Patent ID: 6340209
Filing Date: 2002-01-22
Classification: B60R

Abstract:
A vehicle body acceleration sensor for use with a seat belt comprising:a sensor case which is movably supported by a retractor base attached to a backrest of a vehicle reclining seat; a sensor arm which is pivotally supported by one of the sensor case and the retractor base in such a way as to shift between a first position where lock means is activated so as to prevent rotation of a take-up shaft, around which a webbing is wound, in a direction in which the webbing is drawn-out and a second position where the lock means is deactivated; an inertial body which moves in relation to an inertial body support surface of the sensor case upon receipt of a velocity change greater than a predetermined magnitude to thereby move the sensor arm to the first position; and transmission means for pivoting the sensor case in synchronization with reclining action of the backrest in such a way as to retain the inertial body support surface in an appropriate orientation regardless of reclining angle of the backrest, wherein the lock means is activated by means of movement of the inertial body when an acceleration of predetermined magnitude acts on the vehicle body; wherein the transmission means comprises a transmission member which can be wrapped around a take-up member provided concentrically and in line with the seat reclining pivot of the backrest, and the sensor case is pivoted in agreement with the amount of the transmission member which is wrapped around the take-up member in association with the reclining action of the backrest; wherein when the backrest is reclined forwardly beyond an area which enables an occupant to use the seat, the transmission member is prevented from being wrapped around the take-up member.