Abstract:
A low-cost, strong, and ecological pallet is constructed with pallet blocks having honeycomb cores. The honeycomb cores provide strength in the vertical direction, and their integrity is protected by a honeycomb material overwrap. The honeycomb material wrap provides exceptional strength against lateral forces. The pallet and pallet blocks may be manufactured of kraft material or other sturdy materials.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims the benefit of priority of U.S. Provisional Patent Application Serial No. 60/297,852, filed Jun. 13, 2001. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates generally to packaging articles used in storage and transportation and more particularly relates to shipping pallets.  
         BACKGROUND OF THE INVENTION  
         [0003]    The efficient shipping of articles in national and international industries relies to a great extent on the use of pallets, or shipping decks, upon which goods are stacked and transported. A common use of a pallet is as a deck for allowing the transport and organization of goods by forklifts, including automatic and hand-operated forklifts, and other lifting and moving devices. Pallets are also often used for storing goods between shipments, or for display of products at wholesale and retail vendors.  
           [0004]    Pallets must be strong in the vertical direction to withstand heavy loads and they must be able to withstand considerable lateral force from shipping implements. One shipping practice that exerts considerable lateral force on a pallet is commonly known as “pinwheeling.” In pinwheeling, pallets which are misaligned after being lowered are forced into alignment by the lift forks of a forklift. Because this practice is widespread, it is important that pallets be able to withstand lateral forces.  
           [0005]    One pallet type currently used is a wooden pallet, constructed of wooden beams and decks. While wooden pallets are widely used, they do have significant shortcomings. For example, to dispose of a wooden pallet is a waste of resources. Further, when wooden pallets are broken, they must be repaired or destroyed. Also, wooden pallets are expensive, and to repeatedly use wooden pallets it is necessary to have a system for storing or exchanging the pallets. Another problem associated with wooden pallets is their weight. Wooden pallets tend to weigh seven or eight times that of paper pallets. Wooden pallets are also commonly manufactured with nails, and handlers of wooden pallets risk injury from nails or wood splinters. Plastic pallets are also available, but like wooden pallets they are expensive and not ecological. Plastic pallets may be twice as expensive as wooden pallets to manufacture. There exists a need for a pallet material that is lightweight, strong, and ecologically sound.  
         SUMMARY OF THE INVENTION  
         [0006]    These problems and others are overcome by the pallets and pallet materials of the present invention.  
           [0007]    According to one embodiment of the present invention, a pallet deck is supported by pallet blocks constructed of honeycomb material.  
           [0008]    According to another embodiment of the present invention, a pallet deck is supported by pallet blocks constructed of honeycomb cores reinforced with honeycomb overwraps.  
           [0009]    According to another embodiment of the present invention, a pallet deck is supported by pallet runners constructed of honeycomb material.  
           [0010]    According to another embodiment of the present invention, a pallet deck is supported by pallet runners constructed of honeycomb cores reinforced with honeycomb overwraps.  
           [0011]    The above summary of the present invention is not intended to represent each embodiment, or every aspect of the present invention. This is the purpose of the figures and detailed description which follow. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    Other aspects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings.  
         [0013]    [0013]FIG. 1 is a perspective view of a pallet according to one embodiment of the present invention;  
         [0014]    [0014]FIG. 2 is a perspective view of a support block according to one embodiment of the present invention;  
         [0015]    [0015]FIG. 3 is a cutaway view of a portion of honeycomb material used in the present invention;  
         [0016]    [0016]FIG. 4 is a perspective view of a pallet runner according to one embodiment of the present invention;  
         [0017]    [0017]FIG. 5 is a perspective view of a runner pallet construction according to one embodiment of the present invention;  
         [0018]    [0018]FIG. 6 is a perspective view of a segmented runner pallet construction according to one embodiment of the present invention,  
         [0019]    [0019]FIG. 7 is a perspective view of a supported runner pallet construction according to one embodiment of the present invention; and  
         [0020]    [0020]FIG. 8 is a perspective view of an alternative pallet support block construction according to one embodiment of the present invention.  
         [0021]    [0021]FIG. 9 is a perspective view of a support block according to an alternative embodiment of the present invention.  
         [0022]    [0022]FIG. 10 is a perspective view of a support block having an overwrap that is slit-scored.  
         [0023]    [0023]FIG. 11 a  is a perspective view of a support block according to an alternative embodiment of the present invention.  
         [0024]    [0024]FIG. 11 b  is a frontal view of a stretched core of the support block of FIG. 11 a.    
         [0025]    [0025]FIG. 11 c  is a frontal view of a folded core of the support block of FIG. 11 a.   
     
    
       [0026]    While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the intent is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0027]    [0027]FIG. 1 shows a perspective view looking upwardly from the bottom of a pallet  10  of the present invention. The pallet  10  includes a pallet deck  12  and nine pallet support blocks  14 . The pallet support blocks  14  are spaced so as to provide room for a forklift or other lifting instrument to slide beneath the pallet deck  12  and to lift the pallet  10  and any goods being carried on the pallet  10 . The pallet support blocks  14  are arranged to allow for four-way entry for forklifts or other lifting devices.  
