Patent Publication Number: US-7905183-B2

Title: Structural cardboard runner, pallet, shipping article

Description:
This application claim benefit under 35 U.S.C. §119(e) of provisional application Ser. No. 61/024,304, filed Jan. 29, 2008, entitled PALLET WITH CARDBOARD RUNNER, the entire contents of which are incorporated herein in their entirety. 
    
    
     BACKGROUND 
     The present invention relates to structural cardboard runners, and pallets and shipping articles for material handling. The present invention relates especially to a pallet including cardboard runners, but is not limited to only runners, nor only pallets. 
     Traditional wood pallets are expensive to purchase and maintain. Further, they are not always easily disposed of. In particular, disposal of wood pallets can be problematic in large cities where downtown is congested, because trucks cannot wait at drop off sites. Instead, the trucks must make a return trip (i.e., an “empty run”) to the drop off site through traffic and congestion to pick up empty pallets, wasting considerable time and adding substantially to shipping expense. 
     Cardboard has been used to make pallets and runners of pallets. However, known pallets that incorporate cardboard often lack durability and strength. Further, cardboard runners are problematic because runners experience “horizontal abuse” from fork truck tines as they engage and disengage a pallet to move and/or position the pallets on storage racks, and further experience “vertical abuse” as heavy packages put downward pressure on the runner against uneven ground support and/or storage racks and/or wet surfaces. 
     SUMMARY OF THE PRESENT INVENTION 
     In one aspect of the present invention, a structural beam is provided for use in pallets, where the beam includes a cardboard sheet having a length adapted to match a pallet dimension, the sheet being folded in a width direction to include a cross section with a first portion forming an M shape, a second portion folded across the M shape to form two closed triangles, and a third portion folded around the M shape including sections along and adjacent a first outer leg of the M shape and across the M shape and along and adjacent a second outer leg of the M shape. Adhesive bonds the third portion to the first and second portions. The arrangement forms a beam of sufficient structural rigidity to support the vertical and horizontal “abuse” often received by runners of pallets. 
     In a narrower aspect of the present invention, notches sufficient for fork lift tines are cut into the length of the folded sheet at locations spaced from each other and spaced from ends of the length for matching a typical location of the fork lift tines. 
     In a narrower aspect of the present invention, a pallet is made comprising a deck and at least three of the structural beams defined above attached to a bottom of the deck as runners. The deck can be cardboard or other material. 
     In another aspect of the present invention, a pallet includes a plurality of parallel tubular structural runners made of stiff sheeting, a plurality of structural cross beams made of similar stiff sheeting and positioned orthogonally on the runners, and a deck attached atop the runners and cross beams. The runners and cross beams each include a cross section with internal walls forming an M shape and further with a perimeter wall enclosing the internal walls to form a tubular shape. The runners and cross beams each have mating first notches spaced from but near ends thereof and at least one mating notch at an intermediate location with a size and depth of the first notches and mating notch being such that the runners and cross beams fit snugly matably together at each cross location to form orthogonally-strong structural connections. At least the runners further have second notches for receiving tines of a fork truck. 
     The present invention further includes an article for shipping a product, the article including a plurality of tubular elongated structural beams made of stiff sheeting, the structural beams each including a cross section with internal walls forming an M shape and further with a perimeter wall enclosing the internal walls to form a tubular shape; extending orthogonally to each other to define twelve edges of a box shape. A plurality of corner pieces at each corner of the box shape for supporting a product therein for shipment. 
     These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a fragmentary perspective view of a pallet including cardboard runners. 
         FIG. 2  is an end view of the runner in  FIG. 1 . 
         FIG. 3  is a cross-sectional view of a cardboard sheet. 
         FIGS. 4-4B  are perspective views of a pallet with cardboard runners and cardboard deck,  FIG. 4  being the assembled product,  FIG. 4A  being identical to  FIG. 4  but with the deck removed to better show the criss-crossed runners, and  FIG. 4B  being exploded apart. 
         FIGS. 5-7  are orthogonal views of the pallet shown in  FIG. 4 ,  FIG. 5  being a bottom view and  FIGS. 6-7  being side views. 
