Abstract:
An octagonal bulk bin has sidewalls, end walls and diagonal corner panels interposed between adjacent sidewalls and end walls. Bottom flaps are foldably joined to a bottom edge of the sidewalls, end walls, and diagonal corner panels, and gusset panels connect adjacent side edges of the bottom flaps, facilitating set up of the bulk bin and spacing flap cuts from the corners of the bin to minimize or eliminate initiation of tears in the vertical corners of the bin. A plastic pallet tray has an upstanding lip around its periphery, shaped and sized to closely receive the bottom end of the octagonal bin to reinforce the bottom end and facilitate handling of the bin.

Description:
This application claims the benefit of U.S. provisional patent application Ser. No. 60/712,236, filed Aug. 29, 2005. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to bulk bins, and particularly to a self-locking bottom flap construction for octagonal bulk bins. 
   2. The Prior Art 
   Bulk bins are used in the industry for storing and shipping numerous products, and typically hold 2,000 pounds or more of the product, including flowable or semi-liquid products such as, e.g., comminuted poultry. When flowable products are to be contained in the bin, a bag normally is placed in the bin for receiving the product. The outward force exerted on the sidewalls by flowable products, in particular, is substantial, and tends to bulge the sidewalls outwardly. The bins are commonly made of corrugated cardboard and comprise a plurality of sidewalls joined together along vertical folds. The bottoms of the bins preferably are closed or partially closed by inwardly folded bottom flaps joined to bottom edges of the side walls along horizontal folds. The flaps are separated from one another by slots or cuts extending from an outer edge of the flaps to a point at or near the intersection of the vertical and horizontal folds. This structure creates a weak point where tearing of the vertical fold can initiate. Tearing of the vertical fold can propagate rapidly upwardly, resulting in bursting of the sidewall and failure of the bin, with consequent loss of the stored product. 
   At least partially to minimize the outward bulge of the sidewalls, the industry has adopted bulk bins having an octagonal shape, wherein diagonal corner panels are interposed between adjacent edges of the opposed sidewalls and opposed end walls. In conventional octagonal bins the diagonal corner panels are of less width than either the sidewalls or the end walls of the bin, and although the octagonal configuration reduces the width of the sidewalls and/or end walls in a bin having a comparable capacity and size to a corresponding four-sided bin, thus reducing the extent of outward bulge of the sidewalls and/or end walls, the sidewalls and/or end walls still have substantial width. 
   Bulk bins made of corrugated material are typically manufactured from a single blank that is scored to delineate the sidewalls, end walls, diagonal corner panels, and bottom flaps. The blank is folded and secured at a manufacturer&#39;s joint by the manufacturer, and shipped to the user in a flattened condition. The user then sets the flattened bin on end and opens it up into an expanded tubular configuration. The bottom flaps are then folded inwardly and secured to hold the bin in its set-up condition. Self-locking bottom flaps have been developed to facilitate setting up the bin from its flattened condition to its fully open usable condition. 
   Octagonal bulk bins normally have eight bottom flaps, including two major flaps, two minor flaps, and four diagonal flaps. Conventional octagonal bulk bins with or without self-locking bottom flaps are cumbersome to assemble, and as a result users often seek alternative packaging. Further, the sequence of inward folding of the bottom flaps on a conventional octagonal bulk bin frequently results in creating extra pinch points in the bottom of the bin, e.g., by the diagonal flaps extending into the interior of the box bottom, which can damage the bag and cause it to rupture, thus contaminating the stored product. 
   It would be desirable to have a bulk bin that has all the advantages of an octagonal bulk bin, but that is free of the problems associated with conventional bulk bins, and particularly to have an octagonal bulk bin with bottom flaps, especially self-locking bottom flaps, that is relatively easy to erect into its operative position, is constructed to avoid the formation of weak points where tearing of the vertical fold can initiate and to avoid the formation of pinch points in the bottom. 
