Patent Document

CROSS REFERENCES TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to enclosed plastic containers in general, and to containers for food products in particular. 
     Restaurants, deli counters, and caterers provide convenience and time savings to their customers by preparing various dishes within their facilities for customers to take out for dining within the customer&#39;s home. Many of these dishes are cooked and maintained in a heated condition after preparation, until time of sale. The customer purchases the food item while still hot or warm, and will then take the item home. 
     Warm food products present a special challenge to point of sale packaging. First, because of the temperature difference between the food product and ambient conditions, there is bound to be vapor condensation on any cool container into which the product is placed. Second, if the food product is significantly elevated in temperature, it is desirable to keep the hot product from uncomfortable contact with the user. Moreover, any juices or condensate should be securely retained within the container. In some containers formed from thermoformed plastic sheet, strap handles are provided which fold up from the container base. However, when these straps extend so as to present the narrow thickness of the strap pointing downwards, all of the package weight is carried on the user&#39;s hands through a very small surface area of the user&#39;s hand, reducing the comfort of carrying the loaded container. 
     Rotisserie chicken is an example of a food item sold hot. The hot chicken is removed from a spit or warming rack and is placed into a container, for example a two part thermoformed plastic one. Typically the container has a lid which is pressed into engagement with a base so as to form a peripheral seal around the container. What is needed is a container which is readily assembled by food service personnel, and which can accommodate condensate liquids. Moreover, the container should be conducive to carrying by the customer without requiring too close contact with the heated food item. 
     SUMMARY OF THE INVENTION 
     The container for this invention is suited for carry out heated food items, such as rotisserie chicken, and has a base which is connected to a lid by a mating peripheral closure which defines a liquid tight seal. The closure has an encircling inclined wall on the base, which helps to direct the lid into engagement with the base, and which also defines a cavity within the closure which can retain liquid. The base may be provided with two fold up straps which are retained by structure in the lid to lie generally flat to serve as a convenient carrying handle above the lid. The base has a bottom wall with rib structure allowing it to distend downwardly when loaded with food to space the heated food from the customer&#39;s hand while engaged with the handle. 
     It is an object of the present invention to provide a container for heated food items which can be readily assembled from two parts. 
     It is a further object of the present invention to provide a container for heated food items which can be carried in such a way as to avoid too close contact with the food. 
     It is an additional object of the present invention to provide a container for heated food products which retains liquids. 
     Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded isometric view of a container of this invention. 
         FIG. 2  is an isometric view of the base of an alternative container of this invention having retention handles. 
         FIG. 3  is a schematic cross-sectional view of the closure of the container of  FIG. 1  showing closure portions of the undeformed lid superimposed over closure portions of the undeformed base. 
         FIG. 4  is an enlarged fragmentary cross-sectional view of the closure of the container of  FIG. 1 . 
         FIG. 5  is a perspective view of the base of  FIG. 2  engaged with a container lid. 
         FIG. 6  is a top plan view of the base of the container of  FIG. 2 . 
         FIG. 7  is an isometric view of the base of the container of  FIG. 2 , deformed by the weight of a rotisserie chicken contained therein and shown in phantom view. 
         FIG. 8  is a cross-sectional view of the container of  FIG. 6 , taken along section line  8 - 8 , with the deformed loaded container with rotisserie chicken contained therein shown in phantom view. 
         FIG. 9  is a fragmentary cross-sectional view of an alternative embodiment container having a gap between the base and lid flanges for aid in separation. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring more particularly to  FIGS. 1-9 , wherein like numbers refer to similar parts, a container  20  having a tray or base  22  with a mating lid  24  is shown in  FIG. 1 . Both the base  22  and the lid  24  are preferably formed in the thermoforming process from thin sheets of plastic material, for example polypropylene. Preferably the extruded sheet from which the lid  24  is formed will be passed through a rolling bath coater to apply a defogger to the interior. The container  20  may be used for containing heated food items, and the illustrated embodiment is a rotisserie chicken container, such as will commonly be used at a deli counter. In common use a cooked chicken will be taken from a rotisserie and placed directly in the base  22 . The lid  24  is then pressed on to the base  22 , and held to the base by a closure  26 . The closure  26  is comprised of cooperating molded structures on the base  22  and the lid  24 . 
