| 摘要 |
PROBLEM TO BE SOLVED: To provide a hook release prevention device which prevents a hook from being immediately released even if a door body jams during descent thereof. SOLUTION: The hook release prevention device comprises: a rod 14 penetrating the door body 1 vertically movably; a bracket 15 extending from an upper end of the rod 14 to the vicinity of a hanger ring 2 on an upper surface of the door body 1; and a release inhibiting stopper 16 mounted on the bracket 15 to allow engagement with a hook 3 of an attachment. If the door body 1 is stopped during descent of the attachment having the hook 3 engaged with the stopper 16 and the hanger ring 2, the stopper 16 descends for a while together with the hook 3 to inhibit the hook 3 from rotating. COPYRIGHT: (C)2009,JPO&INPIT
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