| 摘要 |
PURPOSE:To prevent erroneous operation by enabling operation of device through throw-in of coin and throw-in of key switch. CONSTITUTION:An oil drainage device is assembled in such as a service unit 1 at gas station, and upon throwing of a coin into a throw-in port, a switch 43 will close temporarily to close the contact R4' thus to conduct the relay R1 thereby the contacts R1', R1'' are closed to self hold the relay R1. Upon insertion of key into a lock 39 of case 1a and turning, the key switch 45 will close to the left thus to conduct rhe relay R2 thereby the contact R2' will close and self held to supply power to the motor. Consequently, pump is driven to store oil through a nozzle 20 into the oil discharge tank. Upon completion of drainage, the key is turned reversely to interrupt power supply to the motor. |
