| 摘要 |
<p>PURPOSE:To conduct repair work safely when switches are welded by reversing a reversible motor through the reversal switch under a state that the forward- turn switch is non-conduction-held through the OFF operation of the OFF self- holding type forward-turn limit switch. CONSTITUTION:When the forward-turn manually operated switch 21 is pushed, a forward-turn relay 90 is actuated, and the reversible motor 17 is forward turned and winding operation is conducted. When winding reaches an upper limit, the forward-turn operation limit switch 64 is at OFF, and the reversible motor 17 is stopped. When the contact 95 of the forward-turn relay 90 is welded, the OFF of the forward-turn limit switches 67, 69 is held by means of a locking lever because winding operation is conducted even in case of the OFF operation of the forward-turn operation limit switch 64, and the reversible motor 17 is stopped. When repairing, a reversal manually operated switch 22 is pushed and the reversible motor 17 is reversed, and freight is dropped.</p> |
