Positive electrical connecting mechanism

An electrical connecting mechanism comprising an outer shaft member, an inner shaft member, said outer and inner shaft members supported for relative rotary movement about a common axis and having an annular space therebetween, a carrier member in the form of a flat washer located in said space between said outer and inner shaft members and supported for rotation relative to said outer and inner shaft members, a roller mounted on said carrier member, an arcuate groove formed in said carrier member adjacent said roller, three pin-like members rigidly connected to and circumferentially equally spaced about said carrier member for preventing movement thereof along said common axis, a single flexible ribbon-like cable electrically and mechanically connected at one end to said outer shaft member and electrically and mechanically connected at the other end to said inner shaft member, said cable having a length greater than the circumference of the inner shaft member and having a portion intermediate said one end and said other end of said cable located in said arcuate groove so that rotation of said inner shaft member relative to said outer shaft member in one direction causes said cable to drive said carrier member through said groove in the same direction while the cable winds around said inner shaft member, and rotation of said inner shaft member relative to said outer shaft member in a direction opposite to said one direction causes the cable to drive said carrier member through said roller and to unwind from said inner shaft member while being guided by said roller into engagement with said outer shaft member along the inner surface thereof.