Thermoplastic pallet for transporting food goods

Abstract

A plastic pallet, for use with fork lift devices and which meets requirements associated with food handling, has a thermoplastic deck made of two sheets which are spaced part by rigid plastic foam. There are steel beams running in an x-pattern within the foam of the deck. The deck sheets each have a multiplicity of relatively large truncated conical depressions. Holes in the centers of the depressions provide water and air passageways through the deck. The deck sheets are welded together at the locations of the depressions and at their outer edges. The base rails are reinforced by steel beams which are sealed within.

1 . In a pallet for transporting goods, of the type having a base, a multiplicity of spaced apart columns extending upwardly from the base, and a top mounted on the columns which top comprises a rectangular deck, the improvement which comprises: 
 a deck comprising    a top sheet having a substantially planar upper surface, for receiving goods placed on the deck;    a bottom sheet, spaced apart from and substantially parallel to the first sheet; and,    rigid plastic foam with the space between the sheets;    wherein, at least one of said sheets has a multiplicity of spaced apart truncated conical depressions;    wherein the sheets are attached to each other at their edges and at the locations of said truncated conical depressions.    
   
   
       2 . The pallet of  claim 1  wherein both the top and bottom sheets have a multiplicity of spaced apart truncated conical depressions arranged mating patterns; and, wherein the bottoms of the top sheet depressions are attached to the bottoms of the bottom sheet depressions.  
   
   
       3 . The pallet of  claim 1  wherein each depression has a flat bottom.  
   
   
       4 . The pallet of  claim 2  wherein each depression has a flat bottom.  
   
   
       5 . The pallet of  claim 3  wherein the deck has a multiplicity of holes located in the bottoms of said depressions, for passage of water or air through the deck.  
   
   
       6 . The pallet of  claim 1  further comprising at least two metal beams positioned within said rigid plastic foam, each beam running from a corner of the deck to a diagonally opposed corner, wherein the beams form an x-pattern in the plane of the deck.  
   
   
       7 . The pallet of  claim 6  wherein the depressions are arranged in four equilateral triangle shape arrays, with the base of each triangle running parallel to, and centered along, one of the edges of pallet.  
   
   
       8 . The pallet of  claim 1  wherein the top of the pallet comprises a plastic frame which forms the periphery of the top; and wherein the outer edge of the deck is attached to the frame and inset from the outer edge of the top.  
   
   
       9 . The pallet of  claim 6  which further comprises: metal beams within the base.  
   
   
       10 . The pallet of  claim 1  wherein the top comprises an injection molded frame which forms the periphery of the top; wherein said sheets are comprised of two thermoformed sheets welded to each other and to the frame.  
   
   
       11 . The pallet of  claim 1  wherein the top comprises an injection molded frame which forms the periphery of the top; wherein said bottom sheet is injection molded and integral with the frame; and wherein said top sheet is a thermoformed sheet.  
   
   
       12 . The pallet of  claim 1  wherein said truncated conical depressions are have circular cross sections.  
   
   
       13 . The pallet of  claim 5  wherein a portion of said depressions have oblong shapes, for enabling manual grasping of the pallet.  
   
   
       14 . The pallet of  claim 1  wherein the top, columns and base are is predominately made of a high density polyethylene or polypropylene; and, wherein said rigid foam is polyurethane.  
   
   
       15 . A pallet for transporting goods, comprising: 
 a base, comprised of outer rails running in a rectangular pattern and cross rails connecting the centers of opposing side outer rails;    metal beams within the rails of the base;    eight peripheral columns and one center column extending upwardly from the base;    a rectangular top mounted on the peripheral columns, for receiving goods, the top comprising a frame and a rectangular deck, wherein the periphery of the deck is attached to the frame, and the center of the deck is attached to said center column;    wherein the deck comprises: 
 a top sheet having a substantially planar upper surface, for receiving goods placed on the pallet, and a multiplicity of spaced apart truncated conical depressions;  
 a bottom sheet, spaced apart from and substantially parallel to the first sheet; and,  
 rigid plastic foam with the space between the sheets;  
 wherein the sheets are joined together along their outer edges and at the locations of each of said truncated conical depressions; and,  
 wherein the deck has a multiplicity of holes located within the bottoms of said top sheet depressions, for passage of water or air through the deck.  
   
   
   
       16 . The pallet of  claim 15  wherein the bottom sheet has a multiplicity of spaced apart depressions; wherein said depressions of each sheet have flat bottoms with center holes; and wherein the depressions are connected to each other at their flat bottoms.  
   
   
       17 . The pallet of  claim 14  wherein a portion of said depressions have oblong shapes, for enabling manual grasping of the pallet, said oblong depressions located proximate the corners and center of the pallet  
   
   
       18 . The pallet of  claim 15  having the configuration of a GMA pallet with a top which is 40 inches by 48 inches in rectangular dimension; and wherein there is at least one depression for every 25 square inches of deck surface.  
   
   
       19 . The pallet of  claim 15  having the configuration of a GMA pallet with a top which is 40 inches by 48 inches in rectangular dimension, wherein the diameter of each depression at the top surface of the upper sheet is greater than three percent of the dimension of any side of the pallet.  
   
   
       20 . The method of making a pallet for transporting goods, wherein the pallet comprises a base, a multiplicity of spaced apart columns extending upwardly from the base, and a top mounted on the columns which top comprises a frame and a rectangular deck attached to the frame; wherein the deck comprises a top sheet having a substantially planar upper surface, for receiving goods placed on the deck; a bottom sheet, spaced apart from and substantially parallel to the first sheet; and, rigid plastic structural foam with the space between the sheets, connecting sheets; wherein, both sheets have a multiplicity of spaced apart truncated conical depressions; and, wherein the sheets are attached to each other at their edges and at the locations of said truncated conical depressions; which method comprises: 
 a) injection molding plastic to form a body which comprises said frame, said bottom sheet of said deck with said multiplicity of depressions according to a first pattern;    b) thermoforming plastic sheet to form a top sheet of the deck, the deck having a multiplicity of spaced part truncated conical depressions in a pattern which mirrors said first pattern;    c) welding the top sheet to the body, so the periphery of the frame is attached to the frame and so the bottoms of the depressions are attached to the bottoms of the depressions of the bottom sheet; wherein the sheets are spaced apart from each other except where they are welded; and,    d) injecting plastic material into the space between the sheets to form a rigid foam their, where the form is bonded to the sheet surfaces.    
   
   
       21 . The method of  claim 20  which further comprises the steps of placing metal beams upon the first sheet before carrying out step (c), so the beams are included within the foam which is formed.