FIELD OF THE INVENTION This invention relates generally to container assemblies for storing and transporting food, and in particular to an improved structure and method for sealing between the base and lid of a container assembly for storing food.
BACKGROUND OF THE INVENTION There are various container assemblies currently used in the “take-out” food industry and in disposable storage containers for home use which are capable of transporting and storing food for short periods of time. It is important that such container assemblies be sealed sufficiently to prevent leakage of the contents while in transport or storage and to prevent spoilage of the contents caused by the introduction of bacteria or air.
Currently, there are various designs available for such purposes in the food industry. Examples include the folded cardboard container assembly used widely for take-out in Chinese restaurants and other restaurants, aluminum foil base and plastic or cardboard lid container assemblies also used for take-out in restaurants and food stores, fold-over plastic containers (where the lid folds over the base) wherein there is a small protrusion in the lid portion that snaps into a small depression in the base portion, and plastic bags that zip or seal together and are more often used in homes. All of these have deficiencies because they are not air-tight thus permitting air and bacteria to enter and cause spoilage, not leakproof, inconvenient to use, or inefficient for storage.
Container assemblies which consist of a separate base and lid made of plastic typically have one to three seals along the rim of the base and lid. When it is a single seal, it often consists of a single U-shaped, V-shaped, or square protrusion that fits into a mirror image U, V or depression, respectively in the lid (for example, Dais, et al., U.S. Pat. No. 6,789,393; Schultz, et al., U.S. Pat. No. 6,868,980; and Tucker, et al., U.S. Pat. Nos. 6,170,696; 6,467,647; and 6,910,599). When there is more than one seal, they are each interior to the other along the mated rims of the lid and base. The seals have small surface areas to prevent the flow of food, liquids and/or air. It is believed that the small surface area of the seals results in failure of the seal more often than is acceptable. Also, when there is more than one seal, there is often a space between the sealing structures, as in Chen, U.S. Pat. Nos. 6,056,138 and 6,196,404. In that case, it is believed that liquid may be able to leak through the innermost seal into a chamber between the sealing areas, and the liquid in that chamber can provide an independent source of leakage. Therefore, with such double or triple seal container assemblies, leakage can occur when one or more seals are broken.
There is a need for a container assembly having a continuous, large surface area seal along the rim of the base and lid which prevents food leakage and spoilage. In addition, there is a need for a container assembly which may be easily and readily assembled and disassembled. In addition, the container assembly must be of such quality such that it is capable of storing foods for some length of time. Yet another desirable feature is for a container assembly that may be easily and compactly stored.
SUMMARY OF THE INVENTION The present invention is a continuous seal container assembly having a large surface area along the rim of the base and lid wherein the surfaces mate together to essentially eliminate leakage. The rim of the lid is constructed with a plurality of prongs analogous to tines of a fork, with the prongs fitting around mirror image prongs in the rim of the base. In this way there is both a large surface area of mated surfaces in a short linear distance and the path of the mated surfaces is tortuous such that liquids that might otherwise begin to leak through the mating surfaces are impeded from reaching the outer edge of the container assembly. Furthermore, at least one of the prongs in the lid rim has a protrusion that fits into a mirror image depression in the base rim to urge the two surfaces together and hold them in place. In a second embodiment, the outermost prong along the edge of the lid rim also has a protrusion that fits around the outer edge of the base rim further urging the mating surfaces together and locking the lid and base together. These prongs and protrusions in the rim of the lid when dimensioned to fit against or around the corresponding prongs and depressions in the rim of the base form a large surface area of mated surfaces which act as a defense against food leakage out of the container assembly and a defense against the entry of contaminants into the container assembly. Because the mating of the surfaces is a friction fit, the lid can easily be sealed on the base, subsequently pulled off, and resealed with minimal force to permit easy and convenient multiple uses.
