PATENT ABSTRACT
A food tray for holding food and a condiment is formed from a unitary paperboard blank. The food tray has a food compartment and a condiment compartment, and the condiment compartment is deployable from a stowed position overlaying one or more sidewalls of the food compartment to a deployed position for holding condiments. Multiple trays can be stacked in a nested fashion when the condiment compartment is stowed.

PATENT DESCRIPTION
CROSS REFERENCE TO RELATED APPLICATIONS 
       
     This application claims the benefit of the U.S. Provisional patent application No. 60/214,438 filed on Jun. 28, 2000, the contents of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to food trays, and more particularly to food trays having selectively deployable condiment compartments. 
     BACKGROUND OF THE INVENTION 
     Finger foods, such as chicken nuggets, popcorn shrimp, french fries, and onion rings, are often served in paperboard trays. These trays have flat bottom walls and side walls that extend upwardly therefrom at an angle to define a top opening larger than the bottom wall. In the interest of space efficiency, these trays are preferably stackable or nestable so that one tray fits inside another tray. This allows large stacks of trays to be shipped and stored in a relatively small space until needed. 
     Many of the above foods are frequently eaten with condiments such as ketchup, cocktail sauce, and barbeque sauce. Since these foods are often eaten with one&#39;s fingers, a person typically holds a food item in his fingers and dips it into a condiment. When eating in a sit-down restaurant, the condiment may be dispensed directly into the paperboard tray next to or on top of the food product, or a tub of the condiment can be placed on a table next to the consumer. When consuming such products in an automobile or while walking, however, the option of using a tub of condiment becomes more difficult. Furthermore, because semi-liquid condiments tend to run, it is difficult to keep the condiments and food products separate, and a user is often left with some products that are substantially covered with condiment and with condiment spread over the entire bottom wall of the container. The more the container is moved during use, the more the condiment is likely to move. 
     Fast food containers having a condiment compartment, such as the one shown in U.S. Pat. No. 4,126,261 for “Disposable Food Tray With Condiment Container” issued to Cook on Nov. 21, 1978, are known in the prior art. However, in the first embodiment of the invention shown in the &#39;261 patent, a condiment holder must be formed from a separate piece of material and then affixed to the main container, resulting in increased assembly costs. In the second embodiment of the invention shown in the &#39;261 patent, the condiment holder is made from the same blank as the tray, but produces a finished product that is not stackable. 
     It would therefore be desirable to produce a stackable tray having an integral condiment compartment formed from a unitary blank of material. 
     SUMMARY OF THE INVENTION 
     These problems and others are addressed by the present invention which comprises a novel tray structure that is stackable and nestable and that includes one or more fold-out walls that form at least one compartment for holding a condiment substantially separate from a food product. The invention also comprises a unitary blank for making such a tray which blank is cut form a sheet of stock material in a manner that makes efficient use of the material, minimizes waste, and provides for an accurate assembly of the food tray. 
     According to the invention, a tray includes a movable wall or panel foldable between a first position flush with one or more sidewalls of the tray and a second position spaced apart from the one or more sidewalls to define a compartment between the sidewalls and the movable wall. This arrangement allows trays to be stacked and nested when the movable wall is in a stowed position flush with a side wall. When the condiment compartment is in its stowed position, the trays can also be used in the same manner as ordinary trays. To use the condiment compartment, it is merely necessary to flip the wall inwardly from the sidewall. The flexibility of the wall allows the wall to be shifted with very little effort. 
     In a first embodiment of the invention, the condiment compartment is formed across a corner of the tray and connected to two adjacent tray sidewalls. When flipped open into a deployed position, a pyramidal condiment compartment is formed in one corner of the tray. 
     In a second embodiment, a movable wall is formed between two parallel sidewalls of the tray. When flipped open, the wall defines a compartment spanning the length or width of the rectangular tray between the movable wall and one of the tray sidewalls. 
     In a third embodiment, the tray includes two condiment compartments along opposite sides of the rectangular compartment each formed by a moveable wall. 
     In a fourth embodiment, the tray is formed much like the tray of the second embodiment but the top edge of one tray wall and the top edge of the movable wall forming the condiment compartment have curved portions to provide for an increased gripping surface. 
     It is therefore a primary object of the present invention to provide a stackable container having an interior wall that can be deployed to form an interior compartment. 
     It is a further object of the present invention to provide a stackable container having a secondary compartment formed from a unitary blank of material. 
     It is another object of the present invention to provide a stackable food tray having a selectively deployable condiment compartment. 
     It is still a further object of the present invention to provide a food tray having a deployable corner compartment. 
     It is still another object of the present invention to provide a stackable food tray having a condiment compartment that is shiftable between a use and a storage position. 
