| 摘要 |
A crane constructed with two or more lifting tackles suspended from trolleys 41 and 42,43 that are capable of moving along the functional length of the supporting gantry by passing clear of each other when crossing. This may be attained by the trolleys running in parallel tracks (Fig 1) and the tackles with loads swinging clear of each other when crossing; or can be attained by the tackles being suspended from tiered trolleys or half-trolleys successively wider to each other and having the the narrower tackles and lifts 41 lifting through inside the wider set(s) 42,43 when crossing. |
