Abstract: An apparatus for converting the power of a reciprocating member to unidirectional rotation of an output shaft. A reciprocator is connected to a coupling shaft so as to rotate the coupling shaft in alternating directions. Gears and clutches driven by the coupling shaft convert the alternating movement of the coupling shaft to unidirectional rotation imparted to the output shaft. In other embodiments, the reciprocator drives coupling shafts which in turn impart alternating movement to clutch assemblies that cooperate to alternately impart unidirectional rotation to the output shaft.