     It is yet another object of the present invention to provide a unitary blank for forming a food tray having the above characteristics. 
     These features and advantages will be better appreciated and understood by those skilled in the art after reading the following detailed description of several preferred embodiments of the invention in connection with the drawings and appended claims. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     The present invention will now be described, by way of example, with reference to the accompanying drawings, of which: 
     FIG. 1 is a perspective view of a food tray having a condiment compartment according to a first embodiment of the invention; 
     FIG. 2 is a right side elevation view of the tray of FIG. 1; 
     FIG. 3 is a front elevation view of the tray of FIG. 1; 
     FIG. 4 is a top plan view of the tray of FIG. 1 with the condiment compartment wall in a stowed position; 
     FIG. 5 is a top plan view of the tray of FIG. 1 with the condiment compartment wall in a deployed position; 
     FIG. 6 is a plan view of a blank for forming the tray of FIG. 1; 
     FIG. 7 is a perspective view of a food tray according to a second embodiment of the present invention having two condiment compartments both shown in deployed positions; 
     FIG. 8 is a left side elevation view of the tray of FIG. 7; 
     FIG. 9 is a front elevation view of the tray of FIG. 7; 
     FIG. 10 is a top plan view of the tray of FIG. 7 showing only one of the two compartments in a deployed position; 
     FIG. 11 is a plan view of a blank for forming the tray of FIG. 7; 
     FIG. 12 is a top plan view of a food tray according to a third embodiment of the present invention; 
     FIG. 13 is a plan view of a blank for forming the tray of FIG. 12; 
     FIG. 14 is a front elevational view of a food tray according to a fourth embodiment of the invention; and, 
     FIG. 15 is a plan view of a blank for forming the tray of FIG.  14 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, wherein the showings are for the purpose of illustrating several embodiments of the invention only and not for the purpose of limiting same, FIG. 1 illustrates a food tray  10  that is assembled by folding and gluing a unitary blank  12  of paperboard stock. To facilitate the description of the present invention, the tray will be generally described in a position in which it is normally used by a consumer, that is, with the opening for food at the top and with the bottom wall resting on a flat support surface (not shown). 
     Referring to FIGS. 1-6, tray  10  includes a food compartment  11  and a condiment compartment  13 . Food compartment  11  has a pair of opposed first and second sidewalls  18 ,  20 , a front wall  22 , a rear wall  24 , and a bottom panel  26 . First sidewall  18  has an upper edge  28 , and is joined with bottom panel  26  along a first fold line  32 . 
     First and second triangular glue flaps  34 ,  36  are coextensive and integral with the edges of first sidewall  18  and are connected thereto at a second fold line  38  and a third fold line  40  respectively. Second and third fold lines  38 ,  40  are outwardly divergent, making first sidewall  18  trapezoidal. Second triangular glue flap  36  has a concave upper edge portion  42  which, as will be explained hereinafter, provides access to the condiment compartment movable wall so that wall can be moved. 
     Second sidewall  20  has an upper edge  44 , and is joined with the bottom panel edge along a fourth fold line  48  generally running parallel to first fold line  32 . Third and fourth triangular glue flaps  50 ,  52  are integral with rear and front edges of second sidewall  20  and are joined to the second sidewall along a fifth fold line  54  and a sixth fold line  56  respectively, which the fold lines are mutually divergent. 
     Rear wall  24  is trapezoidal, includes an upper edge  60 , and is joined at its lower edge with the rear edge of the bottom panel along a seventh fold line  62  generally perpendicular to first and fourth fold lines  32 ,  48 . Rear wall  24  further includes slanted side edges  64 ,  66 . 
     Front wall  22  has an upper edge  68 , and a bottom edge that meets bottom panel  26  along an eighth fold line  72  generally parallel to seventh fold line  62 . Front wall  22  also includes two opposed slanted side edges  74  and  76  and a concave upper edge portion  78  which overlays the concave edge portion  42  of second triangular glue flap  36  when condiment compartment  13  is in a stowed position. 
     Condiment compartment  13 , which is more specifically defined as the area between first and second triangular walls  80  and  82 , a portion of first sidewall  18 , and a portion of front wall  22 , and which is integral with the food compartment, includes a first triangular wall  80 , a second triangular wall  82  joined and coextensive with first triangular wall  80  along a ninth fold line  90 , a first condiment compartment glue flap  84  joined and integral with first triangular wall  80  along a tenth fold line  88 , and a second condiment compartment glue flap  86  integral and coextensive with second triangular wall  82  along an eleventh fold line  92 . 
     First glue flap  84  is joined and integral with upper edge  68  of front wall  22  along a twelfth fold line  94  from which second portion  16  as a whole is attached to first portion  14  of unitary blank  12 . 
