Abstract:
This invention relates to stackable, open-topped, partially-lidded, and/or fully-lidded shipping and/or display container, and more particularly to a corrugated paperboard stackable container for shipping and displaying products such as, for example, agricultural produce.

Description:
BACKGROUND OF THE INVENTION 
     The present application claims the benefit of priority under 35 USC §119(e) to U.S. Provisional Patent Application 60/702,879, filed Jul. 27, 2005, which is hereby incorporated, in its entirety, herein by reference. 
     1. Field of the Invention 
     This invention relates to stackable, open-topped, partially-lidded, and/or fully-lidded shipping and/or display container, and more particularly to a corrugated paperboard stackable container for shipping and displaying products such as, for example, agricultural produce. 
     2. Prior Art 
     Containers made from corrugated paperboard are commonly used for shipping and storing various products, including agricultural produce. One preferred container includes a bottom wall, opposite side walls, opposite end walls, and an open top. Stacking tabs on the upper edges of the side and/or end walls engage in slots or openings in the bottom of another tray when the trays are stacked on top of one another to achieve stacking stability. These trays offer good stacking strength and stability, and also provide excellent product presentation due to the open top, and the side panel surfaces that permit display of graphics and the like. Further, recent improvements to these trays have included inwardly inclined side or end panels with correspondingly inclined stacking tabs to provide greater resistance to nesting or telescoping of stacked trays, and to allow units to be easily palletized. 
     Typically, these trays are formed from a single blank of corrugated paperboard scored with score lines or cut lines, and folded into a finished tray by automated machines or by hand. Machine forming can be accomplished in a continuous in-line process involving cutting, scoring and folding the trays from continuous sheets of paperboard. In order to achieve a desired stacking strength in conventional produce trays, different weights (thicknesses) of material are used in the construction of the tray. 
     Conventional produce trays have inner and outer side wall panels that form square outer corners and angled or diagonal inner corners. The diagonal inner corners extend into the tray interior space and limit to a certain extent the type, style or number of clamshell grape lugs, for example, that can be placed in the tray. 
     It would be desirable to have a tray with the advantages of the conventional produce tray, but that uses less material in its construction and has interior space to accommodate commonly used clamshell grape lugs, for example. Further, it would be desirable to have a tray or shipping and/or display container that is capable of having either a partially-lidded or fully-lidded feature that allows ventilation and/or access of goods contained therein to the consumer and protects the goods at the same time while in transport and/or during stacking. 
     SUMMARY OF THE INVENTION 
     The present invention is a produce style tray with improved stacking strength and increased interior space, while requiring less material to make than prior art trays. The tray of the invention has inner and outer wall panels that form diagonal corners both inside and outside the tray. In one embodiment, the diagonal corner is single ply and is formed on an outer side wall panel, thus increasing the interior space of the tray while maintaining the diagonal corner configuration, and in another embodiment the inner and outer wall panels each has diagonal corner panel, thus forming double ply diagonal corners. 
     The trays according to preferred embodiments of the invention are formed from blanks of corrugated paperboard cut and scored to form a bottom panel with an end wall panel foldably joined to opposite end edges thereof. Opposite outer side wall panels are foldably joined to the opposite side edges of the bottom panel, and an inner side wall panel is foldably joined to the outer or upper edge of each outer side wall panel. A minor flap is foldably joined along a pair of spaced apart fold lines to each of the opposite ends of at least the outer side wall panels. These minor flaps comprise sealing flaps that are secured relative to respective end wall panels, and the spaced apart fold lines of each pair define between them diagonal corner panels in the erected tray. 
     In one embodiment, diagonal corner panels are formed only in the outer side wall panels. Provision of the diagonal corner panels in the outer side wall panels moves the diagonal corner panels farther out relative to the interior of the tray, thus increasing the interior space over that available in conventional produce trays, wherein the diagonal corner panels are formed on the inner wall panels. Additionally, the inner side wall panels may be devoid of minor flaps extending from their ends, reducing the amount of material required to produce the tray. 
     In another embodiment, minor flaps are foldably joined along pairs of spaced apart fold lines to opposite ends of both the inner and outer side wall panels, forming diagonal corner panels on both the inner and outer side wall panels, resulting in double ply diagonal corners. This construction permits a lighter weight material to be used in forming the tray, while achieving the same strength as obtained in conventional trays that require a heavier weight material. 
     In both embodiments, at least the bottom edges of the minor flaps can extend at an acute angle relative to the bottom edges of the respective side wall panels, whereby when the panels are folded to form an erected tray, the side walls are inwardly inclined, or lean in at their top edge, thus defining a smaller footprint at the top of the tray than at the bottom and helping to prevent an upper tray from telescoping or nesting into a lower tray when the trays are stacked on top of one another. 
     Additionally, the stacking tabs formed on the upper edges of the side and/or end walls extend coplanar with the respective side and/or end wall, i.e., the stacking tabs are inwardly inclined or lean in at the same angle as the respective side and/or end wall, and are adapted to be received in and captured by slots or openings in the bottom of another tray. 
     In a preferred construction, bendable tongues project into the tab-receiving slots from one side thereof and help define a friction lock mechanism to hold the stacking tabs in the slots. 
