GB1307806A - Variable resistors - Google Patents

Abstract

1307806 Variable resistors TRW Inc 9 June 1971 [16 June 1970] 19781/71 Heading H1S A variable resistor 10 comprises a shaft 36 rotatably mounted in a housing 12 consisting of two ports 14, 16. The shaft 36 has a head portion 38 which projects from the housing, an annular flange 42 which prevents longitudinal movement of the shaft, and a square sectioned portion 44 on which a rotor 46 is secured by a snap ring 50 for rotation with the shaft. Rotor 46 is of electrically insulating material, e.g. ceramic and has formed on one side an annular resistive path 54 with spaced ends 54a, 54b. An annular conductive path is formed on the other side of the rotor 46 and is connected to one end 54a of the resistive path by a conductive strip 58. A radially extending lug 52 formed on the rotor 46 engages a similar lug (34), (Fig. 5, not shown), formed on the inside of the housing to limit of rotation of the rotor and shaft. Contacts 60, 62 are each formed with upper portions 60a, 61a located in notches 26, 28 in the lower housing section 16, terminal portions 60d, 62d extending through holes 30, 28 to project from the housing, and end portions 60b, 62b having fingers 60c, 62c which slidably contact the resistive path 54 and the conductive contact path. Thus terminal 62d is always effectively connected to one end 54a of the resistive path 54 and the other terminal 60d varies in contact position as the shaft is rotated. In a further embodiment a second conductive contact path is connected to the end 54b of the resistive path and a third contact and terminal are provided to connect with this second contact path to produce a potential divider.