Upper structure and shoe including upper structure

Abstract

An upper structure includes: an upper body including a stress relaxing portion which is elastically deformable; and a shoelace (a fastening member) attached to the upper body. The stress relaxing portion has: such stretchability that in an elastic range, the stress relaxing portion stretches to become longer when the upper body is pulled with the shoelace than an initial length of the stress relaxing portion; and stress relaxation properties with which the stress relaxing portion relaxes stress with the passage of time from a moment when the upper body is pulled, while remaining in the stretched state.

What is claimed is: 
     
         1 . An upper structure for a shoe, the upper structure comprising:
 an upper body including a stress relaxing portion which is elastically deformable; and   a fastening member attached to the upper body, and configured to keep the upper body fitted to a foot of a wearer when the upper body is in a pulled state in which the upper body is pulled with the fastening member, wherein   in an elastic range, the stress relaxing portion is configured to enter, when the upper body is in the pulled state, a stretched state in which the stress relaxing portion is stretched to become longer than an initial length thereof, and to relax stress with passage of time from a moment at which the upper body enters the pulled state, while remaining in the stretched state.   
     
     
         2 . The upper structure of  claim 1 , wherein
 the upper body is configured so that, when the upper body is released from the pulled state and returns to a state before the pulled state, the stress relaxing portion is restored to a state in which the stress relaxing portion is loose and out of contact with the foot of the wearer in the elastic range.   
     
     
         3 . The upper structure of  claim 1 , wherein
 the stress relaxing portion is disposed in a portion of the upper body, the portion corresponding to a forefoot of the foot of the wearer.   
     
     
         4 . The upper structure of  claim 1 , wherein
 the stress relaxing portion is disposed in a portion of the upper body, the portion corresponding to a midfoot of the foot of the wearer.   
     
     
         5 . The upper structure of  claim 1 , wherein
 the stress relaxing portion is disposed in a portion of the upper body, the portion corresponding to a hindfoot of the foot of the wearer.   
     
     
         6 . A shoe comprising the upper structure of  claim 1 . 
     
     
         7 . The shoe of  claim 6 , further comprising:
 a sole body configured to support the foot of the wearer and fixed to a lower portion of the upper body, wherein   the fastening member is attached to an upper portion of the upper body,   the stress relaxing portion continues from a fixing position at which the lower portion of the upper body and the sole body are fixed together to the upper portion of the upper body, and, is configured to stretch in a direction from a base point corresponding to the fixing position to the upper portion of the upper body when the upper body enters the pulled state.   
     
     
         8 . A shoe comprising the upper structure of  claim 5 , wherein
 the upper body is configured such that the stress relaxing portion stretches in a longitudinal direction while the upper body is pulled forward with the fastening member.