Spring plate for athletic shoe midsole

Abstract

In general, one or more aspects of the disclosure relates to an athletic shoe comprising an upper and a sole. The sole further comprises an upper midsole, a lower midsole and a plate disposed between the upper midsole and the lower midsole. The plate comprises a toe region having a planar shape. The toe region is encapsulated between the upper midsole and the lower midsole. The plate additionally comprises a heel region having a contoured incurvature. The heel region protrudes externally from between the upper midsole and the lower midsole to form a sidewall that encompasses a heel region of the upper midsole. The unique combination of the two shapes of the plate provides comfort and stability as well as enhanced energy return in the heel with less force upon the heel of the wearer and with the sidewalls provides stability and then the planar forefoot shape placed between the two midsoles offers propulsion, at the metatarsal flex and toe area during the gait cycle.

What is claimed is: 
     
         1 . An athletic shoe comprising:
 an upper; and   a sole, wherein the sole further comprises:
 an upper midsole; 
 a lower midsole; and 
 a plate disposed between the upper midsole and the lower midsole, wherein the plate comprises:
 a toe region having a planar shape, wherein the toe region is encapsulated between the upper midsole and the lower midsole; and 
 a heel region having a contoured incurvature, wherein the heel region protrudes externally from between the upper midsole and the lower midsole to form a sidewall that encompasses a heel region of the upper midsole. 
 
   
     
     
         2 . The athletic shoe of  claim 1 , where in the sidewall further encompasses a midfoot region of the upper midsole. 
     
     
         3 . The athletic shoe of  claim 1 , where in the upper midsole and the lower midsole are formed from a foamed thermoplastic elastomer selected from a group consisting of: polyurethane, polyethylene, polyolefin, polyester, co-polyester, polyether, polyamide, styrene block copolymers, vulcanizates, and combinations thereof. 
     
     
         4 . The athletic shoe of  claim 3 , wherein the thermoplastic elastomer is a supercritical foam selected from the group consisting of supercritical ethylene-vinyl acetate, supercritical polyurethane, and combinations thereof. 
     
     
         5 . The athletic shoe of  claim 1 , wherein the upper midsole has a thickness of about 10 mm at a toe region of the upper midsole and about 13 mm at a heel region the upper midsole. 
     
     
         6 . The athletic shoe of  claim 1 , wherein the lower midsole has a thickness of about 8 mm at a toe region of the lower midsole and about 14 mm at a heel region of the upper midsole. 
     
     
         7 . The athletic shoe  claim 1 , wherein the plate for their comprises:
 a midfoot region having an arched shape for supporting an instep of foot of a wearer.   
     
     
         8 . The athletic shoe of  claim 1 , wherein the plate is formed from a thermoplastic elastomer selected from a group consisting of: polyurethane, polyethylene, polyolefin, polyester, co-polyester, polyether, polyamide, styrene block copolymers, vulcanizates, and combinations thereof. 
     
     
         9 . The athletic shoe of  claim 7 , wherein the plate is formed from polyether block amide. 
     
     
         10 . The athletic shoe of  claim 1 , wherein the plate has a thickness of about 2 mm at a toe region of the plate and about 3 mm at a heel region of the plate. 
     
     
         11 . The athletic shoe of  claim 1 , wherein the planar shape of the toe region acts as a propulsion plate that provides a rebound energy return during a gate cycle. 
     
     
         12 . The athletic shoe of  claim 1 , wherein deflection the toe region during a gate cycle provides a rebound energy return when transitioning through the mid foot towards toe-off. 
     
     
         13 . The athletic shoe of  claim 1 , wherein at least the contoured incurvature of the heel region approximates a foot of a wearer. 
     
     
         14 . The athletic shoe of  claim 12 , wherein the contoured incurvature limits compression of the upper midsole during a heel strike of a gate cycle. 
     
     
         15 . The athletic shoe of  claim 13 , wherein a downward force imparted to the upper midsole during the heel strike is transferred radially to the lower midsole according to the contoured incurvature of the heel portion. 
     
     
         16 . The athletic shoe of  claim 14 , wherein radially transferring the downward force from the upper midsole to the lower midsole increases stability for both pronated heel strike and supinated heel strike. 
     
     
         17 . The athletic shoe  claim 1 , wherein the athletic shoe provides an energy return of greater than about 70% when measured at a compression of:
 2000 Newtons over an impulse width of 185 milliseconds; and   1400 Newtons over an impulse width of 170 milliseconds.   
     
     
         18 . The athletic shoe  claim 1 , wherein the plate of the athletic shoe is displaced greater than about 7 millimeters when measured at a compression of:
 2000 Newtons over an impulse width of 185 milliseconds; and   1400 Newtons over an impulse width of 170 milliseconds.   
     
     
         19 . A contoured propulsion plate for an athletic shoe, the plate comprising:
 a toe region having a planar shape, wherein the planar shape of the toe region acts as a propulsion plate that provides a rebound energy return during a gait cycle; and   a heel region having a contoured incurvature, wherein at least the contoured incurvature of the heel region approximates a foot of a wearer.   
     
     
         20 . The contoured propulsion plate of  claim 18 , wherein the plate is formed from a thermoplastic elastomer selected from a group consisting of: polyurethane, polyethylene, polyolefin, polyester, co-polyester, polyether, polyamide, styrene block copolymers, vulcanizates, and combinations thereof. 
     
     
         21 . The contoured propulsion plate of  claim 19 , wherein the plate is formed from polyether block amide. 
     
     
         22 . The contoured propulsion plate of  claim 18 , wherein the plate has a thickness of about 2 mm at a toe region of the plate and about 3 mm at a heel region of the plate. 
     
     
         23 . A method of manufacturing an athletic shoe, the method comprising:
 forming an upper midsole;   forming a lower midsole;   bonding a plate disposed between the upper midsole and the lower midsole, wherein:
 a toe region of the plate is encapsulated between the upper midsole and the lower midsole, wherein the toe region has a planar shape; and 
 a heel region of the plate protrudes externally from between the upper midsole and the lower midsole to form a sidewall that encompasses a heel region of the upper midsole, wherein the heel region has a contoured incurvature. 
   
     
     
         24 . The method of  claim 22 , where in the upper midsole and the lower midsole are formed from a foamed thermoplastic elastomer that is a supercritical foam selected from the group consisting of supercritical ethylene-vinyl acetate, supercritical polyurethane, and combinations thereof. 
     
     
         25 . The method of  claim 22 , wherein the plate is formed from a polyether block amide.