Seat belt retractor

A seat belt retractor, comprising

• a belt shaft rotatably supported in a frame for winding up a seat belt, and
• a blocking device for blocking the belt shaft in a winding off direction, and
• a control disk rotatably supported on the belt shaft, spring-loaded in a of winding up direction and with a cogging, and
• a sensor device with a deflectable inertia mass and a blocking lever which can be deflected by deflecting the inertia mass, which blocks the control disk upon an exceeding of a predetermined vehicle delay by deflecting the inertia mass and with an engagement of the blocking lever brought about as a result into the cogging of the control disk opposite the belt shaft in a direction of withdrawing the belt and as a consequence controls the blocking device, and
• a counter gear unit driven by a rotary movement of the belt shaft, and
• a first switching device which is activated by the counter gear unit and which blocks the control disk after a first predetermined belt webbing withdrawal length in the direction of the belt withdrawal and frees the control disc again after a second predetermined belt webbing intake length, and
• a second switching device which is activated by the counter gear unit and which fixes the blocking lever after a predetermined belt webbing intake length in a non-engagement position into the cogging of the control disk,
• the first switching device as well as the second switching device are activated during the belt webbing intake movement in the second predetermined belt webbing intake length.