| 摘要 |
PROBLEM TO BE SOLVED: To prevent an extreme slowing of descent of a suspension device descended by releasing a mechanical brake due to a braking force of a motor at an emergency, or the like. SOLUTION: A relay circuit 10 permits normal and reverse operation of a direct current motor DM by opening a (b) contact point Rb parallel with a resistor R1 when direct current power supply is normal, and when direct current power supply is lost, the contact point Rb is closed, a switch Q1 is prevented from getting turned on by generated current of a mechanically driven direct current motor by the descent of the suspension device by the operation of an emergency lowering mechanism, whereby generated current of the motor is suppressed and generation of a braking force of the suspension device is restrained. |
