Abstract:
A stackable, open-topped shipping and/or display container for shipping and displaying products having indexable projections for stacking a plurality of such containers, the indexable projections formed from cutouts within the indexing side wall flaps.

Description:
CLAIM OF PRIORITY 
       [0001]    The present application is a Continuation in Part of U.S. patent application Ser. No. 11/495,147, filed Jul. 27, 2006, which claims the benefit of priority under 35 USC §119(e) to U.S. Provisional Patent Application 60/702,879, filed Jul. 27, 2005. The present application further claims the benefit of priority under 35 USC §119(e) to U.S. Provisional Patent Application 61/073,608, filed Jun. 18, 2008, which is hereby incorporated, in its entirety, herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates to stackable, open-topped, shipping and/or display container, and more particularly to a corrugated paperboard, stackable container having indexable projections for shipping and displaying products such as, for example, agricultural produce. 
         [0004]    2. Background of the Invention 
         [0005]    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 sidewalls, 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 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. 
         [0006]    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. 
         [0007]    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. 
         [0008]    It would be desirable to have a tray with the advantages of the conventional produce tray, but that utilizes less material in its construction through further reduction in material in the indexing wall flap thus reducing the size of the blank. A final desirable objective is improved production and runnability in manufacture of a tray. 
       SUMMARY OF THE INVENTION 
       [0009]    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 panels, thus forming double ply diagonal corners. A plurality of indexing stacking tabs are provided which extend above the transition between the respective first and second transitions. Additional embodiments are obviously contemplated and included in variations of the disclosed embodiments. 
         [0010]    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. 
         [0011]    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 outer side wall panels may be devoid of minor flaps extending from their ends, reducing the amount of material required to produce the tray. 
         [0012]    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. 
         [0013]    In both embodiments and other disclosed variations, 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. 
         [0014]    Additionally, the stacking tabs formed through cut-out portions 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 some embodiments, the stacking or indexing tabs project upwardly from an upper edge of at least one of the side walls and end walls wherein each of the indexing tabs is flanked on either side of the side walls (i) by a hinging transition which involves said at least second fold line between a said first side wall flap and a second wall flap, and (ii) further from each hinging transition and the indexing tabs, there is upwardly exposed by both side wall flaps cut edges of the blank, such cut edges being transverse to the flute run direction and being above the level of the hinging transition. The use of cuts on the indexing flaps provide a hinging region that skirt either side of the cuts and provide pop-up-type indexing tabs. Depending on the form of a cut, the tabs are retained against the indexing wall upon setup and use. In one embodiment, a single ply internal stack tab is formed. By reversing the direction of the cut, an external, single-ply stack tab is formed. A “t”-shaped cut provides for a key portion that can be tucked in-between the respective indexing flaps upon folding. A more straight line cut provides for a straighter tab portion that can be folded upon itself and a portion glued or otherwise attached to the remaining tab portion or well such that the tab projects above the transition of the indexing flaps. 
         [0015]    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. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    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: 
           [0017]      FIG. 1  is a plan view of a blank for making a first embodiment of a tray in accordance with the invention; 
           [0018]      FIG. 2  is a plan view of a blank for making a second embodiment of a tray in accordance with the invention; 
           [0019]      FIG. 3  is a plan view of a blank for making a third embodiment of a tray in accordance with the invention; 
           [0020]      FIG. 4  is a top perspective view of a tray according to the first embodiment of the invention; 
           [0021]      FIG. 5  is a top perspective view of a tray according to the second embodiment of the invention; 
           [0022]      FIG. 6  is a partial top-side perspective close up view of the tab structure according to the third embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0023]    Like numerals used herein in reference to different embodiments refer to like elements. 
         [0024]    Referring first 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 by spaced apart fold lines  2  and  4 . Minor flaps  24  and  25  are foldably joined to opposite ends of each of the outer side wall panels along spaced apart fold lines  6  and  8 , 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 . 
         [0025]    The blank illustrated in  FIG. 1  is shown for use in hand set-ups of the assembled container or tray made from the blank. Locking tabs project from the free edge of the side panels, this free edge being the bottom edge in an erected tray. Locking tabs 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 . These locking tabs may or may not be omitted in machine set-up versions of this blank embodiment. 
         [0026]    In the blank embodiment illustrated in  FIG. 1 , cuts  100  are made in the material of the inner and outer side wall panels, on either side of the fold line between them, leaving connecting webs that form stacking or indexing tabs  47  and  49  in a tray erected from the blank. The direction of the cuts  100  and thus which side of the fold line is dictated as to whether the there is a preference for the stacking tabs  47 ,  49  to be formed on either the inner side panels  16 , 17  or outer side panels  12 , 13 . Separating each of the minor/side panels are cuts which leaves hinging regions skirting on either side of the cuts that provide the indexing pop-up projection. As can be seen more outwardly of each hinging region is an exposed cut face provided by (in the preferred form) both of the flaps. 
         [0027]    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 on a subjacent tray when the trays are stacked on top of one another. 
         [0028]    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. 
         [0029]    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. 
