Auxetic structures and footwear with soles having auxetic structures

Abstract

A material that includes at least one layer made of an auxetic structure and articles of footwear having soles comprising the materials. When the material is under tension, it expands in both the direction under tension and in the directional orthogonal to the direction under tension. The articles of footwear have soles that have at least one layer made of a material that has a pattern of apertures to provide the auxetic structure. The apertures are surrounded by sole portions that can rotate or pivot to change the size of the apertures.

What is claimed is: 
     
         1 . An article of footwear comprising an upper and a sole structure, wherein the sole structure comprises:
 a plurality of apertures including a first aperture surrounded by a first sole portion, a second sole portion, a third sole portion, a fourth sole portion, a fifth sole portion and a sixth sole portion;   the first sole portion being connected to the second sole portion at a first hinge portion, the first hinge portion being associated with a first vertex of the first aperture, and wherein the first sole portion has three sides;   the second sole portion being connected to the third sole portion at a second hinge portion, the second hinge portion being associated with a second vertex of the first aperture, and wherein the second sole portion has three sides;   the third sole portion being connected to the fourth sole portion at a third hinge portion, the third hinge portion being associated with a third vertex of the first aperture, and wherein the third sole portion has three sides;   the fourth sole portion being connected to the fifth sole portion at a fourth hinge portion, the fourth hinge portion being associated with a fourth vertex of the first aperture, and wherein the fourth sole portion has three sides;   the fifth sole portion being connected to the sixth sole portion at a fifth hinge portion, the fifth hinge portion being associated with a fifth vertex of the first aperture, and wherein the fifth sole portion has three sides; and   the first sole portion being connected to the sixth sole portion at a sixth hinge portion, the sixth hinge portion being associated with a sixth vertex of the first aperture, and wherein the sixth sole portion has three sides.   
     
     
         2 . The article of footwear of  claim 1 , wherein the three sides of the first sole portion are straight sides, wherein the three sides of the second sole portion are straight sides, wherein the three sides of the third sole portion are straight sides, wherein the three sides of the fourth sole portion are straight sides, wherein the three sides of the fifth sole portion are straight sides and wherein the three sides of the sixth sole portion are straight sides. 
     
     
         3 . The article of footwear of  claim 1 , wherein the plurality of apertures includes a second aperture and a third aperture, and wherein a first side of the first sole portion is associated with the first aperture, wherein a second side of the first sole portion is associated with the second aperture and wherein a third side of the first sole portion is associated with the third aperture. 
     
     
         4 . The article of footwear of  claim 1 , wherein the first sole portion has an approximately triangular geometry, wherein the second sole portion has an approximately triangular geometry, wherein the third sole portion has an approximately triangular geometry, wherein the fourth sole portion has an approximately triangular geometry, wherein the fifth sole portion has an approximately triangular geometry and wherein the sixth sole portion has an approximately triangular geometry. 
     
     
         5 . The article of footwear of  claim 1 , wherein the first sole portion and the second sole portion can pivot with respect to one another about the first hinge portion, wherein the second sole portion and the third sole portion can pivot with respect to one another about the second hinge portion, wherein the third sole portion and the fourth sole portion can pivot with respect to one another about the third hinge portion, wherein the fourth sole portion and the fifth sole portion can pivot with respect to one another about the fourth hinge portion, wherein the fifth sole portion and the sixth sole portion can pivot with respect to one another about the fifth hinge portion and wherein the first sole portion and the sixth sole portion can pivot with respect to one another about the sixth hinge portion. 
     
     
         6 . The article of footwear of  claim 5 , wherein the first sole portion and the second sole portion rotate away from one another when tension is applied across the sole structure, wherein the third sole portion and the fourth sole portion rotate away from one another when tension is applied to the sole structure and wherein the fifth sole portion and the sixth sole portion rotate away from one another when tension is applied to the sole structure. 
     
     
         7 . The article of footwear of  claim 1 , wherein the first aperture has a triangular star geometry. 
     
     
         8 . The article of footwear of  claim 1 , wherein the arrangement of the first through sixth sole portions, the first through sixth hinges, and the plurality of apertures forms an auxetic structure. 
     
     
         9 . The article of footwear of  claim 1 , further comprising an outer covering extending over each of the first through sixth sole portions and into the first aperture, wherein the outer covering forms a ground contacting surface of the sole structure. 
     
     
         10 . The article of footwear of  claim 1 , wherein the plurality of apertures includes at least one blind-hole. 
     
     
         11 . The article of footwear of  claim 1 , wherein the plurality of apertures includes at least one through-hole. 
     
     
         12 . A sole structure for an article of footwear comprising:
 a plurality of apertures, each aperture having a triangular star geometry defined by three interior vertices and three exterior vertices, wherein a first aperture of the plurality of apertures is surrounded by each of a first sole portion, a second sole portion, a third sole portion, a fourth sole portion, a fifth sole portion and a sixth sole portion, and wherein each of the sole portions has a three-sided geometry;   the first sole portion connected to the second sole portion by a first hinge portion that defines a first interior vertex of the first aperture;   the second sole portion connected to the third sole portion by a second hinge portion that defines a first exterior vertex of the first aperture;   the third sole portion connected to the fourth sole portion by a third hinge portion that defines a second interior vertex of the first aperture;   the fourth sole portion connected to the fifth sole portion by a fourth hinge portion that defines a second exterior vertex of the first aperture;   the fifth sole portion connected to the sixth sole portion by a fifth hinge portion that defines a third interior vertex of the first aperture; and   the sixth sole portion connected to the first sole portion by a sixth hinge portion that defines a third exterior vertex of the first aperture.   
     
     
         13 . The sole structure of  claim 12 , wherein the plurality of apertures further includes a second aperture, a third aperture, and a fourth aperture;
 wherein the second hinge portion defines an interior vertex of the second aperture, the fourth hinge portion defines an interior vertex of the third aperture, and the sixth hinge portion defines an interior vertex of the fourth aperture.   
     
     
         14 . The sole structure of  claim 13 , wherein the plurality of apertures further includes a fifth aperture, a sixth aperture, and a seventh aperture;
 wherein the first hinge portion defines an exterior vertex of the fifth aperture, the third hinge portion defines an exterior vertex of the sixth aperture, and the fifth hinge portion defines an exterior vertex of the seventh aperture.   
     
     
         15 . The sole structure of  claim 12 , wherein each of the first through sixth hinge portions elastically deforms to permit relative rotation of connected sole portions when the sole structure is tensioned. 
     
     
         16 . The sole structure of  claim 12 , wherein the arrangement of the first through sixth sole portions, the first through sixth hinges, and the plurality of apertures forms an auxetic structure. 
     
     
         17 . The sole structure of  claim 12 , further comprising an outer covering extending over each of the first through sixth sole portions and into the first aperture, wherein the outer covering forms a ground contacting surface of the sole structure. 
     
     
         18 . The sole structure of  claim 12 , further comprising a ground contacting surface and an upper surface that is opposite the ground contacting surface, wherein each of the plurality of apertures extend into the sole structure from at least one of the ground contacting surface or the upper surface. 
     
     
         19 . The sole structure of  claim 12 , wherein the plurality of apertures includes at least one blind-hole. 
     
     
         20 . The sole structure of  claim 12 , wherein the plurality of apertures includes at least one through-hole.