Abstract: In apparatus for controlling a rapid feed speed of a movable body, for example a table of a machine tool, by using a ball screw, there are provided a converting device for converting the rotation of the ball screw into a force for reciprocating the table, a position detector which judges whether a nut of the ball screw is at an end of the movement of the nut or at a central portion of the movement for issuing a detection signal and a speed reducing device which reduces the number of revolutions of the ball screw when the detection signal is issued.

Abstract: In apparatus for correcting displacement of a movable member of a machine tool wherein the effect caused by the displacement of the movable member is corrected by a correction load applying device supplied with pressurized fluid, there is provided a position detector for detecting the position of the movable member to produce a position signal, a displacement correction value calculator for calculating a displacement correction value in accordance with the position signal for producing a displacement correction signal, and an electromagnetic valve supplied with the displacement correction signal for adjusting the pressure of the pressurized fluid.