Lock releasing device of a retractor provided with an emergency locking mechanism

Claim 1

A seat belt retractor provided with an emergency locking mechanism, the retractor comprising webbing take-up means including a main gear and an auxiliary gear, inertia sensing means adapted to change position responsive to a vehicle speed change of predetermined value, an auxiliary locking member adapted to cooperate with said auxiliary gear, means mounting said auxiliary locking member for movement axially with respect to the auxiliary gear, the auxiliary locking member having an axial position in which it is aligned with said auxiliary gear, the auxiliary locking member when in said axial position having a first position in which it is non-engageable with said auxiliary gear, the auxiliary locking member being movable from the first position responsive to a change in position of the inertia sensing member to a second position in which it is engageable with the auxiliary gear and being movable by the auxiliary gear from the second position to a third position responsive to rotation of the auxiliary gear in a webbing pay-out direction, a main locking member adapted to cooperate with the main gear, the main locking member normally assuming a non-engaging position with respect to the main gear and being movable to an engaging position with respect to the main gear responsive to movement of the auxiliary locking member from the second position to the third position, for locking the take-up means against movement in the webbing pay-out direction, and release means for unlocking the take-up means, the release means comprising a first cam member for moving the main locking member from the engaging position to the non-engaging position, a second cam member for moving the auxiliary locking member axially away from said axial position and means for operating the first and second cam members in unison.