     First triangular wall  80  of condiment compartment  13  has a convex edge portion  96  along its upper edge where, in the folded configuration of the condiment compartment, convex edge portion  96  extends peripherally beyond concave edge portion  78  of the front wall  22  and concave edge portion  42  of second triangular glue flap  36 . Convex edge portion  96  provides a gripping location at which the condiment compartment walls can be gripped and pulled out into a deployed or use position. 
     In the preferred embodiment, first and second triangular walls  80 ,  82  are generally isosceles. That is, tenth fold line  88 , ninth fold line  90 , and eleventh fold line  92  all have about the same length. Moreover, as best seen in FIGS. 5 and 6, the distance between a first point A and a second point B in the assembled, and deployed, condiment compartment  13  is less than the distance between point C and point D of the second portion of panel  16 . These relative distances, as will be explained herein, provide for a snap-out deployment of condiment compartment  13  which allows condiment compartment  13  to stay in a deployed configuration without any condiment inside. As best seen in FIG. 5, condiment compartment  13  has an inverted pyramid shape in its deployed position. 
     It should also be appreciated that the bottom portion of the inverted pyramid shaped condiment compartment is held closely against the lower edge of the front wall of the tray. That is, edge  98  of first glue flap  84  overlays eighth fold line  72  of the tray. 
     The assembly of tray  10  will now be explained with reference to the blank shown in FIG.  6 . First sidewall  18  is folded up along first fold line  32  toward bottom panel  26 . Second sidewall  20  is folded up along fourth fold line  48  toward bottom panel  26 . Rear wall  24  is then folded up along seventh fold line  62 . Next, first triangular glue flap  34  is folded along second fold line  38  inwardly where side edge  66  coincides with second fold line  38  and then glue flap  34  is adhesively bonded onto the back surface of rear wall  24 . Similarly, third triangular glue flap  50  is folded along fifth fold line  54  inwardly and behind rear wall  24  until side edge  64  coincides on top of fifth fold line  54  and then third triangular glue flap  50  is adhesively bonded to the back surface of rear wall  24 . 
     Second and fourth triangular glue flaps  36  and  52  are folded along third and sixth fold lines  40  and  56 , respectively, and are adhesively bonded to the back surface of front wall  22 , where side edge  76  coincides on top of third fold line  40 , and side edge  74  coincides on top of sixth fold line  56 . 
     At this point, food compartment  11  of tray  10  is assembled. Now, the assembly of condiment compartment  13 , which is integral with the food compartment will be described. 
     Second triangular wall  82  is folded under first triangular wall  80  along ninth fold line  90  and the two triangular walls are symmetrically placed on top of one another. Eleventh fold line  92  coincides along tenth fold line  88  as second condiment glue flap  86  partially overlays on first condiment glue flap  84 . 
     Next, second portion  16  as a whole is folded up and into the food compartment along twelfth fold line  94  until first triangular wall  80  and first condiment glue flap  84  are flush with front wall  22  of tray  10 . At this point, upper edge  98  of first glue condiment flap  84  becomes aligned with and eighth fold line  72 . First condiment glue flap  84  is adhesively bonded to the interior surface of front wall  22 . First triangular wall  80  is free to fold along tenth fold line  88 . Also, second triangular wall  82  is free to fold along ninth fold line  90 . 
     Second condiment glue flap  86  is adhesively bonded to the interior side of first sidewall  18  at a location and position which is determined by aligning ninth fold line  90  with third fold line  40  and second triangular wall  82  flush with first wall  18 . This results in the stowed configuration of the condiment compartment. In order to deploy the condiment compartment, the user pulls convex edge  96  of first triangular wall  80  in the direction of the interior of the food compartment. The first and second triangular walls  80  and  82  are flexible thus bend to allow the wall to shift from the stowed position shown in FIG. 4 to the deployed position shown in FIG.  5 . As stated earlier, because the distance between points C and D is longer than the distance between points A and B, the wall snaps open into a deployed position and remains deployed even with no condiment inside. 
     Referring now to FIGS. 12 and 13, a second embodiment of the invention is illustrated. In this embodiment, elements common to the first embodiment are identified by like numerals. The condiment compartment in this embodiment is elongated, spans the width of the tray and deploys and stows relative to the front wall of the tray. Of course, this compartment could also be formed along one of the long sides of the rectangular tray or along the rear wall of the tray. 
