Adjuster for adjusting length of bar of e.g. headrest of vehicle seat, has adjustable wire made from shape memory alloy, and helical gears blocking rear adjustment of adjusting element according to incremental adjusting path

摘要

The adjuster (1) has an adjustable wire made of shape memory alloy and shortened under adjustment of an actuator element (6) during heating. An adjusting element (3) is adjusted with respect to a fixed frame component (2) or a fixed frame attachment. The adjusting element is adjustable during operation of an actuator element around an incremental adjusting path of an adjusting area. Helical gears (10, 11) block a rear adjustment of the adjusting element according to the incremental adjusting path. The actuator element is pretensioned by a spring device in its resting position.