Fabric Straps for Electronic Devices

Abstract

A fabric strap may be used to attach a wearable electronic device to a user's body. The fabric strap may include a stretchable inner fabric layer formed from mesh fabric. A first set of ribs may be formed on a first side of the inner fabric layer and a second set of ribs may be formed on a second opposing side of the inner fabric layer. Load-modifying structures may be located in the ribs and may be used to increase the initial force required to stretch the strap, while allowing additional elongation to occur without requiring increasing force once a certain elongation percentage is reached. The load-modifying structures may be located in upper portions of the ribs and/or may span across openings in the ribs, and may include stitching, stiffeners, fabric layers, metal or plastic materials, spring members, and/or other structures.

What is claimed is: 
     
         1 . A fabric strap for a wearable electronic device, the fabric strap comprising:
 an inner fabric layer having first and second opposing surfaces, wherein the inner fabric layer is configured to elongate along a first direction;   ribs on the first and second opposing surfaces of the inner fabric layer, wherein the ribs have respective openings that each extend along a second direction perpendicular to the first direction; and   load-modifying structures in the ribs that each span across a respective one of the openings.   
     
     
         2 . The fabric strap defined in  claim 1  wherein the load-modifying structures are each separated from the inner fabric layer by a distance when the inner fabric layer is in an unstretched state. 
     
     
         3 . The fabric strap defined in  claim 2  wherein the distance decreases as the inner fabric layer elongates. 
     
     
         4 . The fabric strap defined in  claim 1  wherein the load-modifying structures comprise springs that are parallel to the inner fabric layer. 
     
     
         5 . The fabric strap defined in  claim 4  wherein the springs include multiple springs located at different positions along a respective one of the openings. 
     
     
         6 . The fabric strap defined in  claim 1  wherein the load-modifying structures comprise stitching that spans between first and second opposing sidewalls of a respective one of the ribs. 
     
     
         7 . The fabric strap defined in  claim 1  wherein the load-modifying structures comprise a layer of fabric that spans between first and second opposing sidewalls of a respective one of the ribs. 
     
     
         8 . The fabric strap defined in  claim 1  wherein the load-modifying structures comprise a layer of elastomer that spans between first and second opposing sidewalls of a respective one of the ribs. 
     
     
         9 . The fabric strap defined in  claim 1  wherein the load-modifying structures are removably attached to the ribs. 
     
     
         10 . The fabric strap defined in  claim 1  further comprising stiffening structures located in respective upper portions of the ribs and separated from the inner fabric layer by a gap. 
     
     
         11 . A stretchable fabric strap configured to attach a wearable electronic device to a user, the stretchable fabric strap comprising:
 ribbed fabric having a mesh inner layer that stretches along a first direction and having ribs that protrude from the mesh inner layer along a second direction perpendicular to the first direction; and   stiffening structures located in respective upper portions of the ribs and separated from the mesh inner layer by a gap.   
     
     
         12 . The stretchable fabric strap defined in  claim 11  wherein the stiffening structures comprise coatings located on the respective upper portions of the ribs and wherein the coatings comprise at least one of an elastic film and an adhesive layer. 
     
     
         13 . The stretchable fabric strap defined in  claim 11  wherein the stiffening structures comprise at least one of a metal layer and a plastic layer. 
     
     
         14 . The stretchable fabric strap defined in  claim 11  wherein the stiffening structures are removably attached to the ribs. 
     
     
         15 . The stretchable fabric strap defined in  claim 11  further comprising load-modifying structures that each span across a respective opening in the ribs. 
     
     
         16 . A fabric strap for a wearable electronic device, the fabric strap comprising:
 a stretchable inner fabric layer configured to elongate in a first direction;   a stiffening outer layer; and   a compressible layer interposed between the stretchable inner fabric layer and the stiffening outer layer, wherein the compressible layer is configured to compress as the stretchable inner fabric layer elongates to reduce a distance between the stretchable inner fabric layer and the stiffening outer layer.   
     
     
         17 . The fabric strap defined in  claim 16  wherein the stretchable inner fabric layer comprises a mesh fabric. 
     
     
         18 . The fabric strap defined in  claim 16  wherein the compressible layer comprises foam. 
     
     
         19 . The fabric strap defined in  claim 16  wherein the compressible layer comprises spacer fabric. 
     
     
         20 . The fabric strap defined in  claim 16  wherein the stiffening layer is less elastic than the stretchable inner fabric layer.