BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to bulk bins, and more particularly to bulk bins made of corrugated paperboard with means to resist initiation of tearing of the vertical scores in the bin.
2. Prior Art
Many products are stored and shipped in bulk containers, which are commonly constructed of corrugated paperboard. These containers or bins may be used to hold up to 2400 pounds of product, and are often used to ship and store flowable products. For instance, the poultry industry uses corrugated paperboard bulk bins to ship and store flowable de-boned meat product. Flowable products, in particular, exert an enormous force on the side walls of the bin, tending to cause them to bulge outwardly, especially toward the bottom of the bin.
Bulk containers or bins made of corrugated paperboard have side walls joined along vertical score lines, and bottom flaps are usually joined to the bottom edges of the side walls, with the flaps separated from one another by flap cuts or slots. In conventional constructions the flap slots terminate at or closely adjacent the lower end of the vertical scores, and the stresses exerted on the bin when it is filled with flowable product tend to concentrate in the area where slots terminate adjacent the bottom end of the scores. This stress concentration further tends to focus along an axis leading from the flap slot into the lower end of the vertical score, with the result that splitting of the vertical score is initiated, sometimes resulting in tearing along the entire length of the vertical score and failure of the bin.
Accordingly, there is need for a bulk bin having means to prevent initiation of splitting of the vertical score in a bulk bin, caused by concentration and focusing of stresses into a lower end of the vertical score from the flap slot.
SUMMARY OF THE INVENTION
The invention provides a means for resisting this initiation of a tear along the vertical score line by separating the end of the flap slot from the end of the vertical score line, and modifying the shape of the terminal end of the flap slot to redirect the stress away from the end of the score and thereby eliminate a potential starting point for a split to begin.
More specifically, a shaped cut is made at the end of the flap slot to space the end of the flap slot from the end of the vertical score, with the ends of the cut pointing away from the vertical score.
In one embodiment, the modified slot terminates in a shape much like a modified Greek letter psi (![custom character]()
). This has the effect of moving the termination of the flap slot one inch away from the end of the vertical score line, and placing it in the flap score. This new shape diverts the internal pressure of the contents away from the base of the vertical score.
In a modified version, a “J” shaped cut is placed at the end of the flap slot, with the curved part of the “J” positioned adjacent the base end of the vertical score line and the end of the J shaped cut pointing away from the vertical score and back toward the flap.
Other shaped cuts, such as T-shapes, hook shapes, and the like, can also be utilized so long as they redirect the stresses away from the lower end of the vertical score. Further, the invention can be applied in bulk bin constructions having four, six or eight sides, or any other number of sides, and in bins having single, double or triple wall construction, or other multiple wall thicknesses.
Reinforcing bands, such as, for example, sesame tape, can also be placed around the bin at spaced intervals along its height, beginning one inch above the flap score, to reinforce the bin and resist bulging and/or failure caused by the pressure of the contents.
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 considered 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 a typical octagonal bulk bin in which the invention may be used.
FIG. 2 is a top perspective view of a typical rectangular or square bulk bin in which the invention may be used.
FIG. 3 is a plan view of a blank for making an octagonal bulk bin incorporating one embodiment of the invention.
FIG. 4 is an enlarged plan view of a portion of the blank of FIG. 3, showing in greater detail the embodiment of FIG. 3.
FIG. 5 is an even greater enlarged view, showing the circled portion in FIG. 4.
FIG. 6 is a fragmentary plan view showing the relevant portion of a blank incorporating a prior art arrangement.
FIG. 7 is a fragmentary plan view similar to FIG. 6, showing another embodiment of the invention intended to replace the prior art arrangement of FIG. 6.
FIG. 8 is a fragmentary plan view showing the relevant portion of a blank incorporating anther prior art arrangement.
FIG. 9 is a fragmentary plan view similar to FIG. 8, showing an embodiment of the invention intended to replace the prior art arrangement of FIG. 8.
FIG. 10 is a fragmentary plan view showing the relevant portion of a blank incorporating anther prior art arrangement, wherein the flap slot or cut simply terminates in a straight line oriented toward and in alignment with the end of the vertical score.
FIG. 11 is a fragmentary plan view similar to FIG. 10, showing a further embodiment wherein the flap slot terminates in a “T” shaped cut that redirects stress away from the adjacent end of the vertical score.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An octagonal bulk container made of corrugated paperboard and incorporating the tear preventing means of the present invention is indicated generally at 10 in FIG. 1, and a rectangular bulk container incorporating the tear preventing means of the invention is indicated generally at 11 in FIG. 2. The invention may also be applied to other container configurations, not shown.
