| 摘要 |
A hoist comprises a housing with a first pulley set of a plurality of pulleys rotatably mounted in the housing in a fixed location. A piston member which is in sealing engagement with the housing is movable backwardly and forwardly under the control of fluid pressure admitted to respective sides of the piston and it provides a mounting for a second set of pulleys. A cable or rope is guided around the pulleys of the first and second sets and the end of the cable is passed through the housing and has a lower load-carrying end. The drive is connected to move the piston mounting member backwardly or forwardly in respect to the first set of pulleys for the purpose of lowering or raising the load-carrying end of the rope.
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