Patent Publication Number: US-6705515-B2

Title: Self erecting and collapsible corrugated plastic box

Description:
This invention pertains to collapsible boxes, and more particularly concerns a collapsible and self erecting box made of corrugated plastic. 
     Collapsible corrugated plastic boxes are disclosed and claimed in U.S. Pat. Nos. 6,102,279; 6,102,280; 6,257,484; and 6,349,876. The material used to make the box of the present invention can be made in conformance with those disclosures, and the fold line/score line configurations, handholds and automatically lockable bottom panel arrangements can be provided, if desired, in accordance with the disclosures in the cited patents. 
     It is an object of this invention to provide a reusable plastic container box for materials such as bags of frozen foods which can be quickly erected, used repeatedly over a long period of time without appreciable deterioration or wear, and quickly knocked flat for shipment back to an original box filling point. 
     It is another object of the invention to provide a reusable plastic container box in which at least one of the sides is especially strengthened against damaging deformation or bowing. 
    
    
     Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. Throughout the drawings, like reference numerals referred to like parts. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of a plastic corrugated box made in accordance with the present invention. 
     FIG. 2 is an isometric view of a planar plastic blank from which the box shown in FIG. 1 can be made. 
     FIG. 3 is an isometric view similar to FIG. 2 suggesting initial steps in the making of the box blank shown in FIG. 2 into the box shown in FIG.  1 . 
     FIG. 4 is an isometric view similar to FIGS. 2 and 3 suggesting further steps involved in the making of the box blank shown in FIG. 2 into the box shown in FIG.  1 . 
     FIG. 5 is an isometric view similar to FIGS. 2-4 suggesting further steps involved in the making of the box blank shown in FIG. 2 into the box shown in FIG.  1 . 
     FIG. 6 is an isometric view similar to FIGS. 2-5 suggesting later steps involved in the making of the box blind shown in FIG. 2 into the box shown in FIG.  1 . 
     FIG. 7 is an isometric view similar to FIGS. 2-6 illustrating the erection of the box and the preliminary folding steps involved in creating and securing the box bottom. 
     FIG. 8 is an isometric view similar to FIGS. 2-7 illustrating the final steps involved in creating and securing the box bottom and completing the erection of the box. 
     FIG. 9 is an isometric view similar to FIGS. 7 and 8 illustrating preliminary steps involved in unfolding the bottom flaps from an erected box so as to permit the box to be flattened into a knocked-down configuration. 
     FIG. 10 is an isometric view similar to FIGS. 7-9 illustrating final steps involved in the unfolding the bottom flaps from an erected box so as to permit the box to be flattened into a knocked-down configuration. 
     FIG. 11 is an isometric view similar to FIGS. 2-10 illustrating the final steps involved in flattened flattening the box blank as to permit the box in its knocked-down configuration to be easily and economically shipped for another cycle of use or other purposes. 
    
    
     DETAILED DESCRIPTION 
     While the invention will be described in connection with a preferred embodiment and procedure, it will be understood that it is not intended to limit the invention to this embodiment or procedure. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. 
     Turning first to FIG. 1, there is shown an erected box  20  which can be used for transporting a wide variety of objects such as, for example, bags of frozen vegetables, horticultural products, snack foods, soft goods, paper goods or a whole host of other items, products or things. The box  20  can be referred to as a Merchandising Unit (MU). For example, this MU or box  20  can be used to transport bags of frozen vegetables from a freezer or frozen storage facility to the frozen food display shelves of a grocery store, but it will be understood that it is not intended to so limit this invention in its use. Because the box is constructed of sturdy corrugated plastic material, it can be knocked down into a flattened configuration, returned to a box packing point, re-erected, and used again. 
     The unitary blank  22  from which this box  20  can be made is shown in FIG.  2 . Suitable polypropylene, polystyrene, polyvinyl chloride, polyethylene, or even corrugated paper or other material can be used to form the blank. Panels  31 ,  32 ,  33 , and  34  which will become respective box sides are defined on and in the blank  22  by various hinge or score lines  36 . These score lines  36  can be created in and on the corrugated plastic blank  22  as suggested in the above referenced U.S. Pat. No. 6,102,279, or in other known ways. 
