GB1253371A - Improvements in or relating to variable resistance control devices and to resistance means for use therein - Google Patents

Abstract

1,253,371. Variable resistors. C.T.S. CORP. 4 Nov., 1968 [2 Nov., 1967], No. 52268/68. Heading H1S. A variable resistor has a plurality of discrete portions 53 of a film of resistance material held by a dielectric substrate with which co-operate wiping contact members 62, 63 (Fig. 3) carried by a slidable holder 58. The holder 58 is movable manually by a member 28. The contact members also have contacts wiping on collector members 49. The resistive film elements are "intrinsically equalized" and may be produced by spraying, rolling or otherwise applying a resistive film to a strip of dielectric material moving past work stations A to G (Fig. 7). The dielectric substrate strip may be flexible. After application, marginal portions may be removed by abrading at E. Two separate resistance elements may be formed by removing a central portion to form a slot at 54. Alternatively masking may be used and the resistance elements may be formed transversely across the strip. The contacts 62 may have projections which fit into grooves in carrier 58 and are pressed thereinto when the contacts are pressed on to the resistance element by a polychlorotrifluoroethylene or metal spring member 66. The resistance elements may have taps 44. Special arrangements to prevent wobbling of the contact carrier are also described and are claimed in Specification 1,253,372.