Article of footwear with traction system

Abstract

An article of footwear with a traction system. The traction system includes a plurality of traction elements of various heights on the outsole that undergo rotation within the penetrated substratum while avoiding damage from digging the surface while walking. The plurality of traction elements has a shortened height at pivot points of a foot and a lengthened height away from the pivot points of the foot.

What is claimed is: 
     
         1 . An article of footwear, comprising:
 an upper;   an outsole comprising a plurality of pivot points including a front toe pivot point, a heel pivot point, and a forefoot pivot point located between the front toe pivot point and the heel pivot point, wherein the plurality of pivot points corresponds to a plurality of locations on the outsole about which the article of footwear is configured to rotate while contacting a ground surface;   a midsole, and   a plurality of traction elements comprising (i) a first set of traction elements extending between the heel pivot point and the forefoot pivot point and (ii) a second set of traction elements extending between the forefoot pivot point and the front toe pivot point,   the first set of traction elements having different heights ranging from (i) a first minimum height at or near the heel and forefoot pivot points to (ii) a first maximum height at or near a first midpoint between the heel and forefoot pivot points, wherein all of the traction elements in the first set of traction elements extend away from the outsole to a first plurality of points that lie along a first parabolic arc extending from the heel pivot point to the forefoot pivot point, the first plurality of points positioned at a first plurality of distances from the outsole, the first plurality of distances corresponding to the different heights of the first set of traction elements, wherein the first maximum height corresponds to a peak of the first parabolic arc, and wherein the first minimum height corresponds to one or more ends of the first parabolic arc, and   the second set of traction elements having different heights ranging from (i) a second minimum height at or near the forefoot and front toe pivot points to (ii) a second maximum height at or near a second midpoint between the forefoot and front toe pivot points, wherein all of the traction elements in the second set of traction elements extend away from the outsole to a second plurality of points that lie along a second parabolic arc extending from the forefoot pivot point to the front toe pivot point, the second plurality of points positioned at a second plurality of distances from the outsole, the second plurality of distances corresponding to the different heights of the second set of traction elements, wherein the second maximum height corresponds to a peak of the second parabolic arc, and wherein the second minimum height corresponds to one or more ends of the second parabolic arc,   wherein the first maximum height is greater than the second maximum height.   
     
     
         2 . The article of footwear of  claim 1 , wherein the first set of traction elements comprises (i) a first traction element and a second traction element positioned at the one or more ends of the first parabolic arc and (ii) a third traction element positioned at the first midpoint, wherein the first traction element and the second traction element have a low height, and wherein the third traction element has a high height that is greater than the low height. 
     
     
         3 . The article of footwear of  claim 2 , wherein the first set of traction elements comprises one or more additional traction elements positioned between (i) the first or second traction element and (ii) the third traction element, the one or more additional traction elements having a medium height that is greater than the low height and less than the high height. 
     
     
         4 . The article of footwear of  claim 2 , wherein the second set of traction elements comprises a lengthened traction element positioned at the second midpoint, the lengthened traction element having a medium height that is greater than the low height and less than the high height. 
     
     
         5 . The article of footwear of  claim 4 , wherein the second set of traction elements comprises one or more additional traction elements positioned between (i) the lengthened traction element and (ii) the one or more ends of the second parabolic arc, the one or more additional traction elements having a height that is greater than the low height and less than the medium height. 
     
     
         6 . The article of footwear of  claim 2 , wherein the third traction element comprises a lengthened traction element having a greater height than any other traction element in the second set of traction elements. 
     
     
         7 . The article of footwear of  claim 1 , wherein a height of the first set of traction elements gradually increases from (i) the heel and forefoot pivot points to (ii) the first midpoint between the heel and forefoot pivot points. 
     
     
         8 . The article of footwear of  claim 1 , wherein a height of the second set of traction elements gradually increases from (i) the forefoot and front toe pivot points to (ii) the second midpoint between the forefoot and front toe pivot points. 
     
     
         9 . The article of footwear of  claim 1 , wherein a height of the first set of traction elements gradually decreases from (i) the first midpoint to (ii) the heel and forefoot pivot points. 
     
     
         10 . The article of footwear of  claim 1 , wherein a height of the second set of traction elements gradually decreases from (i) the second midpoint to (ii) the forefoot and front toe pivot points. 
     
     
         11 . The article of footwear of  claim 1 , wherein each traction element between the peak of the first or second parabolic arc and the one or more ends of the first or second parabolic arc has a different height depending on a distance between (i) each traction element and (ii) the peak or the one or more ends of the first or second parabolic arc. 
     
     
         12 . The article of footwear of  claim 1 , wherein the plurality of traction elements have a minimum height between 1 mm and 4 mm and a maximum height between 4 mm and 7.5 mm. 
     
     
         13 . The article of footwear of  claim 1 , wherein the first set of traction elements includes a plurality of spikes positioned in an arch region or a midfoot region of the outsole, wherein the plurality of spikes includes at least one spike with a height corresponding to the first maximum height. 
     
     
         14 . The article of footwear of  claim 1 , wherein the first set of traction elements is formed within a heel region and a midfoot region of the outsole, and wherein the second set of traction elements is formed within a forefoot region of the outsole. 
     
     
         15 . The article of footwear of  claim 1 , wherein the first set of traction elements and the second set of traction elements are separated or spaced apart by one or more flat or substantially flat regions. 
     
     
         16 . The article of footwear of  claim 15 , wherein the one or more flat or substantially flat regions correspond to (i) a portion of the outsole or (ii) a third set of traction elements with a substantially identical or uniform height. 
     
     
         17 . The article of footwear of  claim 1 , wherein the outsole comprises a central portion and a peripheral portion extending around the central portion, wherein the peripheral portion includes the first and second sets of traction elements, and wherein the central portion includes one or more flat surface areas that do not include any traction elements. 
     
     
         18 . The article of footwear of  claim 1 , wherein the first set of traction elements extends along a first length L 1  of the outsole, and wherein the second set of traction elements extends along a second length L 2  of the outsole, wherein L 1  is greater than L 2 . 
     
     
         19 . The article of footwear of  claim 1 , wherein the first set of traction elements and the second set of traction elements include a combination of different types of traction elements. 
     
     
         20 . The article of footwear of  claim 1 , wherein the plurality of traction elements comprise a rubber material and a thermoplastic polyurethane (TPU) material.