Trw Limited

Darin P Mika

Eric R McFarland

An inflator ( ) for inflating an inflatable device includes a housing ( ). A primary propellant ( ) in a primary chamber ( ) in the housing ( ) is ignitable to provide inflation fluid to inflate the inflatable device. A secondary propellant ( ) in a secondary chamber ( ) in the housing ( ) is ignitable to provide inflation fluid to inflate the inflatable device. The inflator (10) includes initiator means ( ) for selectively igniting either the primary propellant ( ) alone or both of the primary and secondary propellants ( ). The inflator ( ) also includes a secondary propellant cap ( ) for closing the secondary chamber ( ) and for maintaining the secondary propellant ( ) in the secondary chamber. The secondary propellant cap ( ) has a first position blocking flow of combustion products of the first propellant ( ) into the secondary chamber ( ) when only the primary propellant is ignited. The secondary propellant cap ( ) is movable by combustion products of the secondary propellant ( ) when ignited from the first position to a second position enabling flow of inflation fluid out of the secondary chamber ( ) to inflate the inflatable device.

Dual stage air bag inflator with secondary propellant cap

An inflator ( ) includes a housing ( ). A first inflation fluid source ( ) in the housing ( ) is actuatable to effect flow of inflation fluid to inflate an inflatable device. A first actuatable initiator ( ) in the housing ( ), when energized, effects actuation of the first inflation fluid source ( ). A second inflation fluid source ( ) in the housing ( ) is actuatable to effect flow of inflation fluid to inflate the inflatable device. A second actuatable initiator ( ) in the housing ( ), when energized, effects actuation of the second inflation fluid source ( ). The housing ( ) has a fluid passage ( ) for directing flow of inflation fluid out of the housing ( ) to the inflatable device. The housing ( ) deforms due to the pressure of inflation fluid in the housing upon actuation of one or both of the inflation fluid sources ( ). The flow area of the fluid passage ( ) increases due to deformation of the housing ( ) and varies in accordance with the pressure of inflation fluid in the housing.

Dual stage air bag inflator

An inflator (,) for providing inflation fluid for inflating an inflatable vehicle occupant protection device includes an inflator housing (,) and an inflation fluid source (,) in the inflator housing actuatable to provide inflation fluid to inflate the inflatable device. The inflator (,) also includes an ignitable material (,) in the inflator housing (,) for, when ignited, actuating the inflation fluid source (,), and an actuatable initiator (,) in the inflator housing for igniting the ignitable material. The inflator (,) includes a first cap (,) over the ignitable material (,) in the inflator housing (,) for containing the ignitable material adjacent the actuatable initiator (,). The first cap (,) is movable away from the initiator (,) upon ignition of the ignitable material (,). The inflator (,) includes a second cap (,) in the inflator housing (,), for limiting movement of the first cap (,) away from the initiator (,) upon ignition of the ignitable material. The inflator housing (,) deforms due to the pressure of inflation fluid in the inflator housing upon actuation of the inflation fluid source (,) to provide a fluid passage (,) for directing inflation fluid out of the inflator housing to the inflatable device. The flow area of the fluid passage (,) varies in accordance with the pressure of inflation fluid in the inflator housing (,).

Air bag inflator

An inflator (10) for inflating an inflatable vehicle occupant protection device includes a housing (20) defining a generally ring-shaped propellant chamber (200) extending around an axis (50) of the inflator. The housing (20) has a fluid outlet (52) for directing flow of inflation fluid out of the housing to the inflatable device. A quantity of ignitable propellant (240) is located in the propellant chamber for, when ignited, producing inflation fluid for inflating the inflatable device. The housing (20) has a fluid passage (90) between the propellant chamber (200) and the fluid outlet (52). The fluid passage (90), which is normally closed, opens upon actuation of the inflator (10) to enable fluid flow from the propellant chamber (200) to the fluid outlet (52). The fluid passage (90), when open, has a variable flow area depending upon the pressure in the housing (20). A heat sink (270) is located in the propellant chamber (200) between the ignitable propellant (240) and the fluid passage (90) for cooling and filtering inflation fluid flowing from the propellant chamber through the fluid passage. The inflator (10) includes a retainer (280) in the propellant chamber (200) between the ignitable propellant (240) and the fluid passage (90) for retaining the heat sink (270) in the propellant chamber upon actuation of the inflator.

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Mesa, AZ, United States of America

Darin P Mika