摘要 |
Safety belt retractors are disclosed in the form of spring driven belt rewinding mechanisms. In some arrangements, a pair of spiral springs act in series or in parallel, one spring applying a constant rewinding torque to a belt storage shaft, the other storing energy when the belt is withdrawn. A ratchet maintains the stored energy and is disengaged by a screw threaded actuator, which moves coaxially to the storage shaft, when the shaft rotates through a number of revolutions. The stored energy is released to supplement the rewinding torque of the first spring. In another arrangement, the ratchet is replaced by an over center spring assembly. An epicyclic gear box drives a coil spring anchorage through a given arc to give an over center action. |