Finally, the container assemblies of the present invention are same size stackable, with one base fitting into the base of the next container assembly, and the lids acting in the same fashion. These features dramatically reduce the storage space required to store said container assemblies with lid and base separated before they are used. The container assemblies are also stackable one on top of the other when in the fully assembled position as well. The present invention is, therefore, a safe, easy to use container assembly that can be used in the food preparation and distribution industries and in the private home.
BRIEF DESCRIPTION OF THE DRAWINGS For a detailed understanding of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a perspective view of a base of a container assembly, consistent with an embodiment of the present invention, viewed from above;
FIG. 2 is a perspective view of the base ofFIG. 1 viewed from below;
FIG. 3 is a perspective view of a lid of a container assembly, consistent with an embodiment of the present invention, viewed from above;
FIG. 4 is perspective view of the lid ofFIG. 3 viewed from below;
FIG. 5 is a perspective view of the base ofFIG. 1 and the lid ofFIG. 3 showing how they fit together;
FIG. 6 is a side, half-section view of the lid ofFIG. 3;
FIG. 7 is a side, half-section view of the base ofFIG. 1;
FIG. 8 is a side, half-section view of the base ofFIG. 1 and the lid ofFIG. 3 separated, but showing how they mate together;
FIG. 9 is a side, half-section view of the base ofFIG. 1 and the lid ofFIG. 3 mated together;
FIG. 10 is an enlarged side, half-section view of the rim of the lid ofFIG. 3 for the first embodiment;
FIG. 11 is an enlarged side, half-section view of the rim of the base ofFIG. 3 for the first embodiment;
FIG. 12 is an enlarged side, half-section view of the rim of the lid ofFIG. 3 for a second embodiment;
FIG. 13 is an enlarged side, half-section view of the rim of the base ofFIG. 1 for the second embodiment;
FIG. 14 is an enlarged, side, half-section view of the rim of the base ofFIG. 1 and of the lid ofFIG. 3 for the first embodiment with the base and lid separated, but showing how they mate together;
FIG. 15 is an enlarged, side, half-section view of the rim of the base ofFIG. 1 and the lid ofFIG. 3 for the first embodiment mated together;
FIG. 16 is an enlarged, side, half-section view of the rim of the base ofFIG. 1 and the lid ofFIG. 3 for the second embodiment separated, but showing how they mate together; and,
FIG. 17 is an enlarged, side, half-section view of the rim of the base ofFIG. 1 and the lid ofFIG. 3 for the second embodiment mated together.
DETAILED DESCRIPTION A detailed description of the invention follows below. Like reference numbers in subsequent figures have the same meaning. As will be described in the figures, the rim of the lid is constructed with a plurality of prongs analogous to tines of a fork, with the prongs fitting around mirror image prongs in the rim of the base. In this way there is both a large surface area of mated surfaces in a short linear distance and the path of the mated surfaces is tortuous such that liquids that might otherwise begin to leak through the mating surfaces are impeded from reaching the outer edge of the container assembly. Furthermore, at least one of the prongs in the lid rim has a protrusion that fits into a mirror image depression in the base rim to urge the two surfaces together and hold them in place. In a second embodiment, the outermost prong along the rim of the lid also has a protrusion that fits around the outer edge of the rim of the base further urging the mating surfaces together and locking the lid and base together. In a secondary feature of the invention, the container assemblies of the present invention are same size stackable, with one base fitting into the base of the next container assembly, and the lids acting in the same fashion. The container assemblies are also stackable one on top of the other when in the fully assembled position as well.
Turning now to the figures.Base100 is shown inFIGS. 1 and 2. InFIG. 1,base100 is viewed from the top. InFIG. 2,base100 is viewed from the bottom. Detailed descriptions of the structure of the rim are set out in the enlarged views of the rim of the base, described below inFIGS. 11 and 13-17.
Lid101 is shown inFIGS. 3 and 4. InFIG. 3,lid101 is viewed from the top. InFIG. 4,lid101 is viewed from the bottom. Detailed descriptions of the structure of the rim are set out in the enlarged views of the rim of the lid, described below inFIGS. 10, 12, and14-17.
