Safety switch for de-energizing a driving motor in the event of stoppage of a shaft driven thereby

Claim 1

THE COMBINATION OF A MOTOR, A DRIVEN SHAFT, A ROTOR HAVING MEANS FOR DRIVING IT FROM THE MOTOR AND HAVING SLIP CLUTCH CONNECTION WITH THE SHAFT FOR NORMALLY OPERATING THE SHAFT FROM THE MOTOR, AN ECCENTRIC CONNECTED WITH THE ROTOR, A YOKE RIDING ON THE ECCENTRIC TO RECEIVE MOTION THEREFROM, A SWITCH MOUNTED ON THE YOKE AND HAVING NORMALLY CLOSED CONTACTS, A MOTOR CONTROLLING CIRCUIT IN WHICH SAID SWITCH IS CONNECTED, AN ARM HAVING FRICTION DRIVE CONNECTION WITH THE SHAFT TO RECEIVE MOTION THEREFROM TENDING TO ROTATE THE ARM WITH THE SHAFT, MEANS FOR OPENING ONE OF THE CONTACTS OF THE SWITCH WITH RESPECT TO THE OTHER OF SAID NORMALLY CLOSED CONTACTS AND CONSTITUTING AN ACTUATOR COMPRISING MEANS FOR RECEIVING MOTION FROM SAID ARM WHEN SUCH MOTION IS IMPARTED FRICTIONALLY TO THE ARM FROM SAID SHAFT, WHEREBY THE SWITCH TENDS TO BE HELD OPEN DURING SHAFT ROTATION, SAID ECCENTRIC AND YOKE CONSTITUTING MEANS EFFECTIVE DURING CONTINUED OPERATION OF THE ECCENTRIC FOR BRINGING ABOUT THE CLOSING OF THE SAID SWITCH CONTACTS OF SAID SWITCH WHEN SHAFT MOTION IS ARRESTED.