Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02582313 2007-03-20
DOMED FOOD CONTAINER SYSTEM
FIELD OF THE INVENTION
[0001] The present invention relates to container system
configurations for foodstuff. More particularly, the invention relates to a
food
packaging containment system that is suitable for heated food items such as
rotisserie chicken and the like, and includes a tray compartment and a lid
member. The container system preferably includes tamper-resistant features,
as well as tamper-evident features that visually evidence unauthorized ingress
if interfered either inadvertently or with the intent to cause harm.
BACKGROUND OF THE INVENTION
[0002] Retail markets have utilized rigid and flexible plastic
containers to protect and display both perishable and fragile food items such
as sandwiches, salads and bakery items. These traditional roles of plastic
packaging are now the minimum expected standards, and the requirements
placed on plastic food packaging continue to expand as increasing demands
are placed upon it. Presentation, brand presence, consumer desires, added
value to enhance commercial competitiveness, differentiation, imagery and
psychology has resulted in the design and application of plastic packaging
becoming more challenging. Convenience and versatility continue to shape
the future of packaging, with consumers gravitating toward packaged
convenience items that minimize the impact on their behavior. This has forced
packaging manufacturers to include social and environmental considerations
into their development process. The provision of multiple compartments in a
1
CA 02582313 2007-03-20
variety of shapes and utilities in rigid plastic containers has been one such
direction that packaging manufacturers have been pursuing.
[0003] Rigid plastic food containers are typically manufactured
from Polystyrene, Polypropylene, Polyethylene Terephthalate (PET),
Polylactide, Polyvinyl Chloride (PVC), or other rigid polymers. They generally
comprise either of two-parts - a tray and lid - or they may be a one-piece
construction with a hinge that modifies one portion of the container to act as
the tray and the other connected portion to act as a lid. Furthermore, they
are
available in a variety of shapes and cross-sections - circular, rectangular,
square, and elliptical, etc.
[0004] The use of such plastics for holding heated food has
gained favor with the rotisserie chicken being one of the fastest growing
applications. However, many currently available food packages have not been
designed to cater to the consumer's needs as related to the handling of such
container systems for heated foods. Heating of the container contents result
in
high temperature fluids and gases result in increased pressure build-up, can
be painful to the touch. Such constraints also place limitations on the
logistical
elements such as containerization of large quantities of heated food product.
This invention provides for a unique approach that achieves this objective.
SUMMARY OF THE INVENTION
[0005] In a preferred embodiment of the invention, the tray and
lid members of the container system possess edges that are designed to
mate with and be releaseably lockable to each other. The releaseably
lockable mechanism is usually accomplished using a snap-fit grip and the
elements comprising the releaseably lockable snap-fit grip enable a force fit
2
CA 02582313 2007-03-20
between the lid member and the tray member of the container system. In this
embodiment, the releaseably lockable mechanism is further designed to have
a uniform cross-section along its entire periphery and is specially configured
to hinder condensate from escaping at the lid-tray interface.
[0006] In another embodiment of the invention, opposing sides
of the lid and tray members are extended to act as handholds to help the
consumer lift the heated container system. Generally, markets that offer
heated food products such as rotisserie chickens in plastic container system
either provide gloves for the consumer to handle the heated package or the
heated package is placed in a cardboard lifting cradle with a handle that
resides over the top of the lid member of the container system. This
embodiment of the present invention eliminates the need for such devices and
additionally enables the food manufacturer and retailer to stack the container
systems.
[0007] Without venting, expansion of the container as a
consequence of heated gases including steam would cause the lid to pop
from the tray member. Vents permit the release of these trapped vapors. In
another embodiment of the invention, the vents are recessed into the top of
the lid member. The recessed vents serve to permit stacking of the containers
without blocking of the vents, thus allowing the food retailer additional
space
savings while maintaining the display effectiveness of the container system.
[0008] In another embodiment of the invention, the lid of the
container system is secured to the tray by means of a tamper-evident tamper-
resistant snap-fit grip mechanism. Rigid plastic tamper-evident packaging
generally provide visible-to-the-naked-eye indication that a container has
3
i I
CA 02582313 2007-03-20
been interfered with, that is, it had previously be opened and then re-closed
prior to purchase. This invention is a novel plastic packaging solution that
improves significantly on the convenience and therefore marketability of food
product.
[0009] Further areas of applicability of the present invention will
become apparent from the detailed description provided hereinafter. It should
be understood that the detailed description and specific examples are
intended for purposes of illustration only and are not intended to limit the
scope of the invention.
[0010]
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will become more fully understood
from the detailed description and the accompanying drawings, wherein:
[0012] Figure 1 is an isometric view of an embodiment of the
present invention showing the disassembled lid and tray members.
