Articles of footwear and shoe soles for midfoot impact region

Abstract

A shoe sole for an article of footwear is described herein. The shoe sole extends in a longitudinal direction from a heel region, through a midfoot region, to a forefoot region. The sole includes a midsole and an outsole. The midsole has an upper surface for attachment to at least one of an insole and a shoe upper, and a lower surface disposed opposite the upper surface. The midsole includes a forefoot cushioning element, a midfoot cushioning element, and a heel cushioning element. The outsole is disposed along the lower surface of the midsole and defines a ground-contacting surface of the sole. The sole has an upwardly convex bottom profile such that an impact region of the sole is defined within the midfoot region, and the midfoot cushioning element is disposed within the midfoot region and directly above the impact region of the sole.

What is claimed is: 
     
         1 . A shoe sole for an article of footwear, the sole extending in a longitudinal direction from a heel region, through a midfoot region, to a forefoot region, the sole comprising:
 a midsole having an upper surface for attachment to at least one of an insole and a shoe upper, and a lower surface disposed opposite the upper surface, the midsole including a forefoot cushioning element, a midfoot cushioning element, and a heel cushioning element; and   an outsole disposed along the lower surface of the midsole and defining a ground-contacting surface of the sole;   wherein the sole has an upwardly convex bottom profile such that an impact region of the sole is defined within the midfoot region, the midfoot cushioning element disposed within the midfoot region and directly above the impact region of the sole.   
     
     
         2 . The shoe sole of  claim 1 , wherein the outsole has a relatively stiff construction along the midfoot region thereby forming a pivot axis within the impact region about which the heel region and the forefoot region pivot, the midfoot cushioning element disposed directly above the pivot axis. 
     
     
         3 . The shoe sole of  claim 2 , wherein the midfoot cushioning element adjoins the outsole along the impact region of the sole, whereby the midfoot cushioning element is configured to absorb energy from an initial impact of the sole along the impact region and transfer energy to a user's foot upon the sole pivoting about the pivot axis 
     
     
         4 . The shoe sole of  claim 1 , wherein the forefoot cushioning element and the heel cushioning element cooperatively define a recess in the midfoot region of the sole, the midfoot cushioning element disposed within the recess and vertically and horizontally between the forefoot cushioning element and the heel cushioning element. 
     
     
         5 . The shoe sole of  claim 1 , wherein the forefoot cushioning element extends a thickness in the forefoot region from the upper surface of the midsole to the lower surface of the midsole, the forefoot cushioning element adjoining the outsole along the forefoot region of the sole and extending from the forefoot region to the heel region. 
     
     
         6 . The shoe sole of  claim 5 , wherein the heel cushioning element is disposed vertically between the forefoot cushioning element and the outsole, the heel cushioning element adjoining each of the forefoot cushioning element and the outsole in the heel region of the sole. 
     
     
         7 . The shoe sole of  claim 1 , wherein the midfoot cushioning element has a hardness less than a hardness of each of the forefoot cushioning element and the heel cushioning element. 
     
     
         8 . The shoe sole of  claim 7 , wherein the midfoot cushioning element has a first hardness, the forefoot cushioning element has a second hardness greater than the first hardnesss, and the heel cushioning element has a third hardness less than the second hardness. 
     
     
         9 . The shoe sole of  claim 1 , wherein the midfoot cushioning element has a first hardness, the forefoot cushioning element has a second hardness greater than the first hardnesss, and the heel cushioning element has a third hardness less than both the first hardness and the second hardness. 
     
     
         10 . The shoe sole of  claim 1 , wherein the shoe sole includes a lateral side and an opposing medial side, the midfoot cushioning element extending from the lateral side to the medial side. 
     
     
         11 . The shoe sole of  claim 1 , further comprising a reinforcing element embedded in the midsole, the reinforcing element having a generally u-shaped cross-section and including a first prong and a second prong connected to one another in the heel region of the sole, each of the first prong and the second prong extending in the longitudinal direction from the heel region to at least the midfoot region to provide stiffness in the longitudinal direction. 
     
     
         12 . An article of footwear comprising the shoe sole of  claim 1  and an upper secured to the midsole. 
     
     
         13 . A shoe sole for an article of footwear, the sole extending in a longitudinal direction from a heel region, through a midfoot region, to a forefoot region, the sole comprising:
 a midsole having an upper surface for attachment to at least one of an insole and a shoe upper, and a lower surface disposed opposite the upper surface, the midsole including a forefoot cushioning element, a midfoot cushioning element, and a heel cushioning element; and   an outsole disposed along the lower surface of the midsole and defining a ground-contacting surface of the sole;   wherein the sole has an upwardly convex bottom profile such that an impact region of the sole is defined within the midfoot region, the midsole having a first hardness in the forefoot region, a second hardness in the heel region less than the first hardness, and a third hardness in the midfoot region above the impact region less than both the first hardness and the second hardness.   
     
     
         14 . The shoe sole of  claim 13 , wherein the outsole has a relatively stiff construction along the midfoot region to form a pivot axis within the impact region about which the heel region and the forefoot region pivot. 
     
     
         15 . The shoe sole of  claim 13 , wherein the forefoot cushioning element has the first hardness, the heel cushioning element has the second hardness, and the midfoot cushioning element has the third hardness. 
     
     
         16 . The shoe sole of  claim 15 , wherein the forefoot cushioning element and the heel cushioning element cooperatively define a recess in which the midfoot cushioning element is disposed, the forefoot cushioning element extending from the forefoot region to the heel region. 
     
     
         17 . The shoe sole of  claim 15 , wherein the midfoot cushioning element has a hardness of between about 35 Asker C and about 55 Asker C. 
     
     
         18 . The shoe sole of  claim 13 , wherein a ratio between the first hardness, the second hardness, and the third hardness is between about 1.0:1.0:1.0 and about 2.0:1.75:1.0. 
     
     
         19 . The shoe sole of  claim 18 , wherein the ratio between the first hardness, the second hardness, and the third hardness is between about 1.2:1.1:1.0 and about 1.6:1.4:1.0. 
     
     
         20 . A shoe sole for an article of footwear, the sole extending in a longitudinal direction from a heel region, through a midfoot region, to a forefoot region, the sole comprising:
 a midsole having an upper surface for attachment to at least one of an insole and a shoe upper, and a lower surface disposed opposite the upper surface,   an outsole disposed along the lower surface of the midsole and defining a ground-contacting surface of the sole   wherein the sole has an upwardly convex bottom profile such that an impact region of the sole is defined within the midfoot region, the outsole having a relatively stiff construction along the midfoot region to form a pivot axis within the impact region about which the heel region and the forefoot region pivot, wherein the heel region curves upward from the midfoot region and has a radius of curvature of between 390 millimeters and about 450 millimeters, and the forefoot region extends upward from the midfoot region and has a radius of curvature of between 360 millimeters and about 420 millimeters.