     As shown in  FIG. 1 , the base  22  has a bottom wall  28  with an inwardly protruding rib structure  30  formed therein. A fluted side wall  32  extends upwardly from the bottom wall  28  and is terminated by a narrow peripheral inside flange  34 . A peripheral closure projection  36  extends upwardly from the inside flange  34 , and is terminated by a peripheral outside flange  54 . As shown in  FIGS. 3 and 4 , the closure projection  36  has a first segment  40  which extends upwardly and outwardly from the inside flange  34 , and a second segment  42  which extends inwardly and upwardly from the first segment. The inside flange  34 , the first segment  40 , and the second segment  42 , define a peripheral recess  44  which receives a protrusion  46  formed on the lid  24  and discussed more fully below. A third segment  48  extends upwardly from the second segment  42 , and is joined to an upper wall  50  which extends upwardly and outwardly and which is joined at a radius to an outside wall  52 . The outside wall  52  extends downwardly from the upper wall, and is formed with an undercut so that it extends slightly inwardly. An outside flange  54  extends outwardly from the base of the outside wall  52 . 
     The lid  24  is preferably formed of transparent or semitransparent plastic, and has a top wall  56  with downwardly and outwardly extending side walls comprised of a front wall  58  and a rear wall  60  joined by two side walls  62 . The side walls are terminated by a continuous peripheral inside flange  64 . A peripheral closure cap  66  projects upwardly from the inside flange. The closure cap  66  has an inside wall  68  comprised of a first segment  70  which extends upwardly and outwardly from the inside flange  64 , a second segment  71  which extends upwardly and inwardly from the first segment, and a third segment  72  which extends upwardly from the second segment to form a radiused transition to a generally horizontal and outwardly extending upper wall  74 . An outside wall  76  extends downwardly from the upper wall  74 , and is formed as an undercut, so that it extends somewhat inwardly beneath the upper wall. A horizontal outside flange  78  extends outwardly from the outside wall  76 . 
     The lid cap  66  and the base projection  36  together form the closure  26  when the lid  24  is pressed onto the base  22 . When the lid  24  first engages the base  22 , generally the lowest portion of the lid, that is the inside flange  64  and the inside wall  68 , touches the inwardly inclined upper wall  50  of the base projection  36 . This inclined upper wall  50  serves to direct the lid portions inwardly as downward pressure is applied, with the result that the lid is self-centering and directed into a sealed condition on the base. This structure facilitates the placing of the lid on the base, and the sealing of the closure by a worker using only one hand. The inside wall  68 , with the outwardly extending protrusion  80  formed by the first segment  70  and the second segment  71 , travels downwardly such that the protrusion  80  engages within the recess  44  defined between the base inside flange  34 , the base first segment  40 , and the base second segment  42 . It is this engagement which defines the primary liquid tight seal between the base  22  and the lid  24 . A secondary seal is provided by the engagement between the undercut lid cap outside wall  76  and the base projection outside wall  52 . The outside flanges  54 ,  78 , engage against each other when the lid is fully seated on the base. Although the closure  26  is generally liquid tight, it should be noted that the entire container is not fully liquid tight, because the lid is preferably provided with vent slits  82 , as shown in  FIG. 1 , to allow the escape of hot gases. 
     Because the food contents of the container  20 , such as the rotisserie chicken  84  shown in  FIGS. 7 and 8 , is usually hot and moist when it is placed in the container, there is a tendency for condensation to form on the cool plastic of the base and lid, and for juices or other moisture to fall onto the base as the food is inserted in the container, and the lid placed on the base. Because the customer will handle the loaded container  20 , it is desirable that, as much as possible, liquids be kept from the exterior of the container. The structure of the closure  26  contributes to this goal by providing a sealed cavity  86  defined between the inside wall  68  and the upper wall  74  of the lid closure cap  66  and the base closure projection  50 . First, liquids deposited or condensed on the inclined base closure projection upper wall  50  will tend to be pushed into the interior  88  of the base  22  by the downward movement of the lid cap inside wall and inside flange as the lid is closed on the base. Second, the cavity  86  provides a volume to retain liquids or water vapors trapped between the base closure projection  50 , and the lid closure cap  66 , preventing such liquids from being forced outwardly from the closure onto the exterior of the container. 
     An alternative embodiment base  90 , shown in FIGS.  2  and  5 - 8 , is identical to the base  22  discussed above, except that the base outside flange  92  is wider, and is die cut to define two handle straps  94  which extend from the front to the rear of the container. As shown in  FIG. 6 , the handle straps  94  are of generally constant width and follow the peripheral contour of the base  90 . Thus each base hand strap  94  has three segments: a front segment  96  which extends from a front portion  98  of the base outside flange, a rear segment  100  which extends from the rear portion  102  of the base outside flange  92 , and a connecting segment  104  which extends between the front segment  96  and the rear segment  100 . It will be noted that the base outside flange is deeper at the front portion  98  and the rear portion  102 , because there is no strap cut away there. The handle straps  94  preferably have a semicircular anti-tear cut  106  where they join the base outside flange front portion  98  and rear portion  102 , to limit tearing of the plastic in those regions which would tend to separate the handle straps from the base. 
