Abstract: A seat belt retractor for a vehicle safety restraint has a spool rotatably mounted in a frame. A ratchet wheel is rotatably mounted to rotate with the spool. A control member is mounted in the frame. A locking pawl is pivotally mounted in the frame to pivot into engagement with the ratchet wheel. A sensor is responsive to the spool. Upon activation of the sensor, a cam surface and a cam follower couple the locking pawl to the control member. The cam surface has a discontinuity arranged so that the cam follower loses contact with the cam at high speeds but stays in contact with the cam surface at low speeds. Preferably, the discontinuity is a raised portion providing a first ramp in one direction in one portion on one side of the discontinuity of the cam surface and a second ramp in a different direction in a second portion of the cam surface on the other side of the discontinuity.