| 摘要 |
<p>An improved hydraulically operated force limiting arrangement for a vehicle safety restraint seat belt, comprises a fluid (2) contained in a vessel, such as a cylinder (1), and movable from one part to another through a valved constriction (8), for example by means of a spring loaded piston (3) or a rotary drive. The valve (8) has a tapering profile to decrease the open area at the constriction as a function of the deceleration of the vehicle in a crash. Preferably the function is such that the area is decreased by a factor of the speed of movement of the occupant to the power n where n is between 1 and 2, so as to absorb a higher proportion of the load for higher speeds. A narrow bypass tube (15) may also be incorporated into the arrangement. This arrangement is an improvement on known systems because the force limitation is more appropriately taylored to the weight of the vehicle occupant and to the severity of the crash. <IMAGE></p> |
