Sole structure for a shoe

Abstract

A hard elastic body ( 10 ) having a longitudinally extending cavity ( 13 ) formed therein is provided mainly at a forefoot region (F) of a sole body. The cavity ( 13 ) is formed of a first curved surface ( 11 ) extending curvedly in a longitudinal direction and a second curved surface ( 12 ) disposed under the first curved surface ( 11 ) and extending curvedly in a longitudinal direction as well. A front and rear end of the second curved surface ( 12 ) is connected to a front and rear end of the first curved surface ( 11 ) respectively and an intermediate portion of the second curved surface ( 12 ) is spaced apart downwardly from an intermediate portion of the first curved surface ( 11 ). A path (PQ 1 ) between the front and rear end of the first curved surface ( 11 ) is substantially equal to a path (PQ 2 ) between the front and rear end of the second curved surface ( 12 ). When the first curved surface ( 11 ) is pressed downwardly, the sole body is deformed in such a way that a rear foot region (R) of the sole body is lifted upwardly.

1 . A sole assembly for a shoe having a sole body, wherein said sole body has a flat-shaped concavity formed at a forefoot region thereof, said cavity is defined by a first curved surface formed of elastic material and a second curved surface disposed under said first curved surface and formed of elastic material, a front and rear end of said second curved surface is coupled to a front and rear end of said first curved surface respectively, an intermediate portion of the second curved surface is located downwardly away from an intermediate portion of said first curved surface, a path between said front end and said rear end of said first curved surface is substantially equal to a path between said front end and said rear end of said second curved surface, and said sole body deforms in such a way that when said first curved surface is pressed downwardly a rear side region of said sole body is lifted upwardly.  
     
     
         2 . The sole assembly of  claim 1 , wherein said cavity is parallelogrammatical in shape.  
     
     
         3 . The sole assembly of  claim 1 , wherein said sole body has a hard elastic body at said forefoot region, said hard elastic body having said cavity formed therein and being harder than said sole body.  
     
     
         4 . The sole assembly of  claim 3 , wherein said elastic body has an upper area including said first curved surface and a lower area including said second curved surface, the bending rigidity of a front side portion of said upper area is lower than that of a rear side portion of said upper area, and the bending rigidity of a rear side portion of said lower area is lower than that of a front side portion of said lower area.  
     
     
         5 . The sole assembly of  claim 4 , wherein a thickness of said front side portion of said upper area is smaller than that of said rear side portion of said upper area, and a thickness of said rear side portion of said lower area is smaller than that of said front side portion of said lower area.  
     
     
         6 . The sole assembly of  claim 4 , wherein a groove or through hole is formed at a portion with a lower bending rigidity, or a rib is formed at a portion with a higher bending rigidity.  
     
     
         7 . The sole assembly of  claim 4 , wherein said rear side portion of said upper area and said front side portion of said lower area have a FRP sheet interposed therein.  
     
     
         8 . The sole assembly of  claim 4 , wherein said rear side portions of said upper area and said lower area of said elastic body are united into a unit on the rear side of said first and second curved surface and extend further rearward, and a rearmost end of an extension of said unit is disposed at a heel region of said sole body.  
     
     
         9 . The sole assembly of  claim 1 , wherein said cavity defined by said first and second curved surface has a reinforced member to increase the rigidity of said sole body or said elastic body in a lateral direction.  
     
     
         10 . The sole assembly of  claim 9 , wherein said reinforcement member is composed of one or more ribs provided on said second curved surface, said ribs extending substantially in a lateral direction.  
     
     
         11 . The sole assembly of  claim 1 , wherein an elastic structure is provided at said forefoot region of said sole body, and said elastic structure is composed of a first plate including said first curved surface and a second plate including said second curved surface, a front and rear end of said second plate being coupled to a front and rear end of said first plate respectively.  
     
     
         12 . The sole assembly of  claim 1 , wherein a soft elastic member softer than said sole body is inserted into at least a portion of said cavity.  
     
     
         13 . The sole assembly of  claim 12 , wherein said elastic member is composed of a plurality of members each extending substantially in a lateral direction.  
     
