Servo actuated steering mechanism for borescope or endoscope

摘要

This invention involves a cable bendable borescope in which opposing cable pairs are displaced to deflect the tip of the borescope in the perpendicular planes of motion. A servo motor is connected to each pair of actuating cables to selectively displace one or the other in accordance with the rotation of the servo motor. A control circuit for rotating the servo motors has a pulse generation network and a modulator circuit for modulating the pulse width to control the degree of rotation of the servo motors. A joystick type of actuator for the control circuit creates a change in variable potentiometers for the two directions of motion of the joystick which, in turn, causes the control circuit to rotate the servo motors for the corresponding plane of motion to produce the desired deflection of the tip of the borescope insertion tube. Tension control, centering and component compensation circuits are provided to limit stress on the cables. The servo motors are slidably mounted on a track with spring anchors to the frame chosen to allow the entire assembly to move to limit tension in the actuating cables to a predetermined amount.