US Patent 7621158 Washing machine and coupling apparatus

A coupling apparatus includes an inner shaft rotatably driven about a longitudinal axis of rotation, an outer shaft concentric with the inner shaft for selective rotation about the longitudinal axis, a coupling element movable between a first position engaging the inner shaft to the outer shaft for rotation therewith, and a second position disengaging the inner shaft from the outer shaft for relative rotation therebetween, and an actuating element connected to the coupling element and operable to move the coupling element between the first position and the second position.