Self-locking fastener assembly and method of making same

Abstract

A fastener assembly includes a threaded fastener having a head and an at least partially threaded shaft extending from the head, an annular washer encircling the shaft adjacent to the head and a gel patch adhered to the shaft next to the washer, the gel patch extending from the shaft far enough to overlap the washer. A method of making the assembly is also described.

1 . A fastener assembly comprising 
 a threaded fastener having a head and an at least partially threaded shaft extending from the head;    an annular washer encircling the shaft adjacent to said head, said washer having a side facing away from the head, and    a gel patch adhered to the shaft adjacent to said side of the washer, said gel patch extending from the shaft far enough to overlap the washer.    
   
   
       2 . The assembly defined in  claim 1  wherein 
 the fastener is a bolt, and    said shaft has a threaded end segment.    
   
   
       3 . The assembly defined in  claim 2  and further including a nut turned down on said threaded end segment of the shaft.  
   
   
       4 . The assembly defined in  claim 1  or  2  wherein the washer is a lock-type washer.  
   
   
       5 . The assembly defined in  claim 1  or  2  wherein the washer is a spring-type washer.  
   
   
       6 . The assembly defined in  claim 1  and further including adhesive microcapsules coating the shaft threads.  
   
   
       7 . The assembly defined in  claim 6  wherein the microcapsules are color-coded to indicate the size of said fastener.  
   
   
       8 . A method of making a self-locking fastener assembly comprising the steps of 
 advancing fasteners each having a head and a threaded shaft extending therefrom in succession to a first assembly station;    advancing washers each having a hole therein, in succession, to said first station under said fasteners;    at said first station, aligning successive fasteners and washers so that each fastener can be deposited in the hole of an underlying washer;    advancing successive fastener/washer subassemblies from said first station to a second station and at said second station applying dabs of liquid plastic to the sides of the shafts of successive subassemblies under the washers thereof;    advancing the dabbed subassemblies, in turn, to a third station where each successive subassembly is subjected to electromagnetic energy which solidifies the liquid plastic dab thereon to form a raised resilient patch which overlaps and retains the washer on the fastener of each successive subassembly to form a self-locking fastening assembly, and    transporting the successive self-locking fastener assemblies from the third station to a collection location.    
   
   
       9 . The assembly defined in  claim 8  including the additional step of selecting the succession of washers from the group consisting of plain washer, lock-type washer and spring-type washer.  
   
   
       10 . The method defined in  claim 8  including the additional step of coating the shaft threads with adhesive microcapsules.  
   
   
       11 . The assembly defined in  claim 10  including the additional step of color-coding said microcapsules on each shaft to indicate the size of the associated fastener.