Recessed glass header for pyrotechnic initiators

Abstract

Disclosed is a pyrotechnic initiator header having a recessed glass insulator. The recessed nature of the glass insulator enhances secure and effective disposition of an ignition pyrotechnic charge droplet to the header in the area of the bridgewire, and also reduces or eliminates the need for machining the header.

We claim:  
     
         1 . A header for use in a pyrotechnic initiator, comprising: 
 a) an electrically conductive eyelet having an upper eyelet surface, and having an eyelet bore defining an inner eyelet surface;    b) a glass insulator having an outer glass surface and an upper glass surface, and having an insulator bore defining an inner glass surface, wherein said outer glass surface is sealed to said inner eyelet surface, and said upper glass surface is disposed below said upper surface of said eyelet; and,    c) an electrically conductive center pin having an upper end, said center pin being disposed within said insulator bore and sealed to said inner glass surface, with said upper end of said center pin being disposed coplanar with said upper eyelet surface.    
     
     
         2 . The header of  claim 1 , wherein said upper eyelet surface is flat.  
     
     
         3 . The header of  claim 1 , wherein said upper end of said center pin is flat.  
     
     
         4 . The header of  claim 1 , wherein said upper eyelet surface is flat, and said upper end of said center pin is flat.  
     
     
         5 . The header of  claim 1 , wherein said upper glass surface is flat.  
     
     
         6 . The header of  claim 4 , wherein said upper glass surface is flat.  
     
     
         7 . The header of  claim 1 , wherein said upper glass surface includes a meniscus.  
     
     
         8 . The header of  claim 4 , wherein said upper glass surface includes a meniscus.  
     
     
         9 . The header of  claim 1 , wherein said center pin includes a circumferential notch above said upper glass surface and below said upper end of said center pin.  
     
     
         10 . The header of  claim 4 , wherein said center pin includes a circumferential notch above said upper glass surface and below said upper end of said center pin.  
     
     
         11 . The header of  claim 1 , further including an ignition pyrotechnic charge droplet disposed on said upper eyelet surface and on said upper end of said center pin, and extending down to said upper glass surface.  
     
     
         12 . The header of  claim 4 , further including an ignition pyrotechnic charge droplet disposed on said upper eyelet surface and on said upper end of said center pin, and extending down to said upper glass surface.  
     
     
         13 . The header of  claim 1 , further including a bridgewire attached between said upper eyelet surface and said upper end of said center pin.  
     
     
         14 . The header of  claim 4 , further including a bridgewire attached between said upper eyelet surface and said upper end of said center pin.  
     
     
         15 . The header of  claim 1 , further including an electrically conductive ground pin attached to said eyelet.  
     
     
         16 . The header of  claim 4 , further including an electrically conductive ground pin attached to said eyelet .  
     
     
         17 . The header of  claim 12 , wherein said header is formed to be attached to a can loaded with an output pyrotechnic charge.  
     
     
         18 . The header of  claim 17 , wherein said header is further formed to be incorporated into an initiator assembly for use in an automotive airbag inflator.  
     
     
         19 . The header of  claim 1 , further including: 
 a) an ignition pyrotechnic charge droplet disposed on said upper eyelet surface and on said upper end of said center pin, and extending down to said upper glass surface; and,    b) a bridgewire secured between said upper eyelet surface and said upper end of said center pin;    wherein said center pin includes a circumferential notch above said upper glass surface and below said upper end of said center pin.    
     
     
         20 . The header of  claim 4 , further including: 
 c) an ignition pyrotechnic charge droplet disposed on said upper eyelet surface and on said upper end of said center pin, and extending down to said upper glass surface; and,    d) a bridgewire secured between said upper eyelet surface and said upper end of said center pin;    wherein said center pin includes a circumferential notch above said upper glass surface and below said upper end of said center pin.