Initiator for an air bag inflator
First Claim
1. An electrically actuatable initiator comprising:
- a retainer;
at least one terminal for electrical connection with vehicle circuitry;
means for supporting said terminal in spaced relation to said retainer and for providing electrical insulation between said terminal and said retainer;
a bridgewire associated with said terminal for, when electrically actuated by current from said terminal, generating thermal energy;
an ignition charge ignitable by said thermal energy;
a metal ignition cup enclosing and supporting said ignition charge, said metal ignition cup being spaced apart from said retainer;
means for electrically insulating said metal ignition cup, comprising a plastic insulation cup overlying said metal ignition cup;
an electrically conductive output charge overlying said insulation cup; and
an electrically conductive output cup overlying said output charge, said insulation cup blocking flow of electric current from said output charge or said output cup to said ignition cup.
1 Assignment
0 Petitions
Accused Products
Abstract
An electrically actuatable initiator (10) for an air bag inflator (20) includes an electrically sensitive ignition charge (280) disposed in an electrically conductive ignition cup (290). A plastic insulation cup (320) overlies the ignition cup (290). The insulation cup (320) electrically insulates the ignition cup (290) to block the flow of electric current into the ignition cup to prevent unintended actuation of the ignition charge (280). A locking ring member (380) is made from a shape-memory alloy which shrinks in diameter when heated above a predetermined temperature. The locking ring member (380) secures an output cup (360) to a retainer (150) and hermetically seals between the output cup and the retainer. A second locking ring member (310) secures the ignition cup (290) to a header (150) and seals between the ignition cup and the header.
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Citations
26 Claims
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1. An electrically actuatable initiator comprising:
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a retainer; at least one terminal for electrical connection with vehicle circuitry; means for supporting said terminal in spaced relation to said retainer and for providing electrical insulation between said terminal and said retainer; a bridgewire associated with said terminal for, when electrically actuated by current from said terminal, generating thermal energy; an ignition charge ignitable by said thermal energy; a metal ignition cup enclosing and supporting said ignition charge, said metal ignition cup being spaced apart from said retainer; means for electrically insulating said metal ignition cup, comprising a plastic insulation cup overlying said metal ignition cup; an electrically conductive output charge overlying said insulation cup; and an electrically conductive output cup overlying said output charge, said insulation cup blocking flow of electric current from said output charge or said output cup to said ignition cup. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An electrically actuatable initiator for use in an air bag inflator, said initiator comprising:
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a metal retainer for connecting said initiator with the inflator; a metal header; at least one metal terminal for electrical connection with vehicle circuitry; a glass-to-metal seal supporting said terminal in spaced relation to said header and said retainer and providing electrical insulation between said terminal and said retainer; an ignition charge in electrical contact with said metal header; a metal ignition cup enclosing said ignition charge, said metal ignition cup being in electrical contact with said metal header and with said ignition charge; a plastic insulation cup overlying said metal ignition cup; and a metal output cup containing an output charge overlying said ignition cup, said metal output cup being in electrical contact with said metal retainer and with said output charge; said plastic insulation cup electrically insulating between (a) said ignition cup and (b) said output cup and said output charge. - View Dependent Claims (9, 10, 11)
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12. An apparatus comprising:
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a first electrically conductive metallic member having first surface means for defining a first passage extending through said first member; a second electrically conductive metallic member spaced apart from said first member, said second member having second surface means for defining a second passage extending through said second metallic member, said first and second passages extending generally parallel to an axis of said apparatus; an electrically conductive first metallic electrode bonded to said second member and extending through said first passage in said first member; an electrically conductive second metallic electrode extending through said first passage in said first member and through said second passage in said second member, said first and second electrodes extending generally parallel to said axis, said second passage having a second passage portion encircling said second metallic electrode; a first body of solid electrically insulating ceramic material fused to said first surface means defining said first passage in said first member and spanning said first passage, said first body being fused to said first and second electrodes in said first passage, said first body also being fused to said second member and spanning said second passage portion between said second electrode and said second member; and a second body of solid electrically insulating ferrite material in said second passage portion in said second member, said second body having an opening through which said second electrode passes. - View Dependent Claims (13, 14, 15, 16, 17)
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18. An electrically actuatable initiator comprising:
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a metal support member; a pyrotechnic charge supported by said support member; an electrical conductor extending through said support member; means for igniting said pyrotechnic charge in response to the conduction of electric current through said electrical conductor; a metal cover, said metal cover encircling said pyrotechnic charge, an inner major side surface of said cover being in abutting engagement with said pyrotechnic charge; an output charge spaced from said pyrotechnic charge; a metal output cup, said metal output cup encircling said output charge and said metal cover, an inner major side surface of said output cup being in abutting engagement with said output charge; means for electrically insulating said pyrotechnic charge from electric current not conducted through said electrical conductor; and sealing means for sealing said cover to said support member; said sealing means comprising a locking ring member circumscribing said cover and compressing said cover radially inward onto said support member to seal said cover to said support member. - View Dependent Claims (19, 20, 21, 22)
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23. An electrically actuatable initiator comprising:
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a retainer; a metal support member spaced apart from said retainer; a pyrotechnic charge supported by said support member; an electrical conductor extending through said support member; means for igniting said pyrotechnic charge in response to the conduction of electric current through said electrical conductor; a metal cover encircling said pyrotechnic charge; an output charge spaced from said pyrotechnic charge; a metal output cup encircling said output charge and said metal cover; sealing means for sealing said cover to said support member; sealing means for sealing said output cover to said retainer; and a glass-to-metal seal abutting said retainer, said header, and said terminal, said glass-to-metal seal providing electrical insulation between said retainer and said header and said terminal. - View Dependent Claims (24, 25, 26)
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Specification