Methods of manufacturing shoe soles

Abstract

The present invention relates to a sole for shoes, in particular to a midsole with support elements for athletic shoes, wherein the midsole and the support elements are made of a common polymer-based material, each exhibiting a different mechanical property. The midsole and the support elements can be made of ethylene vinyl acetate. A method of manufacturing the sole includes connecting the midsole and the support elements to each other by co-vulcanization without the addition of any other materials or procedural steps. Furthermore, the present invention also relates to a shoe including a sole in accordance with the present invention.

What is claimed is:  
     
         1 . A method of manufacturing at least a portion of a sole of an article of footwear, the method comprising the steps of: 
 providing a sole element and a support element, wherein the sole element and the support element comprise a common polymer-based material;    positioning the sole element and the support element in a mold; and    applying at least one of heat and pressure to the mold, thereby attaching the sole element with the support element, wherein the sole element and support element exhibit a different mechanical property.    
     
     
         2 . The method of  claim 1 , wherein the mechanical property is selected from the group consisting of hardness, stiffness, resiliency, and compliancy.  
     
     
         3 . The method of  claim 1 , wherein at least one of the sole element and the support element is made from a partially vulcanized preform.  
     
     
         4 . The method of  claim 1 , wherein the applying step co-vulcanizes the sole element and the support element.  
     
     
         5 . The method of  claim 1 , wherein the polymer-based material comprises ethylene vinyl acetate.  
     
     
         6 . The method of  claim 1 , wherein the support element comprises: 
 a vinyl acetate content of about 18% to about 25%;    at least one peroxide; and    a co-agent.    
     
     
         7 . The method of  claim 6 , wherein the co-agent is selected from the group consisting of acrylates and isocyanates.  
     
     
         8 . The method of  claim 1 , wherein the sole element comprises: 
 a vinyl acetate content of about 18% to about 27%; and    at least one peroxide.    
     
     
         9 . The method of  claim 8 , wherein the sole element further comprises a blowing agent for foaming the sole element in the mold.  
     
     
         10 . A sole for an article of footwear, the sole comprising: 
 a sole element; and    at least one support element, wherein the sole element and the support element comprise a common polymer-based material, each exhibiting a different mechanical property and being attached by co-vulcanization.    
     
     
         11 . The sole of  claim 10 , wherein the polymer-based material comprises ethylene vinyl acetate.  
     
     
         12 . The sole of  claim 10 , wherein the mechanical property is selected from the group consisting of hardness, stiffness, resiliency, and compliancy.  
     
     
         13 . The sole of  claim 10 , wherein at least one of the sole element and the support element is made from a partially vulcanized preform.  
     
     
         14 . The sole of  claim 10 , wherein the support element comprises: 
 a vinyl acetate content of about 18% to about 25%;    at least one peroxide; and    a co-agent.    
     
     
         15 . The sole of  claim 14 , wherein the co-agent is selected from the group consisting of acrylates and isocyanates.  
     
     
         16 . The sole of  claim 10 , wherein the sole element comprises: 
 a vinyl acetate content of about 18% to about 27%; and    at least one peroxide.    
     
     
         17 . The sole of  claim 16 , wherein the sole element further comprises a foam.  
     
     
         18 . The sole of  claim 10 , wherein the support element comprises a hardness of no less than about Shore A 80 to 95.  
     
     
         19 . The sole of  claim 10 , wherein the support element comprises a hardness of no greater than about a Shore D range.  
     
     
         20 . An article of footwear comprising: 
 an outsole;    an inner sole;    an upper; and    a midsole including at least one support element, wherein the midsole and the at least one support element comprise a common polymer-based material, each exhibiting a different mechanical property and being attached by co-vulcanization.