     In another embodiment the container of the invention has opposed side walls, opposed end walls, a bottom wall, and a lid, said bottom wall cooperating with the side walls and end walls to define an interior space. The lid is foldably connected along a fold line to an upper edge of at least one of the end walls, and is foldable relative to the end wall so as to be moveable between an open position and a closed position. The lid may completely cover the interior space, or only partially cover it when in its closed position. A minor flap is on each of the opposite ends of each side wall, and these minor flaps are folded inwardly from the side walls and lie against a respective adjacent end wall. A shaped notch is formed in an upper edge of the minor flap, and a self-locking feature is formed in the lid adjacent each minor flap. Each self-locking feature is defined by spaced cuts extending into the lid from the fold line to form a roll-over flap cut from the lid. The roll-over flap is connected at one end thereof with an associated end wall by a web, and the cuts extend across the fold line at opposite ends of the web and into the end wall to define a heel on said one end of the roll-over flap, said heel being cut from an upper edge of the end wall. Each roll-over flap is folded from the plane of the lid and inwardly and downwardly over an adjacent minor flap to lie against an inner surface of a respective adjacent minor flap, with the web received in the shaped notch and the heel extending upwardly from the roll-over flap and lying against an inner surface of a respective adjacent minor flap. The roll-over flaps hold the minor flaps in position against a respective end wall. Openings are formed in the lid where material has been removed between said cuts to form said roll-over flaps. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing, as well as other objects and advantages of the invention, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like reference characters designate like parts throughout the several views, and wherein: 
         FIG. 1  is a plan view of a blank for making a conventional produce tray. 
         FIG. 2  is a plan view of a blank for making a first embodiment of a tray in accordance with the invention, wherein the tray has single ply diagonal corners. 
         FIG. 3  is a plan view of a blank for making a second embodiment of a tray in accordance with the invention, wherein the tray has double ply diagonal corners and is adapted for manual or hand set-up. 
         FIG. 4  is a plan view of a blank similar to that shown in  FIG. 3 , except the blank is adapted for machine set-up. 
         FIG. 5  is a top perspective view of a pair of stacked together trays having single ply diagonal corners, produced by using the blank of  FIG. 2 . 
         FIG. 6  is an enlarged fragmentary top perspective view of one corner of the stacked together trays of  FIG. 5 , viewed from outside the corner. 
         FIG. 7  is an enlarged fragmentary top perspective view of one of the trays of  FIG. 5 , viewed from inside the corner. 
         FIG. 8  is a top perspective view of a tray made using the blank of  FIG. 3 , wherein the diagonal corners are double ply. 
         FIG. 9  is an enlarged fragmentary top perspective view of one corner of the tray of  FIG. 8 , viewed from inside the corner. 
         FIG. 10  is a plain view of a blank for making an embodiment of a tray in accordance with the invention, wherein the tray has a lid panel and, when constructed in the closed position, is fully lidded. 
         FIG. 11  is an enlarged fragmentary top perspective view of one embodiment of the present invention shown in  FIG. 11 , when the tray is constructed and the lid is in the open position and shows one embodiment of the self locking feature in the locked position. 
         FIG. 12  is an enlarged fragmentary top perspective view of one embodiment of the present invention shown in  FIG. 11 , when the tray is constructed and the lid is in the closed position. 
         FIG. 13  is a plan view of a blank for making an embodiment of a tray in accordance with the invention, wherein the tray has a lid panel and, when constructed in the closed position, is partially lidded. 
         FIG. 14  is one embodiment of the self locking feature of the present invention. 
         FIG. 14A  is an enlargement of the area circled at “A” in  FIG. 14 . 
         FIG. 15  is one embodiment of the notch according to the present invention. 
         FIGS. 15A and 15B  are enlargements showing details of the areas circled at “A” and “B”, respectively, in  FIG. 15 . 
         FIG. 16  is one embodiment of the fastening feature of the present invention. 
         FIG. 16A  is an enlargement showing details of the area circled at “A” in  FIG. 16 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , a blank  10  for producing a conventional produce tray has a bottom panel  11 , outer side wall panels  12  and  13  foldably joined along fold lines  14  and  15  to opposite side edges of the bottom panel, inner side wall panels  16  and  17  foldably joined to the outer or upper edge of the outer side wall panels, end wall panels  18  and  19  foldably joined along fold lines  20  and  21  to opposite ends of the bottom panel, and locking roll-over panels  22  and  23  foldably joined to the outer or upper edges of the end wall panels. Minor flaps  24  and  25  are foldably joined to opposite ends of each of the outer side wall panels along single fold lines  26 , and minor flaps  27  and  28  are foldably joined to opposite ends of each of the inner side wall panels along pairs of spaced apart fold lines  29  and  30 . 
     Locking tabs  31 ,  32  and  33  project from the free edge of panels  16  and  17 , this free edge being the bottom edge in an erected tray. Locking tabs  34  also project from one side edge of the minor flaps  27  and  28 , and corresponding locking tabs  35  project from one side edge of minor flaps  24  and  25 . These side edges correspond to the bottom sides of the minor flaps in an erected tray. In addition, locking tabs  36  and  37  project from opposite ends of the free edge of each of roll-over panels  22  and  23 . 
