Abstract:
The present invention is a container assembly for food and liquids. The container assembly has a lid and a base each of which has a series of prongs. The prongs of the base and lid interlock to form a continuous seal with high surface area and passages with many bends that together prevent air and bacteria from entering the container assembly and prevent food and liquids from leaking out of the container assembly. One or more of the lid prongs has a protrusion that fit into corresponding depressions between the base prongs to urge the rims together and create and maintain the seal. In a second embodiment, the outermost prong of the lid also has a protrusion attached to it which locks around the outermost base prong further urging the rims together and further creating and maintaining the seal.

Description:
FIELD OF THE INVENTION  
       [0001]     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  
       [0002]     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.  
         [0003]     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.  
         [0004]     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.  
         [0005]     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  
       [0006]     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.  
         [0007]     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  
       [0008]     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:  
         [0009]      FIG. 1  is a perspective view of a base of a container assembly, consistent with an embodiment of the present invention, viewed from above;  
         [0010]      FIG. 2  is a perspective view of the base of  FIG. 1  viewed from below;  
         [0011]      FIG. 3  is a perspective view of a lid of a container assembly, consistent with an embodiment of the present invention, viewed from above;  
         [0012]      FIG. 4  is perspective view of the lid of  FIG. 3  viewed from below;  
         [0013]      FIG. 5  is a perspective view of the base of  FIG. 1  and the lid of  FIG. 3  showing how they fit together;  
         [0014]      FIG. 6  is a side, half-section view of the lid of  FIG. 3 ;  
         [0015]      FIG. 7  is a side, half-section view of the base of  FIG. 1 ;  
         [0016]      FIG. 8  is a side, half-section view of the base of  FIG. 1  and the lid of  FIG. 3  separated, but showing how they mate together;  
         [0017]      FIG. 9  is a side, half-section view of the base of  FIG. 1  and the lid of  FIG. 3  mated together;  
         [0018]      FIG. 10  is an enlarged side, half-section view of the rim of the lid of  FIG. 3  for the first embodiment;  
         [0019]      FIG. 11  is an enlarged side, half-section view of the rim of the base of  FIG. 3  for the first embodiment;  
         [0020]      FIG. 12  is an enlarged side, half-section view of the rim of the lid of  FIG. 3  for a second embodiment;  
         [0021]      FIG. 13  is an enlarged side, half-section view of the rim of the base of  FIG. 1  for the second embodiment;  
         [0022]      FIG. 14  is an enlarged, side, half-section view of the rim of the base of  FIG. 1  and of the lid of  FIG. 3  for the first embodiment with the base and lid separated, but showing how they mate together;  
         [0023]      FIG. 15  is an enlarged, side, half-section view of the rim of the base of  FIG. 1  and the lid of  FIG. 3  for the first embodiment mated together;  
         [0024]      FIG. 16  is an enlarged, side, half-section view of the rim of the base of  FIG. 1  and the lid of  FIG. 3  for the second embodiment separated, but showing how they mate together; and,  
         [0025]      FIG. 17  is an enlarged, side, half-section view of the rim of the base of  FIG. 1  and the lid of  FIG. 3  for the second embodiment mated together. 
     
    
     DETAILED DESCRIPTION  
       [0026]     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.  
         [0027]     Turning now to the figures. Base  100  is shown in  FIGS. 1 and 2 . In  FIG. 1 , base  100  is viewed from the top. In  FIG. 2 , base  100  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 in  FIGS. 11 and 13 - 17 .  
         [0028]     Lid  101  is shown in  FIGS. 3 and 4 . In  FIG. 3 , lid  101  is viewed from the top. In  FIG. 4 , lid  101  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 in  FIGS. 10, 12 , and  14 - 17 .  
         [0029]      FIG. 5  shows base  100  and lid  101  viewed from the top. Base  100  and lid  101  are separated in  FIG. 5 , and the dotted lines show how base  100  and lid  101  fit together when they are mated to effect sealing.  
         [0030]      FIG. 6  shows lid  101  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. The rim  102  of lid  101  is discussed in more detail in enlarged views, below, in  FIGS. 10, 12 , and  14 - 17 . Side  103  can be essentially vertical, but is ideally slanted slightly inward from lid rim  102  to lid top member  112  so the lids  101  can be stacked for efficient storage before a container assembly is put into use. Lid  101  also has depression  110  which goes around the circumference of lid  101  and can therefore be seen in  FIGS. 6, 8  and  9  in two places at the top of lid  101 . Top member  112  of lid  101  is flat or slightly bowed into the interior of lid  101  (i.e., downward as drawn in  FIGS. 6, 8  and  9 ).  
