Abstract:
This invention relates to packaging, and more particularly to a bulk bin having improved bulge resistance and easy setup.

Description:
TECHNICAL FIELD  
       [0001]     This invention relates to packaging, and more particularly to a bulk bin having improved bulge resistance and easy setup.  
       BACKGROUND ART  
       [0002]     Many products are shipped and stored in bulk containers made of corrugated paperboard capable of holding in excess of 2,400 pounds of product. Conventional corrugated containers typically have four or eight sides. Four-sided bulk containers are susceptible to excessive side wall bulge when loaded with product, and do not have very great strength for stacking filled containers on top of one another. Eight-sided containers of a size comparable to a four-sided container experience less side wall bulge than the four-sided container due to the narrower side walls in an eight-sided container. Eight-sided containers also have greater stacking strength than a four-sided container. Both four and eight-sided containers are commonly manufactured and shipped to a user in a flattened condition, and then erected by the user to prepare the container for use.  
         [0003]     Round or cylindrical containers are also known in the prior art, and these containers have greater resistance to side wall bulge than eight-sided containers. However, round or cylindrical containers cannot be manufactured and shipped in a flattened condition and then erected by a user.  
         [0004]     A container having sixteen sides is also known in the art, but this container is an open-ended tubular structure with separate end caps applied to close the ends. The use of separate end caps adds to the cost of the container, and in use the tubular structure may tend to “walk up” in the bottom cap, so that the cap is no longer fully seated on the end of the tubular structure and product can leak out of the container.  
         [0005]     Accordingly, there is need for an inexpensive, one-piece, easy to use bulk container that has minimal side wall bulge and that may be manufactured and shipped in a flattened condition, and then easily set up by a user.  
       DISCLOSURE OF THE INVENTION  
       [0006]     The present invention comprises a bulk container that has minimal side wall bulge, and that may be manufactured and shipped in a flattened condition to a user, and easily set up by the user.  
         [0007]     More specifically, the bulk container of the invention has sixteen sides, thereby approximating a cylinder (right circular cylinder) in shape, and achieving the bulge resistance, or very nearly achieving the bulge resistance, of a cylindrical container. Construction of the container of the invention as a sixteen-sided container enables it to be manufactured and shipped in a flattened condition, in contrast to a truly cylindrical container, which must be manufactured and shipped in an erected, ready-to-use condition. Moreover, the container of the invention has integral bottom-forming flaps, thereby avoiding the necessity of using a separate end cap.  
         [0008]     The container is made from a single unitary blank, and has four bottom flaps foldably connected to selected side walls. Locking tabs are formed on the free edges of a first set of opposed flaps for interlocking engagement with the free edges of a second set of opposed flaps to hold the flaps and thus the container in fully erected condition. The locking tabs are easily and quickly engaged simply by folding the flaps into operative folded position and then inserting the locking tabs between the opposed edges of the second set of flaps. At least one flap and adjacent side walls have self-aligning means which become engaged when the flaps are folded into their operative position to square up the container and hold it in position.  
         [0009]     The blank has a generally elongate rectangular shape, with sixteen serially arrayed wall-forming panels foldably connected together at adjacent edges. A seventeenth panel is foldably connected to one end of the blank to serve as a glue panel to secure the blank in a flattened tubular position when the blank is folded upon itself and glued by the manufacturer. A bottom-forming flap is foldably connected to each fourth wall panel, and these wall panels form opposed side wall panels and opposed end wall panels in a container erected from the blank. The remaining wall panels form three diagonal wall panels between each pair of adjacent side and end wall panels. In a preferred construction, the side wall panels have a first width that is greater than the width of any of the remaining panels, and the end wall panels have a second width that is approximately 70% of the width of the side wall panels. First diagonal panels immediately adjacent each of the side and end wall panels are all of the same width and have a third width that is approximately 78% as wide as the side wall panels, and approximately 90% as wide as the end wall panels. Second diagonal panels, located between adjacent first diagonal panels, have a width that is approximately 50% as wide as the first diagonal panels. To produce a container having a symmetrical outside shape, one of the side wall panels is slightly wider than the opposite side wall panel, and one of the end wall panels is slightly wider than the opposite end wall panel, to accommodate the space taken by the glue panel, which, in the particular example shown and described herein, is glued inside the container.  
         [0010]     Four bottom-forming flaps are foldably connected to respective side and end wall panels along one side edge of the blank, and include a pair of major bottom flap panels and a pair of minor bottom flap panels. In the particular example shown and described herein, the minor bottom flap panels are joined to the side wall panels, and the major bottom flap panels are joined to the end wall panels. The minor bottom flap panels each have a width greater than its associated side wall panel, and project at their opposite side edges approximately one-half the width of the adjacent first diagonal panels. The major bottom flap panels each have a width greater than its associated end wall panel, and project at their opposite side edges past the adjacent first diagonal panels, past the second diagonal panels, and approximately one-third the width of the first diagonal panels adjoining the side wall panels. Those portions of the major and minor bottom flap panels extending beyond the side edges of their associated side and end panels are separated from the diagonal panels by cuts extending collinear with the folded connections of the bottom flap panels.  
         [0011]     The outer end edges of the major bottom flap panels, opposite their folded connection, are narrower than the folded edge, and an angled shoulder extends between the narrow outer end edge and adjacent side edges. The narrow end edge has a width adapted to fit closely between the folded connection of the minor bottom flap panels to their associated side wall in a container erected from the blank.  
