Transmission for driving a movable element, particularly a component in a machine tool, at high speed or creep speed

A driving and positioning device for driving a movable element, particularly a component in a machine tool at high speed or creep speed through a specified cycle and for positioning it in required positions corresponding to the desired positions of a stepping motor forming part of the device said device comprising a stepping motor providing a single input, a drive shaft connected to said stepping motor, an epicylic drive connected to the drive shaft and comprising a driven shaft for driving the externally geared movable element, said epicylic drive having one branch for the transmission of high speed to the driven shaft and one branch for the transmission of creep speed to the driven shaft, the branch for the transmission of the high speed to the driven shaft comprising a clutch for connecting and disconnecting the drive shaft to an internally geared part of the epicylic drive and a brake to keep said internally geared part in a fixed position when it is disconnected from the drive shaft by the clutch during creep speed motions, the brake being disconnected from said internally geared part during high speed motions and upon completion of the high speed motion serving as an indexing means wherein the mating brake elements are engageable and disengageable thereby eliminating the deviation of the drive shaft from its desired position within the range between two steps of the stepping motor.