| 摘要 |
<p>The support crane for the working trolley, suspended from the crane down the outside of the building, rests on an array of small air cushions. These are set up under special pivotted pads (9, 10) which assume positions parallel to the ground. The track for the crane comprises a flat bed (3) inclined towards the edge of the building to ensure that the crane always rests at the edge. Electric drive wheels (11) engage a raised ledge (5) near the edge of the building to move the crane around the edge. The air cushion enables the crane to be moved with ease. The system also dispenses with cumbersome, and expensive guide rails for conventional cranes, and the maintainance of the rails.</p> |