   SUMMARY OF THE INVENTION 
   The present invention comprises a bulk bin with self-locking bottom flaps constructed so that the bin is relatively easy to erect, and which avoids the formation of weak points where tearing of the vertical fold can initiate, and avoids the formation of pinch points in the bottom. 
   More particularly, the present invention comprises an octagonal bulk bin having self-locking bottom flaps with gusset panels or web panels connected between adjacent edges of the diagonal flaps and the respective adjacent major and minor bottom flaps, whereby the user has to fold only four bottom flaps inwardly, in contrast to the requirement to fold eight bottom flaps inwardly on conventional octagonal bins, and wherein the cuts or slits separating the bottom flaps from one another terminate in spaced relationship to the vertical folds, thereby eliminating the weak points where tearing of the vertical folds can initiate. The construction and sequence of folding of the bottom flaps also avoids the formation of pinch points. 
   Notches cut in the ends of the minor bottom flaps form a pair of locking tabs on each minor bottom flap, and angled slots cut in the major bottom flaps adjacent their outer edge form openings for receiving the locking tabs. The two major bottom flaps are first folded inwardly to square up the bin, followed by inward folding of the minor bottom flaps. Since the diagonal flaps are connected by gussets to adjacent edges of the major and minor bottom flaps, inward folding of the major flaps initiates inward movement of the minor flaps and diagonal flaps, and subsequent inward folding of the minor bottom flaps into their operative inwardly folded position also causes the diagonal flaps to fold inwardly, with the diagonal flaps essentially sandwiched between the major and minor flaps. By pressing the inwardly folded minor flaps downwardly against the previously inwardly folded major flaps, the locking tabs on the minor bottom flaps engage in the slots in the major bottom flaps to lock the bottom flaps in position and thus hold the bin in its setup condition. 
   Further, in a preferred embodiment of the present invention, the diagonal corner panels have the same or substantially the same width as the end walls, thus reducing the width of the sidewalls and end walls in a bin having a comparable capacity, and thereby reducing outward bulge of the sidewalls and/or end walls. 
   The bulk bin of the invention can be of single wall, double wall or triple wall construction, with or without sesame tape or strap reinforcing, and stretch wrap can be easily applied. 
   The gusset panels not only serve to facilitate setup of the bin and to space the ends of the flap slits from the bottom ends of the vertical folds, but also close the corners of the bin bottom. 
   The bulk bin of the invention can be used with a conventional wooden pallet, or a slip sheet, or can be set directly on a floor surface. Further, applicant has developed a plastic pallet tray for use with octagonal bulk bins, and especially when this pallet tray is used with the bulk bin of the invention it is contemplated that the bins can be stacked on top of one another, something that cannot be done with conventional octagonal bulk bins. Moreover, the plastic pallet tray serves as a jig to facilitate setup of the octagonal bulk bin, and prevents contact between the top of the bin and a floor surface, thereby reducing or eliminating contamination issues. The pallet tray is lightweight and nestable for economy in storage and shipping, is reusable, and has two-way accessibility for a hand jack and four-way accessibility for a fork lift. Although shown and described herein as used with the octagonal bulk bin of the invention, it should be understood that the plastic pallet tray has equal utility with conventional octagonal bulk bins, and with appropriate modification can be used with four-sided bins. 

   
     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 top perspective view of one embodiment of an octagonal bulk bin according to the invention, wherein the diagonal corner panels have less width than the end wall panels. 
       FIG. 2  is a bottom perspective view of a preferred embodiment of the bin of the invention, wherein the end walls and corner panels have the same width. 
       FIG. 3  is a plan view of a blank for making a bin according to the invention, wherein the corner panels have the same width as the end wall panels, for forming the preferred embodiment as shown in  FIG. 2 . 
       FIG. 4  is a plan view of the blank of  FIG. 3 , folded in half into a flattened condition for shipment to a user. 
