US Patent 7215045 Roll-ring conductive wheel

A roll-ring conductive wheel is used to conduct electricity between the inner and outer races of rotating or moving parts. The conductive wheel is a thin-walled metal cylinder with a plurality of spokes connecting the outer cylindrical wall to a central hub. The preferred spokes are arcuate and the wheel is made flexible so that it can be compressed to an elliptical shape between the inner and outer conductive races for good electrical contact and to absorb slight deflections or gap variations between the races. The conductive wheel can have other shapes depending on the configuration of moving parts, such as a truncated cone shape for conical or wedge-shaped races.