oriented radial hinge lines.
Figure 7 is a top plan view of an alternative embodiment according to the
present invention
having a circumferential hinge line and two sets of generally radially
oriented hinge lines, one set
radially outboard of the other. The food container of Fig. 7 further has two
sets of panels, each
set being determined by its radially oriented hinge lines. Further, each set
of panels has two
different widths.
SUMMARY OF THE INVENTION
The invention comprises an invertible food container comprising a first
surface and a
second surface opposed to the first surface. The food container is oriented
concave towards the
first surface and convex relative to the second surface. The food container
comprises a periphery
circumscribing and being disposed in angular relationship relative a central
region. A
circumferentially oriented hinge line divides the central region and
periphery. At least one of the
periphery and central region is articulable about the circumferential hinge
line such that the
concave and convex orientations of the first and second surfaces,
respectively, are transposable
such that the food container may be inverted from a first geometry oriented
concave towards the
first surface to a second geometry oriented concave towards the second
surface.
The present invention also comprises a method for using and inverting the
invertible food
container. The food container has first and second opposing surfaces which are
top and bottom
surfaces respectively. To invert the container, the user may grasp the
container around its
periphery and exert a force to its central region from the convex surface
towards the first. This
use of force will cause the container to invert between the geometries.
Alternatively, the user
may invert a container by removing it from a stack of containers and placing
it in a face-to-face
relationship on the top of the remaining stack and applying a force to its
central region to cause
the container to invert.
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The present invention also teaches a method for manufacturing an invertible
food
container. The food container of the present invention can be manufactured
from paper, plastic
or foam using any of the methods known in the art for forming plates with a
central region and
periphery. In one such process, containers are made with the additional
manufacturing steps
including scoring hinge lines into the container.
DETAILED DESCRIPTION OF THE INVENTION
Referring to Figs. 1 - 3, the food container 10 of the present invention is
shown in its first,
generally plate-like geometry. The food container 10 defines an XY plane and a
Z direction
orthogonal thereto. The food container 10 possesses a first surface 12 which
is a top surface and
is utilized to receive food, etc. The food container 10 also has a second
surface 14, particularly a
bottom surface, which is opposed to the first surfacel2. The food container 10
has a shape,
defined by the edge 28 of the food container 10. While round food containers
are illustrated, the
invention is not so limited. The food container 10 may be oval, square,
rectangular, hexagonal,
octagonal or other regular or irregular polygonal shapes.
As used herein, the following terms have the following meanings. "Invertible"
means that
the food container 10 of the present invention may transform from one geometry
to another via
the application of external force. Preferably, the external force is
mechanical. The two
geometries of the food container 10 are a generally plate-like geometry and a
generally bowl-like
geometry. Typically, the plate-like geometry will have a greater
circumferential dimension,
while the bowl-like geometry will have a greater depth. Depth is measured
perpendicular to the
plane of the food container 10.
The food container 10 according to the present invention is considered to be
bistable. By
"bistable", it is meant that the food container 10 can indefinitely remain in
either the first or
second geometry. The food container 10 does not move from the first geometry
to the second,
from the second geometry to the first or from either geometry to an
intermediate geometry
without external influence. Nor does the food container 10 assume other
geometries or
configurations without external influence. Furthermore, the food container 10
enjoys unexpected
rigidity while in the first geometry and in the second geometry.
The food container 10 inverts between the two aforementioned positions about
one or more
hinge lines 20, 22. A hinge line 20, 22 is a line of weakness that various
sections of the food
container 10 articulate about during inversion. A hinge line 20 may be
"circumferentially
oriented" in that it encloses and typically circumscribes an area generally
central to the food
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container 10 and congruent to its periphery 18. A hinge line 22 may be
"radially oriented" in
that it predominantly extends outwardly from a position at or juxtaposed with
the center of the
food container 10 towards the periphery 18.
