| 摘要 |
<p>A workman's lift platform apparatus has a vertically swingable and extensible boom with a workman's platform at the outer end. A color coding indicating the amount of boom extension is provided on the fly section of the boom, visible to the workman in the platform, and an indicator plate having corresponding color coding is provided adjacent the controls on the platform. The indicator plate in the form of a drum is driven proportionately to the angular movement of the boom by a pair of sheathed, push-pull cables, or by a sheathed torsion cable. In other embodiments, the indicator plate is tilted in proportion to the angular movement of the boom by a sheathed push-pull cable or by a parallel bar linkage. A cursor is provided adjacent the indicator plate, and is part of a gravity-operated pendulum.</p> |
