| 摘要 |
PROBLEM TO BE SOLVED: To make safe surely slow descending operation by vertically supporting a male screw engaged with a female screw elevatably moved together with a cage and for elevatably moving the cage capably of being rotated by a driving device, and suspending it. SOLUTION: A thrust bearing 14 is sandwiched between a supporting material 14 fitted to a cage 3 so as to elevatably mode together with the cage 3 and a worm wheel 11 fixedly secured to a female screw 10, so that the whole weight of the cage 3 and an elevatable part together with the cage 3 is supported with the thrust bearing 14, and the female screw 10 elevatably moving together with the cage 3 and a male screw 1 for elevatably moving the cage 3 are vertically supported so as to be rotatable by a driving device and suspended. Hereby, at emergency stop, sure get-out is made easy. |
