Corrugated pallet constructed of folded, interlocked blanks and method

Abstract

An interlock for the top and bottom members of a foldably-constructed pallet and a method of assembling a pallet wherein the top and bottom members are interlocked. By folding straps around the corners of the pallet, either from one sidewall of the pallet around the corner to the adjacent sidewall or from the top of the pallet to the bottom (and optionally from the bottom of the pallet to the top), and anchoring the end of the strap to the adjacent sidewall or the bottom member of the pallet (and if a second strap folded from the bottom member to the top member is utilized, to the top member), the load-bearing capacity of the pallet is substantially increased.

What is claimed is: 
     
         1 . A method of resisting torsional force exerted on a force resisting structure comprised of top and bottom substantially planar members, either or both of the top and bottom planar members having folded portions forming sidewalls when and assembled to each other in nested relation, comprising the steps of:
 folding a strap formed integrally with the bottom member into contact with the top member;   inserting a tab formed on the end of the strap into a cut formed on the top member; and   retaining the tab formed on the end of the strap in the cut.   
     
     
         2 . The method of  claim 1  wherein a strap formed integrally with the top member is folded into contact with the bottom member for inserting a tab formed on the end of the strap into and retaining within a cut formed on the bottom member. 
     
     
         3 . The method of  claim 1  wherein the tab formed on the end of the strap is driven through the cut by a mandrel that engages the strap. 
     
     
         4 . The method of  claim 1  wherein the tab formed on the end of the strap is retained in the cut by a mechanical fastener. 
     
     
         5 . The method of  claim 1  wherein the tab formed on the end of the strap is retained in the cut by contact between the tab and the material comprising the top member that is deflected by insertion of the tab into the cut. 
     
     
         6 . The method of  claim 1  wherein the tab is retained in the cut by engagement of the material comprising the top member by notches formed in the strap. 
     
     
         7 . The method of  claim 1  wherein the strap is folded into contact with the top side of the top member. 
     
     
         8 . The method of  claim 7  wherein the cut formed on the top member is formed on the top side of the top member. 
     
     
         9 . The method of  claim 1  additionally comprising the steps of:
 folding a strap formed integrally with the top member into contact with the bottom member; 
 inserting a tab formed on the end of the top member strap into a cut formed on the bottom member; and 
 retaining the tab formed on the end of the top member strap in the cut formed in the bottom member. 
 
     
     
         10 . The method of  claim 10  wherein the strap formed integrally with the top member is folded into contact with the bottom member on one side of the corner formed by the sidewalls of the top and bottom members and the strap formed integrally with the bottom member is folded into contact with the top member on the other side of the corner formed by the sidewalls of the top and bottom members. 
     
     
         11 . An interlock for the top and bottom members of a foldably-constructed pallet comprising:
 a strap integral with the material comprising one or both of the top and bottom members of a foldably-constructed pallet, one or both of the top or bottom members being folded to form sidewalls when assembled to each other to form a pallet;   a locking formation formed on the end of said strap;   a knife cut in the material comprising the opposite bottom or top member for receiving the locking formation, said strap being folded over the sidewall and into contact with the opposite bottom or top member with the locking formation inserted into the knife cut at the corner of the pallet.   
     
     
         12 . The interlock of  claim 11  wherein a portion of the material comprising the top or bottom members bears against the locking formation when the locking formation is inserted into the knife cut. 
     
     
         13 . The interlock of  claim 11  additionally comprising means for retaining the locking formation in the knife cut. 
     
     
         14 . The interlock of  claim 13  wherein said locking formation retaining means comprises a notch formed on the locking formation for bearing against the material comprising the top or bottom member when the locking formation is inserted into the knife cut therein. 
     
     
         15 . The interlock of  claim 13  wherein said locking formation retaining means comprises a retaining tab formed when the locking formation is inserted into the knife cut therein. 
     
     
         16 . The interlock of  claim 11  wherein both top and bottom members are provided with a respective locking strap, the locking strap integral with the top member being folded over the sidewall on one side of the corner of the pallet and the locking strap integral with the bottom member being folded over the sidewall of the other side of the corner of the pallet. 
     
     
         17 . A method of interlocking top and bottom substantially planar members in nested relation comprising the steps of:
 folding a flap formed on a substantially planar top member to a position substantially perpendicular to the planar surface of the top member;   folding a flap formed on a substantially planar bottom member to a position substantially perpendicular to the planar surface of the bottom member, the flap on the top member forming a sidewall and the flap on the bottom member forming an end wall when the top and bottom members are in nested relation;   folding a strap extending from either the flap forming the sidewall or the flap forming an end wall around the corner formed by the end wall and sidewall;   inserting the end of the strap into a slot formed in the other of the sidewall or the end wall; and   retaining the end of the strap in the slot.   
     
     
         18 . The method of  claim 17  wherein the slot is provided with a knife cut extending therefrom, the strap being driven through the slot and knife cut by a mandrel that engages the strap. 
     
     
         19 . The method of  claim 18  wherein the strap is retained in the slot by interaction of a tab formed on the end of the strap with the corners formed by the knife cut and the slot. 
     
     
         20 . The method of  claim 18  additionally comprising deflecting the corners formed by the knife cut and the slot in the direction in which the strap is driven by the mandrel to facilitate insertion of the strap into the slot. 
     
     
         21 . Apparatus for assembling the top and bottom blanks of a foldably-constructed pallet in nested relation comprising:
 an intake for taking up and registering a top blank;   an intake for taking up and registering a bottom blank;   clamps for folding the registered top and bottom blanks to form support ribs therein;   a joiner for compressing the folded top and bottom blanks to each other in nested relation to form the pallet; and   a mandrel for folding a strap formed on either of the top or bottom blank into contact with the opposite blank and for inserting the end of the strap into a cut formed in the material comprising the opposite blank for interlocking the top and bottom blanks.   
     
     
         22 . The apparatus of  claim 21  additionally comprising a programmable controller for regulating each of said top intake, said bottom intake, said clamps, said joiner, and said mandrel. 
     
     
         23 . The apparatus of  claim 21  additionally comprising clamps for folding said top and bottom blanks to form sidewalls, the strap being folded into contact with the opposite blank at the corner formed by adjacent sidewalls.