       FIG. 5  is an enlarged fragmentary plan view of a portion of the folded flat blank of  FIG. 4 , showing details of one of the gusset panels. 
       FIG. 6  is an enlarged perspective view of a bin according to the invention, shown in an inverted position and partially expanded during an initial stage of set up, with what would normally be the open top end of the bin being positioned on a plastic pallet according to the invention to aid in squaring up the bin and to prevent contact between the top end of the bin and the ground or floor, thus protecting the top end from contamination. 
       FIG. 7  is an enlarged fragmentary perspective view of a portion of the bottom of the bin of  FIG. 6 , showing a further stage of the bin being set up, wherein the major bottom flaps are folded inwardly. 
       FIG. 8  is a bottom perspective view of the bin of  FIG. 7 , with the bin supported in the plastic pallet, and depicting one of the minor bottom flaps being folded inwardly after both major bottom flaps have been inwardly folded. 
       FIG. 9  is a bottom perspective view of the bin of  FIG. 8 , showing the other minor bottom flap being folded inwardly to its operative position, with the flaps shown interlocked. 
       FIG. 10  shows the bin after all the bottom flaps have been inwardly folded and interlocked, and depicting how a second plastic pallet according to the invention can be placed over the fully folded and interlocked bottom of the bin. 
       FIGS. 11 and 12  show the inverted bin of  FIG. 10  being tilted out of the plastic pallet previously used to protect the open top end of the bin. 
       FIG. 13  shows the bin of  FIGS. 11 and 12  in an upright position, resting on the pallet previously applied to the bottom end of the bin in  FIG. 10 , and depicting a plastic liner bag being inserted in the bin to help contain highly flowable materials when such materials are to be placed in the bin. 
       FIG. 14  shows a fully assembled bin, with reinforcing tape or straps applied and with plastic shrink wrap being applied. 
       FIG. 15  is an enlarged fragmentary perspective view of the circled portion in  FIG. 2 , showing all the flaps folded inwardly to their operative locked position. 
       FIG. 16  is a top perspective view of the plastic pallet tray that can be used with the bin of the invention. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   An octagonal bin in accordance with the invention is indicated generally at  10  in the drawings, and with particular reference to  FIGS. 1 ,  2  and  3 , comprises opposite parallel sidewalls  11  and  12 , opposite parallel end walls  13  and  14 , and diagonal corner panels  15 ,  16 ,  17  and  18  interposed between respective side and end walls. The side and end walls and the diagonal corner panels are joined along vertical folds  20 . Major bottom flaps  21  and  22  are foldably joined to bottom edges of the respective sidewalls along horizontal folds  23 , minor bottom flaps  24  and  25  are foldably joined to bottom edges of respective end walls along horizontal fold lines  26 , and diagonal bottom flaps  27 ,  28 ,  29  and  30  are joined to respective diagonal corner panels along horizontal folds  31 . The major and minor bottom flaps are equally long between their respective folds and free edges, but the major bottom flaps are much wider than the minor bottom flaps, having trapezoidally shaped wings  33  and  34  on opposite side edges thereof. The diagonal bottom flaps are much shorter than the major and minor bottom flaps, having a length between their respective folds and free edges that, in the particular embodiment shown, is only about ⅓ the length of the major and minor flaps. 
   It should be noted that as depicted in  FIG. 1  the end walls are of less width than the sidewalls, and the diagonal corner panels are of less width than the end walls, but as depicted in the preferred embodiment shown in the remaining figures the diagonal corner panels have the same width as the end walls. The present invention is equally applicable to either form. 
   In either form the minor bottom flaps are connected to the diagonal bottom flaps at their respective adjacent side edges by first gusset panels or webs  40 , and the major bottom flaps are connected to the respective opposite side edges of the diagonal bottom flaps by second gusset panels or webs  41 , whereby the slits or cuts  42  separating the major bottom flaps from adjacent diagonal bottom flaps do not extend to the horizontal folds joining these flaps to the respective sidewalls and diagonal panels. Further, the cuts  42  delimit the angled side edges  43  and  44  of the wings  33  and  34  and terminate in J- or hook-shapes  45  pointing away from both the horizontal and vertical folds, thereby redirecting stress away from the lower end of the vertical folds to avoid initiation of a tear in the vertical fold. 