     Slots or openings  38 ,  39  and  40  are provided in the bottom panel closely adjacent to or contiguous with the respective fold lines  14  and  15 , in positions to receive the locking tabs  31 ,  32  and  33  when the panels are folded into operative erected position, and similar but larger openings  41  and  42  are formed in opposite ends of the bottom panel closely adjacent to or contiguous with the fold lines  20  and  21 , in positions to receive the locking tabs  34 ,  35 ,  36  and  37  on the minor flaps and on the roll-over panels, respectively, when the tray is erected. These locking tabs and slots function to hold the tray in its erected position. 
     Cut-outs  45  and  46  are made in the material of the inner and outer side wall panels, spanning the fold line between them, leaving connecting webs  47  and  48  that form stacking tabs  49  and  50  (see, e.g.,  FIG. 5 ) in a tray erected from the blank. 
     Stacking tab-receiving openings  51  and  52  are formed in the bottom panel at opposite ends thereof adjacent to or contiguous with the fold lines  20  and  21  for receiving the stacking tabs  49 ,  50  on a subjacent tray when the trays are stacked on top of one another. 
     Bendable tongues  53  project into the openings  51  and  52  from the side thereof opposite the respective fold lines  14  and  15  and with the openings and stacking tabs form a friction locking mechanism that securely but releasably holds the stacking tabs in the openings. Crushed areas  54  may be formed in the material of the blank along the side of the openings  51  and  52  opposite the side from which the tongues project, to provide additional clearance for stacking tabs extended into the openings. 
     Short relief cuts  60  preferably are made in the material of the blank along opposite sides of all the other openings formed in the bottom panel, defining somewhat flexible or bendable tabs or tongues in each of these openings to facilitate insertion of the locking tabs into the openings. 
     To erect a tray from the blank of  FIG. 1 , the panels  16  and  17  are folded upwardly and inwardly to lie against the respective panels  12  and  13 , and these combined panels are folded upwardly about respective fold lines  14  and  15  into an upright position, with the locking tabs  31 ,  32  and  33  engaged in the slots  38 ,  39  and  40 . The minor flaps  24 ,  25  and  27 ,  28  are then folded inwardly about their respective fold lines  26  and  29 ,  30 , and the end wall panels  18  and  19  are then folded upwardly against the minor flaps, followed by folding the locking roll-over panels  22  and  23  inwardly and downwardly over the minor flaps, with the locking tabs  34 ,  35 ,  36  and  37  engaged in the openings  41  and  42  and the minor flaps sandwiched between the end wall panels and the roll-over panels. 
     It will be noted that each of the minor flaps  24 ,  25 , and  27 ,  28  extend at a slight acute angle relative to the length axis of the respective side wall panels, and the outermost fold line  29  of the pair of fold lines joining minor flaps  27  and  28  to their respective inner side wall panels also is disposed at a corresponding angle. Accordingly, when the panels are all folded into their operative erected positions, the side wall panels are slightly inwardly inclined toward their upper edge. 
     The resulting conventional tray (not shown) has square outer corners defined by the single fold lines  26 , and diagonal inner corners defined by the pairs of fold lines  29  and  30 . 
     It will also be noted that in the particular example shown, the end wall panels  18  and  19  and the associated roll-over panels  22  and  23  have less height than the side wall panels  12 ,  13  and  16 ,  17 , and the minor flaps  24 ,  25 ,  27  and  28  have recessed areas or cut-outs  65 ,  66  in their upper edges where the roll-over panel engages them. This construction provides a ventilation opening  70  (see, e.g.,  FIG. 5 ) in the upper edge of the end walls. The cut-outs  45  and  46 , in addition to defining the stacking tabs, also provide ventilation openings  71  in the top edges of the side walls (see, e.g.,  FIG. 5 ). 
     A first embodiment of a blank for making a tray according to the invention is indicated generally at  80  in  FIG. 2 . This blank differs from that shown in  FIG. 1  in that the minor flaps are omitted from the inner side wall panels  16 ′ and  17 ′, and the minor flaps  24 ′,  25 ′ are joined to their respective outer side wall panels  12 ′,  13 ′ by pairs of spaced fold lines  81 ,  82 , rather than the single fold lines in the prior art. Other components corresponding to those shown in  FIG. 1  are indicated by like reference characters. When the tray is erected by folding the panels of the blank into their operative positions, generally as discussed above, the square corners are eliminated and the diagonal corners are moved outwardly relative to the interior of the tray, affording more space and permitting the tray to accommodate more of the commonly used clamshell lugs used in the grape industry, for example. This embodiment also requires slightly less material than the prior art tray, yet retains the compressive or stacking strength of the former tray. 
     A tray  90  made from the blank of  FIG. 2  is shown in  FIGS. 5 ,  6  and  7 . Note the stacking tabs  49  and  50 , and ventilation openings  70  and  71 . Further, it will be noted that the corners  91  of the bottom panel project beyond the diagonal corners  92 ,  93 ,  94  and  95 , defining a square footprint that rests securely on top of a subjacent tray when the trays are stacked on top of one another, as shown in  FIGS. 5 and 6 . 
     A second embodiment of a blank for making a tray according to the invention is indicated generally at  100  in  FIG. 3 , and like parts are indicated by like reference characters. This form of the invention is generally similar to that shown in  FIG. 2 , except that minor flaps  101  and  102  are foldably joined to the ends of the respective inner side wall panels  16 ″ and  17 ″ along spaced double fold lines  103  and  104 . Accordingly, when the tray is erected, as shown in  FIGS. 8 and 9 , double ply diagonal corners  105 ,  106 ,  107  and  108  are produced. This version of the tray has approximately 24% greater stacking strength than conventional trays of this type. 
