Patent ID: 7883044

Claim:
A seat belt retractor comprising: a spool for retracting a seat belt, wherein the spool has one side in an axial direction of the spool and another side in the axial direction of the spool; a torsion bar disposed inside the spool, wherein the torsion bar has one side in an axial direction of the torsion bar and another side in the axial direction of the torsion bar, wherein the one side of the torsion bar is connected to the one side of the spool, and configured to be capable of absorbing energy of movement of an occupant while being deformed under torsion by a relative displacement of the one side of the torsion bar and the another side of the torsion bar; a pre-tensioner positioned at the another side of the spool and configured to generate a rotating drive force for rotating the spool in a retracting direction of the seat belt in a condition of rapid deceleration of a motor vehicle; a locking device capable of locking the another side of the torsion bar such that a rotation of the spool in a withdrawal direction of the seat belt is suppressed at both an operating time of the pre-tensioner when the pre-tensioner is activated and a non-operating time of the pre-tensioner when the pre-tensioner is not activated; and a locking member disposed at the another side of the spool and connected to the another side of the torsion bar, wherein the locking device comprises a locking gear disposed at the one side of the spool, a joint pin, and a pawl rotatably provided in the locking member, and wherein the locking device is configured to lock the another side of the torsion bar by locking the locking member on a frame with the pawl at the non-operating time of the pre-tensioner by rotating the pawl in a locking direction using the locking gear via the joint pin.