| 摘要 |
PROBLEM TO BE SOLVED: To prevent malfunctioning of an apparatus for preventing over-hoisting by a hoisting device, caused by quick hoisting of a hoisting rope or the oscillation of the rope. SOLUTION: The hoisting device 26 has a hook 5 suspended from the top of the device 26 via the hoisting rope 4. The hoisting device 26 is provided with a spring 29 fixed at its lower end to near the upper end of the hook 5 and extending upwardly along the rope 4, with the rope 4 loosely passed through the spring. A limit switch unit 31 which is actuated when the spring 29 abuts against it is disposed near the top of the device 26; if the spring 29 actuates the limit switch unit 31 because of the over-hoisting of the rope 4, the limit switch unit 31 stops hoisting of the rope 4.
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