     A third embodiment of a blank for making a tray according to the invention is shown at  120  in  FIG. 4 . This form of the invention is essentially the same as that form shown in  FIG. 3 , except that the  FIG. 4  embodiments is designed for machine set-up. Thus, the locking tabs on the inner side wall panels  16 ′″,  17 ′″ and corresponding openings, and the locking roll-over panels are omitted. Further, the minor flaps  121  and  122  on the outer side wall panels  12 ″,  13 ″ are shorter in length than the minor panels  24 ′,  25 ′ on the  FIG. 3  embodiment, since these flaps are not captured between the end panel and a roll-over panel, but are adhesively secured to the end panels  123  and  124 , respectively. It will be noted that the end panels  123  and  124  are configured differently on their upper edges, having recessed areas  125  to form ventilation openings 
     The stacking tabs can be positioned on either the end panels or the side panels and either the side walls or the end walls can be inwardly inclined. Further, the tray can be sized to be modular (half-sized or full sized) to allow interlocking with other trays that have stacking tabs properly positioned. The tray also can be made in various sizes (footprints) to accommodate two tabs per side or end or one tab per side or end. 
     The present invention also relates to a tray and/or container with the advantages of the conventional produce tray and/or the above-mentioned embodiments of the present invention and further has either a fully-lidded or partially-lidded feature that allows ventilation and/or access of goods contained therein to the consumer and protects the goods at the same time while in transport and/or during stacking.  FIGS. 10 and 11  represent exemplified embodiments of blanks that, when constructed into their corresponding tray/container, have a fully-lidded feature and partially-lidded feature, respectively. 
     In an additional aspect of the invention, a blank generally referred to as  150  is shown in  FIG. 10 . A blank  150  differs from those conventional and inventive blanks described above 
     ( FIGS. 1-3  and  5 - 9 ) in that the roll over panels  22 , 23  are not provided and the blank  150  contains a lid panel  151 , 152 . The lid panel  151 , 152  may be connected, preferably foldably connected via a fold line  156 , to an end wall panel  18 , 19 . In this embodiment, the end wall panel  18 / 19  may be longer, shorter, or equal to that of either of the inner side wall panel  16 , 17  and/or the outer side wall panel  12 , 13 . As shown in  FIG. 10 , the end wall panels  18 / 19  are longer than that of either of the inner side wall panels  16 , 17  and/or the outer side wall panels  12 , 13 . 
     When the blank  150  is constructed, the lid panel  151 , 152  may be in an open or closed position.  FIG. 11  shows one embodiment where the lid panel  151 , 152  is in the open position, while  FIG. 12  shows one embodiment where the lid panel  151 , 152  is in the closed position. It can be appreciated that to place the lid panel  151 , 152  is in the open position, the lid panel  151 , 152  is folded upwardly to be approximately perpendicular to the bottom panel  11 . When in the open position, the lid panel is spaced away from the interior space  500  of the tray/container, thereby allowing access to the interior space and any goods/products contained therein. The lid panel  151 , 152  may be folded inwardly as well so as to be placed is in the closed position, where the lid panel  151 , 152  is spaced above a portion of the interior space of the tray/container, thereby reducing access to the interior space and any goods/products container therein. In the closed position, the lid panel  151 , 152  provides not only vertical stacking strength, but also protects the goods/products contained therein the interior space of the tray/container. Although the lid panel may be spaced in any orientation relative to the bottom, side and/or end wall panels,  FIG. 12  provides a preferred embodiment that, when in the closed position, the lid panel  151 , 152  is approximately parallel to the plane of the bottom panel  11  and/or approximately perpendicular to the inner side wall panel  16 , 17  and/or the outer side wall panel  12 , 13 . Further, in this preferred embodiment, the lid panel  151 , 152  is approximately parallel to the end wall panel  18 , 19  . In addition, the lid panel  151 , 152  is spaced above a top edge of at least one inner side wall panel  16 , 17  and/or at least one outer side wall panel  12 , 13 , when the lid panel  151 , 152  is in the closed position. 
     The size of each lid panel  151 , 152  may be of any size and shape, so long as when the lid panel  151 , 152  is in the closed position it is spaced above at least a portion of the interior space provided by the tray/container. In a preferred embodiment as shown in  FIG. 12 , each lid panel  151 , 152  has a width and/or length so each lid panel  151 , 152  is spaced above about half of the interior space of the tray/container when in the closed position, thereby resulting in approximately the entire interior space being covered by the lid panel  151 , 152 . In alternative embodiments, it may be desirable to replace a plurality of lid panels  151 , 152  with a single lid panel  151 , 152  that achieves the above. In further alternatives, one or more lid panel  151 , 152  may be used and have a size and shape that, when in the closed position, does not cover the entire interior space of the tray/container. Further, one or more lid panel  151 , 152  may be used and have a size and shape that, when in the closed position, may or may not cover the entire interior space of the tray/container and may or may overlap one another. 
