Fast food container
This is a division of Ser. No. 826,719 filed Aug. 22, 1977, now abandoned. 
    
    
     FIELD OF THE INVENTION 
     Deformable plastic containers made of foamed polystyrene and other materials are widely used in the food service field where containers are filled, stored, and supplied to the consumer at a later time. For the hot sandwich use, these are generally made in one piece having a common hinged border and a snap-in closure opposite said hinge. 
     DESCRIPTION OF THE PRIOR ART 
     Schubert et al. U.S. Pat. No. 3,935,962 (1976) discloses hot food containers similar to the container dislcosed herein and said patent is incorporated herein by reference, attention being particularly drawn to the container shown in FIG. 6 of said patent. 
     SUMMARY OF THE INVENTION 
     The object of my invention is to provide a new and useful container for a food product, such as a hamburger, having an improved latch. 
     Broadly, my invention resides in a deformable container comprising top and base members with outwardly sloping sidewalls hingedly attached along one wall and provided with latch means adapted to maintain said container closed. The latch means disclosed provides a secure closure, but one which is easily closed and opened. The latch includes a generally U-shaped cutout or notch on the lip providing two tabs extending outwardly from the top portion of the container which engage two slots in the sidewall of the lower portion. The slots are provided in the downwardly extending portion of a projection which extends inwardly from the tip of the lower portion and downwardly to the sloping sidewall. Due to the flexible nature of the container, pressure on the top or lid of the container permits deforming of the lid inwardly to permit insertion of and removal of the tabs from the slots. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 illustrates three containers stacked one upon the other. 
     FIG. 2 shows a fragmentary side view of one container stacked upon another. 
     FIGS. 3, 4 and 5 show various bottom configurations. 
     FIGS. 6, 7 and 8 are fragmentary top views of the front portion of the container in the process of being closed, FIG. 6 before closure, and FIG. 8 showing the locked position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 illustrates three of the containers with the closure locked stacked one upon another, these being 10, 10&#39; and 10&#34;. 
     FIG. 2, a fragmentary side view of two of the stacked containers in greater detail. The top container 10 is shown resting upon the lower container 10&#39;. Each container is provided with a lower portion having a base 12, upwardly sloping rear wall 14, front wall 16, and sidewalls 18. The bottom wall 12 is provided with a series of projections 20 adapted to maintain a food article positioned above the general level of the base 12 and to permit air circulation between said food article and said base. This also permits air circulation between containers. Near the upper portion of the bottom of the container there is provided an outwardly and upwardly shelf area 22 which terminates in lip 24. This shelf extends completely across the front almost completely along the sides. The top of container 10&#39;, shown in FIG. 2, contains a rear wall 26, front wall 28 and sidewalls 30. As shown in FIG. 1, the top 32 of the container is flat. Near the bottom of the top 30, there is an outwardly projecting lip 24 which rests in the shelf 22 of the bottom portion of the container. At the junction of the top portion and the bottom portion of the container, a hinge 36 is provided. The lip 24 on the bottom portion of the container extends downwardly to connect with hinge portion 36 as shown at 38, this resulting in a steam outlet space 40 between the top and bottom portions. 
     FIG. 3 shows a bottom plan view of the base 12 of container 10 provided with a series of grooves 42 extending across the bottom 12 of the container. Modifications are shown in FIGS. 4 and 5, FIG. 4 shows grooves 44 and 46 running diagonally between the sides of the container. FIG. 5 shows concentric circular grooves 48 and diagonal grooves 50 extending between corners of the bottom of the container. These projections permit circulation of air between the food product and the bottom, these configurations permit escape of steam present and reduce steam condensation in the food product. 
     FIGS. 6, 7 and 8 illustrate the features of the latch of my invention and show the container in the unlatched, in the process of being latched, and latched condition, respectively. Reference numerals similar to those set forth above are used in these figures. FIG. 6 illustrates the structure of front wall 16 which is provided with an inwardly protruded surface 52. The front portion of lip 34 on top of the container is provided surface 52. The front portion of lip 34 on top of the container is provided with a generally U-shaped cutout or notch 54 located in line with the inwardly protruded surface 52. As a result of this construction, tab portions 56 and 58 are formed. The front lip 24 on the bottom portion of the container has a shoulder 59 which extends inwardly from the lip 24 toward the hinge and downwardly to the shoulder portion 22. Two slots 60 and 62 are provided in the downwardly sloping wall of the projection 59 which are aligned with tabs 56 and 58. The wall portion between the slots strengthens shoulder 59. 
     In the process of closing the container, as shown in FIG. 7, the thumb or finger 64 of the operator is shown deforming the top front side wall so that tabs 56 and 58 are retracted sufficiently to drop into slots 60 and 62. The arrow indicates the direction of movement. 
     After depressing the top portion to its fully closed position such that lip 34 on the top portion contacts the shelf 22 on the lower portion, the pressure against inwardly protruding surface is removed and the tabs 56 and 58 extend into the slots 60 and 62 thereby extending under the lip 24 of the lower portion. 
     This results in a firmly locked package but one which is easily opened by the customer by pressing on the inwardly protruding surface 52 thereby unlatching the tabs from the slots. This constitutes an improvement over prior art locking systems which involve more complicated fastening systems or the use of longer slots which tend to weaken the article, and prevent a secure latch. The vertical portion of the member 59 in large measure produces this improvement and strengthens this portion of the container. 
     The improved structure disclosed herein is suitable for use within any container, but we believe it will find its greatest use in the insulated food package such as a hamburger container. Such products are made by thermoforming a foamed polystyrene sheet, but other plastic materials can be used. 
     While we have described a preferred embodiment of my invention, it will be obvious to those skilled in the art that additional modifications can be made while coming within the broad scope of my invention. For instance, latch means of the type described can be substituted for the hinge to produce a container latched on two sides as in FIG. 7 of Schubert et al. U.S. Pat. No. 3,935,962 supra.