Arrangement for over-riding the inadvertent actuation of a trip device in a motor control circuit

Claim 1

AN IMPROVED CONTROL CIRCUIT FOR A MOTOR DRIVEN APPARATUS COMPRISING: A VOLTAGE SOURCE; A SERIES CIRCUIT CONNECTED ACROSS SAID VOLTAGE SOURCE AND INCLUDING A TRIP DEVICE, A SWITCH, AND A SAFETY RELAY; SAID TRIP DEVICE BEING CLOSED UNDER NORMAL CONDITIONS TO PERMIT INITIAL ENERGIZATION OF SAID SAFETY RELAY ON ACTUATION OF SAID SWITCH; AT LEAST TWO NORMALLY OPEN, GANGED CONTACTS WHICH CLOSE ON ENERGIZATION OF SAID SAFETY RELAY TO COMPLETE FIRST AND SECOND HOLDING CIRCUITS FOR SAID SAFETY RELAY ACROSS THE VOLTAGE SOURCE; SAID FIRST HOLDING CIRCUIT INCLUDING SAID TRIP DEVICE, AT LEAST ONE OF SAID GANGED CONTACTS, AND SAID SAFETY RELAY; SAID SECOND HOLDING CIRCUIT INCLUDING ADDITIONAL CONTACT MEANS WHICH ARE OPEN DURING MOTOR OPERATION AND CLOSED WHEN SAID MOTOR IS STOPPED, AT LEAST ONE OF SAID GANGED CONTACTS, AND SAID SAFETY RELAY; SAID SAFETY RELAY BEING DE-ENERGIZED AFTER INITIAL ENERGIZATION ONLY WHEN SAID TRIP IS OPENED DURING OPERATION OF SAID MOTOR.