         [0028]    The pallet deck  12  may be constructed of a honeycomb material, which is described in greater detail below. Alternatively, the pallet deck  12  may be made of a corrugated material. The corrugated pallet deck  12  may consist of one or more layers of corrugated material, depending on the application. For example, if the pallet deck  12  is to hold light items may only need a single corrugated layer. If the items stacked on the pallet deck  12  are heavier, two or even three layers of corrugated material may be needed. Alternatively, the corrugated layers may be cross-laminated. Corrugated materials are stronger in one direction than another. A first corrugated layer is set, while a second corrugated layer is rotated  90  degrees and then laminated onto the first layer. This causes the pallet deck  12  to be strong in all four directions. It is also contemplated that the pallet deck  12  may be any combination of corrugated, honeycomb, and/or cross-laminated construction.  
         [0029]    Turning now to FIG. 2, a pallet support block  14  is shown. The pallet support block  14  of FIG. 2 is constructed with a support block core  16  reinforced with a support block overwrap  18 . As shown in FIG. 2, the support block core  16  has an approximately rectangular cross-section which is surrounded on four sides by the support block overwrap  18 . Alternatively, pallet support blocks  14  may be constructed with the support block core  16  and reinforced by a support block overwrap  18  on fewer sides. The support block overwrap  18  provides the pallet support block  14  with resistance to lateral forces encountered during storage and shipment of the pallet  10 .  
         [0030]    The support block overwrap  18  may be made of honeycomb material, which is described in greater detail below. When the support block overwrap  18  is made of honeycomb material, the honeycomb material must be shaped to fit around the cross-section of the support block core  16 . This may be accomplished through the use of corner structures  20 . To make the corner structures  20 , a flat sheet of honeycomb material may be slit-scored (FIG. 10), scored and crushed, or cut in a “V” shape, to provide the material with an ability to fold along desired lines. Crushed segments  22  of honeycomb material are visible in FIG. 2. Once the honeycomb material of the support block overwrap  18  has been scored, crushed, or cut and folded, the fold may be kept intact through the use of adhesive in the corner structure  20 . Alternatively or additionally, folds in the support block overwrap  18  may be kept intact through the use of adhesive along the areas where the support block overwrap  18  contacts the support block core  16 . When the support block overwrap  18  is made of a single sheet of honeycomb material formed around the shape of the support block core  16 , an overwrap seam  24  results.  
         [0031]    The support block overwrap  18  may be made of a wide range of thicknesses, with over-wrap thicknesses of from about 0.25 inches to about two inches being particularly useful. The overwrap may further be placed so that the honeycomb structure is oriented at a variety of angles, with a preferred orientation having the strongest dimension of the overwrap perpendicular to the surfaces of the support block core  16 .  
         [0032]    Turning now to FIG. 3, a honeycomb panel  26  is shown in a cutaway view to illustrate its structure wherein a honeycomb core  28  is sandwiched between a top face sheet  30  and a bottom face sheet  32 . The honeycomb core  28  comprises a plurality of abutting partition walls  34  which extend generally perpendicularly between the top and bottom face sheets  30  and  32 . The partition walls  34  form a plurality of abutting elongate hexagonal cells  36  having opposed bottom and top hollow-cell hexagonal faces on opposite sides of the honeycomb core  28 . The top face sheet  30  and the bottom face sheet  32  are respectively abutted to the top and bottom hexagonal faces of the core  28 .  
         [0033]    Preferably, the honeycomb core  28  and the top and bottom face sheets  30  and  32  are made of a kraft paper. The face sheets  30  and  32  can be made of various weights of material. For example, the face sheets  30  and  32  may be made of paper or linerboard ranging from  26  pound paper or linerboard to 90 pound paper or linerboard, though heavier or lighter weights may also be used. Further, the face sheets  30  and  32  may be made of two different weights of paper or linerboard. Alternatively, one or both of the face sheets  30  and  32  may be made of chip board, a heavier duty paper product than 90 pound linerboard. Chipboard ranging from a thickness of about 8 mils to about 50 mils may be used, though thicker or thinner thicknesses of chipboard may be desirable in some applications. The core material may likewise be made of a variety of materials and weights. Twenty-six pound and 33 pound paper or liner board are preferred as the core material, though heavier or lighter paper or liner board may be used depending on the particular application. When honeycomb structures of the present invention are made of paper, an entire pallet  10  may be recycled with other paper products.  
         [0034]    The hexagonal cells  36  have an internal diameter “W” ranging from about 0.375 of an inch to about 1.2 inches. Materials other than paper, linerboard, or chip board can also be used for the face sheets  30  and  32  and the honeycomb core  28 . The support block  12  may be designed to withstand up to 240 lbs/block of dynamic weight and up to 1200 lbs/block of static weight, though higher weight limits may be supported.  