       FIGS. 10 and 13  show exemplified embodiments of a first blank  150  and a second blank  250  containing the lid panel  151 , 152 . The lid panel has outside edges  207 , 208 , 216 . The lid panel  151 , 152  also contains at least one fastening feature  200  (discussed in detail below). When the lid panel  151 , 152  is in the closed position, the fastening feature  200  helps secure and fasten the lid panel  151 , 152  so as to immobilize the lid panel  151 , 152  when the lid panel  151 , 152  is spaced above a portion of the interior space of the tray/container, thereby locking the lid pane 1   151 , 152  into the closed position and securing it so as to protect goods/products within the interior space. The lid panel  151 , 152  also contains a portion of a self locking feature  170 . A further portion of the self locking feature  170  is contained by the end wall  18 / 19  as well. In the embodiment shown in  FIG. 10 , the lid panel contains a portion of the fold over flap  160  and a portion of a web  153  of the self locking feature  170 . When the lid panel  151 , 152  is in either the closed or open position, the fold over flap  160  and the self locking feature  170  help secure and lock the end wall panel  18 / 19  and the lid panel  151 , 152  to the minor flaps  24 ,  25 ,  27 , and  28  when the tray/container is erected. In a preferred embodiment, the self locking feature  170  contains the web  153  that engages a notch  180 , preferably in the shape of a hook  184  (described below) that is located at the top edges of the minor flaps  24 ,  25 ,  27 , and  28 . Therefore, the self locking feature  170  not only helps to maintain the lid panel  151 , 152  in the open and closed positions, but also provides burst and stacking strength to the entire erected tray/container. 
     The lid panels do not contain the locking tabs  36  and  37  because the lid panels do not serve the same function as the roll over panels  22  and  23  mentioned above. Therefore, there may not be any locking of the lid panels into the openings  41  and  42  as mentioned above because at least a portion of the lid panel, as defined above, does not roll over to a position that is approximately perpendicular to the plane of the bottom panel  11 . One preferable self locking feature is shown as  170  ( FIG. 10 ). This self locking feature is preferably located such that a portion of it is contained within the lid panel  151 , 152  and a portion of it is contained within the end panel  18 , 19 . The self locking feature  170  contains a web  153  and a fold over flap  160  that contains a heel  164 . The web  153  is defined by cuts or relief slits  154  and  155  made transversely across fold line  156 , and interrupting the fold line  156 , the fold line  156  preferably extending completely across the width of lid panel  151  and/or  152 , except at the webs  153  and the relief slits  154 , 155  (See  FIG. 14 ). Short fold promoting slits  157   a  and  157   b  are preferably made approximately parallel to the fold line  156  on opposite sides thereof the web  153  in locations to define the length of the webs when the lid panel  151 , 152  and the end panel  18 / 19  are folded and erected into their locked position, placing the lid panel  151 , 152  in either its open or closed position. In other words, the fold promoting slits  157   a  and  157   b  initiate folding at opposite ends of the web  153  along fold lines  140141 , extending through the fold promoting slits. The length of the web  153 , as defined by the spacing between the relief slits  154 , 155 ; and thus between the fold lines  140 , 141  that may or may not extend through them, is substantially the same as the combined thicknesses of the total number of overlapping end panels. In an alternative embodiment, the structural integrity of the web  153  may be compromised, for example, the web  153  may be crushed to facilitate the self-locking function of this feature. Preferably, the structural integrity of the web is compromised in an area between the relief slits  154 ,  155  and fold promoting slits  157   a  and  157   b . Preferably, when crushed, the crush is made on the surface of the web  153  that faces inwardly of the container when the container is erected. Crushing of the web  153  enables the web to extend more deeply into a notch  180  positioned to receive the same (described below), and provides a sharper fold along the fold lines  140 / 141  promoted by the slits  157   a  and  157   b . It also enables other dimensions of the container to be tightened up, as described more fully below, developing a tighter and more reliable self locking arrangement. 
     The dimensional relationships of the self locking feature  170  can best be seen with particular reference to  FIG. 14 . The spacing between the slits  157   a  and  157   b  is selected to be substantially the same as the combined width of the total number of overlapping end panels  18 , 19 . It should be noted that the relief slits  154  and  155  extend slightly beyond slit  157   a  a distance “C”, defining relief slits for the fold over flap  160  (discussed above and in more detail below. Slit  157   a  is spaced from fold line  156  a distance “A” approximately equal to a thickness of one of the end panels  18 / 19 , and slit  157   b  is spaced on the opposite side a distance “D” approximately equal to the combined thickness of the total number of overlapping end panels  18 , 19 , minus the thickness of one panel. 
