Articles of footwear with localized traction regions

Abstract

Articles of footwear with localized traction regions. An article of footwear includes an upper with a shell and a sole assembly coupled to the upper. The sole assembly includes an outsole with a traction surface and a heel region from which a heel projects. The sole assembly and the upper collectively define a foot compartment. The traction surface includes a plurality of distinct localized traction regions, each of which has a traction coefficient that is different than that of at least one other localized traction region. The traction surface further defines and/or includes a stirrup glide surface. The stirrup glide surface is configured to permit the article of footwear to be selectively inserted into and removed from a stirrup of a saddle by sliding along a tread surface of the stirrup without obstruction by the stirrup.

1 . An article of footwear, comprising:
 an upper that includes a shell sized and shaped to receive and extend around a foot of a wearer; and   a sole assembly coupled to the upper, the sole assembly including:
 an outsole with a traction surface positioned on a bottom side of the outsole when the wearer stands upon a flat ground surface while wearing the article of footwear; and 
 a heel region from which a heel projects; 
   wherein the sole assembly and the upper collectively define a foot compartment sized to receive a wearer's foot when the article of footwear is donned by the wearer;   wherein the traction surface includes:
 an arch region proximal to the heel region; 
 a midfoot region on an anterior side of the arch region; 
 a forefoot region on an anterior side of the midfoot region; 
 a toe region on an anterior side of the forefoot region; 
 a lateral portion on a lateral side of the traction surface; 
 a medial portion on a medial side of the traction surface; 
 a central portion that separates the lateral portion from the medial portion; and 
 a plurality of distinct localized traction regions, wherein each distinct localized traction region has a traction coefficient that is different than the traction coefficient of at least one of the plurality of localized traction regions; wherein the traction coefficient is defined as a ratio of a threshold shear force applied on an engaged surface by the distinct localized traction region to a normal force applied on the distinct localized traction region by the engaged surface when the distinct localized traction region is in static contact with the engaged surface; and 
   wherein the traction surface defines a stirrup glide surface extending from the toe region of the traction surface to the arch region of the traction surface; wherein the stirrup glide surface is configured to permit the article of footwear to be selectively inserted into and removed from a stirrup of a saddle by sliding along a tread surface of the stirrup without obstruction by the stirrup.   
     
     
         2 . The article of footwear of  claim 1 , wherein the stirrup glide surface includes the plurality of distinct localized traction regions. 
     
     
         3 . The article of footwear of  claim 1 , wherein the stirrup glide surface further extends from the lateral portion of the traction surface to the medial portion of the traction surface. 
     
     
         4 . The article of footwear of  claim 1 , wherein the stirrup glide surface lacks a ledge that extends from the lateral portion of the traction surface to the medial portion of the traction surface and in a direction perpendicular to a longitudinal axis of the traction surface. 
     
     
         5 . The article of footwear of  claim 1 , wherein the outsole includes a first outsole surface that is flat, wherein the stirrup glide surface has an average glide surface depth, as measured from the first outsole surface, and wherein the stirrup glide surface does not include a feature that has a depth that differs from the average glide surface depth by more than 50% of the average glide surface depth. 
     
     
         6 . The article of footwear of  claim 1 , wherein the threshold shear force is applied to the engaged surface by the localized traction region in a direction parallel to the traction surface, and further wherein the threshold shear force is a force that may be applied to the engaged surface by the localized traction region while maintaining the localized traction region in static contact with the engaged surface. 
     
     
         7 . The article of footwear of  claim 1 , wherein the plurality of distinct localized traction regions includes a longitudinal traction region that extends across as least two of the arch region, the midfoot region, and the forefoot region and a transverse traction region that extends across at least two of the lateral portion, the central portion, and the medial portion. 
     
     
         8 . The article of footwear of  claim 1 , wherein the plurality of distinct localized traction regions includes a first traction region with a first traction coefficient positioned at least partially in the forefoot region and a second traction region with a second traction coefficient positioned at least partially in the arch region, and wherein the first traction coefficient is greater than the second traction coefficient. 
     
     
         9 . The article of footwear of  claim 8 , wherein the first traction region extends across the lateral portion, the central portion, and the medial portion of the traction surface. 
     
     
         10 . The article of footwear of  claim 1 , wherein the outsole includes a first outsole surface that is flat, and further wherein the traction surface includes a plurality of spaced-apart traction members that project from the first outsole surface. 
     
     
         11 . The article of footwear of  claim 10 , wherein at least one traction member of the plurality of spaced-apart traction members includes a posterior segment and an anterior segment, wherein the posterior segment includes a posterior surface that tapers toward the first outsole surface at a posterior taper angle defined between a plane of the first outsole surface and the anterior segment as measured through a body of the traction member, wherein the anterior segment includes an anterior surface that tapers toward the first outsole surface at an anterior taper angle defined between the plane of the first outsole surface and the posterior surface as measured through the body of the traction member, and wherein the anterior taper angle is different than the posterior taper angle. 
     
     
         12 . The article of footwear of  claim 11 , wherein each of the posterior taper angle and the anterior taper angle is less than 60 degrees. 
     
     
         13 . The article of footwear of  claim 1 , wherein the article of footwear is an equestrian riding boot, and wherein the upper further includes a shaft that extends upwards from the shell. 
     
     
         14 . The article of footwear of  claim 1 , wherein the upper is free of a mechanical fastening mechanism configured to be selectively engaged and released by the wearer to selectively adjust the size of the upper. 
     
     
         15 . The article of footwear of  claim 1 , wherein the traction surface includes more than two distinct localized traction regions. 
     
