| 摘要 |
<p>A linear actuator (10) includes a rotatable element (60) mounted about a threaded shaft (44). First and second moving members (86, 88) are mounted within a housing (30) and are disposed on opposite sides of an annular collar (65) formed on the rotatable element (60). The moving members (86, 88) are movable between a first position disengaging the rotatable element (60) from bearing surfaces (70, 72) at opposite ends of the housing (30) to prevent rotation of the rotatable element (60) and the threaded shaft (44), and a second position spaced from the rotatable element (60) to enable the rotatable element (60) to move axially into engagement with one of the bearings (70, 72) to permit free rotation of the rotatable element (60) and the threaded shaft (44). Pairs of angularly extending ramp surfaces (94, 96) on each moving member (86, 88) slide within angled slots (100, 102) in the housing (30) to guide movement of the moving members (86, 88).</p> |