The circumferential/radially oriented hinge lines 20, 22 may be provided by
any means
well known in the art. The circuniferential/radially oriented hinge lines 20,
22 are lines of
weakness in the food container 10. The circumferential/radially oriented hinge
lines 20, 22 allow
the food container 10 to invert in a predetermined manner. The hinge lines 20
and 22 may be
disposed on the first surface 12, or the second surface 14 of the food
container 10, or both. If
hinge lines 20, 22 are disposed on both the first and second surfaces 12, 14
of the food container
10, the hinge lines 20, 22 may be disposed directly opposite from the
corresponding hinge lines
20, 22 on the opposite surface 12, 14 of the food container 10. Alternatively
radial hinge lines 22
may be disposed on one surface 12, 14 and circumferential hinge lines 20
disposed on the other
surface 12, 14.
Material can be cut or removed from the food container 10 to form the
circumferential/radially oriented hinge lines 20, 22. Preferably, however,
material is compressed
or densified to form the circumferential/radially oriented hinge lines 20, 22.
Scoring design and
techniques are well known in the plate making art. The hinge lines 20, 22 may
be continuous or
comprise discrete segments separated by lands. If the food container' 10 is
provided with a
waterproof finish on one surface 12, 14, it may be desirable to arrange the
hinge lines 20, 22 so
that surface 12, 14 is intact and the waterproof capability remains.
The food container 10 is divided into two discrete regions by the
circumferentially oriented
hinge line 20, a central region 16 and a periphery 18. The central region 16
is the primary
location to place food items. The "central region 16" of the food container 10
is internal to the
circumferentially oriented hinge line 20. Intermediate the circumferentially
oriented hinge line
20 and the edge, or border, of the food container 10 is the periphery 18 of
the food container 10.
The periphery 18 circumscribes the central region 16, providing a generally
annular shape.
The periphery 18 may be disposed in angular relationship, typically obtuse,
relative to the
central region 16. The periphery 18 is typically raised during use relative to
the central region
16, which minimizes or prevents the occurrences of spillage of food from the
edge of the food
container 10. The periphery 18 will typically have two sections, a wall
section 36 which is
characterized by having an upward and outward slope relative to the central
region 16, and a top
rim section 38 which defines the edges 28 of the food container 10. In one
embodiment of the
present invention, the central region 16 may be reinforced. Reinforcement of
the central region
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16 is illustrated in commonly assigned U.S. Pat. No. 6,179,203 B1 issued Jan.
30, 2001 to
Toussant et al. A relatively stiffer central region 16 allows
the food container 10 to invert more easily and to hold more food material.
The hinge line
may be formed into the food container 10 by scoring, a process that is well
known in the art.
Scoring creates a "living hinge," as the term is known in the art. In the case
of a plastic
container, the living hinge can be molded into the container as is also well
known in the art.
Referring to Figs. 4-5, the circumferentially oriented hinge line 20 may take
various forms
around the central region 16. For example, it may form a star-like or a daisy-
like shape. As used
herein, a "star" shape is a geometric figure with multiple sides, oriented
concave inwards,
towards the center. A daisy shape, on the other hand, is a geometric figure
with multiple sides,
concave outwards and away from the center. Alternatively, the
circumferentially oriented hinge
line 20 may form a circle, or other closed polygon, around the central region
16. While not
preferred, the food container 10 of the present invention may employ a
circumferentially oriented
hinge line 20 that is discontinuous, eccentric or not centered relative to the
central region 16
and/or periphery 18 of the food container 10.
Referring to Figs. 4-7, the food container 10 may also have radially oriented
hinge lines 22.
The radially oriented hinge lines 22 extend primarily in a radial direction
from the approximate
center of the central region 16. Preferably the radially oriented hinge lines
22 are disposed only
outbound of the circumferential hinge line 20. As illustrated in Fig. 6, the
radially oriented hinge
lines 22 may be disposed in a spiral configuration.
If radially oriented hinge lines 22 are utilized with the food container 10,
preferably they
are disposed outward of the circumferential hinge line 20. If the radially
oriented hinge lines 22
are disposed internal to the circumferential hinge line 20, the radially
oriented hinge lines 22 may
weaken the central region 16 of the food container 10.
