| 摘要 |
A seat belt retractor has a belt reel with a restraint belt attached thereto and biased in the belt winding direction of rotation by a windup spring. A detent mechanism comprised of a pawl and ratchet normally permits belt winding reel rotation by the windup spring and is movable to a detenting position wherein the pawl engages the ratchet to hold the belt in a nontensioned restraining position about the occupant. A control mechanism comprised of a control disc and a blocking disc operate the pawl between the detenting and undetenting positions in response to rotation of the discs through less than one revolution between one limit at which rotation in the unwinding direction is stopped and another limit at which rotation in the winding direction is stopped. The pawl coacts with the discs to define the limits of rotation. A friction clutch acts between the discs and the reel to rotate the discs as a unit with the reel and permit continued rotation of the reel after the discs are stopped at their respective limits of rotation by the pawl. A selected operator actuated means such as the vehicle door is operably connected with the pawl to move the pawl out of its rotation limiting coaction with the blocking disc and control disc so that the discs are freed for unitary rotation with the belt reel, thereby terminating the relative rotation between the discs and the reel so that the windup spring need not overcome the frictional impediment normally exerted on the reel by slippage of the friction clutch. |
