Wedge braking system for multi-stage lifts

摘要

Apparatus for braking relative vertical movement between two vertical members includes a ramp mounted on one of the members to oppose a vertical face on the other. If the ramp member accelerates downwardly a wedging roller is wedged between the ramp and the vertical face. This roller is on a slide rod which normally compresses a spring carried at the bottom of the ramp, but downward acceleration on the ramp results in expansion of the spring and movement of the wedging roller into wedging position to stop the acceleration.