| 摘要 |
<p>An apparatus (10) has an inertia assembly (14) which includes a moveable ball (60) for movement from a rest position under the influence of a predetermined change in vehicle inertia. A cap (64) is mounted to engage the ball (60) and to be displaced upon movement of the ball (60) from its rest position. A sensor assembly (16) detects movement of the cap (64). The sensor assembly (16) includes a photodiode (90) which directs a beam of light (92) to impinge upon a phototransistor (96). The cap (64) has a projection member (80) which is moved to interrupt the beam of light (92) when the ball (60) moves from its rest position. In the preferred embodiment, the sensor assembly (16) provides a signal which is used to control activation of a vehicle occupant restraint (18). In the preferred embodiment, the vehicle occupant restraint (18) is a seat belt retractor (18), which has a rotatable spool (134) and ratchet wheels (138). A pawl (142) is engageable with the ratchet wheels (138) to block rotation of the spool (134) when the beam of light (92) is interrupted upon movement from the ball (60) from its rest position, and thereby prevent further withdrawal of a seat belt (140) from the retractor (18). Also in a preferred embodiment, the apparatus is adjustable to vary the amount of the predetermined change in vehicle inertia. <IMAGE></p> |
