Article of apparel with comfort strap

Abstract

A backpack includes a bag portion and at least one shoulder strap coupled to the bag portion. The at least one shoulder strap includes a non-elastic first strap portion coupled to an elastic second strap portion. The second strap portion is auxetic or near auxetic such that a Poisson's ratio of the second strap portion is less than a Poisson's ratio of the first strap portion.

What is claimed is: 
     
         1 . A backpack comprising:
 a bag portion; and   at least one shoulder strap coupled to the bag portion, the at least one shoulder strap including a non-elastic first strap portion coupled to an elastic second strap portion, wherein a Poisson's ratio of the second strap portion is less than a Poisson's ratio of the first strap portion.   
     
     
         2 . The article of apparel of  claim 1  wherein the second strap portion is auxetic. 
     
     
         3 . The article of apparel of  claim 1  wherein the second strap portion is near auxetic. 
     
     
         4 . The article of apparel of  claim 1  wherein the second strap portion is a shoulder pad of the shoulder strap. 
     
     
         5 . The article of apparel of  claim 1  wherein the second strap portion includes a base layer comprising a four way stretch material and a polymer layer coupled to the base layer, wherein the polymer layer is defined by a repeating pattern of reentrant shapes. 
     
     
         6 . The article of apparel of  claim 5  wherein the polymer layer is further defined by voids formed within each of the reentrant shapes. 
     
     
         7 . The article of apparel of  claim 1  wherein the second strap portion is provided by a corrugated length of fabric with a plurality of elastic cords woven into the fabric. 
     
     
         8 . A backpack comprising:
 a bag portion comprising a plurality of panels, the plurality of panels including a non-elastic first panel and an elastic second panel, wherein a Poisson's ratio of the second panel is less than a Poisson's ratio of the first panel; and   at least one shoulder strap coupled to the bag portion.   
     
     
         9 . The article of apparel of  claim 8  wherein the second panel is auxetic. 
     
     
         10 . The article of apparel of  claim 8  wherein the second panel is near auxetic. 
     
     
         11 . The article of apparel of  claim 8  wherein the second panel is arranged on a forward-facing side of the backpack. 
     
     
         12 . The article of apparel of  claim 8  wherein the second panel includes a base layer comprising a four way stretch material and a polymer layer coupled to the base layer, wherein the polymer layer is defined by a repeating pattern of reentrant shapes. 
     
     
         13 . The article of apparel of  claim 12  wherein the polymer layer is further defined by voids formed within each of the reentrant shapes. 
     
     
         14 . The article of apparel of  claim 8  wherein the second panel is provided by a corrugated length of fabric with a plurality of elastic cords woven into the fabric. 
     
     
         15 . A bag comprising:
 a bag portion; and   at least one shoulder strap coupled to the bag portion, the at least one shoulder strap including a non-elastic first strap portion coupled to an elastic second strap portion, wherein the second strap portion is comprised of an auxetic structure.   
     
     
         16 . The backpack of  claim 15  wherein the auxetic structure includes a base layer comprising a four way stretch material and a polymer layer coupled to the base layer, wherein the polymer layer is defined by a repeating pattern of reentrant shapes. 
     
     
         17 . The article of apparel of  claim 16  wherein the polymer layer is further defined by voids formed within each of the reentrant shapes. 
     
     
         18 . The article of apparel of  claim 17  wherein the reentrant shapes are auxetic hexagons. 
     
     
         19 . The article of apparel of  claim 15  wherein the auxetic structure is near auxetic. 
     
     
         20 . The article of apparel of  claim 15  wherein second strap portion is provided as a shoulder pad of the at least one shoulder strap.