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Description  |
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BACKGROUND OF THE INVENTION
Fast food restaurants have commonly prepackaged the individual components
of a hot meal and placed it on a warming tray or under infrared lamp to
keep the food warm until sale and consumption. With the standard sandwich
menu of many fast food and carry-out restaurants, these individual
packages proved adequate; however, for certain items of the menu, the
individual packages proved unsatisfactory, and therfore difficulties were
experienced in preparing and packaging these foods ahead of time.
It is desirable that certain items in fast food or drive-in restaurants be
capable of being prepared prior to the actual sale and stored for a short
period of time in a hot and appetizing condition until sale to a patron.
Storage in fast food restaurants generally presents the problem of the
efficient use of space. If the prepared food requires a large amount of
space by reason of its numbers or size, restaurant operators will stack
the individual food items vertically to conserve in space and also to more
efficiently dispense the food items.
With individual items, the use of a container roughly the size of the
sandwich, having a hinged top for easy access to the food item and
composed of a polystyrene material, has proven itself very desirable, for
a number of reasons, in keeping the food hot and fresh during the
temporary storage period prior to consumption. Due to its relatively small
size, there is sufficient structural strength provided by the corners of
such a container so that it may be efficiently stacked and stored in large
quantities yet only a small amount of counter space is utilized.
However, when such a container is made larger for use with standard meals,
such as scrambled eggs and sausage, or perhaps a chicken dinner, it has
been found that the hot temperatures at which it is necessary to keep the
food can destroy the structural integrity of the polystyrene material and
render the packages incapable of being stacked for efficient storage. If a
conventional disposable plate and lid or cover were used, those high
temperatures necessary for, say, some breakfast items, would cause the
plastic material of which it is formed to lose its structure and sag. In
so doing, a stack of these conventional plates and lids, when filled with
hot food items, would sag, thereby collapsing the plates and lids and
crushing the food or unbalancing the stack and causing the stack to
topple. Further, even though the temperatures may not be high enough to
cause sagging and the subsequent toppling of the packages, the temperature
of the stacked packages may be sufficiently high to cause the polystyrene
material packages to stick to one another in an undesirable manner.
SUMMARY OF THE INVENTION
It is therefore, an object of this invention to provide the capability of
storing hot prepared food for limited periods of time.
It is another object of this invention to provide a food package which has
the structural strength to permit the stacking of the food package one on
top of another when containing hot prepared food.
It is yet another object of this invention to provide a cooling capability
between each food package of a stacked pile of food packages.
A further object of this invention is the most efficient use of space
within a food package to provide more efficient heating within the
package.
These and other objects are accomplished by the subject invention wherein
there is provided a food package or container having a bottom plate and a
top lid or cover, the cover being adapted to be placed over all but an
outside rim portion of the bottom plate. The cover is spherical, being
concave in a side view (FIG. 9) and oval in a top view (FIG. 2), and has a
series of strengthening ribs integrally molded into the cover. The overall
concave-oval shape of the cover gives it an inherent strength while using
a minimum of material. In the interior of the cover, the convex-oval shape
provides a minimum of space to be heated while keeping the prepared foods
warm.
The raised ribs on the outside of the cover, in addition to providing added
strength and a surface for stacking the packages on top of one another,
also space a package from the package on which it is supported and thereby
provide a cooling effect to both the package surfaces in contact. The
foregoing tends to prevent the package from reaching a temperature high
enough to weaken and deform, that is, the package retains its structural
integrity.
The bottom, or plate, of the food plate package has a flat area onto which
the food is placed. About the flat area is a continuous sidewall enclosing
the flat area. Spaced from this flat area on the sidewall is a peripheral
ridge on which the top cover rests. Above this ridge are handle portions
by which the package may be lifted. The sidewall also has slots on
opposing sides above the ridge. Tabs, integral with the top cover, are
insertable into the corresponding slots for retaining the cover in
position over the plate.
When the covers are secured to their plate by the tabs, they may be stacked
for temporary storage of the prepared foodstuffs or for take out purposes
without structural deterioration of the packages through either
instability or deformation through excessive heat of the packages
themselves.
