Abstract: A variable electrical resistance device for monitoring displacement of a mechanical component such as a vehicle road wheel suspension system having a housing; an electrically resistive track and conductive slip ring on a support in the housing; electrically conductive wipers on a rotatable carrier provided with a spindle for coupling to the component. The wipers traverse the resistive track and the slip ring respectively. The support is mounted on springs or flat strips of resilient metal, so as to be displaceable away from and towards the wipers. A solenoid, of double-acting type or acting in association with the bias of the springs, has an armature operating to effect displacement of the support away from and towards the wiper whereby contact between the wiper and track may be broken, or the contact pressure therebetween reduced, when monitoring is not required, thereby prolonging the life of the wiper and track assembly.

Abstract: A rotary variable electrical resistance device comprises a housing; a spindle, arranged for rotation in the housing to adjust the setting of the device, and arranged to be rigidly secured to the end of a rotatably supported shaft serving as an extension of the spindle or whose angular rotation is to be monitored by the device and such that the shaft effectively supports the resistance device. The housing is restrained from rotation by a member such as a pin on a disc secured to a support by a ring shaped member and engaging an opening or recess in a flange secured to the housing. Clearance between the members allows the device to be displaced to follow displacement of the shaft resulting from play in bearings supporting the shaft or misalignment or bending of the shaft and obviates the necessity for the expensive and bulky flexible couplings of the prior art.