Filament Wound U-Shaped Support Units for Footwear

Abstract

A method is described for manufacturing a U-shaped support unit for use in footwear. A shaft mandrel has a longitudinal axis and a cross-section with at least one U-shape region. An enclosed shape of composite material is formed over the shaft mandrel which includes one or more layers of resin-impregnated reinforcing fibers. One or more cuts are made through the enclosed shape to create U-shaped support units adapted for use as a weight bearing structure in footwear.

1 . A method for manufacturing a U-shaped support unit for use in footwear, the method comprising:
 providing a shaft mandrel having a longitudinal axis and a cross-section with at least one U-shape region;   forming an enclosed shape of composite material over the shaft mandrel, the composite material including one or more layers of resin-impregnated reinforcing fibers;   cutting through the enclosed shape of composite material to create U-shaped support units adapted for use as a weight bearing structure in footwear.   
     
     
         2 . A method according to  claim 1 , wherein forming the enclosed shape includes using an automatic filament winding machine to wind reinforcing fibers around the shaft mandrel. 
     
     
         3 . A method according to  claim 2 , wherein winding the reinforcing fibers includes rotating the shaft mandrel about its longitudinal axis. 
     
     
         4 . A method according to  claim 1 , further comprising:
 incorporating the U-shaped support units into footwear as compliant weight bearing structures.   
     
     
         5 . A method according to  claim 1 , wherein the reinforcing fibers are impregnated with resin by use of a resin impregnating system prior to being formed on the shaft mandrel. 
     
     
         6 . A method according to  claim 1 , wherein the reinforcing fibers are impregnated with resin by resin injection after being formed on the shaft mandrel. 
     
     
         7 . A method according to  claim 1 , wherein forming the enclosed shape includes pressing an outer molding surface over at least a portion of the composite material to form an outer surface of the enclosed shape. 
     
     
         8 . A method according to  claim 1 , wherein forming the enclosed shape includes curing the composite material of the enclosed shape for a period of time prior to cutting. 
     
     
         9 . A method according to  claim 1 , wherein the composite material is cured for a period of time after cutting. 
     
     
         10 . A method according to  claim 1 , wherein forming the enclosed shape includes placing a non-fiber structural member onto the shaft mandrel which becomes incorporated into the composite material.