Pressure relief system for footwear

Abstract

A shoe having a last which includes a shape and volume that reflects the thickness of an internal sock liner, and a shoe interior made specifically for inclusion of the sock liner. The sock liner itself includes an anatomically shaped foot bed surface with a cupped heel, contoured arch, radiused forepart and beveled toe area. The sock liner material specifications and thicknesses are engineered or tuned to have a high amount of deflection when compressed without getting stiff.

1 . A shoe sole construction comprising:
 an outsole;   a sockliner having an anatomical shape which creates at least about a 75% contact rate between a wearer's foot and a top surface of the sockliner during weight bearing of the wearer's foot by the sockliner, the sockliner comprised of a material having a hardness between about 10 C and 70 C on the Asker C scale, having a material density of between about 0.05 g/cc and 0.60 g/cc, and having a thickness of between about 5 mm and 50 mm at the heel center and between about 3 mm to 35 mm at the forefoot center, where the anatomical shape and material composition of the sockliner cause it to deflect by about 25% at about 25 psi and by about 50% at about 70 psi;   wherein a top surface of the outsole is sized and shaped to receive and conform to a bottom surface of the sockliner.   
     
     
         2 . The shoe sole of  claim 1  wherein the sockliner is comprised of one of: polyurethane, SEBS foam, EVA, rubber sponge, latex and/or a co-polymer blended foam. 
     
     
         3 . The shoe sole of  claim 1  wherein the deflection of the sockliner is about 25% during weight bearing when a wearer is standing thereon. 
     
     
         4 . The shoe sole of  claim 1  wherein the deflection of the sockliner is about 50% during weight bearing when a wearer is running. 
     
     
         5 . The shoe sole of  claim 1  wherein the outsole includes a midsole. 
     
     
         6 . The shoe sole of  claim 1  wherein sockliner includes a midsole. 
     
     
         7 . The shoe sole of  claim 1  wherein the sockliner is raised at the midfoot region to underlie the medial arch of the wearer's foot. 
     
     
         8 . The shoe sole of  claim 1  wherein the sockliner is cupped at the hind foot region to underlie a wearer's heel. 
     
     
         9 . The shoe sole of  claim 8  wherein peripheral edges of the sockliner are raised at the hind foot region from a medial side to a lateral side of the sockliner to wrap around a wearer's heel. 
     
     
         10 . The shoe sole of  claim 1  wherein the sockliner includes a radiused forepart region and a beveled toe area at the forefoot region. 
     
     
         11 . The shoe of  claim 1  wherein the outsole is comprised by at least one of: leather, elastomer, and polymer. 
     
     
         12 . The shoe sole of  claim 1  wherein the sockliner yields a target threshold pressure of 40 psi or below.