As illustrated by Fig. 7, the radially oriented hinge lines 22 may be disposed
in the
periphery 18. The radially oriented hinge lines 22 divide the periphery 18
into panels 24.
The food container 10 of Fig. 7 has a generally round edge 28 in the first
geometry. When
inverted to the second geometry the same food container 10 has a polygonal
shaped edge 28 due
to the inflection of panels 24.
The radially oriented hinge lines 22 according to the present invention may be
multi-
planar. By "multi-planar" it is meant that the radially oriented hinge lines
22 traverse a single
direction and extend, at least for a discernible distance, in a direction
having a vector component
perpendicular to the initial direction. While not wishing to be bound by
theory, it is believed that
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during inversion of food container 10, panels 24 become distorted and unstable
which leads to the
tendency of food container 10 to be stable in either the first or second
geometry but require an
external influence to cause it to invert from one geometry to another.
The present invention may be practiced with several different variations of
the radially
oriented hinge lines 22. The radially oriented hinge lines 22 may intercept or
be spaced apart
from the circumferentially oriented hinge line 20. The radially oriented hinge
lines 22 may
extend radially outwardly to the edge 28 of the food container 10. The number
of radially
oriented hinge lines 22 may range from about three to about twelve. Typically
the number of
radially oriented hinge lines 22 is from about six to about nine. The radially
oriented hinge lines
22 are typically equally spaced about the periphery 18. The method of making
the radially
oriented hinge lines 22 is scoring or molding; the same process used to make
the
circumferentially oriented hinge line 20.
The shape and size of the food container 10 is defined by the edge 28. It is
to be
recognized that the dimensions and relative proportions of the periphery 18
and central region 16
of the food container 10 will vary according to the exact size and intended
use of the food
container 10. While a round food container 10 is illustrated in Fig. 1, one of
ordinary skill will
recognize that any suitable shape and depth of food container 10 may be
selected for use with the
present invention. Other suitable shapes include squares, rectangles, ovals,
stars, various
polygons, etc.
Referring to Figures 1 - 3, the present invention is shown at three stages in
the inversion
process. The food container 10 is preferably constructed to acconnnodate
manual inversion
between both geometries. Figure 1 shows the food container 10 in its first
geometry. As noted
above the first geometry is plate-like. Fig. 2 shows the application of force,
indicated by the
arrow, to the central region 16 of the food container 1'0. Hands grasp the
food container 10,
typically at the periphery 18. While the food container 10 is firmly held, a
force 32 is exerted
towards the second surface 14 in the central region 16. At the same time, a
moment 34 is applied
along the periphery 18. In Figure 3 the food container 10 is shown inverted to
its second
geometry as a bowl.
The food container 10 according to the present invention may be made of a
rigid material,
particularly a material which provides for inversion, as noted above. Suitable
rigid materials
include foam, plastic, and various other synthetic materials. The food
container 10 may be made
of cellulose and, if so, may be made of solid bleached sulfite or layers of
various types of fibers
including recycled cellulose. If desired, additional rigidity and thermal
insulating capability may
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be provided by the materials selected for the food container 10. Additionally,
the materials of the
food container 10 need not be the same throughout.
A multi-ply the food container 10 may be made of corrugated board. Such a food
container
may comprise multiple plies disposed in face-to-face relationship. A multi-ply
food container
10 comprises at least three plies, a first ply, a second ply and a third ply.
A second ply is
interposed between the first ply and the third ply, so that the first and
third plies are spaced apart
from each other by the second ply. The second plies provides an air space
between the first and
third ply. The air space may help in reducing heat transfer through the food
container 10. A
suitable construction is illustrated in commonly assigned WO 99/53810 filed in
the names of
Plummer et al.
Corrugated board comprises a generally flat layer, and a corrugated layer. The
corrugated
layer is not joined at all geometries to the flat layer, but instead has ribs
which are spaced apart
from the flat layer and troughs joined to the flat layer. The ribs and troughs
are often straight and
parallel, but may be sinusoidal. In cross section, a rib may be S-shaped, C-
shaped, Z-shaped, or
have any other configuration know in the art. Furthermore, if desired, a
second flat panel may be
joined to the corrugated medium and disposed oppositely from the first flat
panel.