     Handholds and handhold openings  37  and  38  can be provided in the end walls  32  and  34  as shown in FIGS. 1-4 and as indicated in U.S. Pat. No. 6,102,279. The flaps from which these and openings  37  and  38  are constructed can be full flap cutouts, comprising the entire material as suggested in FIG. 10 of that &#39;279 patent, or they can be less than full flaps, constructed by removing a portion of the material which would otherwise be included in the flat. 
     To permanently assemble a box blank  22  into a box  20 , upper panels  41 ,  42 ,  43  and  44  are first folded over against the respective inner surfaces of the side panels  31 - 34  as suggested in FIG. 3 by arrows A; and the panels  41 - 44  are permanently secured to the inner surfaces of the box side panels  31 - 34  by suitable spots  46  of adhesive or other known means. 
     This step and arrangement of the upper panels  41 - 44  provides strong, smooth vertical box sides and strong, smooth top horizontal edges  51 ,  52 ,  53 , and  54 . These rolled-over edges  51 - 54  provide several advantages and features of the invention. First, the rolled-over edges  51   1 - 54  obviate any danger that a customer or box user might be scratched by inadvertently rubbing against the rough, open, exposed top edges which would otherwise be presented. In addition, the rolled-over edges  51 - 54  provide additional structural rigidity along the top of all four sides of the box. In further accordance with the invention, the rolled-over top edges  51 - 54  prevent dirt and contaminants from migrating into the otherwise opened and exposed flutes of the corrugated plastic or other material forming the box from migrating into the corrugation flutes. If the box should need to be cleaned, the rolled over edges allow box cleaning without water getting into the flutes from the top of the box. This is especially important if the box is to be used as a freezer box, since water trapped within the flutes might later freeze and expand, thereby damaging or splitting the box corrugation and sides. 
     The box panels are next folded along the score lines  36  into the configuration indicated in FIGS. 4 and 5. 
     In accordance with the invention, an L-shaped or chair-shaped glue flap or end panel  60  (FIGS. 2 and 3) is attached, at a glue flap score or hinge line  61 , to one end wall panel  34 , and when the box is assembled, that glue flap or panel  60  is secured by adhesive  62  or other known means to a side wall panel  31  which is located at the opposite end of the blank  22 , as suggested in FIGS. 2 and 3. 
     It will be noted that the top panel  41  has a horizontal length somewhat less than the wall panel  31  to which it is attached, so that it will closely internest with the upper portion  60 A and the lower portion  60 B of the adjacent glue flap panel  60 , as shown particularly in FIG.  1 . When the blank is so assembled, the four side walls  31 ,  32 ,  33  and  34  are each attached to the adjacent side walls along two end creases or hinges  36 , as can be envisioned by comparing FIGS. 1,  5  and  6 . 
     The box thus created is sturdy, yet inexpensive. In accordance with an aspect of the invention, cracking, bowing, folding, tearing or bending of side wall  31  is discouraged by the L or chair shape of the glue flap end panel  60  when that flap  60  is glued to the side wall  31 , because the side wall lower portion  60 A is extended across a relatively great number of the corrugations of that corrugated side wall  31 ; and because the upper portion of the side of flat  60 B extends across a relatively few of the side wall corrugations, as can be seen especially in FIG.  1 . During box use, interior loads which tend to bow the side wall  31  are thus spread across a relatively great number of corrugations of the side wall  31 , and are not concentrated at any one corrugation. By avoiding the concentration of bowing forces at any one un-reinforced corrugation, bowing action and box side mis-folding is avoided. If the box blank were to mis-folded along a particular corrugation, the box might not erect correctly, and might jam automatic box set up equipment. 
     Additional and cooperating anti-cracking and anti-bowing support for the side walls  31 - 34  is provided by the upper flaps  41 - 44  when they are glued to the side walls  31 - 34  as suggested in FIG.  3  and as described above. As suggested above and in FIG. 1, the flap  41  is sized and shaped so as to internest with the flap  60 , so that substantially complete horizontal support is provided across each of the side walls  31 - 34 . 
