Abstract
A crane for loading and unloading a cargo includes multi-stage trolley. The multi-stage trolley for a crane includes a first trolley movable in a longitudinal direction along a boom of the crane; a second trolley movable in a lateral direction on the first trolley; a hoisting wire provided in the longitudinal direction along the boom; spreader connected to the hoisting wire through the first trolley and the second trolley and supported by the hoisting wire, the spreader being movable in a vertical direction according to a movement of the hoisting wire. The multi-stage trolley further includes a sheave block unit for changing a direction of the hoisting wire to maintain a vertical level of the spreader constant when the first trolley and/or the second trolley is moved.
Originalsprog | Engelsk |
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IPC | B66C 11/ 20 A I |
Patentnummer | US2011247991 |
Land/Område | USA |
Prioritetsdato | 08/04/2010 |
Prioritetsnummer | KR20100032270 |
Status | Udgivet - 13 okt. 2011 |