     
         14 . The sole assembly of  claim 1 , wherein a bottom surface of said sole body constitutes a sole ground contact surface.  
     
     
         15 . The sole assembly of  claim 1 , wherein said first and second curved surface crosses a thenar eminence of a wearer's foot in a longitudinal direction.  
     
     
         16 . The sole assembly of  claim 1 , wherein said first and second curved surface crosses a first proximal phalanx of a wearer's foot in a lateral direction.  
     
     
         17 . The sole assembly of  claim 1 , wherein said first and second curved surface crosses a fifth proximal phalanx of a wearer's foot in a lateral direction.  
     
     
         18 . The sole assembly of  claim 1 , wherein said cavity penetrates said sole body in a lateral direction.  
     
     
         19 . A sole assembly for a shoe having a sole body, wherein said sole body has a flat-shaped cavity formed at a forefoot region thereof, said cavity is defined by a first curved surface formed of elastic material and a second curved surface disposed under said first curved surface and formed of elastic material, a front and rear end of said second curved surface is coupled to a front and rear end of said first curved surface, respectively, an intermediate portion of the second curved surface is located downwardly away from an intermediate portion of said first curved surface, and the bending rigidity of said forefoot region of said sole body changes at two stages of a first bending rigidity to a second bending rigidity as the progress of bending at the time of bending motion of said forefoot region of said sole body.  
     
     
         20 . The sole assembly of  claim 19 , wherein said bending rigidity changes from said first bending rigidity to said second bending rigidity by substantially closing said cavity.  
     
     
         21 . The sole assembly of  claim 19 , wherein a soft elastic member softer than said sole body is inserted into at least a portion of said cavity.  
     
     
         22 . The sole assembly of  claim 21 , wherein said elastic member is composed of a plurality of members each extending substantially in a lateral direction.  
     
     
         23 . The sole assembly of  claim 19 , wherein a bottom surface of said sole body constitutes a sole ground contact surface.  
     
     
         24 . The sole assembly of  claim 19 , wherein said first and second curved surface crosses a thenar eminence of a wearer's foot in a longitudinal direction.  
     
     
         25 . The sole assembly of  claim 19 , wherein said first and second curved surface crosses a first proximal phalanx of a wearer's foot in a lateral direction.  
     
     
         26 . The sole assembly of  claim 19 , wherein said first and second curved surface crosses a fifth proximal phalanx of a wearer's foot in a lateral direction.  
     
     
         27 . The sole assembly of  claim 19 , wherein said cavity penetrates said sole body in a lateral direction.  
     
     
         28 . A sole assembly for a shoe having a sole body, wherein said sole body has a flat-shaped cavity formed at a forefoot region thereof, said cavity is defined by a first curved surface formed of elastic material and including a downwardly convex curve and a second curved surface disposed under said first curved surface, formed of elastic material and including a downwardly convex curve, a front and rear end of said second curved surface is coupled to a front and rear end of said first curved surface respectively, an intermediate portion of the second curved surface is located downwardly away from an intermediate portion of said first curved surface, and said sole body deforms in such a way that when said first curved surface is pressed downwardly a rear side region of said sole body is lifted upwardly.  
     
     
         29 . The sole assembly of  claim 28 , wherein a soft elastic member softer than said sole body is inserted into at least a portion of said cavity.  
     
     
         30 . The sole assembly of  claim 29 , wherein said elastic member is composed of a plurality of members each extending substantially in a lateral direction.  
     
     
         31 . The sole assembly of  claim 28 , wherein a bottom surface of said sole body constitutes a sole ground contact surface.  
     
     
         32 . The sole assembly of  claim 28 , wherein said first and second curved surface crosses a thenar eminence of a wearer's foot in a longitudinal direction.  
     
     
         33 . The sole assembly of  claim 28 , wherein said first and second curved surface crosses a first proximal phalanx of a wearer's foot in a lateral direction.  
     
     
         34 . The sole assembly of  claim 28 , wherein said first and second curved surface crosses a fifth proximal phalanx of a wearer's foot in a lateral direction.  
     
     
         35 . The sole assembly of  claim 28 , wherein said cavity penetrates said sole body in a lateral direction.