   The gusset panels or webs  40  and  41  are seen best in  FIGS. 4 ,  5  and  7 . The first web  40  is formed by a first fold score  46  extending substantially collinear with the side edge of the associated minor bottom flap, and a second fold score  47  extending to a free outer edge of a respective diagonal bottom flap and at about a  300  angle relative to the first fold, with the first and second folds converging adjacent the closest intersection of the vertical and horizontal folds  20  and  26 , respectively. Relief cuts  48  and  49  are made in each of the fold scores  46  and  47 , extending over approximately one-third of a mid-portion of the length of the respective fold scores, and terminating at their ends in short transverse cuts  50  and  51  to prevent propagation of the cuts  48  and  49 . 
   The second gusset panel or web  41  is defined by a first fold score  55  substantially collinear with the angled side edge  43  and extending from the base of the hook-shaped cut  45  to adjacent the closest intersection of a vertical and horizontal fold  20  and  26 , respectively, and a second fold score  56  oriented at about a  300  angle relative to the first fold score and extending from the nose of the hook  45  to converge with the first fold score adjacent said closest intersection. 
   With regard to the gusset panels  40  and  41  and cuts  42  and  45 , it should be noted that the shape of cut  45  need not be limited to a J-shape but can have any shape that redirects stress away from the end of cut  42  and avoids initiation of tearing along one of the gusset panel fold scores  55 ,  56  or along one of the vertical folds  20 . For example, the cut could be shaped as a modified Greek letter psi, or an inverted modified Greek letter psi, or a T, L, U, V, etc as described in applicant&#39;s copending prior U.S. application Ser. No. 10/316,966, filed Dec. 11, 2002. Moreover, the point where the gusset panel fold scores  46 ,  47  or  55 ,  56  intersect can be located at the horizontal fold score  23 ,  26  or  31  or spaced a short distance therefrom. 
   A self-locking structure is defined by a pair of triangularly shaped notches  60  and  61  in the free edge of each of the minor bottom flaps, defining a pair of locking tabs  62  and  63  on the corners of the minor bottom flaps, and by a pair of angled slots  64  and  65  formed in the major bottom flaps near their free edge in a position to receive the locking tabs when the major and minor bottom flaps are folded inwardly over the bottom of the bin. 
   To erect the bin, it is placed in an inverted position with its bottom end up as seen in  FIG. 6 . If desired, to aid in squaring up the bin and to prevent contamination of the top end of the bin, the inverted bin may be placed on a plastic pallet  100 . The major bottom flaps  21  and  22  are first folded inwardly as seen in  FIG. 7 , followed by inward folding of the minor bottom flaps  24  and  25 . The minor flaps are then pressed downwardly against the major flaps, causing the major flaps to move downwardly slightly into the box to bring the locking tabs  62  and  63  into aligned registry with the slots  64  and  65 . When downward pressure is released, the flaps spring back upwardly, with the tabs extending into the slots to interlock the flaps together in a generally planar position closing the bottom of the bin, as seen in  FIG. 2 . It will be noted that the locked minor bottom flaps also capture the diagonal bottom flaps to hold them in their inwardly folded position. 
