Abstract:
The pallet constructed of a rubber composite is made from rubber that includes recycled rubber, natural rubber, sulfur and a filler material. The pallet has an upper member and a lower member that interconnect to resemble a traditional American model wooden pallet. Although an assembly of just two molded components, it appears to be constructed of a number of planks attached to two or more cross beams. In an alternative embodiment, it resembles a European model wooden pallet by appearing to be constructed of a number of planks attached to two grids, each of which is attached to opposite surfaces on a plurality of support blocks.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to pallets for storing and transporting goods, and more particularly, to a pallet constructed of a rubber composite.  
         [0003]     2. Description of the Related Art  
         [0004]     The use of pallets for storing and transporting products is well known in the arts. Pallets are rectangular raised platforms adapted for movement by forklifts. Traditionally, pallets have been constructed of wood, each with an upper face and a lower face separated by two or more crossbeams to enable the tines of a forklift to be inserted between the faces. Typically, the cost of a pallet constructed of wood is between ten and fifteen dollars.  
         [0005]     Over the last several years, the use of wood packaging for foreign shipments has received much international attention due to the possible spread of pests and diseases. As a result, the European Union and other NAFTA countries are moving toward the adoption of the International Plant Protection Convention (IPPC), which sets forth standards for treating wood packaging. Significantly, the IPPC requires that wooden pallets used for international shipments be treated, i.e., fumigated.  
         [0006]     Because treating wooden pallets has several drawbacks, transporters and pallet manufacturers have considered using pallets constructed of plastic. However, although plastic pallets do not need to be treated for pests and diseases, they are more expensive to produce than wooden pallets. Typically, the cost of a plastic pallet is between eighty and eighty-five dollars, which is more than five times the cost of producing a wooden pallet.  
         [0007]     Consequently, a non-wooden pallet with a lower production cost is desired. Such a pallet would need to be produced from a material that is less expensive than plastic, such as rubber. The cost of rubber is between five and twenty percent of the cost of plastic, and the cost of producing a pallet constructed of hard rubber is estimated to cost between twenty and thirty dollars at the current market price of rubber.  
         [0008]     Examples of patents for plastic pallets are provided by U.S. Pat. No. 5,579,686, issued Dec. 3, 1996 to B. L. Pigott et al. (plastic pallet assembly); U.S. Pat. No. 5,887,529, issued Mar. 30, 1999 to M. John et al. (modular pallet with interlocking inserts); U.S. Pat. No. 6,029,583, issued Feb. 29, 2000 to S. F. LeTrudet (pallet with attachable upper and lower members); U.S. Pat. No. 6,109,190, issued Aug. 29, 2000 to R. G. Hale et al. (materials handling pallet); U.S. Pat. No. 6,199,487, issued Mar. 13, 2001 to L. Coddington (modular pallet structure) and U.S. Pat. No. 6,216,608, issued Apr. 17, 2001 to M. E. Woods et al. (plastic pallet). However, none of these teach a non-wooden pallet constructed of a low cost material, such as rubber.  
         [0009]     Accordingly, none of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus a pallet constructed of a rubber composite solving the aforementioned problems is desired.  
       SUMMARY OF THE INVENTION  
       [0010]     The present invention is a pallet constructed of a rubber composite that includes recycled rubber, natural rubber, sulfur and a filler material. The pallet has an upper member and a lower member that interconnect to resemble a traditional American model wooden pallet. Although an assembly of just two molded components, the pallet of the present invention has the appearance of being constructed of a number of planks attached to two or more crossbeams. In an alternative embodiment, the pallet of the present invention resembles a European model wooden pallet by appearing to be constructed of a number of planks attached to two grids, each of which is attached to opposite surfaces of nine support blocks.  
         [0011]     Accordingly, it is a principal object of the invention to provide a pallet constructed of a rubber composite.  
         [0012]     It is another object of the invention to provide a pallet that does not require fumigation or other treatment prior to foreign shipment and is less expensive to produce than plastic pallets.  
         [0013]     It is a further object of the invention to provide a pallet that resembles a wooden pallet but is constructed of materials other than wood.  
         [0014]     Still another object of the invention is to provide a pallet constructed of a rubber composite that is shaped and dimensioned to work with existing automated loading and shipping equipment.  