DESCRIPTION OF THE DRAWINGS
Further objects of this invention, together with additional features
contributing thereto and advantages accruing therefrom, will be apparent
from the following description of one embodiment of the invention when
read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a perspective view of one embodiment of the complete package of
the subject invention;
FIG. 2 is a top view of one embodiment of the subject invention;
FIG. 3 is a left side view of one embodiment of the subject invention,
showing the raised ridges and a bottom plate;
FIG. 4 is a front view of one embodiment of the subject invention, showing
the tab and slot retaining means;
FIG. 5 is a bottom view of one embodiment of the subject invention;
FIG. 6 is an exploded view of one embodiment of the subject invention,
showing the ridge on which the cover rests;
FIG. 7 is an inside view of the top cover of the subject invention;
FIG. 8 is a perspective view of three or more food plate packages, stacked
one on top of the other; and,
FIG. 9 is a cross-sectional view of a single unit taken along the line 9--9
of FIG. 2, showing a stacked arrangement and the raised ribs and the paths
between the ribs by which air may circulate between stacked containers.
DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 3, there is shown a food package container 10
having a top cover or lid 12 and a bottom plate 14. These may be formed of
any lightweight material, which, though inexpensive enough to be
disposable, should possess thermally insulative properties and sufficient
strength for the purposes hereinafter described. In general, a foamed
polystyrene material, being an excellent thermal insulator, thermoplastic,
compatible with foodstuffs and inexpensive, is the material of choice,
although other materials having these features may be found suitable.
The cover 12, in plan view, is oval in shape and in side view is a partial
convex shape (FIG. 9). A peripheral ridge or band 34 (see also FIG. 6)
defines the lower edge of the cover 12 and is adapted to rest on a
corresponding supportive ridge or band 32 on the plate 14, as shown in
FIG. 6. The band 34 of the cover 12, and the band 32 of the bottom plate
14, thus provide an intimate contact or seal to prevent the loss of heat
from the food and prolongs the period of time in which food may be kept at
an appetizing temperature. The bottom plate 14, which conforms in plan
view to the shape of the top cover 12, is substantially bowl-shaped having
side walls 54 and a generally flat bottom 46 to give the entire package
great stability. The interior plate bottom 53 is also flat, allowing for
the placement of various foodstuffs in the conventional manner. The plate
portion 14 has a peripherally outwardly flared upstanding side portion 54
which serves to keep the food within the package without leakage of any
fluids seeping from or inherent in the food.
The flared side wall 54 also allows nesting of the bottom plate for storage
prior to use. The peripheral side portion 54 curls into a lip 35 at its
uppermost portion to help retain the integrity of the bottom plate. At
opposing ends of this peripheral lip are handles or grips 30, by which the
entire food plate package may be lifted.
The top cover 12 has a pair of tabs 40, each on an opposing side of the
cover 12. Slots 42 are formed on the side wall 54 above the supportive
band 32. The tabs 40, upon slight deformation of the top 12 caused by
pressing the sides at the point of the tabs 40 inward, slip into the slots
42 for retention of the cover 12 by the bottom plate 14 (FIG. 2).
Both the cover 12 and the bottom plate 14 are easily nestable for separate
storage in a minimum of space prior to use.
The cover 12 has a series of raised support and reinforcing ribs 16 about
the periphery of the cover extending substantially radially inwardly, in
spaced relation. The support ribs 16 provide important functions when the
food packages 10 are stacked one on top of the other, as indicated in FIG.
8. More specifically, the ribs 16 provide a stable support area or surface
for the package resting on them and also provide paths for the circulation
of air between the stacked packages. These ribs 16 present upper surfaces
18, which are substantially horizontal and raised from the surface of the
cover 12, though to a much greater degree near the periphery of the cover
34 from which it is spaced, see FIG. 8. The lower portion 20 of the rib
broadens in width as it extends to the surface of the cover 12 providing a
stable support surface. The height of the ribs, with respect to the cover
exterior, decreases as they approach the center. Thus, overall, the ribs
present a uniform support base for the plate of a package resting on top.