     A flap  100  is attached to front wall  22  along a perforated cut line  102 , and spans the width of the upper edge of front wall  22 . When folded over front wall  22  and attached thereto as described below, this flap will form a condiment compartment  113  having a main wall  104 . Condiment compartment  113  shown in an open position in FIG. 12, further includes a first triangular portion  106  integral with main wall  104  along a fourteenth fold line  118  on one side, and integral with a third glue flap  108  along a fifteenth fold line  120  on the opposing side. A second triangular portion  110  is integral with main wall  104  along a sixteenth fold line  116  on one side, and is joined and integral with a fourth glue flap  112  along a seventeenth fold line  114 . A glue flap  124  is integral with the lower edge of main wall  104  along an eighteenth fold line  122 . Fourteenth and sixteenth fold lines  116 ,  118  are divergent. 
     It should be appreciated that condiment compartment  113  is the area confined between first and second triangular portions  106  and  110 , main wall  104 , front wall  22 , and is closed off on the corners along the fifteenth and seventeenth fold lines  120  and  114 , and on the bottom along eighth fold line  72  of bottom panel  26 . All edges of the condiment compartment are glued to the sidewalls and/or bottom wall of the tray thus providing a good seal to hold a condiment in place. 
     As stated hereinabove, main wall  104  is joined with front wall  22  on the unitary blank along the perforated thirteenth line  102 , which may is scored along most of its length and connected to wall  22  at a small number of locations. This arrangement holds panel  100  to wall  22  during manufacture and assembly, but allows a user to easily break the connections between wall  22  and panel  100  when the tray is assembled so that the condiment compartment can be deployed. 
     The food compartment is assembled in the same way as the first embodiment explained hereinabove. The condiment compartment  113  is assembled as follows: First, top portion  124  is slightly folded outwardly along eighteenth fold line  122 . Next, main wall  104  is folded inwardly into the food compartment along thirteenth fold line  102  and is placed flush with front wall  22 . Eighteenth fold line  122  overlays eighth fold line  72  and top portion  124  rests on the top surface of bottom panel  26  and is adhesively bonded thereon. 
     Fourth glue flap  112  is adhesively bonded to the inner surface of second sidewall  20  and seventeenth fold line  114  overlays sixth fold line  56  and side edge  74  of front wall  22 . Similarly, at the opposing side, third glue flap  108  is adhesively bonded to the inner surface of first sidewall  18  in such configuration that fifteenth fold line  120  overlays third fold line  40  and side edge  76  of front wall  22 . Therefore, second portion  100  is adhesively bonded and secured to first portion  14  where in the stowed position and configuration of the condiment compartment, main wall  104  is flush with front wall  22 , bottom portion  124  is secured on the top surface of bottom panel  26 , and third and fourth glue flaps  108 ,  112  are secured to first and second sidewalls  18 ,  20 . To deploy condiment compartment  113 , main wall  104  is pulled away from front wall  22  breaking the few connections therebetween. 
     As best seen in FIG. 12, the distance E-F-G-H is greater that the distance between points E and F, and therefore, when panel  104  is moved away from front wall  22 , front panel  22  and the triangular panels  106  and  110  are deformed until panel  104  reaches the position shown in FIG.  12 . Because these panels also need to be deformed to move panel  104  back against front wall  22 , the condiment compartment tends to stay in an open position, even when it is empty. 
     Referring now to FIGS. 7-11, a third embodiment of the invention is illustrated. This embodiment is identical to the second embodiment described above, except a second identical condiment compartment is utilized at the opposing side of the tray along rear wall  24 . Reference numerals with primes are used to designate portions of the second compartment, for example the second compartment  113 ′ includes a wall  104 ′ corresponding to wall  104  of the second embodiment. The production and assembly of this embodiment will easily be understood from reading the above description of a tray having single compartment spanning its width and will not be described further. 
     A fourth embodiment of the invention is shown in FIGS. 14 and 15. This embodiment is substantially the same as the second embodiment described above except in the area of the top edges of the front wall and the condiment compartment wall. FIG. 14 shows a front view of a fourth embodiment of the invention. The container includes a front wall  220  having a top edge  222  which includes first and second linear outer portions  224 ,  226  and a sinusoidal central portion having a first arched section  228  curving away from front wall  220  and a second arched section  230  cut into front wall  220 . The panel further includes a wall  232  that shifts to form a condiment compartment as described above. Wall  232  has a top edge  234  with a first portion  236  arching away from the center of wall  232  and a second portion  238  cutting into wall  232 . When the container is assembled, first arched section  236  of wall  232  overlies the second arched section  230  of front wall  220 . This arrangement produces a wall for forming a condiment compartment that functions substantially the same as the previous embodiment but which provides an increased gripping surface to make the condiment compartment wall  232  easier to separate from front wall  220 . A blank for forming a tray according to this embodiment is shown in FIG.  15 . 
     While preferred embodiments have been shown and described, various modifications and changes may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration only, and such illustrations and embodiments as have been disclosed herein are not to construed as limiting to the claims.