   The bin  10  is made from a single unitary blank B, as shown in  FIG. 3 . The blank comprises a generally rectangularly shaped piece of corrugated material of suitable weight, e.g., single wall, double wall, or triple wall, having a plurality of first, parallel, spaced apart fold scores  20  delimiting sidewall panels  11  and  12 , end wall panels  13  and  14 , and diagonal corner panels  15 ,  16 ,  17  and  18 . Second fold scores  23 ,  26  and  31 , extending perpendicular to the first fold scores  20 , define, respectively, bottom edges of the sidewall panels  11  and  12 , end wall panels  13  and  14 , and diagonal corner panels  15 ,  16 ,  17  and  18 . A plurality of bottom-forming flap panels  21 ,  22 ,  24 ,  25  and  27 - 30  are joined along respective fold scores  23 ,  26  and  31  to the bottom edges of respective wall panels. Panels  21  and  22  form the major bottom flaps, panels  24  and  25  form the minor bottom flaps, and panels  27 - 30  form the diagonal bottom flaps in a bin erected from the blank. Generally trapezoidally shaped side extensions or wings  33  and  34  are foldably joined to opposite side edges of the major bottom flap panels along the fold scores  20 . The diagonal bottom flap forming panels  27 - 30  are foldably joined to respective adjacent side edges of adjoining major and minor bottom flap forming panels by first and second gussets  40  and  41 . 
   The major bottom flap forming panels  21  and  22  are separated from adjoining diagonal flap forming panels by cuts  42  extending at about a 45° angle from a side edge of the respective panel to a point spaced a substantial distance from a respective fold score  23  or  31 . The cuts  42  define angled side edges  43  and  44  of the wings  33  and  34  and terminate in J- or hook-shapes  45  pointing away from the fold scores  23 ,  26  and  31 . The second gussets  41  interconnect the major bottom forming flap panels and adjacent diagonal flap forming panels in the area between the J-shaped cuts  45  and the fold scores  23 ,  26  and  31 . 
   The first gusset  40  comprises a triangular web delimited by a pair of fold scores  46  and  47  diverging at an angle of about 30° and extending from a point near but spaced from a respective fold score  23 ,  26  and  31  and its juncture with an adjacent fold score  20  to the free outer edge of a respective diagonal flap panel. Fold promoting cuts  48  and  49  are made along a short portion of the length of the fold scores  46  and  47 , and short transverse cuts are made across the ends of the cuts  48  and  49  to prevent propagation of the cuts  48  and  49 . The fold scores  46  are in general coaxial alignment with a respective adjacent fold score  20  and a side edge of a respective minor bottom flap panel. 
   The second gusset  41  comprises a triangular web delimited by a pair of fold scores  46  and  47  diverging at an angle of about 30° and extending from a point near but spaced from a respective fold score  23 ,  26  and  31  and its juncture with an adjacent fold score  20  to a respective J-shaped cut  45 . 
   A pair of generally V-shaped notches  60  and  61  are formed in the free outer edges of each minor bottom flap panel  24  and  25 , defining a pair of locking tabs  62  and  63  on the outer corners of the minor bottom flap panels. 
   Angled slots  64  and  65  are formed in an outer side edge portion of each major bottom flap panel  21  and  22 . 
   The plastic pallet tray  100 , when used with a bin, including the octagonal bin of the invention, facilitates set up of the bin, protects the top end of the bin from contamination, and also assists in resisting outward bulge of the sidewalls due to the outward pressure of the material stored therein. Moreover, it is contemplated that use of the pallet tray will enable the bins to be stacked on top of one another. 
   As seen best in  FIG. 16 , the pallet tray  100  comprises a deck  101  with an upstanding lip or flange  102  around its periphery, sized and shaped to closely receive the bottom end of the octagonal bin. Thus, the pallet tray is not only capable of functioning as a jig to aid in setting up the bin, but it also reinforces the bottom end of the tray to help it resist outward pressure from the contents of the bin. The pallet tray further includes legs or supports  103  projecting downwardly from the bottom surface of the deck, defining spaces therebetween for receipt of a hand jack or the tines of a fork lift. The legs are hollow, as seen best in  FIG. 6 , and are shaped so that the legs of one pallet tray can nest or telescope into the legs of a subjacent pallet tray for nestable stacking of the pallet trays.