Footwear sole plate with non-parallel waves of varying thickness

Abstract

A sole structure for an article of footwear has a sole plate that may include a midfoot region, and also may include a forefoot region or a heel region. The sole plate may have a foot-facing surface with ridges extending longitudinally in the midfoot region and in the forefoot region or heel region. The sole plate may have a ground-facing surface with grooves extending longitudinally in correspondence with the ridges. A thickness of the sole plate from the foot-facing surface to the ground-facing surface may vary at a transverse cross-section of the sole plate through the ridges, or along a length of at least one of the ridges, or at both the transverse cross-section and along the length of the at least one of the ridges. The ridges may have crests at least some of which may extend non-parallel with one another in a longitudinal direction of the sole plate.

What is claimed is: 
     
         1 . A sole structure for an article of footwear comprising:
 a foam midsole extending in a forefoot region and a midfoot region of the sole structure; and   resilient material interfacing with the foam midsole, having a stiffness greater than a stiffness of the foam midsole, and arranged in longitudinally-extending portions spaced apart from one another and extending continuously in the midfoot region and the forefoot region in a longitudinal direction of the sole structure.   
     
     
         2 . The sole structure of  claim 1 , wherein the longitudinally-extending portions of the resilient material extend only in the midfoot region and the forefoot region. 
     
     
         3 . The sole structure of  claim 1 , wherein the resilient material is one of a fiber strand-lain composite, a carbon-fiber composite, a thermoplastic elastomer, a glass-reinforced nylon, wood, or steel. 
     
     
         4 . The sole structure of  claim 1 , wherein:
 a foot-facing surface defined by the longitudinally-extending portions of the resilient material is concave in the longitudinal direction of the sole structure in the forefoot region; and   a ground-facing surface defined by the longitudinally-extending portions of the resilient material is convex in the longitudinal direction of the sole structure in the forefoot region.   
     
     
         5 . The sole structure of  claim 1 , wherein a lateral-most one of the longitudinally-extending portions of the resilient material curves in the longitudinal direction to follow a curved lateral edge of the sole structure. 
     
     
         6 . The sole structure of  claim 1 , wherein a medial-most one of the longitudinally-extending portions of the resilient material curves in the longitudinal direction to follow a curved medial edge of the sole structure. 
     
     
         7 . The sole structure of  claim 1 , wherein the longitudinally-extending portions of the resilient material are configured to underlie metatarsal-phalangeal joints of a wearer. 
     
     
         8 . The sole structure of  claim 1 , wherein the longitudinally-extending portions are spaced further apart from one another at a first transverse cross-section in the midfoot region than at a second transverse cross-section in the forefoot region. 
     
     
         9 . The sole structure of  claim 1 , wherein there are four longitudinally-extending portions. 
     
     
         10 . The sole structure of  claim 1 , wherein the resilient material includes longitudinally-extending ridges. 
     
     
         11 . The sole structure of  claim 10 , wherein there are five longitudinally-extending ridges. 
     
     
         12 . The sole structure of  claim 1 , wherein the foam midsole includes a first foam layer secured to a foot-facing surface of the longitudinally-extending portions of the resilient material and a second foam layer secured to a ground-facing surface of the longitudinally-extending portions of the resilient material. 
     
     
         13 . The sole structure of  claim 12 , wherein the first foam layer and the second foam layer are portions of an upper portion and a lower portion of a single, unitary, one-piece foam midsole. 
     
     
         14 . The sole structure of  claim 13 , wherein the first foam layer and the second foam layer have one or more of different compressive stiffnesses, different material compositions, or different densities. 
     
     
         15 . The sole structure of  claim 1 , wherein the foam midsole is disposed between the longitudinally-extending portions of the resilient material.