     The self locking feature may contain a fold over flap  160  that is defined by cut lines  161 ,  162 , and  163 . In this embodiment, the cut lines are such to define a fold-over flap  160  that is approximately trapezoidal in shape. However, the use of more or less cut lines may be implemented to promote any shape or size of the fold over flap  160 . The fold over flap  160  is folded downwardly alongside a surface of the end panel  18 , 19 , and/or in the alternative, a surface of the minor flap  24 , 25 , 27 , 28 , so as to help position and secure the end wall panel  18 / 19  and the lid panel  151 , 152  in the properly erected from when the lid panel is in either the open or closed position. The fold over flap  160  contains at least one heel  164  that, when erected to place the lid panel  151 , 152  in either the open (see  FIG. 11 ) or closed (See  FIG. 12 ) position (or to place the self closing feature  170  in its locked position (see  FIG. 11 ), extend upwardly and above the fold lines  140 , 141  that extend through slits  157   a ,  157   b . The upper edge  166  of the heel  164  is preferably spaced above the top edges of the end wall  18 / 19 , and the top edges of the minor flap  24 , 25 , 27 , 28 ; thus preventing the fold over flap  160  from disengaging from its locked position. Although the heel  164  may be any size, it is preferable that the upper edge of the heel  166 , when the fold over flap  160  is in its operative folded position (i.e. the locked position seen in  FIG. 11 ), is spaced below the upper edge of the notch  180 , more preferably the upper surface of the web  153  resting in the notch  180 , a distance “B” equal to at least the combined thickness of two panels; helping to secure the roll-over flap in its locked position. 
     It is preferable to use the self locking feature  170  with a notch  180  in which the web  153  resides and/or with which the web  153  is engaged, when the self locking feature  170  is folded to be operable for securing the end panel  18 , 19  and the lid panel  151 , 152  in the open and/or closed position. When the blank/tray/container contains a notch  180  (See  FIGS. 10 and 15 ), it is preferable that the notch  180  be contained within the minor flaps  24 ,  25 ,  27 , and  28 . More preferably, the notch  180  is located at the top edges  181 , 182  of the minor flaps  24 ,  25 ,  27 , and  28  that are formed from the cut outs  45  in the blank. While the notch may be of any size and/or shape, in a preferable embodiment the notch  180  is at least one “hook” or shaped recess notch formed at one or more of the top edge  181 , 182  of the minor flaps  24 , 25 , 27 , 28 . When erected to place the lid panel  18 / 19  in either the open or closed position, this hook or shaped recess notch engage a surface of the web  153  of the self locking feature  170  present in the lid panel  151 / 152  and the end panel  18 / 19 . Further, this “hook” or shaped recess notch acts as a positive detent against the edge of the fold over flap  160 , preventing it from opening when the lid panel  18 / 19  is either in the open or closed position. Preferably, the notch  180  is formed from a shaped cut  183  in one top edge  181 , 182  of at least one of the minor flaps  24 , 25 , 27 , 28 , forming an undercut nose or hook  184  at one side of the notch  180 . It should be noted that the cut  183  also extends into the bottom of the notch  180 . 
     When the lid panel  18 , 19  is positioned in either the open or closed position, the hook  184  on each flap  24 , 25 , 27 , 28  may point toward and/or away from the inner  12 , 13  and outer  16 , 17  side wall panel connected with the minor flap  24 , 25 , 26 , 27 . Thus, when the fold over flap  160  is folded inwardly and downwardly over the in-turned minor flaps  24 , 25 , 27 , 28  and the associated end panel  18 / 19  and when the web  153  is pulled down into the notches  180 , at least a portion of the fold over panel  160  is engaged beneath the hook  184 . When the hook  184  points toward the inner  12 , 13  and outer  16 , 17  side wall panel to which the associated the minor flap is joined, any outwardly directed force on the inner  12 , 13  and outer  16 , 17  side wall will tend to pull the associated minor flap and hook  184  toward the fold over flap  150  or web  153 , tightening the engagement the portion of the web  153  beneath the hook  184 , and securing the web  184  against displacement from the notch  180 , thereby preventing/reducing the tendency for release of the fold over flap  160 . It should be noted that while the hook  184  may be constructed in any manner, size and/or shape, a preferably construction of the hook  184  is rounded, having a tapered lead-in  185  that facilitates movement of the edge of the web  153  past the hook  184 . 
     The lid panel may also contain at least one fastening feature  200 . The fastening feature may be located anywhere within the lid panel  151 , 152 , but preferably towards the outer edge  207 / 208  of the lid panel  151 , 152 . The fastening feature  200 , when folded in the operable structure, is used to fasten and secure the lid panel, when positioned in its closed position. In a preferred embodiment the lid panel is positioned on the top edge of at least one of the inner and outer side walls  12 , 13 , 16 , 17  and/or end walls  18 , 19 . In an alternative, the lid panel  151 / 152  may be fastened and/or secured to a top edge of the minor flaps  24 ,  25 ,  27 ,  28 . While the above are a preferred embodiments, the fastening feature  200  may be used to fasten the lid panel  151 , 152  to any surface of the blank/tray/container so long as the surface to which the lid panel  151 , 152  is fastened contains a means for receiving the fastening feature  300 , preferably a receiving tab  301  that positions the lid panel  151 , 152  in its closed position. The receiving tab  301  may be a further means to aid in the stacking of folded trays/containers. More preferably, at least one receiving tab  301  is located at the top edge of at least one of the side walls  12 ,  13 ,  16 ,  17  and/or end walls  18 , 19 ; or, at a top edge of the minor flap  24 , 25 , 26 , 27  or  28 . The receiving tab  301  may be the result of a cut out in the blank  45 . In a preferred embodiment, the tab is formed from at least one connecting web  47 , 48  See  FIGS. 1-3  and  5 - 9 ). The connecting web  47 , 48 , when the inner side wall panels  16  and  17  are folded upwardly and inwardly to lie against the respective panels  12  and  13 , preferably create a receiving tab  301  that may be used as a means for receiving the fastening feature  200 . This tab may also be used at the same time for stacking purposes as discussed above (see the discussion above on stacking tabs  49 ,  50 ; stacking tab openings  51 ,  52 ; and bendable tongues  53  and  FIGS. 1-3  and  5 - 9 ). Thus the receiving tab  301  can serve a dual purpose function, preferably as a means for receiving at least one fastening feature  300  of at least one lid panel  151 , 152 ; and, as a means to secure vertically stacked trays/containers to one another. 
