Method of manufacturing a midsole for a shoe and construction therefor

Abstract

The present invention is directed to a method of manufacturing a midsole for a shoe and the structure of the resulting midsole. The midsole includes a core of a first plastic material and a peripheral wrap of a second plastic material. The wrap has an outer peripheral surface comprising at least a portion of an outer peripheral surface of the midsole. The method includes the steps of molding a peripheral wrap from a sheet stock of the first plastic material by applying compressive forces on the sheet stock in a direction which i substantially perpendicular with the outer surface of the sheet stock, placing the wrap around the inner peripheral surface of a mold which approximates the shape of the midsole, and pouring the first plastic material in the mold.

We claim: 
     
       1. A method of manufacturing a peripheral wrap element for a shoe midsole to be secured to a shoe outsole, the wrap formed from a plastic closed cell foam material, the wrap having an outer surface comprising at least a portion of an outer peripheral surface of said midsole, the wrap being separate from said outsole, said method comprising the steps of: placing a sheet stock of plastic closed cell foam material having an inner and an outer surface into a mold; and   compressing said sheet stock with the mold by moving said mold in a direction aligned substantially perpendicular to said outer surface of said sheet stock to form a contoured outer surface on said sheet stock, wherein said contoured outer surface of said sheet stock comprises said outer surface of said wrap, wherein said contoured outer surface of said wrap comprises at least a portion of said outer peripheral surface of said midsole and is separate from said outsole, and wherein an inner surface of said wrap which is opposite said contoured outer surface of said wrap engages said mold during compression of said sheet stock.   
     
     
       2. A method of manufacturing a peripheral wrap for a shoe midsole to be attached to a shoe outsole, the wrap composed of a plastic closed cell foam material, the wrap having a contoured outer surface comprising at least a portion of an outer peripheral surface of the midsole and an inner surface to be placed in contact with the peripheral surface of a core portion of the midsole, the wrap being separate from said outsole, said method comprising the steps of: placing a sheet stock of plastic closed cell foam material to form the peripheral wrap into a mold having opposing first and second surfaces;   contacting one surface of the plastic closed cell foam material with the first surface of the mold;   contacting the opposite surface of the plastic closed cell foam material with the second surface of the mold; and   forming the contoured outer surface of the wrap on the one surface of the plastic closed cell foam material by moving the first and second surfaces of the mold toward one another to compress the plastic closed cell foam material between the first and second surfaces of the mold whereby the compressive forces producing the contoured outer surface of the wrap are directed substantially perpendicular with respect to the peripheral surface of the core portion of the midsole.   
     
     
       3. A method of manufacturing a peripheral wrap element for a shoe midsole to be secured to a shoe outsole, the wrap formed from a plastic closed cell foam material, the wrap having an outer surface comprising at least a portion of an outer peripheral surface of said midsole, the wrap being separate from said outsole, said method comprising the steps of: placing a sheet stock of plastic closed cell foam material to form said peripheral wrap into a mold; and   compressing said plastic closed cell foam material with said mold to form a contoured outer surface of said wrap, wherein said contoured outer surface of said wrap comprises at least a portion of said outer peripheral surface of said midsole and is separate from said outsole, and wherein when said wrap is placed on said midsole, the compressive forces producing said contoured outer surface of said wrap have been directed substantially perpendicular with respect to said outer peripheral surface of said midsole. .Iadd.   
     
     
       4.  A method of manufacturing a peripheral wrap element for a shoe midsole to be secured to a shoe outsole, the wrap formed from a plastic closed cell foam material, the wrap having an outer surface comprising at least a portion of an outer peripheral surface of said midsole, the wrap being separate from said outsole, said method comprising the steps of: placing plastic closed cell foam material to form said peripheral wrap into a mold; and   compressing said plastic closed cell foam material with said mold to form a contoured outer surface of said wrap, wherein said contoured outer surface of said wrap comprises at least a portion of said outer peripheral surface of said midsole and is separate from said outsole, and wherein when said wrap is placed on said midsole, the compressive forces producing said contoured outer surface of said wrap have been directed substantially perpendicular with respect to said outer peripheral surface of said midsole. .Iaddend..Iadd.5. A method according to claim 4, wherein said plastic closed cell foam material comprises a preform having a shape which approximates the shape of said peripheral wrap. .Iaddend.