The ribs impart sufficient strength to the cover so that the cover itself
has a structural strength beyond that normally associated with a foamed
polystyrene object, and can support loads many times in excess of its
normal capacity. This improved capacity allows many such food plate
packages to be stacked, conserving a great amount of space.
These ribs may take any form, however, in the preferred embodiment, a path
for the circulation of air to the central portion 22 of the cover 12 is
provided. For example, U-shaped ribs forming a series of stylized "M"'s,
which comprise a design logo of the assignee of the present invention, is
depicted in the drawings. The bight of each of the U-shaped ribs extends
towards the center of the cover whereby channels 24 remain between each
stylized "M" for the circulation of air to the central portion 22 (FIGS. 2
and 9). Air spaces 25 are also created by the ribs 16 which allow the heat
from a stacked package above to dissipate, reaching a cooler level before
contact with the cover exterior 12, while also providing for the
circulation of air to the plate of the package stacked above. The effect
of these ribs can be seen to provide a minimum of contact between adjacent
packages in a stack, and at the same time, provide a maximum of support to
allow many packages to be stacked on top of one another. Spaced ribs
radiating from points spaced from the center of the cover may be used and
are contemplated as within the subject invention.
The present inventive food plate packages 10 may be stacked, one on top of
the other, with the bottom plate 14 of the food package being supported by
the ribs 16 on the food package top cover 12 below it. Further, while so
stacked, the ribs 16 also provide a cooling effect to the package to
prevent the loss of its structural strength.
The inherent strength associated with the spherical shape present in the
subject invention, in combination with a series of ribs 16, is more than
adequate to support a plurality of the stacked food packages of the
subject invention.
The top cover 12 retains its strength by eliminating the buildup of heat
caused from the close association of adjacent packages when stacked by
circulating air through channels (FIG. 9) and thereby cooling off the
center portion 22 of the top cover 12. The natural convection currents
(shown as arrows in FIG. 8), resulting from the proximity of the hot food
plate packages 10 in a stack (FIG. 8), provide sufficient air flow through
the channels 24 to cool the individual food plate packages in a stack. The
convection currents established by the channels 24 are enhanced by the
heating and cooling systems of restaurants which necessarily provide a
constant, fresh flow of air to both the cooking and dining areas of the
restaurant. Thus, the food packages will tend to be maintained at a
temperature below that which would cause it to sag and even below that
which would cause sticking of adjacent food packages.
While raised ribs generally have been found adequate to provide support,
ribs having a flat upper surface have been found somewhat more desirable
sice they tend to provide more friction and to prevent the sliding of one
food plate package over another. Therefore, in the preferred embodiment,
the top surface 18 of each rib is substantially flat (FIG. 9). When the
flat bottom 46 of the lower plate 14 is placed on the top cover of another
food plate package, as when stacking (see FIG. 8), a relatively large
surface area 18 of the cover 12 is in frictional contact with the bottom
plate 14. The foregoing prevents sliding of the individual packages in the
stack and thus, are convenient for both carry-out and temporary storage
purposes.
In addition to the structural characteristics of cover 12, its spherical
shape of its interior 48 also aids in keeping the food contents at the
desired hot temperatures. As can be appreciated from FIG. 7, interior 48
provides adequate room for the foodstuffs placed therein, and yet the air
space within the interior of the cover 12 is kept to a minimum. In this
manner, the warmed food loses a minimum of heat in reaching a temperature
equilibrium with the air contained in the package, and thus, stays warmer
longer.
The flat bottom 46 (FIG. 5), when resting on the ribs 16 of the package
beneath, as stated above, gives the stack of packages 50 great stability,
enough to withstand forces which would normally be sufficient to overturn
the stack 50. Of course, the primary concern, that of keeping the food
warm and fresh, is accomplished in spite of the extremity of the outdoor
elements encountered.
Upon a consideration of the foregoing, it will become obvious to those
skilled in the art that various modifications may be made without
departing from the invention embodied herein. Therefore, only such
limitations should be imposed as are indicated by the spirit and scope of
the appended claims.
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