Vehicle seat belt retractor

Claim 1

A vehicle seat belt retractor having a frame, a belt reel rotatably mounted on the frame, an emergency locking mechanism for locking the belt reel to the frame against rotation in the belt-unwinding direction in response to rapid acceleration of the vehicle and including a reel-locking pawl pivotably mounted on the frame for engagement with a ratchet wheel affixed to the belt reel and an actuator plate coupled to the reel-locking pawl and movable in response to rotation of the belt reel in the belt-unwinding direction upon operation of the emergency locking mechanism to cause the reel-locking pawl to engage the ratchet wheel, and a belt-clamping mechanism including a fixed clamping member mounted on the frame and a movable clamping member carried on a lever arm mounted on the frame for pivotal movement between an inactive position in which the clamping members are spaced apart such that the belt can pass freely between them and a clamping position in which the movable clamping member clamps the belt against the fixed clamping member and prevents it from moving, and a link pivotably coupled to the lever arm and controlling the movements of the lever arm between the inactive and clamping positions, characterized in that the link is pivotably attached to the frame such as to form with the lever arm a compound lever, in that the link includes a projection selectively engageable with the ratchet wheel, and in that the link is resiliently biassed to engage a cam follower portion thereof with a cam surface of the reel-locking pawl such that the link is pivoted in response to movement of the reel-locking pawl into engagement with the ratchet wheel by camming action of the cam surface and cam follower portion to engage the projection of the link with the ratchet wheel, whereby the rotation of the ratchet wheel in the belt-unwinding direction causes the link to pivot about its pivot mounting on the frame and to move the lever arm and movable clamping member to the clamping position.