| 摘要 |
The pulley block, for use in lifting tackle, consists of a grooved roller (16) between two side plates (12,28). One plate can be opened for passing a rope round the pulley or removing it. Above the roller the pulley block has a locking element (21) with a spiked grooved surface (26) which allows the rope to run over the pulley in one direction but prevents it from running in the other. The locking element is mounted on a hollow pivot (18) which lies parallel to the pulley roller pivot (14). A spring clip can be passed through the hollow pivot and corresponding apertures (52) in the pulley block side plates, locking the second plate (28) in its closed position. |