     After the flap  60  is attached, the side panel  31  is then folded over the blank  22  as indicated by arrow B in FIG. 5, resulting in a finished box flat  26  as shown in FIG.  6 . 
     Erection of the box flat  26  into a three-dimensional box is easily accomplished as suggested in FIGS. 7 and 8. As shown in FIGS. 2 and 3, each of the panels  31 - 34  has a depending bottom flap  71 ,  72 ,  73  and  74 , and each of these depending bottom flaps can be folded along the score/hinge lines  77 . To create a sturdy but reconfigurable bottom, flat  73  is first folded upwardly as suggested in FIG.  8 . Flaps  72  and  74  are folded horizontally inwardly as suggested by arrows C in FIG.  7 . Finally, flap  71  is folded downwardly as suggested by arrow D in FIG.  7 . The flap  71  is then pushed further downwardly and inwardly until a distal tongue  75  is extended through the slot created by the four flaps  71 ,  72 ,  73  and  74  as suggested in FIG. 8, thereby locking all four flaps  71 - 74  in place as shown in FIG.  8 . Easily followed instructions can be provided by imprinting the legends “fold first” on flap  73 ; “fold second” on flaps  72  and  74 ; and “fold third” on flap  71 . 
     In accordance with another aspect of the invention, the erected box shown in FIGS. 8 and 9 can be easily and quickly “knocked flat” back into the flat configuration  26  shown in FIGS. 6 and 11. As shown in FIG. 9, this can be accomplished by first pushing inwardly on the flap  71  in the direction of arrow E. this action, when completed, frees all four flaps from engagement with the other flaps. Thereafter, the flaps  72  and  74  can be folded outwardly as suggested in FIG. 10 by arrows F, and flap  73  and then be folded outwardly as suggested by arrow G. Next, the original flap  71  can be folded outwardly from its temporary position inside the box cavity. The box can then be “knocked flat” into a flattened configuration by simply pushing on the sides  32  and  31  as suggested by arrows H in FIG.  11 . If desired, starting instructions for this collapsing reconfiguration procedure can be provided by including a suitable legend such as “collapse box flat for return by pushing bottom panel number three inward” on any suitable side wall  31 - 34 . 
     In accordance with yet another aspect of the invention, it is intended that this easily set up and easily collapsed box  20  can be repeatedly reused and recycled. For example, the box flats  26  can be provided at one or more packing stations. There, personnel can erect or set up the box into its configuration shown in FIG.  1 . The box can then be filled with, for example, bagged packages of frozen foods such a frozen vegetables or other material. A top (not shown) can then be fastened across the top of the open box, and the box can be placed with other filled boxes on a pallet. The palletized boxes then can be shipped to a grocery store or other distribution facility. There, the top can be removed and the boxes placed upon, for example, frozen food display racks or other support structure in frozen food display facilities (not shown). In carrying out the invention, it is contemplated that the boxes can be provided in sizes which will snuggly mate or fit within the display racks. When the box  20  is empty, it can be removed from the display rack, cleaned if necessary, knocked flat as in accordance with the procedure described above, and shipped back to the original packing stations 
     Although these corrugated plastic boxes  20  may initially cost somewhat more than boxes of similar size made of corrugated cardboard paper, the plastic boxes can be reused time and time again. The effective cost of reusing these novel boxes will fall, over a period of time, to an amount significantly less than the cost of single-use corrugated cardboard paper boxes of similar size and shape. Because the plastic boxes are reasonably attractive, they can be sized and shaped to be placed directly upon the display supports. Because they need not be unpacked, additional labor cost savings can be realized. Because the boxes are significantly stronger than comparable corrugated cardboard paper boxes, damage to the goods and to the boxes themselves is significantly reduced, thus further reducing the overall cost of using these boxes. The boxes have good stacking strength, and they do not degrade in humid or harsh environments. The constituent plastic and the finished boxes can be provided in virtually any desired color.