Abstract: The switch assembly comprises a single inertial sensing mass which is magnetically biased to an initial position along a path of travel within an enclosure. In this position, the mass holds a normally closed arming switch open. A normally open discriminating switch is disposed in the path of travel of the mass to be closed by the mass upon the occurrence of a velocity change indicating that a passive occupant restraint device such as an air bag should be deployed. Travel of the mass from the initial position releases the arming switch before the discriminating switch closes.

Abstract: An inertia switch assembly comprises an inertia switch assembly element encapsulated by potting material within a housing. The inertia switch assembly element comprises a non-magnetic enclosure containing an inertial mass and switch contacts. The switch contacts are connected by conductors that become terminals parallel with and spaced radially of the enclosure as they pass through an aperture in the housing. This aperture is closed by a closure on the terminals. Potting material is kept from intruding into the enclosure by a sealed closure which closes an open end of the enclosure and through which the conductors pass. The housing has an integral shroud surrounding the terminals to thereby form a connector plug structure for connetion with a mating connector plug structure leading to a circuit controlled by the switch assembly. The housing also has a triangular-shaped base containing apertures at each apex to provide for attachment of the housing to a wall.