Altematively, the food container 10 may be molded from a pulp slurry or
pressed from a
blank between mating plate-shaped dies. Both methods of manufacture are well
known in the art.
In common practice, bowls are typically deeper and encompass more volumetric
capacity
than plates of comparable diameter. Plates are typically shallower in depth
with relatively less
volumetric capacity. The food container 10 according to the present invention
enjoys greater
volumetric capacity in its bowl-like second geometry than in its plate-like
first geometry. This
second bowl-like geometry is especially useful for containing liquid-type
foods or foods that have
a tendency to flow such as soup, stew, cereal, ice cream and similar foods.
Plates, on the other
hand, are often used for holding foods which are more solid and tend to
maintain their shape such
as steak, sandwiches, cake, ete.
In the present invention, it has been discovered that the volumetric capacity
of the bowl-
like second geometry of the food container 10 can be increased by increasing
the diameter,
particularly in the rim section 38, of the food container 10 while it is in
the first plate-like
geometry. Unexpectedly, this increases the depth, hence and volumetric
capacity, of the second
bowl-like geometry.
To illustrate this point, a number of different invertible food containers 10
were made and
their first and second volumetric capacities were measured using the following
procedure. First,
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the food container 10, while in its first plate-like geometry, was placed in a
laboratory balance,
taking care to have the top rim portion 38 of the container level and
supporting the food container
so that it would maintain its geometry and shape upon filling with water. The
balance was
tared. The food container 10 was filled with water having a specific gravity
of 1 gram/cubic
centimeter until the top of the water was visibly level with the top rim
section 38 of the food
container 10. The weight of the water was noted and recorded in cubic
centimeters as the first
volumetric capacity of the food container 10.
The water was removed from the food container 10. The food container 10 was
dried and
inverted to its second bowl-like geometry. The food container 10 was again
placed on the
laboratory balance with its top rim section 38 level and supported to maintain
its geometry and
shape when filled with water. The balance tare was verified, then the bowl-
like geometry food
container 10 was filled with water with a specific gravity of 1 gram/cubic
centimeter until the top
of the water was visibly level with the top rim of the food container 10. The
weight of the water
was noted and recorded as the second volumetric capacity.
The ratio of the second volumetric capacity to the first volumetric capacity
was calculated
and recorded. Also, the ratios of the depths and diameters were measured and
recorded.
If a food container 10 absorbs water in either geometry, one skilled in the
art would know
how to protect the container surface from water penetration or damage while
still achieving
accurate volumetric capacity measurements. Also, if the top rim section 38 of
the container is
irregular, one skilled in the art would know to measure the depth of the food
container 10 from
the lowest point of the rim section 38 surface to the low point of the central
region 16 and would
note the weight when the water is even with the low point of the top rim
section 38.
The depth of the container in its first geometry and second geometry was
measured and
recorded in millimeters. A Starrett scale held in a vertical position can be
used for this purpose.
If desired, a straight edge may be placed horizontally across the food
container 10 to assist in the
depth measurement. The following examples illustrate the depth and volumetric
capacity
comparisons of various samples of the present invention.
Example 1:
A disposable foam food container 10, illustrated in Figs. 1-3, having a gently
sloping
periphery 18 was tested as described above. This food container 10 did not
have radially oriented
hinge lines 22. A circumferentially oriented hinge 20 line was provided as a
circle
approximately the diameter of the central region 16 of the food container 10
in its first plate-like
geometry.
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Example 2:
A disposable paper food container 10 having a periphery 18 with a rather steep
wall
section 36 and a top rim section 38 in its first plate-like geometry was
tested. Its
circumferentially oriented hinge line 20 was a circle approximately the
diameter of the central
region 16 of the food container 10 in its first plate-like geometry. This
container did not have
radially oriented hinge lines 22.