         [0030]    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. 
         [0031]    Referring to  FIGS. 1 and 4 , To erect a tray from a blank, 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. 
         [0032]    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. 
         [0033]    It will also be noted that in example illustrated in  FIGS. 1 and 4 , 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  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. Equal sized end wall panels and side wall panels may of course be used. 
         [0034]    As illustrated in  FIG. 2 , a second embodiment of a blank for making a tray according to the invention. This blank differs from that previously disclosed in  FIG. 1  in that the stacking tabs  147 ,  149  are formed by generally trapezoidal or rectangular cuts  155  that span from the outer side panels  12 , 13  through inner side panels  16 , 17  and the respective fold lines between such panels. As can be seen, each stacking tab  147 ,  149  is bisected and thus further comprises ascending portions  160 ,  164  and descending portions  162 ,  166 , respectively. Referring to  FIG. 5 , when the tray is erected by folding the panels of the blank into their operative positions, generally as discussed above, ascending portions  160 ,  164 , rise above the transition between the inner and outer panels. The descending portions  162 ,  166  are then fold down from the ascending portions and into gaps  170  formed in the inner side walls through the creation of the stacking tabs in the blank. The descending portions are then adhered or otherwise attached to the inner surface of the respective outer side walls, as shown in  FIG. 5 . One will note that roll over panels  22  and  23  are not shown in  FIGS. 2 and 5 , but may be used in this embodiment 
         [0035]    The third embodiment of a blank for making a tray according to the invention is illustrated in  FIG. 3 . This third embodiment is a variation of the second embodiment differs from that previously disclosed in  FIG. 2  in that the stacking tabs  247 ,  249  are formed by generally T-shaped cuts  255  that span from the outer side panels  12 , 13  through inner side panels  16 , 17  and the respective fold lines between such panels. As can be seen, each stacking tab  147 ,  149  is bisected and thus further comprises ascending portions  260 ,  264  and descending and locking portions  262 ,  266 , respectively. Referring to  FIG. 6 , when the tray is erected by folding the panels of the blank into their operative positions, generally as discussed above, ascending portions  260 ,  264 , rise above the transition between the inner and outer panels. The descending portions  262 ,  266  are then fold down from the ascending portions and into gaps  170  formed in the inner side walls through the creation of the stacking tabs in the blank. The locking extensions  268  of the descending portions inserted and retained between the inner and outer side panels, as shown in  FIG. 6 . One will again note that roll over panels  22  and  23  are not shown in  FIGS. 3 and 6 , but may be used in this embodiment 
         [0036]    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. 
         [0037]    The disclosed container also may have 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, as disclosed in co-pending U.S. patent application Ser. No. 11/495,147, having a publication number 2007/0051789 
         [0038]    In other embodiments, the width of the side and end walls, as well as the major and 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. 
         [0039]    It should be noted that the walls (end or side) of the disclosed embodiments of the tray/container may contain more than one end panel and/or more than one minor flap panel and/or more than one major 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 two 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. 
         [0040]    Further, while not required, it is preferred that the blank/tray/container have vent holes located therein. For example, at least one vent hole can be located in a side wall of one embodiment of a blank according to the present invention, at least one vent hole can be 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 
         [0041]    Pop up type indexing projection which extends above the transition between the first and second indexing wall flaps in the erected container could alternatively be a different form such as that utilized by a number of companies where an even greater cut out has part thereof folded back and adhesively or otherwise reattached to some part of the indexing wall. 
         [0042]    Persons skilled in the art will appreciate that scallops or the like can be provided between the hinging regions and outwardly flanking cuts that provide the support regions. Such scallops are optional. In another alternative embodiment, the indexing lugs are provided at the lesser ends and no provision is made for truncating of the corners. Those skilled in the art will appreciate however, the provision of the indexing lugs and corresponding openings on either the greater or lesser sides of the rectangular base does not dictate the form that must be used. Particularly with the end indexing forms, even one projection only may suffice per indexing wall. 
         [0043]    As will be appreciated by one skilled in the art, a shorter blank is achieved through the use of slits, rather than slices. It has been shown through empirical testing that the configuration of the disclosed inventive tray has at least the same strength as prior art trays, such as the DEFOR® tray and improvements thereof as disclosed in U.S. application Ser. No. 10/818,460, Publication No. 2004/0256448, but with reduced blank size and thus fiber input. Blank size is typically reduced by 7% over prior art designs by creating the fold-over stacking tab from the external panel of the tray that folds to the inside when assembled. In the case of the design disclosed in U.S. application Ser. No. 10/818,460, test results indicated up to a 20% increase in strength. Nonetheless, the teachings of U.S. application Ser. No. 10/818,460 are incorporated herein by reference. 
         [0044]    It is noted that while the embodiments shown in the appended drawings and described herein generally relate to either so-called hand setup and machine setup versions of the disclosed containers and blanks, the use of locking tabs on hand set up version, or lack thereof on machine set up versions, are not intended to be limited to the particular design illustrated herein and such choice of the use of locking tabs depends on the intended use and set-up of the container. 
         [0045]    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