FIG. 5 showsbase100 andlid101 viewed from the top.Base100 andlid101 are separated inFIG. 5, and the dotted lines show how base100 andlid101 fit together when they are mated to effect sealing.
FIG. 6 showslid101 in a side, half-section view. The shaded portions are in the plane of the paper. The unshaded portions are the perspective view of the structures as they wrap around into the dimension perpendicular to the paper. Therim102 oflid101 is discussed in more detail in enlarged views, below, inFIGS. 10, 12, and14-17.Side103 can be essentially vertical, but is ideally slanted slightly inward fromlid rim102 tolid top member112 so thelids101 can be stacked for efficient storage before a container assembly is put into use.Lid101 also hasdepression110 which goes around the circumference oflid101 and can therefore be seen inFIGS. 6, 8 and9 in two places at the top oflid101.Top member112 oflid101 is flat or slightly bowed into the interior of lid101 (i.e., downward as drawn inFIGS. 6, 8 and9).
FIG. 7 showsbase100 in a side, half-section view. The shaded portions are in the plane of the paper. The unshaded portions are the perspective view of the structures as they wrap around into the dimension perpendicular to the paper. Therim105 ofbase100 is discussed in more detail in enlarged views, below, inFIGS. 11 and 13-17.Side106 can be essentially vertical but ideally is slanted slightly inward frombase rim105 tobase bottom member113 so thebases100 can be stacked for efficient storage before a container assembly is put into use.Base100 also hasprotrusion108 which goes around the circumference ofbase100 and can therefore be seen inFIGS. 7, 8 and9 in two places at the bottom ofbase100.Bottom member113 ofbase100 is flat or curved slightly into the interior of base100 (i.e., upward as drawn inFIGS. 7, 8 and9).
FIGS. 8 and 9show base100 andlid101 together in side, half-section views. InFIG. 8,base100 andlid101 are separated. The dotted lines show how base100 andlid101 fit together. InFIG. 9,base100 andlid101 are mated together to effect storage. The distance between the outer edges ofprotrusion108 ofbase100 is slightly less than the distance between the inner edges ofdepression110 oflid101. In this way, a number of closed container assemblies can also be stacked.
It should be noted thatFIGS. 1 through 8 are drawn to show a circular shape forbase100,lid101, and therefore the container assembly taken as a whole. However, any reasonable shape can be utilized, for example circular, oval, square, or rectangular, without changing the meaning or function of any of the structures described herein or claimed below.
The principal features of the invention are shown inFIGS. 10-17. The first embodiment is shown inFIGS. 10, 11,14 and15. A second embodiment is shown inFIGS. 12, 13,16 and17.FIG. 10 shows an enlarged side, half-cut view ofrim102 oflid101. As shown, there are three prongs. The prong represented byreference number120 is attached directly and vertically tolid101. A second prong, represented byreference number122 is the outermost part of the structure. A third prong, represented byreference number123 has a protrusion,124, attached to the prong. Although three prongs are shown (reference numbers120,122, and123), wherein oneprong123 contains theprotrusion124, any number of prongs can be utilized, with any number of the inner prongs having theprotrusion124 attached to that prong.
FIG. 11 shows an enlarged, side, half-cut view ofrim105 ofbase100. InFIG. 11, there is one less prong,130 and136, then there are prongs in the rim oflid101. Thespace131 that is betweenprongs130 and136 and isopposite prong123 ofFIG. 10 has adepression132 into whichprotrusion124 ofFIG. 10 fits so the tworims102 and105 can be snapped together and hold. Clearly, the length ofside120 ofFIG. 10 must be the same length asside134 ofprong130, while thelength133 ofprong136 and thelength137 ofprong130 inFIG. 11 must be the same length asprong123 inFIG. 10, and the length ofprong122 ofFIG. 10 must be the same as the length ofprong135 ofFIG. 11. Also, the length ofprongs130 and136 must be the same as the lengths ofspaces129 and128 between the prongs inFIG. 10. InFIG. 11, although two prongs are shown (reference numbers130 and136) any number of prongs can be utilized, as long as they are one less than the number of prongs in the lid ofFIG. 10. Furthermore, any number of the prongs can havespaces131 withdepressions132 at the end ofsides132 and133 wherein the depressions mate with theprotrusion124 ofFIG. 10 as long as there are the same number of space and depression structures inFIG. 11 as there are inner prong and protrusion structures as inFIG. 10.
