Electrical contact assembly and method and apparatus for assembling the

Abstract

A full rotational freedom, substantially zero friction electrical contact assembly for conducting electrical currents between relatively rotatable members of sensitive instruments such as gyroscopic devices and the like and a method of and apparatus for the assembly thereof is disclosed. Each electrical transfer unit of the assembly comprises a pair of coaxial, concentric, coplanar, continuous, concave conductor rings, one mounted on a relatively fixed member and the other mounted on the rotatable member, the relative diameters of the rings providing a substantial annular radial gap therebetween. A resilient, electrically conducting, continuous, filamentary loop is disposed in the radial gap such that its generally flat outside surface contacts and rolls on the concave surfaces of the concentric conductor rings. The loop/conductor interface provides self-capturing and retaining forces to accommodate any misalignment between the rings and movements of the loop within the radial gap in a vibratory and/or shock environment all without producing frictional torques on the rotatable member. The critical dimensional parameters of the concave conductor ring surface and the loop, particularly its free (unassembled) diameter relative to the radial distance between the concentric conductors, its thickness and width, and its material characteristics are selected so as to provide: substantially zero friction and coupling torque on the rotatable member; maximum retention capability; maximum current conduction; and maximum life.