Header with overlying eyelet

Abstract

Disclosed is a pyrotechnic initiator header having an eyelet overlying a recessed primary glass insulator. The recessed region can be filled with a secondary glass insulator and/or a pyrotechnic ignition charge.

We claim:  
     
         1 . A header for use in a pyrotechnic initiator, comprising: 
 a) an electrically conductive eyelet having an upper eyelet surface and an eyelet bore defining an inner eyelet surface;    b) a primary 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;    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; and,    d) a bridgewire attached between said upper eyelet surface and said upper end of said center pin.    
     
     
         2 . The header of  claim 1 , wherein said upper glass surface is flat.  
     
     
         3 . The header of  claim 1 , wherein said upper glass surface includes a meniscus.  
     
     
         4 . The header of  claim 1 , further including an ignition charge droplet that includes a portion that is disposed between said center pin and said inner eyelet surface and extends below the plane of said upper eyelet surface.  
     
     
         5 . The header of  claim 4 , wherein said droplet further includes a portion that extends above the plane of said upper eyelet surface.  
     
     
         6 . The header of  claim 4 , wherein said ignition charge droplet extends down to said upper glass surface.  
     
     
         7 . The header of  claim 6 , wherein said center pin includes a circumferential notch above said upper glass surface and below said upper end of said center pin.  
     
     
         8 . The header of  claim 1 , further comprising a secondary glass insulator disposed between said center pin and inner eyelet surface, said secondary glass insulator having an upper surface that does not protrude above the plane of said upper eyelet surface.  
     
     
         9 . The header of  claim 8 , wherein said primary glass insulator and said secondary glass insulator are made from pressed parts.  
     
     
         10 . The header of  claim 8 , wherein said upper surface of said secondary glass insulator is substantially flat.  
     
     
         11 . The header of  claim 8 , wherein said upper surface of said secondary glass insulator includes a meniscus.  
     
     
         12 . The header of  claim 11 , further including an ignition charge droplet that includes a portion that is disposed between said center pin and said inner eyelet surface and extends below the plane of said upper eyelet surface.  
     
     
         13 . The header of  claim 1 , further including an electrically conductive ground pin that is welded, soldered, or press-fit onto said eyelet.  
     
     
         14 . The header of  claim 1 , wherein said eyelet is cold-formed.  
     
     
         15 . The header of  claim 1 , wherein said eyelet is formed by stamping.  
     
     
         16 . The header of  claim 1 , wherein said eyelet includes at least one punched hole.  
     
     
         17 . The header of  claim 15 , wherein said eyelet primarily consists of 1010 carbon steel.  
     
     
         18 . The header of  claim 1 , wherein said eyelet, primary glass insulator, and center pin are selected of materials to result in a compression seal when subjected to a suitable glass sealing process.  
     
     
         19 . The header of  claim 1 , wherein said header is formed to be attached to a can loaded with an output pyrotechnic charge.  
     
     
         20 . The header of  claim 19 , wherein said header is further formed to be incorporated into an initiator assembly for use in an automotive airbag inflator.