Initiator with a bridgewire in contact with slurry-loaded pyrotechnic charge at a position of relatively low void formation

Abstract

A pyrotechnic initiator with a bridgewire in contact with a slurry-loaded pyrotechnic charge at a position of relatively low void formation, at an edge of the charge.

What is claimed is:  
     
         1 . An initiator comprising: 
 a) a header assembly including a top, an eyelet, a glass insulator, and a first pin;    b) an exposed electrical initiating element at said top of said header assembly;    c) a first ignition charge adjacent to said top surface of said header assembly, said ignition charge being adjacent to and in heat-transferring relationship with said electrical initiating element; and,    d) said first ignition charge being a dried slurry, said first ignition charge being in contact with said electrical initiating element at an edge of said first ignition charge.    
     
     
         2 . The initiator of  claim 1 , wherein said electrical initiating element is a bridgewire.  
     
     
         3 . The initiator of  claim 2 , wherein said first ignition charge is above said bridgewire.  
     
     
         4 . The initiator of  claim 3 , wherein said glass insulator has a convex annular top surface.  
     
     
         5 . The initiator of  claim 1 , wherein said glass insulator has a flat top surface that is substantially flush with said top surface of said header assembly.  
     
     
         6 . The initiator of  claim 3 , wherein said bridgewire is in intimate contact with said glass insulator.  
     
     
         7 . The initiator of  claim 6 , wherein said bridgewire is a flattened bridgewire.  
     
     
         8 . The initiator of  claim 2 , wherein said first ignition charge is further in contact with said electrical initiating element at a position of said first ignition charge that has a height no greater than fifty times the diameter of said bridgewire.  
     
     
         9 . The initiator of  claim 2 , wherein said first ignition charge is below said bridgewire.  
     
     
         10 . The initiator of  claim 9 , further comprising a second ignition charge that is adjacent to and in heat-transferring relationship with said electrical initiating element, said second ignition charge being a dried slurry, said second ignition charge being in contact with said electrical initiating element at a bottom edge of said second ignition charge.  
     
     
         11 . The initiator of  claim 10 , wherein said first ignition charge is further in contact with said electrical initiating element at a position of said first ignition charge that has a height no greater than fifty times the diameter of said bridgewire, and said second ignition charge is further in contact with said electrical initiating element at a position of said second ignition charge that has a height no greater than fifty times the diameter of said bridgewire.  
     
     
         12 . The initiator of  claim 3 , wherein said first ignition charge is not pressed against said top of said header assembly by a pressure of more than 50 psi.  
     
     
         13 . The initiator of  claim 12 , further comprising an output charge on top of said first ignition charge.  
     
     
         14 . The initiator of  claim 13 , further comprising an intermediary slip plane between said first ignition charge and said output charge.  
     
     
         15 . A method of making an initiator, comprising the following steps: 
 a) providing a header assembly including a top, an eyelet, a glass insulator, and a first pin;    b) providing an exposed electrical initiating element at said top of said header assembly;    c) loading a first ignition charge in the form of a slurry, adjacent to said top surface of said header assembly and in heat-transferring relationship with said electrical initiating element; and,    d) drying said first ignition charge so that said first ignition charge remains in heat-transferring relationship with said electrical initiating element at an edge of said first ignition charge.    
     
     
         16 . The method of  claim 15 , further comprising the step of rendering the portion of said first ignition charge adjacent to said electrical initiating element the thinnest portion of said first ignition charge.  
     
     
         17 . The method of  claim 16 , wherein said step of rendering comprises axially spinning said header assembly while it is being loaded with said first ignition charge.  
     
     
         18 . The method of  claim 15 , further comprising the step of centrifuging said header assembly while it is being loaded with said first ignition charge.  
     
     
         19 . The method of  claim 15 , wherein step c) comprises loading said first ignition charge into a recess in said top of said header, the method further comprising the steps of loading a second ignition charge onto said top of said header assembly, and drying said second ignition charge.  
     
     
         20 . The method of  claim 19 , further comprising the step of selecting slurry compositions for said first and second ignition charges that result in minimal void creation in said edges of said first and second ignition charges upon said steps of drying.