     As shown in  FIG. 5 , once the container is loaded with the food item  84 , and the lid  24  is closed on the base, the handle straps  94  are lifted up from the base and forced over the ribs  108  which protrude from the lid side walls  62 . The connecting segments  104  of the straps  94  are then received within a recess  110  defined between two ribs  112  which protrude from the rear wall  60 . The rear wall ribs  112  extend upwardly and project above the lid top wall  56 . The recess  110 , however, has a surface  114  which terminates at or about at the same level as the lid top wall  56 . The ribs  112  are preferably positioned closer to one another than the combined widths of the straps  94 , causing the strap&#39;s to overlap one another as they extend across the top wall  56  of the lid  24 . The effect is that the straps  94  extend across the lid top wall  56  with the width of the straps facing toward the top wall. The straps  94  are then slightly spaced from the lid top wall to readily permit a customer&#39;s fingers to be inserted beneath the straps  94  to lift the container  20 . Because the straps  94  are generally horizontal as they extend across the lid top wall, there is a larger surface area to engage the customer&#39;s fingers, and thus there is less tendency of the plastic to press into the customer&#39;s hands or cause discomfort. The straps  94  may be about one half inch wide. The straps will preferably be between about 0.015 to 0.025 inches thick. 
     The lid  24  may have a frontwardly protruding label bubble  116  extending from the front wall  58  of the lid. As the straps  94  extend down along the lid front wall  58 , they may engage opposite sides of the bubble  116  as they extend to the front portion  98  of the base peripheral outside flange  92 . 
     It should be noted that although the structures of the invention have been illustrated as part of a rotisserie chicken container, the inventive features may also be incorporated in rectangular or circular containers, or other shaped food containers. 
     As shown in  FIGS. 6-8 , the container base  90  is preferably formed with a bottom wall  28  rib structure  30  which deforms downwardly when an unresisted load is applied. Dimensions will be given for the illustrated embodiment, which has a bottom wall about 7¾ inches long from front to back, and about 5½ inches wide from side to side, although other container types according to the invention may vary in dimension. The rib structure  30  stiffens the base  90 , and also can elevate the food product from liquid within the container. The bottom wall has a central platform  118  which extends upwardly from a lower encircling segment  120  about ¼ inch. The lower encircling segment  120  marks the lowermost portion of the base  90  as molded, and extends inwardly from the lower margin of the sidewall  32 . The platform  118  has roughly the same shape as the bottom wall, but is spaced inwardly about one inch from the side wall  32  to generally engage the lid top wall  56  when set upon a similar container. Two generally parallel longitudinal ribs  122  extend across the platform  118  and project upwardly about ¼ inch from the platform. The longitudinal ribs  122  extend from the lower encircling segment  120  at the front of the base to the rear of the base. Short bridging ribs  124  are evenly spaced parallel to one another and extend laterally between and connect the two longitudinal ribs  122 . The bridging ribs are about one-half inch wide and extend above the level of the platform about ¼ inch, but not as high as the longitudinal ribs. A plurality of cross ribs  126  extend outwardly from each longitudinal rib  122  to the encircling segment  120 . The cross ribs  126  protrude upwardly from the platform  118  about the same height as the longitudinal ribs, but extend outwardly from the platform to the encircling segment  120 . 
     The function of the bottom wall rib structure  30 , as shown in  FIGS. 7 and 8 , is to deflect or pivot downwardly when a sufficient load is applied to the longitudinal ribs and the cross ribs. For example, when a chicken  84  is placed within the base  22 , the longitudinal ribs are pivoted downwardly, and the cross ribs pivot from the encircling segment  120 . The effect of this downward pivoting is to increase the volume retained within the base, and thereby either allow a larger chicken to be contained in the base, or allow a greater distance between the top of the chicken and the handle straps  94 , thus helping to space the heated contents of the container more distantly from the hands of the purchaser who is carrying the container. It will be noted that when the bottom wall rib structure is supported on a supporting surface, the full deflection will not occur until the container is lifted off the supporting surface. 
     An alternative embodiment container  128 , shown in  FIG. 9 , has a lid  129  substantially the same as the lid  24  discussed above, with the difference that a lid horizontal outside flange  130  is spaced above the base outside flange  54  in a closed condition, to facilitate separation of the lid from the base. The spacing may be approximately the thickness of the plastic sheet from which the lid is formed. 
     It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces all such modified forms thereof as come within the scope of the following claims.

Technology Category: b