Seat belt retractor

Abstract

A seat belt retractor is provided in which a torsion bar of an energy absorption mechanism and a ratchet wheel of an emergency locking mechanism can be easily combined in a constant angular phase without requiring any special precise working, which always stably operates without causing any problem such as that the emergency locking mechanism is out of synchronization, and in which an energy can be effectively absorbed without accompanying any time delay. As means for attaining the object, a coupling portion of a torsion bar with respect to a ratchet wheel , and an insertion hole of the ratchet wheel into which the coupling portion is to be fitted and squeezed are made to have a polygonal section shape in which concaves and convexes are formed at a predetermined interval in a circumference direction, and a rib-like projection for biasing the torsion bar in the insertion hole in the rotating direction in drawing out of the webbing to cause respective concaves and convexes to come mutually in press contact with each other in the direction is formed on an inner face of the insertion hole . Thus, the torsion bar and the ratchet wheel are always combined in a constant angular phase, and any time delay cannot be caused in twist deformation of the torsion bar