Abstract: A machine tool having a grinding wheel for grinding a workpiece mounted on a table. The machine tool is provided with a truing apparatus for truing the grinding wheel and a measuring device for measuring the diameter of the grinding wheel after every truing operation. Both of the truing apparatus and the measuring device are mounted on a movable base. The movable base is moved between its retract position at the outside of the table and a forward position above the table. The movable base is move to the forward position to bring the truing apparatus and the touch sensor into predetermined positions for truing and measuring operations. After the truing and measuring operations, the movable base is moved away from the table and is retracted to its retract position. The truing apparatus is provided with a truer support shaft whose rotational shaft intersects with a horizontal plane with an angle of 45.degree., and a truer attached to the truer support shaft.

Abstract: A thermal displacement compensating apparatus capable of compensating for the thermal displacement of the main spindle of a machine tool is disclosed. A feed back scale and a measuring head are provided in order to detect the actual position of the front end portion of the spindle head. Furthermore, a distance sensor is provided for detecting the thermal extension of the main spindle with respect to the spindle head. The output signal from the distance sensor is used for modifying the present position detected by the measuring head or modifying a commanded target position. With this arrangement, a tool attached to the front end portion of the main spindle is moved to the commanded position regardless of the thermal displacement of the spindle head and the main spindle.

Abstract: A tool clamping device for clamping a tool on a main spindle or releasing the same from the main spindle, which includes: a main spindle rotatably supported on a headstock; a push rod extended through the spindle hole of the main spindle so as to be axially slidable, urged rearward by a weak spring and capable of being moved axially for fixing a tool to or releasing the same from the main spindle; a clamping spring for pressing the push rod rearward; a sleeve disposed contiguously with one end of the clamping spring so as to be movable relatively to the push rod; a first interlocking mechanism formed between the push rod and the sleeve so as to interlock the sleeve with the push rod when the sleeve moves in a direction to allow the expansion of the clamping spring and to release the sleeve from the push rod when the sleeve moves in a direction to compress the clamping spring; a second interlocking mechanism capable of being disengaged by the movement of the push rod in a direction to compress the clamping spr

Abstract: A machine tool having a gate-type construction and provided with a tool magazine (11). The tool magazine (11) is mounted between a pair of support portions (3a) of a gate-shaped column (3) and above a work support table (2). The tool magazine (11) is composed of a plurality of tool holders (16) each holding a tool (17), and a driving device (18) for moving the tool holders (16) back and forth. This arrangement permits an efficient use of the working space on the work support table (2), and makes it possible to reduce the sizes of the support table (2) and a bed (1).