Note: Descriptions are shown in the official language in which they were submitted.
10'7~;~44
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 therefore
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 effi-
cient 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.
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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 effi-
cient 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.
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 with a food package to provide more
efficient heating within the package.
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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 (FIGURE 9) and oval in a top
view (FIGURE 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 spaces a
package from the package on which it is supported and
thereby provides 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 corres-
ponding slots for retaining the cover in position over the
plate.
`-``` 1~76044
. I
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 struc-
tural deterioration of the packages through either
instability or deformation through excessive heat of the
packages themselves.
According to the above objects, from a broad
aspect, the present invention provides a package of light-
weight thermoplastic material for use in the storage of
heated foods. The package is effective to maintain the heat
and flavor of hot food contained therein. The lightweight
thermoplastic material normally deforms if a wall of the
package reaches the temperature of the hot foods, as occurs
when adjacent packages are stacked on each other without
provision for the circulation of cooling air between the
adjacent packages~ The package comprises in combination
a plate which is shaped to receive heated foods and a
generally bowl-shaped cover adapted to cover the plate to
maintain the foods in a heated condition. A plurality of
ribs are formed on an outside surface of the cover and are
spaced each from the other. Each of the ribs is raised from
the outside surface to form a planar upper surface. Each of
the planar upper surfaces of the plurality of ribs cooperate
to form a substantially horizontal upwardly facing support
surface to receive a plate of a similar package. Each of the
ribs has at least one generally U-shaped portion to form a
bight. The bight of each of the U-shaped ribs generally
extends towards the center of the cover from a point in
close proximity to the pariphery of the cover. The spacing
between each of the ribs defines a channel directed toward
the center of the cover to allow passage of cooling air over
the cover and under the plate of a vertically adjacent
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1076044
package to maintain the temperature of the outside surface
of the cover below that of the food contained ther~in,
thereby preventing deformation of the cover due to excessive
heat while maintaining the foods at a temperature su.itable
for consumption and simultaneously providing substantially
rigid support for a stack of packages.
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:
FIGURE 1 is a perspective view of one embodiment
of the complete package of the subject invention;
FIGURE 2 is a top view of one embodiment of the
subject invention,
FIGURE 3 is a left side view of one embodiment of
the subject invention, showing the raised ridges and a bottom
plate,
FIGURE 4 is a front view of one embodiment of the
subject invention, showing the tab and slot retaining means;
FIGURE 5 is a bottom view of one embodiment of the
subject invention;
FIGURE 6 is an exploded view of one embodiment of
the subject invention, showing the ridge on which the cover
rests;
FIGURE 7 is an inside view of the top cover of the
subject invention,
FIGURE 8 is a perspective view of three or more
food plate packages, stacked one on top of the other, and
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1~761)44
FIGURE 9 is a cross-sectional view of a single
unit taken along the line 9-9 of FIGURE 2, showing a
stacked arrangement and the raised ribs and the paths
between the ribs by which air may circulate between stacked
containers.
Referring to FIGURES 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 mate-
rials having these features may be found suitable.
The cover 12, in plan view, is oval in shape and in
side view is a partial c~nve~ shape (FIGURE 9). A peripheral
ridge or band 34 (see also FIGURE 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
FIGURE 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
s,~
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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 fodd 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 bottoln plate 14
(FIGURE 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 around the periphery of the cover extend-
ing 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 FIGURE 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 suhstantiaLly horizontal and raised from the surface
of the cover 12, though to a much greater degree near the
periphery of the covsr 3~, see FIGURE 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
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1076~44
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, a series of stylized "M"'s, which comprises a design
logo of the assignee of the present invention, is depicted
in the drawings whereby channels 24 remain between each
stylized "M" for the circulation of air to the central
portion 22 (FIGURES 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.
1076()~
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 tha~ adequate to support a plura-
lity of the stacked food packages of the subject invention.
The top cover 12 retains its strength by eliminatingthe buildup of heat caused from the close association of
adjacent packages when stacked by circulating air through
channels (FIGURE 9) and thereby cooling off the center portion
22 of the top cover 12. The natural convection currents
(shown as arrows in FIGURE 8), resulting from the proximity of
the hot food plate packages 10 in a stack ( FIGURE 8), provide .
sufficient air flow through the channels 24 to cool the indi-
vidual food plate packages in a stack. The convection cur-
rents established by the channels 24 are enhanced by the heat-
ing 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 since 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~RE 9).
When the flat bottom 46 of the lower plate 14 is placed on
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the top cover of another food plate package, as when stacking
(see FIGURE 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 FIGURE 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 (FIGURE 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 inven-
tion embodied herein. Therefore, only such limitations
should be imposed as are indicated by the spirit and scope
of the appended claims.
