Automatic locking retractor with lock-up delay

Abstract

A seat belt retractor has a belt reel rotatably mounted on a frame and a spring biasing the reel in the belt winding direction of rotation. A pawl is spring biased toward engagement with the reel to lock the reel against belt unwinding rotation. An automatic locking mechanism includes a control disc which is frictionally clutched to the reel for limited rotation therewith and has an abutment moving to a pawl blocking position upon belt unwinding reel rotation. A subsequent belt winding reel rotates the control disc abutment to an unblocking position permitting movement of the pawl toward engagement with the reel. A toggle linkage has a normal extended position which maintains the pawl in a disabled position irrespective of the condition of the control disc. An inertia and attitude sensing pendulum collapses the toggle linkage when the vehicle experiences an inertia condition or attitude change of predetermined magnitude to release the pawl for control by the control disc. A timing element driven by reel rotation restores the toggle linkage to the extended condition whenever the belt is fully wound on the reel and permits collapse of the toggle linkage by the pendulum at any time subsequent to unwinding of the belt from the fully wound condition.