Abstract: A seat belt clamp comprises a clamp member which clamps the belt against a frame base when an abnormally high pull-out force is exerted on the belt. The clamp member is forced toward the belt by the combined effects of the wedging action of a roll around which the belt turns against a wedging surface of the clamp member and oblique guides on the frame which cam the clamp member toward the base and away from the roller. Springs urge both the roller and the clamp member toward released positions for easy, smooth release of the belt when the high pull-out force ceases.