         [0015]     Yet another object of the invention is to provide a pallet that is free of mold, sawdust and insects, and that does not warp or readily burn.  
         [0016]     It is an object of the invention to provide a pallet that is constructed in part from recycled materials.  
         [0017]     It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.  
         [0018]     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]      FIG. 1  is a perspective view of a pallet constructed of rubber composite according to the present invention.  
         [0020]      FIG. 2  is an exploded view of the pallet of  FIG. 1 .  
         [0021]      FIG. 3  is a front view of a pallet constructed of rubber composite according to the present invention.  
         [0022]      FIG. 4  is a side view of a pallet constructed of rubber composite according to the present invention.  
         [0023]      FIG. 5  is a section view drawn along lines  5 - 5  of  FIG. 4 .  
         [0024]      FIG. 6  is a perspective view of an alternative embodiment of a pallet constructed of rubber composite according to the present invention.  
         [0025]      FIG. 7  is an exploded view of the pallet of  FIG. 6 .  
         [0026]      FIG. 8  is a perspective view of a second alternative embodiment of a pallet constructed of rubber composite according to the present invention.  
         [0027]      FIG. 9  is a perspective view of a third alternative embodiment of a pallet constructed of rubber composite according to the present invention.  
         [0028]      FIG. 10A  is a fragmented view of an upper member of a pallet according to the present invention showing a notch.  
         [0029]      FIG. 10B  is a fragmented view of a lower member of a pallet according to the present invention showing a holding wedge. 
     
    
       [0030]     Similar reference characters denote corresponding features consistently throughout the attached drawings.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0031]     The present invention is a pallet constructed of rubber composite designated generally as  10  in the drawings. In appearance, it resembles a traditional American model wooden pallet as shown in  FIG. 1 . It is assembled from two injection-molded components including an upper member  30  and a lower member  50 , as shown in  FIG. 2 .  
         [0032]     The upper member  30  is molded such that it has a number of planks  32  attached to three crossbeams  34 . The crossbeams  34 , also known as stringers among pallet manufacturers, are substantially the same length, are substantially parallel to each other, and run front-to-back across the pallet  10 . Likewise, the planks  32  are substantially the same length, are substantially parallel to each other, and run side-to-side across the pallet  10 . The bottom side of each plank  32  is attached to the top edge of each of the crossbeams  34  with each plank  32  oriented substantially perpendicular to each crossbeam  34 .  
         [0033]     Similarly, the lower member  50  is also molded such that it has a number of planks  52  attached to three crossbeams  54 . The crossbeams  54  are substantially the same length, are substantially parallel to each other, and run front-to-back across the pallet  10 . The planks  52  are substantially the same length, are substantially parallel to each other, and run side-to-side across the pallet  10 . The bottom edge of each of the crossbeams  54  is attached to the top of each plank  52  with each plank  52  being oriented substantially perpendicular to each crossbeam  54 .  
         [0034]     Each of the crossbeams  54  in the lower member  50  has three holding wedges  56  protruding from one of its sides, and each of the crossbeams  34  in the upper member has three corresponding notches  36  (see  FIGS. 10A and 10B ) in one of its sides. Each holding wedge  56  is triangular in section with a horizontal base  62 , a side adjoined to the crossbeam and a side  64  that slopes downward away from the crossbeam. The surfaces of the base  62  and the sloped side  64  are rectangular. Each notch  36  is a recessed square sized to accommodate a holding wedge  56 .  
         [0035]     When the upper member  30  is lowered onto the lower member  50  with corresponding crossbeams  34  and  54  aligned, each holding wedge  56  snap-fits into a mating notch  36 . Once snapped into notches  36 , the holding wedges  56  prevent the two members  30  and  50  from being separated and also prevent any relative front-to-back lateral movement between the members  30  and  50 .  
         [0036]     Each crossbeam  34  and  54  has two arches, a front arch  70  and a rear arch  72 , extending upward from its bottom surface, as shown in  FIGS. 2 and 4 . The front arches  70  are positioned such that they all align when the upper  30  and lower members  50  are assembled. Likewise, the rear arches  72  also align when the members  30  and  50  are assembled. The arches  70  and  72  allow the pallet  10  to be lifted by a forklift from either of its sides, as an alternative to being lifted from the front or back of the pallet.  
