Seat belt retractor mechanism

Claim 1

A seat belt retractor mechanism having a belt receiving reel means rotatably extending between spaced sidewalls of a support bracket, the reel means including a shaft having a ratchet plate at each of its ends in proximity to an inner side of a sidewall, the ratchet plates having peripheral ratchet teeth, a locking bar paralleling the reel means shaft pivotally mounted in the sidewalls for movement into engagement with the ratchet plates to lock the reel against rotation in seat belt protraction direction, and an inertia sensor coupled to the locking bar for driving the latter into ratchet plate engagement upon acceleration of the sensor, the inertia sensor comprising a pendulum suspended from a support plate mounted on the outer side of one of the sidewalls, wherein the improvement comprises: the reel shaft having an extension projecting through the sidewall supporting the pendulum, an annular ratchet plate keyed to the shaft extension, the annular ratchet plate having internal ratchet teeth, a lever pivotally suspended from the shaft extension with its free end in abutting relation to the locking bar, a pawl pivotally mounted on the pivotally suspended lever for swinging movement into and out of engagement with the annular ratchet, and a bell crank means mounted on the outer side of the one sidewall coupled to the pawl and responsive to acceleration displacement of the pendulum for pivoting the pawl into engagement with the annulus ratchet, rotation of the reel caused by protraction forces exerted on the belt immediately following pendulum displacement causing the annular ratchet to bodily shift the engaged pawl in a direction to pivot the locking bar into locking engagement with the reel ratchet plates to prevent further belt protraction movement.