Pneumatic diaphragm having a bias weave pattern

Abstract

A diaphragm is provided that includes a tubular sidewall and a first elastomeric material. The tubular sidewall has an open end and an enclosed end and comprises fabric having a plurality of yarns disposed in a bias weave pattern. The first elastomeric material is disposed over the fabric at a predetermined thickness.

1 . A diaphragm comprising: 
 a tubular sidewall having an open end and an enclosed end, the sidewall comprising fabric having a plurality of yarns in a bias weave pattern; and    a first elastomeric material disposed over the fabric at a predetermined thickness.    
   
   
       2 . The diaphragm of  claim 1 , wherein the bias weave pattern is a herringbone pattern.  
   
   
       3 . The diaphragm of  claim 1 , wherein the bias weave pattern comprises at least a first yarn crossed over a second yarn at an angle.  
   
   
       4 . The diaphragm of  claim 3 , wherein the angle is less than about 60°.  
   
   
       5 . The diaphragm of  claim 1 , wherein the fabric comprises at least a first pair of yarns crossed over a second pair of yarns at an angle.  
   
   
       6 . The diaphragm of  claim 1 , wherein the fabric has a yarn count of at least 50 yarns per square inch.  
   
   
       7 . The diaphragm of  claim 1 , wherein the fabric is rolled, and the tubular sidewall includes an inner sidewall and an outer sidewall.  
   
   
       8 . The diaphragm of  claim 1 , wherein the bias weave pattern comprises a first yarn crossed over a first pair of yarns and crossed under a second pair of yarns adjacent the first pair of yarns.  
   
   
       9 . The diaphragm of  claim 1 , wherein each yarn of the plurality of yarns comprises a plurality of fibers and the plurality of fibers has a twist angle that is greater than about 45 degrees.  
   
   
       10 . The diaphragm of  claim 1 , wherein the enclosed end is clamped.  
   
   
       11 . The diaphragm of  claim 1 , further comprising a backing plate to which the enclosed end is bonded.  
   
   
       12 . A diaphragm comprising: 
 a tubular sidewall having an open end and an enclosed end, the sidewall comprising fabric including a first yarn crossed over a second yarn at an angle that is less than about 60° and forming a bias weave pattern, each yarn comprising a plurality of fibers having a twist angle that is greater than about 45 degrees; and    a first elastomeric material disposed over the fabric at a predetermined thickness.    
   
   
       13 . The diaphragm of  claim 12 , wherein the fabric comprises at least a first pair of yarns crossed over a second pair of yarns at the angle.  
   
   
       14 . The diaphragm of  claim 12 , wherein the fabric has a yarn count of at least 50 yarns per square inch.  
   
   
       15 . A method for forming a diaphragm for use in a pneumatic actuator, the method comprising the steps of: 
 forming a fabric tube having a tube diameter and a uniform bias angle around its circumference;    using a preform-shaping tool having a top component and a bottom component, where an inner surface of the top component includes a preform shaped integrally formed therein, and disposing the fabric tube between the top and bottom components;    shaping the fabric tube to reduces a diameter of the fabric tube and decrease each of the bias angles to form a fabric preform having a top-hat shape; and    impregnating the fabric preform with an elastomer.    
   
   
       16 . The method of  claim 15 , wherein the step of forming includes the step of braiding threads to form the fabric tube.  
   
   
       17 . The method of  claim 16 , wherein the step of braiding includes varying the tube diameter and bias angle of the tube.  
   
   
       18 . The method of  claim 15 , wherein the step of forming includes cutting a fabric on a bias and stitching together opposite ends of the fabric to form the fabric tube.  
   
   
       19 . The method of  claim 15 , wherein the step of braiding includes varying the fabric tube diameter and bias angle.  
   
   
       20 . The method of  claim 15 , wherein the step of forming the tube includes stitching together opposite ends of a strip of fabric cut on the bias.