Abstract: A device is provided for use with an actuator having an actuator shaft which indicates when the torque on the actuator shaft exceeds a predetermined limit. The device comprises a housing which carries a pair of limit switches. A shaft extension is operatively connected with the actuator shaft so that axial force on the actuator shaft, which is proportional to the shaft torque, is transmitted to the shaft extension. A hub and Belleville washer arrangement translates the axial force on a shaft into a proportional axial movement of the hub while a radially extending member from the hub includes a portion positioned adjacent the limit switch. Thus, when the axial force in one direction on the shaft exceeds a first predetermined amount, the radially extending member activates one limit switch which in turn is connected to an indicator.

Abstract: A valve actuator is provided for use in conjunction with a valve having an actuating member movable between a first position in which the valve is closed and a second position in which the valve is open. The valve actuator comprises a reversible motor having its output mechanically connected to the actuating member. The actuation of the motor is controlled by a circuit having a microprocessor. An optical sensor on the valve actuating member provides an input signal to the microprocessor indicative of the position of the valve and the position of the valve corresponding to both the open and closed position are stored in a memory accessible to the microprocessor. When the actuating member attains a desired position, the microprocessor is programmed to generate a stop signal which deactivates the motor.