         [0012]     An aligning tab projects from the end of each first diagonal panel adjoining each end wall panel, and from the end of the second diagonal panels adjoining said first diagonal panels. A plurality of holes or slots are formed in each major bottom flap panel in positions to be aligned with the aligning tabs when a container is erected from the blank, and the aligning tabs extend into the holes to square up the container and hold it squared.  
         [0013]     A plurality of cuts are made in the outer end edge of each minor bottom flap panel, opposite its folded edge, and form a T-shaped locking tab with laterally outwardly projecting arms that are adapted to flex when the locking tab is inserted between the confronting end edges of the major bottom flaps, and then spring back out behind the confronting end edges to lock the minor bottom flaps in inwardly folded position over the major bottom flaps, and thus hold the flaps in operative folded position in a container erected from the blank.  
         [0014]     To erect a container, the flattened tubular construction as supplied by the manufacturer is expanded by the user to an open tubular configuration and inverted so that the bottom flaps are oriented upwardly. The major bottom flaps are then folded inwardly, so that the aligning tabs extend into the slots to square up the container. The minor bottom flaps are then folded inwardly, and the T-shaped locking tabs pressed downwardly so that the laterally outwardly projecting arms flex past the confronting edges of the major bottom flaps. Upon release of pressure on the locking tabs, the locking arms spring out behind the confronting edges of the major bottom flaps, locking the flaps in their inwardly folded operative position. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     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:  
         [0016]      FIG. 1  is an exploded top perspective view of a prior art sixteen-sided container.  
         [0017]      FIG. 2  is a top perspective view of a sixteen-sided container according to the invention.  
         [0018]      FIG. 3  is a bottom perspective view of the container of  FIG. 2 , showing the bottom flaps and locking tabs in operative locked position.  
         [0019]      FIG. 4  is an enlarged top plan view of the container of  FIG. 2 , showing the relationship of the T-shaped locking tabs and bottom flaps on the interior of the container.  
         [0020]      FIG. 5  is a plan view of a blank for making the container of the invention.  
         [0021]      FIG. 6  is a plan view of a partially assembled container according to the invention, as manufactured in a flattened tubular condition.  
         [0022]      FIG. 7  is a bottom perspective view of the container of the invention, shown expanded into an open tubular configuration and inverted to an upside down position for folding the bottom flaps.  
         [0023]      FIG. 8  is a view similar to  FIG. 7 , showing one of the major bottom flaps folded inwardly over the end of the container, and depicting how the aligning tabs and slots interengage to square up the container.  
         [0024]      FIG. 9  is a view similar to  FIG. 8 , showing the other major bottom flap in its inwardly folded position.  
         [0025]      FIG. 10  is a view similar to  FIG. 9 , showing one of the minor bottom flaps folded inwardly.  
         [0026]      FIG. 11  is a view similar to  FIG. 10 , showing the other minor bottom flap folded inwardly, and one of the T-shaped locking tabs being pressed down between the confronting edges of the major bottom flaps.  
         [0027]      FIG. 12  is a view similar to  FIG. 11 , showing the other T-shaped locking tab being pressed into locked position. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0028]     Referring more specifically to the drawings, a prior art sixteen-sided container is indicated generally at  10  in  FIG. 1 . This container comprises an open-ended sixteen-sided tube  11 , and top and bottom end caps  12  and  13  which are fitted onto the ends of the tube.  
         [0029]     A sixteen-sided container according to the invention is indicated generally at  20  in  FIGS. 2-4  and  6 - 12 . This container comprises a sixteen-sided side wall  21  having integrally formed bottom flaps  22 ,  23 ,  24  and  25 . The side wall  21  includes opposed side wall panels  26  and  27  and opposed end wall panels  28  and  29 . First diagonal wall panels  30  and  31  are located adjacent each side wall panel and each end wall panel, and second diagonal wall panels  32  are located between adjacent first diagonal wall panels. In the preferred embodiment, the side wall panels  26  and  27  have a greater width than the end wall panels  28  and  29 , and the first diagonal wall panels  30  and  31  are approximately twice as wide as the second diagonal wall panels  32 .  
         [0030]     The bottom flaps include a pair of opposed major bottom flaps  22  and  24  foldably connected to respective opposite end wall panels  28  and  29 , and a pair of opposed minor bottom flaps  23  and  25  foldably connected to respective opposite side wall panels  26  and  27 .  
         [0031]     Aligning tabs  40  project from the ends of first diagonal wall panels  30  and  31  and adjacent second diagonal wall panels  32 , and these tabs engage in slots or openings  41 ,  42  in the major bottom flaps to square up the container and hold it square.  
         [0032]     T-shaped locking tabs  50  are formed in the free end edge of the minor bottom flaps  23  and  25 , and have laterally outwardly projecting arms  51 ,  52  that flex when the locking tab is pressed through the space between the confronting edges of the major bottom flaps and then spring out behind the major bottom flaps to hold the tabs in locked position.  
         [0033]     A blank B from which the container may be erected is shown in  FIG. 5 . The blank includes the side and end wall panels  28 ,  29  and  26 ,  27 , respectively, and the first and second diagonal wall panels  30 ,  31  and  32 , respectively, foldably connected together in series at adjoining edges along fold lines  33 . The bottom flaps  22 ,  24  and  23 ,  25  are foldably joined to respective side and end wall panels along one edge of the blank, and a glue flap  34  is foldably connected to one of the second diagonal wall panels  32  at one end of the blank.