[0013] Figure 2 is a plan view of the container system in Figure
1.
[0014] Figure 3 is a plan view of the bottom of the tray member
in Figure 2.
[0015] Figure 4 is an enlarged perspective view of a recessed
vent depicted in Figure 1.
[0016] Figure 5 is a side view of the assembled container
system in Figure 1.
4
CA 02582313 2007-03-20
[0017] Figure 6 is an enlarged cross-sectional view of the
releaseably locking mechanism and handle of the container system in taken in
the 5-5 plane in Figure 2.
[0018] Figure 7 is a side view of an embodiment of the present
invention.
[0019] Figure 8 is a cross-sectional view of the container
systems in Figure 2 taken along the line 7-7 in Figure 2.
[0020] Figure 9 is a fragmentary sectional view of the
releaseably locking mechanism of the container system taken in the Y-Y
plane of Figure 8.
[0021] Figure 10 is a fragmentary sectional view of a portion of
the tray member of the container system taken in the Z-Z plane of Figure 8.
[0022] Figure 11 is cross-sectional view of two container
systems each similar to that depicted in Figure 8 illustrating how the food
container systems is stacked.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] The present invention will now be described more fully
hereinafter with reference to the accompanying drawings, in which a preferred
embodiment of the invention is shown. This invention may, however, be
embodied in many different forms and should not be construed as limited to
the embodiments set forth herein; rather, this embodiment is provided so that
this disclosure will be thorough and complete and will fully convey the scope
of the invention to those skilled in the art.
5
CA 02582313 2007-03-20
[0024] Referring to the drawings and in particular to Figures 1 &
2, there is shown a dome-shaped, rigid polymer construct food container
system according to the present invention. The food container system
includes a lid member 2 and tray member 4 which forms the primary recess
into which heated foodstuff, such as a rotisserie chicken, is placed.
[0025] The lid and tray members 2, 4 of the container system
can be molded, through known thermoforming manufacturing means, from a
single sheetline of polymer material work piece into a predetermined shape
and thickness as required. The lid and tray members 2, 4 of the container
system may also be formed, through known thermoforming manufacturing
means, into a curvilinear geometry to thereby provide the end user with a
variety of polygonal shapes. In the container system of the invention, the lid
member 2 has geometry that permits even mating with the tray member 4 at
their peripheral edge. Additionally, mating between lid member 2 and tray
member 4 is releaseably lockable and achieved using a snap-fit grip 25. As
shown, the releaseably lockable mechanism is a slotable mechanical interface
wherein the tray member snap-fit grip component 33 is the male element and
the lid member snap-fit grip component 31 is the female element. Rib element
16 increases the rigidity and strength of the in the lid member handhold 15.
Separating the lid member 2 from the tray member 4 is facilitated by pulling
the lid member handhold 15 away from the tray member handhold 17. Also
shown are raised ribbed sidewalls 10, 11 in the lid and tray members that
improve the overall rigidity of the container system.
[0026] Also shown is the planar surface 12 of the lid member 2
that is bordered by a raised rib periphery 3, 3' with the raised rib periphery
3,
6
CA 02582313 2007-03-20
3' separated at their ends by recessed vents 14, 18. In addition to improving
the structural integrity of the lid member, the raised rib periphery 3, 3'
serves
to hold in place the tray member 4 of a second identical container system that
may be stacked on the lid member 2. This feature is illustrated in greater
detail in Figure 11. The lid member 2 may be made from material that are
dissimilar from the material used to make the tray member 4 so that when
temperatures are elevated, dissimilar coefficients of thermal expansion of the
lid member 2 and the tray member 4 increase the effectiveness of the
mechanically fastening of the releaseably lockable snap-fit grip and thereby
promote the retention of heated gases and condensate. The raised retaining
ribs 38, 38' is designed restrict movement of the food product contents
generally so that they stay within the central portion of the tray member 4.
[0027] Figure 3 further illustrates the complementary female
grooved elements 21, 22 & 24 that form a mechanical fit with the raised rib 3
of the lid member 2. The female grooved element 21 sitting on the lid member
planar surface 12 is illustrated in Figure 2. The female grooved elements 22,
24 are straddled by the raised rib periphery 3, 3' and sit above but are not
in
mechanical contact with the recessed vents 14, 18.
[0028] The extended flange lip 23 of the tray member is defined
by the points 13 and 54, and extending outwards to points 9 and 39, and
raised rib 6, together form the tray member handhold 19. Similarly, the
extended flange lip 37 of the tray member defined by the points 27 and 55,
and extending outwards to points 29 and 50, and raised rib 8, together form
the tray member handhold 17. This design significantly increases the rigidity
and the strength of the handholds 17 and 19 of the tray member 4. Together
7
d 1
CA 02582313 2007-03-20
with the lid member handhold 15, tray member handholds 17, 19 give the
consumer increased control when both lifting and opening the heated
container system.