The second embodiment is seen inFIGS. 12 and 13. The additional structure of this second embodiment is theprotrusion127 attached to theoutermost prong122. Clearly, the length ofprong120 must be at least as great as the length ofprong135 ofFIG. 13.Protrusion127 can then snap aroundprong136, urging the rim of the lid and the rim of the base together and further contributing to sealing of the lid and base together. All other reference numbers inFIGS. 12 and 13 are the same as the reference numbers inFIGS. 10 and 11 and have the same meaning.
FIGS. 14 and 15 show enlarged, side, half-section views of the rims of the base and lid for the first embodiment. The additional teaching inFIGS. 14 and 15 relative toFIGS. 10 and 11 is seen in the shading and illustration of how the rim of the lid and rim of the base fit together. With respect to the shading, the shaded portions are in the plane of the paper. The unshaded portions are the perspective view of the structures as they wrap around into the dimension perpendicular to the paper. InFIG. 14, the dotted lines show howlid101 andbase100 fit together when they are mated to effect sealing, more specifically how the rim of thelid102 and the rim of the base105 fit together. InFIG. 15, thelid101 and thebase100, more specifically the rim of thelid102 and the rim of the base105 are mated together. InFIG. 14, the reference numbers and their meaning are the same as inFIGS. 10 and 11. The reference numbers have been omitted inFIG. 15, but they can be seen inFIGS. 10, 11 and14.
FIGS. 16 and 17 show enlarged, side, half-section views of the rims of the base and lid for the second embodiment. The additional teaching inFIGS. 16 and 17 relative toFIGS. 12 and 13 is seen in the shading and illustration of how the rim of the lid and rim of the base fit together. With respect to the shading, the shaded portions are in the plane of the paper. The unshaded portions are the perspective view of the structures as they wrap around into the dimension perpendicular to the paper. InFIG. 16, the dotted lines show howlid101 andbase100 fit together when they are mated to effect sealing, more specifically how the rim of thelid102 and the rim of the base105 fit together. InFIG. 17, thelid101 and thebase100, more specifically the rim of thelid102 and the rim of the base105 are mated together. InFIG. 16, the reference numbers and their meaning are the same as inFIGS. 12 and 13. The reference numbers have been omitted inFIG. 17, but they can be seen inFIGS. 12, 13 and16.
InFIGS. 10-17, with the exception of theprotrusions124 and127 and thedepression123, the prongs and spaces of the base and lid rim structures are shown as essentially rectangular, that is, with all angles essentially being right angles. The essence of the invention is not dependent on shape. Any reasonable geometric shapes, including but not limited to U-shapes and V-shapes, can be used. Furthermore, the internal protrusion has been described as being attached to the lid rim and the corresponding depression has been described as being part of the base rim. The reverse locking system can also be used. The only requirements are that the lid rim structure and base rim structure match exactly so that there are no spaces along the mated rims, and that there be a sufficient number of turns in the path between the mated rim surfaces such that flow is sufficiently impeded. That is, the only requirements are that the prongs of the lid rim match the spaces of the base rim, the prongs of the base rim match the spaces of the lid rim, the internal protrusions of the lid rim match the internal depressions of the base rim (or the reverse if that is the design utilized), the external protrusion of the lid rim in the second embodiment be sized to lock exactly around the outermost prong of the outermost base rim prong, and that there be a multiplicity of prongs—no fewer than three in the lid rim and correspondingly no fewer than two in the base rim.
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form, and details, may be made therein without departing from the spirit and scope of the invention.