| 摘要 |
<p>A road towable platform having a sectional mast for rapid erection at the face of a structure for the performance of work thereon. The platform is vertically driven on the mast by means of dual independent drives each comprising a motor, a centrifugal overspeed brake, a triple reduction spur gear train, and a pinion engaging an independent rack on the mast. Each motor also has an integral disc brake engaged when the power is off.</p> |
