| 摘要 |
PURPOSE:To keep off pre-wear in lining of an emergency brake as well as to prevent a lowering of emergency brake performance from occurring, by detecting a fact that a machine comes to a stop after operating a service brake and thereby operating the emergency brake. CONSTITUTION:During normal operation, when a command to stop a machine is generated out of an operation commander 34, a service brake (unillustrated herein) is set in motion whereby the machine decelerates. When rotation in the machine approximates to almost nearly zero, a speed switch 120 is cut off and thereby a contact 12X opens. Therefore, a relay 10 is unenergized, making a contactor 75 open. With this, an emergency brake coil 8 becomes unenergized whereby the emergency brake operates. If the service brake does not generate regular braking torque, such a time as being required till the switch 120 operates after generation of a stop command of the commander 34 is prolonged anyway so that a timer 12 operates. In consequence, a contact 20 opens, causing the contact 2X to open and the relay 10 to be unenergized, thus the emergency brake operates. Simultaneously, a buzzer 15 operates and a red lamp is lighted, giving an alarm. |
