Midsole Structure for an Athletic Shoe

Abstract

The midsole structure for an athletic shoe includes a midsole body made of foamed resin, and a sheet composite extending at least from the ball of the foot portion to the toe portion in the midsole body and comprising a plurality of foamed rubber sheets that are overlapped and shifted in the longitudinal direction. The sheet composite comprises a single sheet at the toe portion and a plurality of sheets at the ball of the foot portion.

What is claimed is: 
     
         1 . A midsole structure for an athletic shoe comprising:
 a midsole body that is made of foamed synthetic resin; and   a sheet composite extending at least from a ball of a foot portion to a toe portion in said midsole body and comprising a plurality of foamed rubber sheets that are overlapped and shifted in a longitudinal direction,   wherein said sheet composite includes a single sheet at said toe portion and a plurality of sheets at said ball of the foot portion.   
     
     
         2 . The midsole structure according to  claim 1 , wherein said midsole body includes a stepped concave portion that is open to a foot-sole-contact-surface side and that has a difference in level in the longitudinal direction, and said sheet composite is housed in said concave portion. 
     
     
         3 . The midsole structure according to  claim 1 , wherein said midsole body includes a stepped concave portion that is open to a ground-contact-surface side and that has a difference in level in the longitudinal direction, and said sheet composite is housed in said concave portion. 
     
     
         4 . The midsole structure according to  claim 1 , wherein said midsole body includes a stepped concave portion that passes through said midsole body in a thickness direction and that has a difference in level in the longitudinal direction, and said sheet composite is housed in said concave portion. 
     
     
         5 . The midsole structure according to  claim 1 , wherein said midsole body includes a stepped inner space that has a difference in level in the longitudinal direction and said sheet composite is housed in said inner space. 
     
     
         6 . The midsole structure according to  claim 1 , wherein said sheet composite is disposed at a forefoot portion of said midsole body. 
     
     
         7 . The midsole structure according to  claim 6 , wherein said sheet composite is disposed at a heel portion of said midsole body. 
     
     
         8 . The midsole structure according to  claim 1 , wherein said sheet composite extends from a heel portion through a midfoot portion to a forefoot portion of said midsole body. 
     
     
         9 . The midsole structure according to  claim 7 , wherein said sheet composite that is disposed at said heel portion of said midsole body is separated in the longitudinal direction from said sheet composite that is disposed at said forefoot portion of said midsole body. 
     
     
         10 . A midsole structure for an athletic shoe comprising:
 a midsole body that is made of foamed synthetic resin; and   a sheet composite extending at least from a ball of a foot portion to a toe portion in said midsole body and comprising a first sheet and a second sheet that are made of foamed rubber and that are overlapped and shifted in a longitudinal direction, each of said first sheet and said second sheet having a front end disposed on a front side thereof and a rear end disposed on a rear side thereof in the longitudinal direction,   wherein said front end of said first sheet is located in front of said front end of said second sheet at said toe portion of said midsole body.   
     
     
         11 . The midsole structure according to  claim 10 , wherein said front end of said first sheet contacts said midsole body from above. 
     
     
         12 . The midsole structure according to  claim 10 , wherein said rear end of said first sheet extends to the rear of said rear end of said second sheet. 
     
     
         13 . The midsole structure according to  claim 10 , wherein said first sheet is disposed at a forefoot portion and a heel portion of said midsole body and said second sheet comprises a forefoot sheet portion disposed at said forefoot portion of said midsole body and a heel sheet portion disposed at said heel portion of said midsole body, said forefoot sheet portion and said heel sheet portion are separated from each other in the longitudinal direction.