Abstract: A control system is provided for allowing complex shapes to be machined on a workpiece at high speed. The control system is computer controlled and receives workpiece profile data which are converted into a succession of tool position signals during machining. Not all the digital signals are calculated at one time, a number of future digital signals are calculated during a succession of time intervals. In each time interval, a tool position signal is outputted which is of a constant amplitude corresponding to the required tool position and which is fed to a signal processor where it is converted into a continuous signal which so changes progressively that at successive time intervals, equal to the time intervals of the tool position signals, the amplitude of the continuous signal is related to the successive values of the tool position signals. This continuous signal is fed to a closed-loop control system which controls the movement of the tool holder in accordance with the continuous signal.

Abstract: A machine tool for machining rotating workpieces at high rotational speeds and, in particular, with multiple tool movements within a revolution of the workpiece, comprises a low-inertia high-torque motor having an output shaft and a tool holder mounted for movement relatively to the motor. A cam or other single element connection drivable connects the output shaft and the tool holder and the motor can be operated by control apparatus to so oscillate the output shaft that the tool is moved rapidly back and forth in phase with the output shaft oscillation and in correspondence with the rotation of the workpiece to perform required machining movements.