Method and apparatus for an improved initiator and retainer

Abstract

An initiator is provided for use with an initiator holder. The initiator comprises a can; at least two electrodes; an explosive charge positioned to be ignited when electrical charge is passed through said electrodes; and a body portion surrounding the electrodes. The body portion may have a first portion with a first cross-sectional area and a second portion having a second cross-sectional area, wherein the second cross-sectional area has a shape different from the first cross-sectional area and wherein the second cross-sectional area is less than 40% of the first cross-sectional area; wherein the second portion is shaped to extend outward from an opening in the holder when the body portion is seated in the holder.

1 . An initiator for use with an initiator holder, said initiator comprising: 
 a can;    at least two electrodes;    an explosive charge positioned in the can and configured to be ignited when electrical charge is passed through said electrodes; and    a body portion surrounding at least a portion of said electrodes, said body portion having a first portion with a first cross-sectional area and a second portion having a second cross-sectional area, said first cross-sectional area measured at the interface with the second portion;    said second cross-sectional area having a shape different from said first cross-sectional area and wherein said second cross-sectional area is less than 40% of said first cross-sectional area;    wherein said second portion is shaped to extend outward from an opening in the holder when the body portion is seated in the holder.    
   
   
       2 . The device of  claim 1  wherein the first cross-sectional area has a circular shape.  
   
   
       3 . The device of  claim 1  wherein the second cross-sectional area has a race track shape.  
   
   
       4 . The device of  claim 1  wherein the second cross-sectional area has a shape selected from one of the following: rectangular, race track shape with a cutout, oval, square, triangular, three-legged, rectangular with at least one rounded end, rectangular with a cutout, or combinations of these shapes.  
   
   
       5 . The device of  claim 1  wherein the first body portion is made of a material selected from a list consisting of: polybutylene terephthalate, polybutylene naphthalate, high strength polyamide, nylon 6,12, nylon 10,12, nylon 12,12, nylon 66, thermoplastic aromatic polyamides, Amodel™ polyphthalamide, polyether-amides; polyimides, Aurum™ (MTC America); polyether-imides, polyether-ketones (PEK), polyether-ether-ketones (PEEK), polyether-ketone-ether-ketone-ketones (PEKEKK), and high temperature thermoplastic aromatic polyketone polymers, liquid crystal polymers (LCP), Vectra™ A515.  
   
   
       6 . The device of  claim 1  wherein the second portion is shaped to surround the side portions of at least two of said electrodes.  
   
   
       7 . The device of  claim 1  wherein the second portion is shaped to prevent rotation of the initiator about its longitudinal axis when placed in the holder.  
   
   
       8 . The device of  claim 1  wherein body portion has a section with a conical shape, said section having conical surfaces at a 45 degree angle.  
   
   
       9 . The device of  claim 1  wherein the body portion includes a marker positioned to indicate polarity of the electrodes.  
   
   
       10 . The device of  claim 1  wherein the body portion has a 1.33 mm height.  
   
   
       11 . The device of  claim 1  wherein the body portion has a 6.45 mm diameter.  
   
   
       12 . The device of  claim 1  wherein interface between a surface of the first portion of the initiator and an inner surface of the holder is capable of holding the body portion in a manner sufficient to withstand a backpressure of at least about 200 megapascals pushing the body portion against the inner surface of the holder.  
   
   
       13 . The device of  claim 1  wherein the holder has a shape capable of holding the body portion in a manner sufficient to withstand a backpressure of at least about 220 megapascals pushing the body portion against an inner surface of the holder.  
   
   
       14 . The device of  claim 1  wherein the holder is capable of holding the body portion in a manner sufficient to withstand a backpressure of at least about 250 megapascals pushing the body portion against an inner surface of the holder.  
   
   
       15 . The device of  claim 1  further comprising at least one bridgewire coupling said electrodes together.  
   
   
       16 . The device of  claim 1  wherein the area of the second portion is less than 10% of the area of the first cross-sectional area when measured at the widest point of the first portion.  
   
   
       17 . An initiator for use with a holder, said initiator comprising: 
 a can;    at least two electrically conductive pins;    an explosive charge configured to be ignited when electrical charge is passed through said pins; and    a body having a first portion with a circular cross-section relative to a longitudinal axis of the initiator and a second portion having a rectangular cross-section relative to a longitudinal axis of the initiator.    
   
   
       18 . The device of  claim 17  wherein the rectangular cross-section includes a cutout or notch portion.  
   
   
       19 . The device of  claim 17  wherein the rectangular cross-section includes at least one rounded end portion.  
   
   
       20 . An initiator for use with a holder, said initiator comprising: 
 a can;    a plurality of electrodes;    an explosive charge configured to be ignited when electrical charge is passed through said electrodes; and    means for supporting and positioning said plurality of electrodes, wherein at least a portion of said means extends outward from the holder when the means are seated against the holder.    
   
   
       21 . An initiator holder comprising: 
 a housing with an inner surface and an outer surface, said inner surface having a shape to receive an initiator body having a first portion and a second portion;    an opening on said housing, said opening sized and shaped to receive the second portion of the initiator body, an area of said opening being less than 40% of an cross-sectional area of the first portion of the body, said first cross-sectional area measured at the interface with the second portion.    
   
   
       22 . The device of  claim 21  wherein the inner surface conforms to the shape of the initiatory body.  
   
   
       23 . The device of  claim 21  further comprising: 
 said opening having a race-track shape.    
   
   
       24 . The device of  claim 21  wherein said holder can withstand at least 250 megapascals of pressure when the initiator body is pressed against the holder.  
   
   
       25 . The device of  claim 21  wherein the opening has area of about 9.34 mm 2 .  
   
   
       26 . A micro gas generator including at least one holder of  claim 21 .  
   
   
       27 . An airbag inflator including at least one holder of  claim 21.