Sole structure and shoe including the sole structure

Abstract

A sole structure includes a first midsole portion made of a first material; a second midsole portion made of a second material; and an exterior portion made of a third material having higher rigidity than the first material and the second material. A boundary portion of an overlap portion in which the first midsole portion and the second midsole portion overlap with each other in a top-bottom direction includes a first boundary portion defined by a line and located on each of a medial side and lateral side in side view and extending in a foot length direction. The exterior portion covers the first boundary portion from outside of the first midsole portion and the second midsole portion.

What is claimed is: 
     
         1 . A sole structure comprising:
 a first midsole portion made of a first material;   a second midsole portion which is made of a second material that is the same as or different from the first material, and at least part of which is stacked above or below the first midsole portion; and   an exterior portion made of a third material having higher rigidity than the first material and the second material,   wherein   a boundary portion of an overlap portion in which the first midsole portion and the second midsole portion overlap with each other in a top-bottom direction includes a first boundary portion defined by a line and located on each of a medial side and lateral side in side view and extending in a foot length direction, and   the exterior portion covers the first boundary portion from outside of the first midsole portion and the second midsole portion.   
     
     
         2 . The sole structure of  claim 1 , wherein
 the exterior portion includes a pair of side wall portions located on the medial side and lateral side, and   each of the pair of side wall portions covers the first boundary portion in a lateral direction of the first midsole portion and the second midsole portion.   
     
     
         3 . The sole structure of  claim 2 , wherein
 the boundary portion of the overlap portion further includes a second boundary portion defined by a line and located at a bottom of the first midsole portion and a bottom of the second midsole portion in bottom view,   the exterior portion includes a bottom portion located below the first midsole portion and the second midsole portion, and   the bottom portion covers the second boundary portion from under the first midsole portion and the second midsole portion.   
     
     
         4 . The sole structure of  claim 3 , wherein
 the bottom portion extends from a position of a midfoot portion to a position of a forefoot portion of a foot of a wearer in the sole structure.   
     
     
         5 . The sole structure of  claim 4 , wherein
 the bottom portion includes an upper surface on which a first reinforcement portion made of a fourth material having higher rigidity than the third material is provided.   
     
     
         6 . The sole structure of  claim 1 , wherein
 the first material is a material having higher rebound properties than the second material,   the second material is a material having higher impact absorbing properties than the first material and having lower rebound properties than the first material,   the first midsole portion is located at part of the sole structure that corresponds to a position of at least a forefoot portion of a foot of a wearer, and   the second midsole portion is located at part of the sole structure that corresponds to a position of at least a rear foot portion of the foot of the wearer.   
     
     
         7 . The sole structure of  claim 6 , wherein
 the overlap portion is located at part of the sole structure that ranges from a position of a midfoot portion to a position of a front portion of the rear foot portion of the foot of the wearer.   
     
     
         8 . The sole structure of  claim 7 , wherein
 the first boundary portion extends from a lower side to an upper side of the sole structure while extending from the position of the midfoot portion to the position of the front portion of the rear foot portion of the foot of the wearer in the sole structure.   
     
     
         9 . The sole structure of  claim 1 , wherein
 each of the first material and the second material is a material softer than the third material and having higher rebound properties than the third material,   the first midsole portion is located at part of the sole structure that ranges from a position of a forefoot portion to a position of a front portion of a rear foot portion of a foot of a wearer, and   the second midsole portion is located at part of the sole structure that ranges from a position of a midfoot portion to a position of the rear foot portion of the foot of the wearer.   
     
     
         10 . The sole structure of  claim 1 , wherein
 the first material is a material having higher rigidity than the second material,   the second material is a material softer than the first material and having higher rebound properties than the first material,   the first midsole portion is located at part of the sole structure that ranges from a position of a forefoot portion to a position of a midfoot portion of a foot of a wearer, and   the second midsole portion is located at part of the sole structure that ranges from a position of the forefoot portion to a position of the rear foot portion of the foot of the wearer.   
     
     
         11 . The sole structure of  claim 10 , wherein
 the overlap portion is located at part of the sole structure that ranges from the position of the forefoot portion to the position of the midfoot portion of the foot of the wearer, and   in the overlap portion, the first midsole portion is located below the second midsole portion.   
     
     
         12 . The sole structure of  claim 11 , wherein
 the first boundary portion extends from a lower side to an upper side of the sole structure while extending from the position of the midfoot portion to the position of the forefoot portion of the foot of the wearer in the sole structure,   the sole structure further includes a second reinforcement portion made of a fourth material having higher rigidity than the third material, and   the second reinforcement portion is disposed at the first boundary portion and is stacked between the first midsole portion and the second midsole portion.   
     
     
         13 . A shoe comprising: the sole structure of  claim 1 .