The particular octagonal container 10 depicted in FIG. 1 is of unique construction, and is described more fully in applicant's copending published application, number US 2002 0096559-A1, published Jul. 25, 2002, the disclosure of which is incorporated by reference in full herein. In this container, the diagonal corner panels 12 and 13 have the same width as the end walls 14 and 15, whereby in a container of given volume and adapted to fit a particular size pallet, the side walls 16 and 17 are of reduced width relative to a conventional container in which the diagonal corner panels are narrow and the side walls are wider, with concomitant increased risk of bulging of the side walls when the container is filled with product. The narrower side walls in the container of the invention reduce the risk of bulging of the side walls. It should be understood, however, that the invention is applicable to octagonal containers having other dimensional relationships. The container 10 is shown in FIG. 1 resting on a pallet P, although that does not form a part of the present invention.
The invention can be best understood with reference to FIGS. 3-11 The blank B from which the container 10 is formed is shown in plan view in FIG. 3, and comprises a series of rectangular panels that form the walls 12-17, and a glue flap 18 on one end. The panels are joined to one another along parallel score lines 20 extending transversely across the blank from a top edge 21 thereof to a flap score 22 at a bottom edge. A plurality of interlocking bottom forming flaps 23, 24 and 25 are foldably joined to the bottom edge of the blank along the flap score 22, as more fully described in copending published application number US 2002 0096559-A1. The flaps are separated from one another at adjacent edges by cuts or flap slots 26 and 27. In the embodiment shown, a particular construction of interlocking flaps is employed, with some of the cuts 26 extending parallel to and in alignment with the vertical scores 20, and other cuts 27 extending at an angle to the vertical scores. All the cuts terminate near the end of the respective scores.
In some conventional constructions, as shown in FIG. 10 for example, the flap slot 26′ simply terminates in axially aligned, slightly spaced relationship to the end of the vertical score 20. This construction is especially susceptible to initiation of tearing along the vertical score 20 because of concentration of stresses at the end of the cut, which are directed or focused toward and into the adjacent end of the score.
FIG. 6 depicts a prior art arrangement wherein the flap slot 27′ extends angularly relative to the vertical score 20, and an upwardly open hook shaped cut 30 is made at the terminal end of the flap slot to at least partially alleviate the shortcomings of the arrangement shown in FIG. 10. However, the cut 30 has a relatively small radius and ends in a vertically directed point 31 that is closely adjacent the vertical score 20. With this arrangement, it is still possible for stress to be concentrated and focused along the axis of the flap slot and into the lower end of the vertical score, with the result that initiation of tearing of the vertical score can occur at this point.
In the invention, a larger radius, i.e., ⅜ inch, hook shaped cut 40 is made in the material of the flaps, as shown in FIG. 7, and inverted from the prior art arrangement so that it opens downwardly, with the terminal end 41 of the hook pointing away from the end of the score and laterally back into the adjoining flap. With the arrangement of the invention, the end of the flap slot 27 is spaced a greater distance from the score 20, and the end 41 of the cut points laterally away from the end of the vertical score so that stress is redirected away from the score and back into the flap, thereby avoiding initiation of tearing of the vertical score at this point.
In the prior art arrangement shown in FIG. 8, wherein the flap slot 26′ extends in alignment with the vertical score 20, a relatively small radius downwardly open hook shaped cut 45 similar to that shown in FIG. 6 is made at the terminal end of the flap slot, with the end 46 of the cut 45 pointing generally vertically, or parallel to the score 20 and flap slot 26′. This construction is not entirely satisfactory for preventing concentration of stress in the lower end of the vertical score and initiation of tearing of the score at this point.
As shown in FIG. 9, the invention solves this problem by making a cut 50 resembling a slightly modified Greek letter psi (ψ) at the end of the flap slot, spaced into the respective flaps and away from the end of the score, with the ends 51 and 52 of the cut 50 extending about ¼ inch laterally outwardly and away from the end of the score to redirect stress away from the end of the score. This avoids concentration of stress into the lower end of the score and prevents initiation of tearing of the score at this point.
A variation of termination of the flap slot 26 is shown in FIG. 11, wherein a short transverse cut 55 is made across the end of the flap slot, forming a “T” shaped configuration spaced from the adjacent end of the vertical score 20, and which redirects stress laterally away from the vertical score.
The corrugated material around the cuts 50 preferably is crushed at 60 to prevent bulking of material when the flaps are folded about their respective fold lines and interlocked with one another. These crushed areas are made on a one inch radius, with the shape as shown in FIG. 5. Crushed areas 61 are also formed along the edges of the flaps, as shown in FIG. 3, to prevent bulking of material in this area.
If desired, additional reinforcing in the form of sesame tape 70 may be applied in the walls of the container at spaced locations along its height.
Although particular embodiments of the invention are illustrated and described in detail herein, it is to be understood that various changes and modifications may be made to the invention without departing from the spirit and intent of the invention as defined by the scope of the appended claims.
Patent Application
20070152027