[0029] Turning to Figure 4, shown therein is a fragmentary
enlarged view of the recessed vent 18 of the present invention. The recessed
vent 18 is straddled by the raised edge 28 of the raised rib periphery 3 and
the raised edge 30 that leads to the planar surface 12 of the lid member 2.
For
illustrative purposes, venting means is achieved through the flap 26
comprising the recessed vent 18; however, any suitable perforation large
enough to permit hot gas to pass through would suffice.
[0030] Turning to Figures 5 and 6, therein is shown a side view
of the embodiment of present invention in Figure 1 and the enlarged
fragmentary cross-section of the lid and tray members' handhold elements 15,
17. Also shown is the releaseably lockable snap-fit grip mechanism 25 that
secures the lid member 2 and tray member 4 together when the container
system is assembled. The raised rib element 16 ends on an flat edge 32 that
is vertically displaced from tray member edge 34 to facilitate gripping by
fingers and further provides a gap 36 to allow the consumer to pry open and
separate the lid member 2 from the tray member 4.
[0031] Turning to Figure 7, therein is shown a side view of a
variation of the embodiment of the present invention as in Figure 1. As shown,
the container system is a single piece construction with its lid member 2 and
tray member 4 hingeably attached with a hinge 35.
[0032] Turning now to Figure 9, therein is shown an enlarged
cross-sectional view of the releaseably lockable snap-fit grip 25 of the
present
8
a
CA 02582313 2007-03-20
invention. The elements comprising the releaseably lockable snap-fit grip 25
are integral parts of the lid member 2 and tray member 4, wherein the tray
member snap-fit grip component 33 is the male element that slots into the
female lid member snap-fit grip component 35 element. Improved retention of
the fluids and hot gases is achieved by the five choke points 42, 44, 46, 48 &
49. The choke points serve to hinder the passage of fluids or gases from the
interior of the container system. The planar surface 51 lying between choke
points 42 and 46 but coincident with choke point 44, and the planar surface 53
lying between choke points 46 and 49 but coincident with choke point 48 are
angled relative to each other making a concave with angle f2 between the two
surfaces such that a tight fit is achieved. Edges 47 and 49 of the tray member
4 are incident with the choke points 42 and 49, and as shown, the edges are
vertically displaced by a distance L, wherein the interior edge 47 is lower
relative to the exterior edge 49. In order to remove the lid member 2 from the
tray member 4, the lid edge 43 is lifted up. The differential ledge height L
serves to facilitate the opening of the container system by permitting the lid
member element of the snap-fit grip to pivot about the ledge 47.
[0033] Turning now to Figure 10, therein is shown an enlarged
cross-sectional view of a portion of the tray member 4 illustrating the raised
rib
edge 38 that is located in the interior near the periphery of the tray member
4.
The raised ribs 38, 38' as shown in Figure 1 is designed encourage the food
product to remain within the central portion of the tray 4. The greater the
height M of the raised rib edge 38, the greater its ability to encourage the
food product to remain within the central portion of the tray 4. The height of
9
1
CA 02582313 2007-03-20
raised rib edge 38 is limited by the thermoforming or other manufacturing
process used to produce the tray member 4.
[0034] Also shown in Figure 10 is the sloped portion 20 of the
tray member 4 lying between the raised rib edge 38 and the tray footing 40.
The slope is at an angle (3 from the horizontal plane and is designed to
encourage the hot condensate and other fluids to flow toward the tray footing
40. The sloped portion 20 of the tray member 4 is also identified in Figure 1
and Figure 3.
[0035] Turning finally to Figure 11 therein is shown a cross-
sectional view of a first container system 45 of the present invention that is
stacked on top of a second container system 43 of the present invention. The
first container system 45 is held in place by a mechanical fit between raised
rib peripheries 3, 3' of the lid member 2 of the second container system 43
into which the complementary raised ribs that form the foot 40, 40' of the
tray
member 4 of the second container system 45 slotably interfaces.
[0036] Plastic packaging sealing mechanisms generally include
snap-fit grips that effectively provide a leak-proof seal that allows the
consumer to open, close and releaseably lock the container system multiple
times. Some of the advantages of this aspect of the invention are that food
freshness can be extended then would otherwise occur without sealing and
spillage of the food content is prevented.
[0037] Although particular embodiments of the invention have
been described in detail for purposes of illustration, various modifications
and
enhancements may be made without departing from the spirit and scope of
+. I
CA 02582313 2007-03-20
the invention. Accordingly, the invention is not to be limited except as by
the
appended claims.
11
