Fire-collaspible cross-beamed pallet

Abstract

A plastic pallet has reinforcing beams which fail during a fire due to the effects of heat, so the pallet prematurely collapses and thus the rate of heat evolution is diminished, sufficient to meet fire standards. In one embodiment metal beams embedded in the plastic of the pallet have lengths which are shorter than the span between the rails of a pallet rack. They drop down and cause pallet collapse, when the surrounding plastic softens or melts. In another embodiment, the beam is a metal, fiberglass or graphite reinforced composite thermoplastic, which loses strength when the matrix softens or otherwise fails. In another embodiment, a metal beam has two parts which are connected by a thermoplastic fitting which softens and the fails during a fire.

1 . A thermoplastic pallet, useful for transporting goods by means of forklift devices, the pallet storable in a rack having opposing side rails, by resting opposing lengthwise edges of the pallet on the rails, the pallet comprising: 
 a plastic portion configured to span the distance between the rails of the rack, wherein at least one cross beam is secured on or within said plastic portion, the cross beam and plastic portion configured such that said cross beam and plastic portion will structurally fail upon exposure to heat from a fire.    
   
   
       2 . A thermoplastic pallet in accordance with  claim 1 , wherein said at least one cross beam has a length and location within the pallet, so that one end of the beam is configured such that it is inward from the lengthwise edge of the pallet and inward from the vertical extension of the inner edge of the rail of the storage rack, and wherein, when the plastic portion softens, the end of the beam will fall downwardly from the rack.  
   
   
       3 . A thermoplastic pallet in accordance with  claim 1 , wherein said at least one cross beam has a length and location within the pallet, so that both ends of the beam are configured such that they inward from the lengthwise edges of the pallet and inward from the vertical extension of the inner edges of the rail of the storage rack, and wherein, when the plastic portion softens, an end of the beam will fall downwardly from the rack.  
   
   
       4 . A thermoplastic pallet in accordance with  claim 1 , wherein said at least one cross beam includes at least one reinforcing material engineered to degrade when exposed to heat from a fire, such that the reinforcing beam will fail upon exposure to heat from a fire.  
   
   
       5 . A thermoplastic pallet in accordance with  claim 4 , wherein said cross beam comprises two materials that will not melt or degrade upon exposure to heat from a fire, coupled with a material that will melt or degrade upon exposure to heat from a fire, such that the beam will fail upon exposure to such heat.  
   
   
       6 . A thermoplastic pallet in accordance with  claim 5 , wherein said cross beam comprises lamellae bound by a thermoplastic or other heat degradable adhesive, or by an injected encapsulating plastic layer.  
   
   
       7 . A thermoplastic pallet in accordance with  claim 1 , wherein said cross beam is at least partially embedded in plastic.  
   
   
       8 . A thermoplastic pallet in accordance with  claim 1 , wherein said cross beam is a metal material.  
   
   
       9 . A thermoplastic pallet in accordance with  claim 1 , wherein said cross beam is a composite material.  
   
   
       10 . A thermoplastic pallet in accordance with  claim 2 , wherein said pallet includes a plurality of cross beams, and wherein at least two of the beams have ends that overlie different rack rails.  
   
   
       11 . A thermoplastic pallet in accordance with  claim 1 , wherein said pallet includes at least one beam that is configured to be generally parallel to a rack rail.  
   
   
       12 . A thermoplastic pallet in accordance with  claim 1 , wherein said cross beam is a perforated steel box beam.  
   
   
       13 . A thermoplastic pallet in accordance with  claim 1 , wherein width of the pallet is 48 inches and the length of the cross beam is no more than 42 inches.  
   
   
       14 . A thermoplastic pallet in accordance with  claim 1 , wherein the pallet includes a plurality of cross beams, and wherein all cross beams have the same length.  
   
   
       15 . A thermoplastic pallet in accordance with  claim 9 , wherein the composite is a fiber selected from the material group consisting of metal, graphite and glass.  
   
   
       16 . A method of reducing the rate of evolution from a thermoplastic pallet during a fire, wherein the pallet is stored in a rack, the opposing lengthwise edges of the pallet resting on opposing side rails of the rack; wherein the pallet has at least one cross beam provided in the pallet and running at least partially between said opposing sides to provide strength to the pallet, wherein said at least one cross beam is configured to fail relative to a remainder of the pallet upon exposure to heat from a fire.  
   
   
       17 . A method in accordance with  claim 16 , wherein the cross beam has with a length and location within the pallet, so that an end of the cross beam lies inwardly from the vertical plane of the innermost portion of a rail of the rack when the pallet is stored in a rack, so that when the material of the pallet weakens upon heating in a fire, the end of the cross beam drops downwardly to thereby enable the pallet to fall downwardly and reduce the rate of heat evolution.  
   
   
       18 . A method in accordance with  claim 16 , wherein the cross beam includes at least one component that is designed to fail upon exposure to the heat of a fire to thereby enable the pallet to fall downwardly and reduce the rate of heat evolution.  
   
   
       19 . A method in accordance with  claim 18 , wherein said cross beam comprises two materials that will not melt or degrade upon exposure to heat from a fire, coupled with a material that will melt or degrade upon exposure to heat from a fire, such that the beam will fail upon exposure to such heat.  
   
   
       20 . A method in accordance with  claim 19 , wherein said cross beam comprises lamellae bound by a thermoplastic or other heat degradable adhesive, or by an injected encapsulating plastic layer.