         [0031]      FIG. 7  shows base  100  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. The rim  105  of base  100  is discussed in more detail in enlarged views, below, in  FIGS. 11 and 13 - 17 . Side  106  can be essentially vertical but ideally is slanted slightly inward from base rim  105  to base bottom member  113  so the bases  100  can be stacked for efficient storage before a container assembly is put into use. Base  100  also has protrusion  108  which goes around the circumference of base  100  and can therefore be seen in  FIGS. 7, 8  and  9  in two places at the bottom of base  100 . Bottom member  113  of base  100  is flat or curved slightly into the interior of base  100  (i.e., upward as drawn in  FIGS. 7, 8  and  9 ).  
         [0032]      FIGS. 8 and 9  show base  100  and lid  101  together in side, half-section views. In  FIG. 8 , base  100  and lid  101  are separated. The dotted lines show how base  100  and lid  101  fit together. In  FIG. 9 , base  100  and lid  101  are mated together to effect storage. The distance between the outer edges of protrusion  108  of base  100  is slightly less than the distance between the inner edges of depression  110  of lid  101 . In this way, a number of closed container assemblies can also be stacked.  
         [0033]     It should be noted that  FIGS. 1 through 8  are drawn to show a circular shape for base  100 , lid  101 , 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.  
         [0034]     The principal features of the invention are shown in  FIGS. 10-17 . The first embodiment is shown in  FIGS. 10, 11 ,  14  and  15 . A second embodiment is shown in  FIGS. 12, 13 ,  16  and  17 .  FIG. 10  shows an enlarged side, half-cut view of rim  102  of lid  101 . As shown, there are three prongs. The prong represented by reference number  120  is attached directly and vertically to lid  101 . A second prong, represented by reference number  122  is the outermost part of the structure. A third prong, represented by reference number  123  has a protrusion,  124 , attached to the prong. Although three prongs are shown (reference numbers  120 ,  122 , and  123 ), wherein one prong  123  contains the protrusion  124 , any number of prongs can be utilized, with any number of the inner prongs having the protrusion  124  attached to that prong.  
         [0035]      FIG. 11  shows an enlarged, side, half-cut view of rim  105  of base  100 . In  FIG. 11 , there is one less prong,  130  and  136 , then there are prongs in the rim of lid  101 . The space  131  that is between prongs  130  and  136  and is opposite prong  123  of  FIG. 10  has a depression  132  into which protrusion  124  of  FIG. 10  fits so the two rims  102  and  105  can be snapped together and hold. Clearly, the length of side  120  of  FIG. 10  must be the same length as side  134  of prong  130 , while the length  133  of prong  136  and the length  137  of prong  130  in  FIG. 11  must be the same length as prong  123  in  FIG. 10 , and the length of prong  122  of  FIG. 10  must be the same as the length of prong  135  of  FIG. 11 . Also, the length of prongs  130  and  136  must be the same as the lengths of spaces  129  and  128  between the prongs in  FIG. 10 . In  FIG. 11 , although two prongs are shown (reference numbers  130  and  136 ) any number of prongs can be utilized, as long as they are one less than the number of prongs in the lid of  FIG. 10 . Furthermore, any number of the prongs can have spaces  131  with depressions  132  at the end of sides  132  and  133  wherein the depressions mate with the protrusion  124  of  FIG. 10  as long as there are the same number of space and depression structures in  FIG. 11  as there are inner prong and protrusion structures as in  FIG. 10 .  
         [0036]     The second embodiment is seen in  FIGS. 12 and 13 . The additional structure of this second embodiment is the protrusion  127  attached to the outermost prong  122 . Clearly, the length of prong  120  must be at least as great as the length of prong  135  of  FIG. 13 . Protrusion  127  can then snap around prong  136 , 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 in  FIGS. 12 and 13  are the same as the reference numbers in  FIGS. 10 and 11  and have the same meaning.  
         [0037]      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 in  FIGS. 14 and 15  relative to  FIGS. 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. In  FIG. 14 , the dotted lines show how lid  101  and base  100  fit together when they are mated to effect sealing, more specifically how the rim of the lid  102  and the rim of the base  105  fit together. In  FIG. 15 , the lid  101  and the base  100 , more specifically the rim of the lid  102  and the rim of the base  105  are mated together. In  FIG. 14 , the reference numbers and their meaning are the same as in  FIGS. 10 and 11 . The reference numbers have been omitted in  FIG. 15 , but they can be seen in  FIGS. 10, 11  and  14 .  
         [0038]      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 in  FIGS. 16 and 17  relative to  FIGS. 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. In  FIG. 16 , the dotted lines show how lid  101  and base  100  fit together when they are mated to effect sealing, more specifically how the rim of the lid  102  and the rim of the base  105  fit together. In  FIG. 17 , the lid  101  and the base  100 , more specifically the rim of the lid  102  and the rim of the base  105  are mated together. In  FIG. 16 , the reference numbers and their meaning are the same as in  FIGS. 12 and 13 . The reference numbers have been omitted in  FIG. 17 , but they can be seen in  FIGS. 12, 13  and  16 .  
         [0039]     In  FIGS. 10-17 , with the exception of the protrusions  124  and  127  and the depression  123 , 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.  
         [0040]     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.