Electrical rotary potentiometer

Abstract

Rotary potentiometers known in the art having sensitive adjustment of the control knob require a stepdown gearing and have differing moments of friction that vary between devices. By contrast, in a rotary potentiometer of this invention a control knob (3) is mounted on at least three balls (6) that move, guided by a cage disk (7), in a housing groove (8) formed by a radial wall (9) and an axial wall (10), against which the balls (6) are urged by a load pressure of a conical bearing surface (11 or 12) of the control knob (3). The radial and axial wall bearing surfaces have contact and resistive strips (13, 14) that are short circuited by the balls (6). The control knob (3) has a stop lug (15) which contacts housing lugs (16) to limit a manipulation adjustment angle (4) and which, during operational adjustment, contacts at least one of two stop lugs (17) of the cage disk (7), which are positioned at an angle that corresponds approximately to one-half the manipulation adjustment angle (4) and the resistor tap angle (5). This design results in reduced cost and functional improvement.

Dependencies are inferred from the claim text.