Abstract: An electrically actuatable initiator (10) for an air bag inflator (20) includes an ignition charge (190) which is ignitable by thermal energy from a resistive element (130). The resistive element (130) is formed on a substrate (110) as part of a chip (100). The chip (100) is secured to a header (40) by a portion (156, 158, 160, 162) of a glass to metal seal (150). The resistive element is electrically connected to terminals (60, 90) of the initiator (10) by brazing with braze preforms (170, 180). The brazed electrical connections are made during the same heating operation in which a glass preform is melted to form the mechanical connection provided by the glass to metal seal (150).

Abstract: An air bag inflator (10) includes an igniter (142) for actuating the inflator in response to receiving an electrical signal. The igniter (142) has a pair of electrical terminals (144, 146) for electrical contact with an electrical connector (152) to receive the electrical signal from the electrical connector. A retainer (150) supports the igniter (142) adjacent the inflator (10). A shorting clip (200) establishes a short circuit between the terminals (144, 146) of the igniter (142) when the electrical connector (152) is not in electrical contact with the terminals. A crimp portion (180) of the retainer (150) engages the shorting clip (200) to block movement of the shorting clip relative to the retainer. The shorting clip (200) includes means (240, 242) for maintaining the electrical connector (152) in electrical contact with the electrical terminals (144, 146).

Abstract: Inflation fluid (18) for an inflatable vehicle occupant protection device, such as an air bag (12), is contained in a pressure vessel (30) at an elevated storage pressure. The pressure vessel (30) further contains ignitable material (18) which, when ignited, heats the inflation fluid (18). An ohmic heating element (92) is maintained in an ignitable heat transferring relationship with the ignitable material (18) under the influence of the storage pressure. When the vehicle experiences a predetermined collision-indicating condition, an actuating level of electric current is directed through the heating element (92) to ignite the ignitable material (18). The storage pressure is monitored by monitoring an electrical characteristic, such as the resistance, of the heating element (92) which has a predetermined relationship to the storage pressure.

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.

Abstract: An air bag inflator (14) includes a pressure vessel (40), an initiator (42) and a filter (38). The pressure vessel (40) has a sealed chamber (44) containing inflation fluid under pressure, and includes a rupturable closure wall (100) which blocks the inflation fluid from exiting the chamber (44). The initiator (42) releases the inflation fluid to exit the chamber, and includes a casing (122) centered on an axis. The casing (122) contains pyrotechnic material which, when ignited, produces combustion products for rupturing the closure wall (100). The filter (38) is a sintered metal screen which filters the inflation fluid. The sintered metal screen (38) has an elongated tubular shape extending longitudinally over the casing (122) radially outward from the casing (122).