| 摘要 |
PROBLEM TO BE SOLVED: To provide a chain gate that can surely lower chains into a lower limit position in power interruption and perform lifting operation of the chains using a ball screw. SOLUTION: The chain gate 1 limits passing of vehicles by erecting the ball screw 5 in a gatepost 2, supporting the upper and lower ends of a ball screw shaft 6 by bearings 21, 22, connecting a driving device 31 to the upper end, connecting the chain to a connecting implement 3 lifted together with a ball screw nut 7 lifted by the rotation of the ball screw shaft 6, and rotating the ball screw shaft 6 by the driving device 31 to lift the chain. The chain gate 1 comprises an elastic energizing device 10 for energizing the lower end of the ball screw shaft 6 by a spiral spring to move the ball screw nut 7 into a lower limit position in power interruption. Since the ball screw nut 7 moves into the lower limit position in power interruption to surely lower the chain into the lower limit position, passing of vehicles or the like is not blocked. COPYRIGHT: (C)2008,JPO&INPIT
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