     
         16 . The article of footwear of  claim 1 , wherein the plurality of distinct localized traction regions includes:
 (i) a first traction region located in the lateral portion of the forefoot region, the central portion of the forefoot region, and the medial portion of the forefoot region;   (ii) a second traction region located in the central portion of the midfoot region; and   (iii) a third traction region located in the lateral portion of the midfoot region and the lateral portion of the arch region; and wherein:   (i) the first traction region has a traction coefficient of 1.4;   (ii) the second traction region has a traction coefficient of 0.6; and   (iii) the third traction region has a traction coefficient of 0.9.   
     
     
         17 . The article of footwear of  claim 1 , wherein the plurality of distinct localized traction regions includes:
 (i) a first traction region located in the medial portion of the toe region;   (ii) a second traction region located in the central portion of the forefoot region and the medial portion of the forefoot region;   (iii) a third traction region located in the medial portion of the midfoot region and the medial portion of the arch region;   (iv) a fourth traction region located in the central portion of the midfoot region and the central portion of the arch region; and   (v) a fifth traction region located in the lateral portion of the midfoot region and the lateral portion of the arch region; and wherein:   (i) the first traction region has a traction coefficient of 1.2;   (ii) the second traction region has a traction coefficient of 2.3;   (iii) the third traction region has a traction coefficient of 1.4;   (iv) the fourth traction region has a traction coefficient of 1.1; and   (v) the fifth traction region has a traction coefficient of 2.0.   
     
     
         18 . The article of footwear of  claim 1 , wherein the plurality of distinct localized traction regions includes:
 (i) a first traction region located in the medial portion of the forefoot region, the central portion of the forefoot region, and the central portion of the midfoot region;   (ii) a second traction region located in the lateral portion of the forefoot region;   (iii) a third traction region located in the medial portion of the midfoot region, the central portion of the midfoot region, and the lateral portion of the arch region; and   (iv) a fourth traction region located in the lateral portion of the midfoot region, the central portion of the arch region, and the lateral portion of the arch region; and wherein:   (i) the first traction region has a traction coefficient of 1.9;   (ii) each of the second traction region and the third traction region has a traction coefficient of 0.9; and   (iii) the fourth traction region has a traction coefficient of 2.3.   
     
     
         19 . The article of footwear of  claim 1 , wherein the plurality of distinct localized traction regions includes:
 (i) a first traction region located in the lateral portion of the forefoot region, the central portion of the forefoot region, and the medial portion of the forefoot region; and   (ii) a second traction region located in the medial portion of the midfoot region and the medial portion of the arch region; and wherein:   (i) the first traction region has a traction coefficient of 1.7; and   (ii) the second traction region has a traction coefficient of 2.4.   
     
     
         20 . The article of footwear of  claim 1 , wherein the plurality of distinct localized traction regions includes:
 (i) a first traction region located in the medial portion of the forefoot region;   (ii) a second traction region located in the central portion of forefoot region, the central portion of the midfoot region, and the medial portion of the midfoot region; and   (iii) a third traction region located in the lateral portion of the forefoot region and the lateral portion of the midfoot region; and wherein:   (i) the first traction region has a traction coefficient of 2.3;   (ii) the second traction region has a traction coefficient of 1.0; and   (iii) the third traction region has a traction coefficient of 2.3.   
     
     
         21 . An article of footwear, comprising:
 an upper that includes a shell sized and shaped to receive and extend around a foot of a wearer; and   a sole assembly coupled to the upper, the sole assembly including:
 an outsole with a traction surface positioned on a bottom side of the outsole when the wearer stands upon a flat ground surface while wearing the article of footwear; and 
 a heel region from which a heel projects; 
   wherein the sole assembly and the upper collectively define a foot compartment sized to receive a wearer's foot when the article of footwear is donned by the wearer;   wherein the traction surface includes at least one distinct localized traction region with a corresponding traction quality; wherein the outsole includes a first outsole surface that is flat;   wherein the at least one distinct localized traction region includes a plurality of spaced-apart traction members that project from the first outsole surface; wherein at least one traction member of the plurality of distinct localized traction members includes a posterior segment formed form a first material and an anterior segment formed from a second material that is different than the first material; and   wherein the traction surface defines a stirrup glide surface extending from a toe region of the traction surface to an arch region of the traction surface; wherein the stirrup glide surface is configured to permit the article of footwear to be selectively inserted into and removed from a stirrup of a saddle by sliding along a tread of the stirrup without obstruction by the stirrup.   
     
     
         22 . The article of footwear of  claim 21 , wherein the first material includes at least one of carbon fiber, a composite material, a nylon, a thermoplastic material, polyvinyl acetate, polyethylene vinyl acetate (PEVA), a rubber, a resin, a polyester, a polyether, a metal, an alloy, and a metalloid, and wherein the second material includes at least one other of carbon fiber, a composite material, a nylon, a thermoplastic material, polyvinyl acetate, polyethylene vinyl acetate (PEVA), a rubber, a resin, a polyester, a polyether, a metal, an alloy, and a metalloid. 
     
     
         23 . The article of footwear of  claim 21 , wherein the posterior segment includes a posterior surface that tapers toward the first outsole surface at a posterior taper angle defined between a plane of the first outsole surface and the posterior surface as measured through a body of the traction member, wherein the anterior segment includes an anterior surface that tapers toward the first outsole surface at an anterior taper angle defined between the plane of the first outsole surface and the anterior surface as measured through the body of the traction member, and wherein the anterior taper angle is different than the posterior taper angle. 
     
     
         24 . The article of footwear of  claim 23 , wherein the posterior taper angle and the anterior taper angle differ by at least 10 degrees. 
     
     
         25 . The article of footwear of  claim 21 , wherein each of the plurality of spaced-apart traction members project less than 5 mm from a portion of the outsole immediately adjacent the traction member.