Abstract: Double epicyclic gear structure including a housing, a drive shaft rotatably mounted within the housing, first epicyclic gear structure mounted on the drive shaft, an input shaft connected to drive the first epicyclic gear structure, speed control structure connected to the sun gear of the first epicyclic gear structure for regulating the speed of rotation thereof, second epicyclic gear structure mounted on the drive shaft and engaged with the first epicyclic gear structure for rotation therewith, a brake band for stopping rotation of the planet gears of the second epicyclic gear structure and one-way clutch means mounting the ring gear of the second epicyclic gear structure on the drive shaft whereby on stopping of rotation of the planet gears about the drive shaft the drive shaft is driven in a forward direction, a brake band operable to prevent rotation of the ring gear of the second epicyclic gear structure and one-way clutch means mounting the planet gears for rotation on the drive shaft whereby on stopp

Abstract: An improved reversible overrunning clutch is disclosed of the type including a central driver member that is axially shiftable by helical spline means between clutch engaged positions relative to axially spaced forward and reverse clutch members, respectively, mounted on an output shaft. Automatic shift control means operable in accordance with the direction of rotation of the rotary input drive means are provided for shifting the central driver member toward a readiness position immediately adjacent the appropriate clutch member, thereby insuring the correct directional operation of the unit. In order to maintain the central driver member in position, friction drag spring means are provided which afford rotational resistance between the central drive member and the output shaft.