         [0037]      FIG. 3  shows a front view of the pallet  10  with the two outer crossbeams  34  extending downward from the upper member  30 , and with two crossbeams  54  extending upward from the lower member  50  and fitting snugly against the inner face of the outer crossbeams  34  such that the crossbeams  34  and  54  prevent any side-to-side lateral movement between the upper  30  and lower members  50 .  FIG. 5  shows a cross section of the pallet  10 . A holding wedge  56  on each of the lower member crossbeams  54  is engaged in a corresponding notch  36  on an upper member crossbeam  34 , such that the upper and lower members  30  and  50  cannot be separated or moved laterally relative to each other.  
         [0038]      FIG. 8  shows a slight variation of the pallet, designated  200  in  FIG. 8 , having injection molded upper  230  and lower  250  members joined together in which the planks  232  of the upper member  230  extend slightly beyond the rectangular boundary formed by the crossbeams  234  and  254  to form an overhang  238 . The overhang  238  facilitates shrink-wrapping the pallet  200  and its load.  
         [0039]      FIG. 9  shows another variation of the pallet, designated  300 , having injection molded upper  330  and lower  350  members in which a retaining wall  302  extends upward from the periphery of the upper member  330 . The retaining wall  302  helps prevent shifting loads from falling off of the pallet  300 .  
         [0040]      FIGS. 6 and 7  depict an embodiment of a pallet of the invention designated as  100  that resembles a European model wooden pallet. This pallet  100  is also an assembly of an upper member  130  and a lower member  150 .  
         [0041]     The upper member  130  is molded such that it has a number of planks  132  attached to the top of a grid  134 , with the underside of the grid  134  attached to the tops of a plurality of support blocks  136 . The planks  132  are substantially the same length, substantially parallel to each other and run side-to-side across the pallet  100 . The grid  134  is substantially flat, being formed with three planks running side-to-side and three planks running front-to-back. The support blocks  136  are all substantially the same length and substantially parallel to each other.  
         [0042]     Similarly, the lower member  150  is also molded such that it has a number of planks  152  attached to the bottom of a grid  154 , with the top of the grid  154  attached to the bottoms of nine support blocks  156 . The planks  152  are substantially the same length, substantially parallel to each other and run side-to-side across the pallet  100 . The grid  154  is substantially flat, being formed with three planks running side-to-side and three planks running front-to-back. The nine support blocks  156  are all substantially the same length and substantially parallel to each other.  
         [0043]     Each of the support blocks  156  in the lower member  150  has a holding wedge  158  protruding from one of its sides, and each of the support blocks  136  in the upper member has a corresponding notch in one of its sides, similar to the notch  36  shown in  FIG. 10A . Each holding wedge  158  is triangular with a horizontal base, a side adjoined to the support block  156  and a side that slopes downward away from the support block  156 . The surfaces of the base and the sloped side are rectangular. Each notch is a recessed square sized to accommodate a holding wedge  158 .  
         [0044]     When the upper member  130  is lowered onto the lower member  150  with the peripheral edges of each member aligned, each holding wedge  158  snap-fits into a mating notch. Once snapped into the notches, the holding wedges  158  prevent the two members  130  and  150  from being separated and also prevent front-to-back lateral movement between the members  130  and  150 . Because all of the outer support blocks  136  extend from the upper member  130 , and because support blocks  156  extending from the lower member  150  fit snugly against them  136 , the support blocks  136  and  156  prevent side-to-side lateral movement between the upper  130  and lower members  150 . The pallet  100  can also be formed with an overhang to facilitate shrink-wrapping or a retaining wall to help prevent shifting loads from falling off of the pallet.  
         [0045]     All of the above embodiments are formed via injection molding using a rubber composite that includes recycled rubber, natural rubber, sulfur and a filler. A forty-five pound pallet is formed from a composite with about twenty pounds of recycled rubber, between about ten and fifteen pounds of natural rubber, about five pounds of sulfur and one or more fillers, such as plastic or coal ash.  
         [0046]     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.