Initiator for air bag inflator

Abstract

An apparatus (,) for inflating an inflatable vehicle occupant protection device (,) comprises a container (,) defining a chamber (,). The container (,) has a portion (,) which is rupturable to form an opening in the container. A quantity of inflation fluid (,) is stored under pressure in the chamber (,). An electrically actuatable initiator (,) is connected with the container (,) for rupturing the rupturable portion (,) of the container to enable flow of inflation fluid (,) out of the inflator (,). The initiator (,) comprises an ignitable primary charge (,) and electrically energizable means (,) for igniting the primary charge. The initiator (,) further comprises a secondary charge (,) ignitable by the primary charge (,). The secondary charge (,) comprises an ignitable metal in solid form which liquefies when ignited by the primary charge (,). The primary charge (,) when ignited generates combustion products under pressure which ignite the secondary charge (,) and direct the liquefied metal into engagement with the rupturable portion (,) of the container (,) to help open the rupturable portion of the container. In a preferred embodiment, the secondary charge (,) is thermite.