Wrapped shift washer

Abstract

A shift washer which is used in a blind fastening system. The shift washer is made using a process of wrapping a piece of wire stock around a mandrel. This process provides significant cost advantages compared to the process of machining the shift washer. A flange can be provided on the shift washer to prevent the shift washers from nesting with one another and results in easier assembly of the blind fasteners.

The invention claimed is:  
     
         1 . A shift washer for use with a fastening system, said shift washer comprising: 
 a first portion having opposite first and second ends;    a second portion having opposite first and second ends, said second portion being attached to and extending from said second end of said first portion, said second portion being at least partially offset from said first portion; and    a frangible portion between said first portion and said second portion;    wherein said shift washer is formed by wrapping a material around a mandrel.    
     
     
         2 . A shift washer as defined in  claim 1 , further including a flange attached to and extending outwardly from said second end of said second portion.  
     
     
         3 . A shift washer as defined in  claim 1 , wherein the inner diameter of said first portion is larger than the outer diameter of said second portion.  
     
     
         4 . A shift washer as defined in  claim 2 , wherein the outer diameter of said flange is larger than the inner diameter of said first portion.  
     
     
         5 . A shift washer as defined in  claim 1 , wherein said material is wire.  
     
     
         6 . A shift washer as defined in  claim 1 , wherein said shift washer further includes a slot.  
     
     
         7 . A shift washer as defined in  claim 6 , wherein the angle of said slot is sixty degrees or less.  
     
     
         8 . A shift washer as defined in  claim 1 , wherein the diameter of said first portion is smaller at its first end than at its second end.  
     
     
         9 . A shift washer as defined in  claim 2 , wherein said flange is tapered and the angle between said flange and said second portion is larger than 90 degrees.  
     
     
         10 . A method of forming a shift washer comprising the steps of: 
 forming a piece of wire to form a first portion, a second portion offset from said first portion and a frangible portion between said first portion and said second portion;    cutting said wire to a predetermined length to form two free ends;    providing a mandrel;    wrapping said wire around said mandrel.    
     
     
         11 . A method of wrapping a shift washer as defined in  claim 10 , further including the step of forming said wire to include a flange.  
     
     
         12 . A method of wrapping a shift washer as defined in  claim 10 , further comprising the step of placing said mandrel and said wire within a groove of a brace.  
     
     
         13 . A method of wrapping a shift washer as defined in  claim 10 , further including the step of: 
 forcing said free ends against said mandrel such that said free ends are spaced apart from each other at a predetermined distance.