Abstract: A control unit, adapted to control a reversible, variable-speed electrical motor includes a control lever protruding through a U-shaped slot in a housing. Movement of the lever from one side to the other of the U-shaped slot controls the direction of rotation of the motor, and its position along a side of a slot determines the speed of rotation. The control lever is mounted to a pivotally mounted support member, which carries a linear potentiometer operated by the control lever, and includes a protruding portion which carries a toggle switch. The handle of the toggle switch is substantially restrained from motion, so that the switch is actuated to reverse the motor when the control lever is moved from one side of the U-shaped slot to the other.

Abstract: A squeeze type manual actuator including a control arm with a pair of hand grips extending from the upper end of the arm, at least one of the hand grips being mounted on the arm for movement toward and away from the other hand grips. The hand grips are provided with gripping pads and have a normal spacing in which the pads are respectively engageable by the palm and finger tips of one hand of the operator. The movable hand grip engages a plunger having a return spring. A signal producing device is coupled to the plunger for producing an output signal of pre-selected polarity and which varies in accordance with plunger displacement. In the preferred embodiment of the invention the arm has upper and lower sections with limited lost motion between them in opposite directions from a neutral position.

Abstract: A potentiometer including a resistance track and a wiper element adapted for relative movement with respect thereto includes first, second and third terminals connected respectively to each end of the resistance track and to the wiper element. The potentiometer further includes conductive means to effectively reverse the electrical positions of the terminals connected to either end of the resistance track.