Patent ID: 7300013

Claim:
A seat belt retractor comprising: a seat belt retractor; an actuator for unlocking and locking the seat belt retractor; a sensor housing; an inertial sensor disposed in and movable relative to the sensor housing for detecting changes in vehicle acceleration, the inertial sensor interacting with the actuator to lock and unlock the seat belt retractor; and the inertial sensor having a wide portion and a narrow portion, the inertial sensor comprising an inertial sensor mass having a body partially embedded in the wide portion in an elastomeric material, the body of the inertial sensor mass having a greater density than the elastomeric material, a first portion of the inertial sensor mass comprises a portion of an exterior surface of the body that is free of the elastomeric material contacts the actuator at zero acceleration at a first portion, wherein the elastomeric material substantially surrounds an exterior circumferential surface of the wide portion such that the elastomeric material in which the wide portion is embedded contacts the sensor housing when the inertial sensor tips in response to changes in vehicle acceleration.