Motion transmitting system

A motion transmitting device having an input shaft and a concentric output shaft assembly, and an eccentrically rotated gear driven by the input shaft to provide an eccentric output. The gear has teeth which engage and subsequently disengage with independently movable meshing elements, such as pins. A pair of datum members have round holes to individually guide and limit movement of the meshing elements within predetermined limits of orbital motion relative to the datum members. The eccentric output drive of the gear is converted to rotary motion of the output shaft assembly. The input shaft and the output shaft assembly are rotatable about a common axis.