Sole assembly for an article of footwear

Abstract

A footwear construction having a strobel-stitched bottomed upper and a sole assembly with a topsole disposed above the strobel board. The topsole is manufactured from a foam having an average modulus at a stress of 535 kilopascals of from about 750 kilopascals to about 950 kilopascals. The foam also has an energy efficiency of at least about 78%, and a dynamic compression set of less than about 10%. The sole assembly may include an inner sole disposed above the topsole. The inner sole may be manufactured from EVA foam. The topsole may have a thickness of at least 1 mm, the inner sole may have a thickness of at least 3 mm, and the total thickness of the topsole and inner sole may be at least 5 mm. The sole assembly may include a midsole, and possibly an outsole, disposed below the strobel board.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
         1 . An article of footwear, comprising:
 an upper having a bottom closed by a strobel board, said upper having a lasting allowance joined to said strobel board in a butt-seam by a stitch;   a midsole disposed below said strobel board;   a topsole disposed above said strobel board, said topsole manufactured from foam having an average modulus at a stress of 535 kPa of between about 750 and 950 kPa and an energy efficiency of at least about 80% and a dynamic compression set of less than about 8%; and   an inner sole disposed above said topsole.   
     
     
         2 . The article of footwear of  claim 1  wherein said topsole has a thickness of at least 1 millimeter and said inner sole has a thickness of at least 3 millimeters; said topsole and said inner sole having a combined thickness of at least 5 millimeters in a central portion of a forefoot region of the article of footwear. 
     
     
         3 . The article of footwear of  claim 1  wherein said topsole has a thickness of at least 3 millimeters and a combined thickness of said topsole and said inner sole is at least 5 millimeters in a central portion of a forefoot region of the article of footwear. 
     
     
         4 . The article of footwear of  claim 2  wherein said topsole extends through a forefoot region, an arch region and a heel region of the article of footwear. 
     
     
         5 . The article of footwear of  claim 2  wherein said topsole is laminated to said strobel board. 
     
     
         6 . The article of footwear of  claim 5  wherein said topsole is formed directly on said strobel board. 
     
     
         7 . The article of footwear of  claim 6  wherein said strobel board defines an opening, said topsole generally disposed above said strobel board and having a downward extension extending into said opening. 
     
     
         8 . The article of footwear of  claim 6  wherein said strobel board defines an opening, said topsole generally disposed above said strobel board and having a downward extension extending through said opening to a distance substantially below said strobel board. 
     
     
         9 . A sole assembly for an article of footwear having an upper bottomed with a strobel board, comprising:
 a midsole disposed below the strobel board;   a topsole disposed above the strobel board, said topsole manufactured from foam having an average modulus at a stress of 535 kPa of between about 750 and about 950 kPa and an energy efficiency of at least about 80% and a dynamic compression set of less than about 8%; and   an inner sole disposed above said topsole.   
     
     
         10 . The sole assembly of  claim 9  wherein said topsole has a thickness of at least 1 millimeter and said inner sole has a thickness of at least 3 millimeters; said topsole and said inner sole having a combined thickness of at least 5 millimeters in a central portion of a forefoot region of the article of footwear. 
     
     
         11 . The sole assembly of  claim 10  wherein said inner sole is manufactured from EVA. 
     
     
         12 . The sole assembly of  claim 10  wherein said inner sole is manufactured from foam having an energy efficiency of less than about 80% and a dynamic compression set of greater than about 10%. 
     
     
         13 . The sole assembly of  claim 12  wherein said topsole is laminated to said strobel board. 
     
     
         14 . The sole assembly of  claim 13  wherein said topsole has a first thickness in forefoot region and a second thickness in a heel region, said first thickness being greater than said second thickness. 
     
     
         15 . The sole assembly of  claim 14  wherein said strobel board defines an opening. 
     
     
         16 . The sole assembly of  claim 15  wherein said topsole extends into said opening. 
     
     
         17 . An article of footwear comprising:
 an upper having a closed bottom, said upper defining a foot-receiving space above said closed bottom;   a topsole disposed in said foot-receiving space, said topsole manufactured from foam having an average modulus at a stress of 535 kPa of between about 750 and 950 kPa and an energy efficiency of at least about 80% and a dynamic compression set of less than about 8%; and   an inner sole disposed in said foot-receiving space above said topsole, said inner sole manufactured from a foam having an energy efficiency of less than about 80% and a dynamic compression set of greater than about 10%;   wherein said topsole has a thickness of at least 1 millimeter and said inner sole has a thickness of at least 3 millimeters; said topsole and said inner sole having a combined thickness of at least 5 millimeters in a central portion of a forefoot region of the article of footwear.   
     
     
         18 . The article of footwear of  claim 17  wherein said upper is closed by a strobel board, said topsole being joined to said strobel board. 
     
     
         19 . The article of footwear of  claim 18  wherein said upper includes a lasting allowance, said strobel board joined to said lasting allowance in a butt seam, said topsole extending over said strobel board, said butt seam and said lasting allowance. 
     
     
         20 . The article of footwear of  claim 19  wherein said topsole is an expanded TPU foam or a TPE foam.