     The above mentioned fastening feature  200  may be any fastening feature  200  so long as it serves the function of securing/fastening at least one lid panel  151 / 152  to at least one surface of the tray/container. In a preferred embodiment, the fastening feature  200  contains a fastening flap  202 / 203  having an outer side edge  204 / 205  that projects farther away from the center of the bottom panel  11  than an outer side edge  207 / 208  of the lid panel  151 / 152 . In an alternative embodiment, the fastening flap and the lid panel may share the same outer edges. More preferably, the lid panel  151 , 152  contains a plurality of fastening features  200 , most preferably two fastening features  200 . When a plurality of fastening features are present, it is preferred that at least two are located towards the outer side edge  207 , 208  of the lid panel  151 , 152 . In a preferred configuration of the blank, the fastening features  200  are positioned such that a distance between an outer side edge  204  of a first fastening flap  202  and that of an outer edge  205  of a second fastening flap  203  is greater than the distance between the outside edges  207  and  208  of the lid panel  151 , 152 . In an alternative embodiment, the distance between an outer side edge  204  of a first fastening flap  202  and that of an outer edge  205  of a second fastening flap  203  is approximately equal to the distance between the outside edges  207  and  208  of the lid panel  151 , 152 . In a further alternative embodiment, the distance between an outer side edge  204  of a first fastening flap  202  and that of an outer edge  205  of a second fastening flap  203  is less than the distance between the outside edges  207  and  208  of the lid panel  151 , 152 . 
     The fastening feature  200  includes a cut out portion  209  (See  FIG. 16 ) that, when the lid panel  151 , 152  is folded upwardly and inwardly towards any of the above-mentioned means for receiving the fastening feature  300 , forms an opening  220  (See  FIG. 11 ) such that the receiving means  300  may interlock with the fastening means  200 . In a preferred embodiment, the receiving means  300  is a receiving tab  301 , preferably formed from at least one connecting webs  47  and  48  as described above and can aid in secure stacking of trays/containers as described above, as well as aid in the securing/fastening of the lid panel  151 / 152 . 
     The fastening flap  202 / 203  includes a fastening tab or heel  210 . When the lid panel  151 , 152  is in the closed position, the fastening tab  210  functions to provide friction force against a side of the receiving tab  301  so as to provide greater fidelity of interlocking the fastening feature  200  with the means for receiving the fastening feature  300 . In the preferred embodiment, the fastening tab  210  is formed from cut lines  211 ,  212 , and  213 . Although the fastening tab may be any size and shape, in the preferred embodiment, cut lines  211  and  212  are positions to be approximately perpendicular to the outer side edge  207 , 208  of the lid panel  151 , 152 . While cut line  213  may be of any shape, it is preferably to be in the form that creates a fastening tab that has a greater distance between the outer edges  214  and  215  of the fastening tab  210  and the outer edges  204 , 205  of the fastening flap  202 , 203  than the distance between the middle edge  217  of the fastening tab  210  and the outer edges  204 , 205  of the fastening flap  202 . In the preferred embodiment, when the tray/container is constructed so that the lid panel  151 , 152  is in the closed position, the fastening flap  202 , 203  is folded towards the receiving tab  301  and then outwardly (away from the interior of the tray/container) and downwardly over the outside surface of the outer side panel  12  such that the receiving tab  301  penetrates into the opening left by the cut out portion  209 , e.g. a locked position (see  FIG. 13 ). The fastening flap  202 , 203  may also fold in a manner that positions it between the inner side wall panel  16 , 17  and the outer side wall panel  12 , 13 , e.g. a locked position. This folding may also be accommodated by compromising a surface of the fastening flap, preferably by crushing at least a portion of the fastening flap (similar to crushing the web  153  discussed above). The receiving tab  301  may preferably be in frictional contact with the inner edges of the opening left by the cut out portion  209 . This folding caused the fastening tab  210  to project upwardly above the upper edge of the inner and/or outer side wall  12 , 13  and  16 , 17 and slightly towards the interior of the tray/container, resting closely beside, if not in frictional engagement with, the receiving tab  301  that not only penetrates, but may preferably protrude, through the opening  220  left by the cut out portion  209 , e g. a locked position (see  FIG. 13 ). The fastening tab  210  acts similarly to the heels  164  of the preferred self locking feature  170  described above; and, may preferably extend above the top edge of the inner  12 / 13  and/or outer  16 / 17  side walls so as to be in contact with a portion of the receiving tab  301  in a manner that prevents the fastening flap  202  from disengaging from a locked position. 