         FIGS. 8-9  are enlarged perspective views of an end connection and a middle connection, respectively, of criss-crossed runners as shown in  FIG. 4A . 
         FIG. 10  is a perspective view of a packaging article for material handling, the packaging article including a space frame of criss-crossed cardboard runners and including foam corner supports for a piece of furniture. 
         FIG. 11  is a perspective view of an alternative foam corner. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     A pallet  20  ( FIG. 1 ) includes a deck  21  and three runners  22  (also called “structural beams” herein) adhered to its bottom surface. Each runner  22  is a cardboard sheet having a length adapted to match a pallet dimension. The term “cardboard” as used herein is intended to include paper, plastic, and other stiff sheet material equivalent to the strength and structure of paper and cardboard. The sheet is folded in a width direction to include a first portion (sections  23 - 26 ) forming an M shape, a second portion (section  27 ) folded across the M shape to form two closed triangles  32  and  33 , and a third portion (sections  28 - 31 ) folded around the M shape. The section  28  extends along and adjacent a first outer leg (section  23 ) of the M shape. Section  29  extends across the M shape and section  30  extends along and adjacent a second outer leg (section  26 ) of the M shape. Adhesive bonds the third portion to the first and second portions at locations  35 - 37 , which include large flat adjacent areas well suited for high bonding strength. Adhesive can also be located at locations  38 - 41  if desired and if additional stability of the M shape is desired. Notches  49  are cut into the runners  21  at locations spaced from each other and from ends of the runners  21 . The notches  49  have a width for receiving a fork truck tine, and further have a depth of about 70%-90% of a depth of the runner  22 , such that the unsupported vertical wall of cardboard is minimized in order to minimize damage to the runners  22  from the fork truck tines sliding in and out and when lifting the pallet  20 . 
     The present runner forms a structural beam that is surprisingly and unexpectedly strong and durable, and that is well suited for use as a runner to provide sufficient structural rigidity to withstand the stress and the vertical and horizontal “abuse” often received by pallets. For example, my testing showed that the illustrated runner can hold up to 5,000 pounds using 42 DW Cor corrugated cardboard. I believe this strength and stability comes in large part from the V-shaped internal support that stabilizes the outer “box” of the runner in diagonal directions from opposing corners to a center-point of a wall opposite the corners, thus providing optimal structure to prevent a parallelogram-type collapse. This V-shape has been found to be stronger than other configurations that I have tested, including X, W, Z and single-angled-wall shapes. Also, the double walls on the opposing sides and top of the runner provide strength in a manner well suited for cardboard sections held together by adhesive bonding since they provide large flat surface areas. The double walls also provide protection for the internal structural diagonally-strong V shape. It contemplated that an additional section of cardboard can be extended across the bottom of the runner to form a double wall completely around the M shaped portion of the runner if desired, such as if additional material is desired at a bottom of the runner where supporting surfaces rub (i.e. racks and/or floor surfaces). Also, it is contemplated that the present runner can be used with the “M” shaped portion being either inverted (see  FIG. 1 ) or upright (i.e., upside down from  FIG. 1 ) when in a pallet. 
     Different cardboards and sheets can be used for the present runner. As noted above, 42 DW Cor corrugated cardboard works well based on testing for typically sized runners and pallet loads. However, other corrugated cardboards can be used, such as 32 C, 44 C, 42 DW*, and 42 DW. 
     The illustrated deck is also made of cardboard material. It is contemplated that the same cardboard can be used for the runner, or it can be a different grade of cardboard or paper sheet material. Further, a sheet other than cardboard can be used if desired, such as wood, plastic, or composite, and also the sheet can be treated to include properties desired for particular applications. Notably, the present runner  22  presents a large flat top surface and large bonding area for receiving adhesive. This adds considerably to a strength of the overall pallet, due to the large bonding area. Also, where corrugated cardboard is used for both the runner and the deck, with the bonded corrugated sheets extending in parallel juxtaposed positions where they support each other and also help distribute stress. 
