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