     The above-mentioned lid panel, fastening feature, self-locking feature and means for receiving the fastening feature embodiments should be understood to be able to be utilized with any blank/tray/container/packaging system, including those containing 4, 5, 6, 7, 8, or even greater sides. Further, those tray/container/packaging system&#39;s that contain at least one inner and at least one outer wall may include these embodiments, especially those having an inner/outer wall corner configuration as follows: square/square, diagonal/diagonal, square/diagonal and diagonal/square. Any one or more of the above configurations may be used in the tray/container/packaging system that contains the above embodiments. For example, an eight-sided tray/container/packaging system having at least four corners may have at least four corners of the diagonal/diagonal inner/outer wall configuration. Alternatively, an eight-sided tray/container/packaging system having at least four corners may have at least three corners of the diagonal/diagonal inner/outer wall configuration and at least one corner of the diagonal/square configuration. The above examples are not meant to be limiting in any fashion. Further, in the above examples and embodiments, a square corner is one in which at least one side wall and at least one end wall contact each other to form a corner having about an angle of about 90°. Further, in the above examples and embodiments, a diagonal corner is one in which at least one side wall and at least one end wall contact each other to form a corner having about an angle that is greater than about 90°. This is only representative and not meant to be limiting in any manner. 
     In other embodiments the width of the side and end walls, as well as the minor flaps may be smaller or larger than what is described herein. If larger, then the inside space of the constructed tray/container/packaging system would increase in volume. One example of such a conventional tray/container/packaging system is represented in US Published Patent Application 2006-0091194 having U.S. Ser. No. 11/303,898, filed Nov. 19, 2005, which is hereby incorporated, in their entirety, herein by reference. 
     In additional alternative embodiments, the lid panel  151 , 152  may have a width and/or length that is equal to or less than half the width and/or length of the bottom panel  11 . In an additional embodiment, the blank may contain two lid panels, each having a width and/or length that are each approximately equal to half the width and/or length of the bottom panel  11 ; thus creating approximately a fully-lidded tray/container when the tray/container is erected from the blank and both lid panels  151 , 152  are in the closed position; which may placed the lid panels  151 , 152  about parallel to the plane of the bottom panel  11 . In a further embodiment, the blank may contain two lid panels  151 , 152  , each having a width and/or length that are each equal to less than half the width and/or length of the bottom panel  11  (but still have a width and/or length that is greater than about 1 inch); thus creating approximately a partially-lidded tray/container when the tray/container is erected from the blank and both lid panels  151 , 152  are in the closed position, preferably the lid panels  151 , 152  are positioned about parallel to the plane of the bottom panel  11 . 
     In a further alternative embodiment, the lid panels  151 , 152  contain at least one self-locking feature; and, the lid panel  151 , 152  may also contain at least one locking tab  36 / 37  in the case that a portion of the lid panel  151 , 152  does roll over to a position that is approximately perpendicular to the plane of the bottom panel  11 , performing a similar function as the roll over panel  22 , 23 . In the alternative, the fastening feature may further contain at least one locking tabs  36 , 37 , enabling it to perform a similar function as the roll over panel  22 , 23 . The performance and function of the roll over panel is discussed above. 
     In a further alternative embodiment, the blank/tray/container of the present invention may contain a plurality of self locking features  170 . However, it is preferable that each lid panel  151 , 152  contain at least one, preferably two, self locking features  170 . Of course, there will preferably be a number of notches  180  that equal the number of self locking features  170  present in the tray/container, although there also may be more or less. However, the blank may preferably contain more notches  180  than self locking features  170  due to when there are multi-wall embodiments and the notches within each wall should preferably align up approximately squarely when the blank is constructed into the corresponding tray/container. The notches may be of any size and positioned anywhere. Although, it is preferable that the notches are positioned such that when the blank is folded in its operable form, a notch positioned and contained in one minor flap is aligned with a notch that is positioned and contained in an adjacent minor flap. In order to accomplish this in the preferred embodiment of the blank, the notch of a minor flap  27 / 28  is preferably approximately a mirror image of the notch of an adjacent minor flap  24 / 25 . 
     It should be noted that the walls (end or side) of the tray/container may contain more than one end panel and/or more than one minor flap panel and/or more than one side wall panel folded therein, as well as any combinations thereof to form a multi-layered wall configuration. The multilayered or multiwalled end wall may have at least 2 walls, preferably three or more. Further, portions of the walls may be multiwalled, while other portions are single walled structures. In addition, the end walls may be longer and/or wider than the side walls. Further, end wall panels may be longer and/or wider than the side wall panels. Further, the side walls may be longer and/or wider than the end walls. Further, side wall panels may be longer and/or wider than the end wall panels. Accordingly, the relative length and width of the side and end walls may be of any relative length and width. 
     Further, while not required, it is preferred that the blank/tray/container have vent holes located therein. For example,  FIG. 10  shows at least one vent hole  600  located in a side wall of one embodiment of a blank according to the present invention, while  FIGS. 11  an  12  show at least one vent hole  600  located in the side walls of one embodiment of a tray/container according to the present invention. The location, position, size and geometry of the vent hole within the blank/tray/container may vary greatly and in any manner so long as it does not destroy the operability of any one or more of the embodiments of the present invention 
     While the invention has been described and illustrated with reference to one or more preferred embodiments thereof, it is not the intention of the Applicants that the invention be restricted to such detail. Rather, it is the intention of the Applicants that the invention be defined by all equivalents, both suggested hereby and known to those of ordinary skill in the art, of the preferred embodiments.