Linear locking seat belt retractor

Mechanism for retracting a vehicle seat belt and locking the belt against extension includes a track mounted on the vehicle body and a belt carriage mounted on the track for movement in the belt extending and retracting directions. A return spring biases the carriage in the belt retracting direction. The belt carriage has a locking knife edge engageable with a knife edge on the track to lock the belt carriage against belt extending movement when the carriage is pivoted bodily relative the track. A spring mounted on the carriage slidably bears upon the track to urge the carriage to a normal position wherein the locking edge is spaced from engagement with the track. The seat belt is attached to the carriage by a yoke which bodily pivots the carriage to engage the locking edge with the track upon attempted rapid extension of the belt.