     Modification 
     A modified pallet  20 A ( FIGS. 4-9 ) is similar to pallet  20 , and similar components and features are similarly identified but with the addition of the letter “A”. Modified pallet  20 A includes parallel runners  22 A (three shown) ( FIGS. 4-4B ) that are notched and criss-crossed with additional runners  22 A (three shown) (also called “cross beams”) to form an interconnected orthogonal matrix, with all parallel runners  22 A and additional runners  22 A lying in a common plane. The runners  22 A are similar to runners  22  in that they include similar portions  23 - 26  forming an M shape, and additional outer portions  27 - 31  to enclose the M shape. When combined with a top deck  21 A, the pallet  20 A formed is orthogonally rigid and surprisingly strong. The notches  50 A ( FIG. 4B ) in the runners  22 A extend to half a depth of the runners  22 A and have a length that exactly matches a width of the criss-crossed runners  22 A. 
     By this arrangement, the marginal material around the notches  50 A is supported by the criss-crossed runners  22 A, such that they form orthogonally rigid joints when connected. Further, the notches  50 A into the internal M shape cut the angled walls formed by portions  24 A- 25 A to a half-height. These half-height angled walls engage mating parts of the criss-crossed runner  22 A, thus further strengthening the joint. The criss-crossed connection of runners  22 A is quick, relatively easy, and very effective in strength and function, especially when bonded with a glue or adhesive. Further, adhering the top deck  21 A to the orthogonal matrix of runners  22 A further rigidifies the pallet  20 A. It is noted that the illustrated deck  21 A is flush with an end of the runners in one direction, but extends about an inch off the end of the perpendicular runners. It is contemplated that the deck can be modified as desired for particular applications, such as by having slits or holes as desired to anchor product thereon. It is also contemplated that an outer edge can be doubled back onto the deck if desired to create a physical lip around a part or all of the pallet&#39;s perimeter. It is contemplated that the notches  49 A for receiving fork truck tines can be on all runners  22 A if desired, thus permitting a fork truck to engage its tines from any of the four sides of the pallet  20 A. 
     Structural beams  22 B,  22 B′,  22 B″ ( FIG. 10 ) are identical in cross section to the beams  22  and  22 A, but beams  22 B are used to form a space frame article  60 B useful for material handling purposes, such as for shipping large product (see desk shown in  FIG. 10 ) and/or for storing large product in a protected environment. The illustrated article  60 B includes four long beams  22 B, four vertical end beams  22 B′, and four horizontal end beams  22 B″, the beams  22 B,  22 B′,  22 B″ each extending generally parallel one of the twelve edges of the desk product shown in  FIG. 10  when assembled onto the product. The long beams  22 B and vertical end beams  22 B′ include notches  50 B so that they can be mated together to form orthogonally-rigid connections, allowing them to form a rectangular front frame and a rectangular rear frame. The foam corner pieces  63 B are then placed on and engage corners of the product being shipped, and the rectangular front and rear frames are pressed against the product  61 B and foam corner pieces  63 B to hold them in place. The horizontal end beams  22 B″ include a notch  50 B, but the notches  50 B on the end beams  22 B″ are fit onto an uncut region  64 B of the long beams  20 B in a manner holding the front and rear frames together on the product. It is noted that additional beams  22 B,  22 B′, and/or  22 B″ can be used at intermediate locations to further stiffen and support the beams used at corners of the product. 
     Notably, a variety of different pieces can be used in place of the illustrated foam corner pieces  63 B, and also that the corner pieces can be a variety of different shapes depending on their functional requirements. For example, the foam corner pieces  63 B define a channel  65 B for receiving the long beams  22 B, but the vertical end beams  22 B′ engage an outer surface  66 B of the corner pieces  63 B, and the horizontal end beams  22 B″ engage a top (or bottom) surface  67 B of the corner pieces  63 B. Contrastingly, the modified foam piece  63 C includes channels  65 C,  66 C, and  66 C for receiving each of the beams  22 B,  22 B′, and  22 B″, respectively. It is contemplated that the corner pieces can include more or less channels, and be made of different materials (such as cardboard or other plastic rather than foam), and also can be simply a sheet to separate the product from the cardboard runner (where the product has an aesthetic surface that can be scratched). 
     It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.