         [0035]    In some embodiments, the support block  14  may include a pressure sensitive adhesive. The adhesive is used to attach the support block  14  to the pallet deck  12  or any other surface. By providing adhesive on the support block  14 , the end user may omit the step, providing greater customer satisfaction with the product.  
         [0036]    The pressure sensitive adhesive may be a prefabricated tape, a liquid adhesive, or a hot melt adhesive. If the liquid adhesive or hot melt adhesive is used, a release paper may be provided on the adhesive. The liquid adhesive may be a polyvinyl acetate or ethyl vinyl acetate.  
         [0037]    Turning now to FIG. 4, a pallet runner  38  is shown. The pallet runner  38  is another form of pallet support for use with the present invention. The pallet runner  38  may be an elongated version of the pallet support block  14 , or it may be constructed differently. The pallet runner  38  shown in FIG. 4 has two layers of honeycomb core  28  surrounded by a corrugated overwrap  40 . The pallet support block  14  may also be constructed in this manner. Alternative constructions, such as a single layer of honeycomb core  28  surrounded by a corrugated overwrap or a double layer of honeycomb core  28  surrounded by a honeycomb overwrap may be used to construct either a pallet support block  14  or a pallet runner  38 .  
         [0038]    The pallet runner  38  is shown in use with a pallet deck  12  in FIG. 5. In this embodiment, three pallet runners  38  are arranged to allow for a forklift to pick up the pallet  10 . The pallet runner  38  provides greater beam strength than the support blocks  14 , since the runner  38  stretches across the entire width of the pallet deck  12 . The pallet runners  38  may be designed to handle up to 30 lbs/inch in dynamic weight and up to 150 lbs/inch in static weight.  
         [0039]    Another embodiment, illustrated in FIG. 6, combines the strength of the runner  38  and the accessibility of the support block  14 . In this embodiment, the pallet deck  14  is shown being supported by a segmented runner  42 . The segmented runner  42  includes a plurality of single layered runners  44  that extend across the entire width of the pallet deck  12 . The single layered runners  44  may be made of a single layer of honeycomb as described in reference to FIG. 2 above.  
         [0040]    Throughout the length of the single layered runners  44 , blocks  46  are attached to the single layered runners  44 . The blocks  46  may be constructed the same as the pallet support blocks  14  described above, or they may be constructed differently. In some embodiments, both the blocks  46  and the single layered runners  44  may be surrounded by an overwrap  48 , providing for dual protection at the points where the blocks  46  and the runners  44  overlap. Alternatively, the overwrap  48  may only go around the outside of the block  46  and runner  44  structure. In some embodiments, the overwrap  48  may be made of a honeycomb material, or it may be made of a corrugated material. This embodiment is useful because it combines the strength of the runner with the four way entry capability of the support blocks.  
         [0041]    Turning now to FIG. 7, the pallet  10  is illustrated having a plurality of runners  38  and a bottom sheet  50 . One end of the runner  38  is attached to the pallet deck  12 , while the other end is attached to the bottom sheet  50 . The bottom sheet  50  provides added support to the pallet  10 . The bottom sheet  50  provides further stability to the runners  38 , making the overall pallet  10  more sturdy. The bottom sheet  50  may be made of a honeycomb material as shown in FIG. 3, or it may be made of a corrugated material or paper or liner board.  
         [0042]    Turning now to FIG. 8, a pallet block  52  according to another embodiment of the invention is illustrated. In this embodiment, the pallet block  52  includes a core  54  and an overwrap  56 . The core  54  is made of two layers  58 ,  60  of honeycomb material. The overwrap  56  may be made of a honeycomb material or it may be made of a corrugated material.  
         [0043]    In some alternative embodiments, the core  54  may be provided with face sheets covering the honeycomb inside of the core  54 . The covering may be entirely made of chipboard or linerboard.  
         [0044]    Turning now to FIG. 9, a support block  70  according to an alternative embodiment of the present invention will be described. The support block  70  includes an overwrap  72 , in place of the honeycomb core of the embodiments described in reference to FIGS. 2 and 8. The overwrap  72  may be wrapped numerous times to add to the strength of the support block  70 . Also, the overwrap  72  may be thicker than the overwraps  18 ,  56  described in FIGS. 2 and 8, to further strengthen the support block  70 .  
         [0045]    Turning now to FIGS. 11 a - c,  a support block  80  according to an alternative embodiment of the present invention will be described. The support block  80  includes a honeycomb core  82  and an overwrap  84 . In this embodiment, the honeycomb core  82  is made of a slit and reverse-slit scored and folded material. As shown in FIG. 11 b,  the core  82  includes a plurality of slits  86  and reverse slits  88 . The slits  86  and reverse slits  88  allow the honeycomb core  82  to be folded as is illustrated in FIG. 11 c.    
         [0046]    While the present invention has been described with reference to one or more particular embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present invention. Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of the claimed invention, which is set forth in the following claims.