Example 3:
A disposable paper invertible food container 10 having a periphery with a
rather steep wall
section 36 and a radially enlarged top rim section 38 relative to Example I in
its first plate-like
geometry was tested. This test showed that enlarging the rim section radially
increases the depth
and volumetric capacity of the second bowl-like geometry without changing
these characteristics
in the first plate-like geometry. This food container 10 had a circular
circumferentially oriented
hinge line 20 approximately the diameter of the central region 16 of the food
container 10 in its
first plate-like geometry. This food container 10 did not have radially
oriented hinge lines 22.
Example 4:
A disposable paper invertible food container 10 having a periphery 18 with a
rather steep
wall section 36 and a top rim section 38 with an intermediate radial extension
in its first plate-like
was tested. The geometry was otherwise similar to that of the two previous
examples. This food
container 10 had a circular circumferentially oriented hinge line 20
approximately the diameter of
the central region 16 of the food container 10 in its first plate-like
geometry. This food container
did not have radially oriented hinge lines 22.
CA 02441360 2005-12-19
The data are summarized in Table I below.
TABLE I
Exam le 1 Exam le 2 Exam le 3 Exam le 4
Central Region Diameter cm 14.3 16.5 16.5 16.5
First Geomegy, Plate Pro erties
Diameter, cm 22.4 25.8 24.4
Depth, mm 17 22 21 21
Volumetric Ca aci , cc 531.2 506 431 431
Second GeomeLri, Bowl Pro erties
Diameter, cm 21.1 24.7 23
Depth, nun 27 33 41 38
Volumetric Ca aci , cc 666.4 701 1250 775.8
Ratios
Diameter: Plate/Bowl 1.06 1.04 1.06
Depth: Bowl/Plate 1.59 1.50 1.95 1.81
Volumetric: Bowl/Plate 1.25 1.39 2.90 1.80
Table I illustrates that a food container 10 according to the present
invention may have a
second volumetric capacity which is at least 25%, 50% or even 100% greater
than the first
volume. The first and second volumes are associated with the plate-like and
bowl-like
geometries, respectively. Table I also illustrates the food container 10 may
have a depth.
associated with the second geometry which is at least 25 %, 50% or even 75%
greater than the
depth associated with the first geometry.
If desired, a plurality of the food containers 10 may be packaged, stored, and
shipped in a
nested configuration. In a nested configuration the first surface 12 of the
food container 10 is
placed in contacting relationship with the second surface 14 of an adjacent
food container 10.
Using the nested configuration footprint can be conserved if the bowl geometry
or depth can be
conserved if the plate configuration is used.
The plurality of nested food containers 10 may be used to facilitate the
inversion process.
For example, one food container 10 may be separated from the nested plurality.
The nested
plurality may be placed on a supporting surface, such as a table or
countertop, with the convex
second surfaces 14 facing upwardly. The separated food container 10 is then
placed congruent
with and top of the nested plurality of food containers 10 with the convex
second surfaces 14 in
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contacting relationship. An inverting force 32 is applied to the separated
food container 10, and
resisted by the nested plurality, thus making inversion easier to accomplish.
Alternatively, the
nested plurality of food containers 10 may be placed on the supporting surface
with the concave
first surfaces 12 facing upwardly. The separated food container 10 is placed
congruent with and
on top of the nested plurality with the concave first surfaces 12 in
contacting relationship. Again,
an inverting force 32 is applied to the separated food container 10, and
resisted by the nested
plurality, thus making inversion easier to accomplish.
If desired, a plunger may be used to apply the inverting force 32. The plunger
should be
sized to approximate the central region 16 of the food container 10 if the
concave first surfaces
12 are contacting or the periphery 18 if the convex second surfaces 14 are
contacting. Common
household items, such as lids, coasters, etc. may be used for the plunger.
While disposable food containers 10 have been described above, it is to be
recognized that
durable and reusable food containers 10 are within the scope of the claimed
invention as well.
Additionally, the materials from which the food container 10 is made need not
be the same
throughout. For example, different materials may be used for the central
region 16 and the
periphery 18. Additionally, the food container 10 may further comprise a cover
in either
geometry, for storage of perishable contents, etc. Many other combinations and
variations are
feasible and within the scope of the appended claims.
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