WERKZEUGMASCHINE

PCT No. PCT/EP96/04551 Sec. 371 Date Aug. 15, 1997 Sec. 102(e) Date Aug. 15, 1997 PCT Filed Oct. 19, 1996 PCT Pub. No. WO97/25181 PCT Pub. Date Jul. 17, 1997The machine tool comprises a machine stand (10) with a vertically movable vertical carrier (12) carrying a spindle head (SK1) for treatment of a workpiece. To exchange the spindle head (SK1) against a new spindle head (SK2), an exchange unit (15) is provided, comprising an exchange arm (16) pivotable by 90 DEG about a vertical axis (37). Two holding couplings (17,18) are mounted above each other on the exchange arm (16), each adapted to carry a spindle head (SK1,SK2). A delivery means (21), gripping the spindle heads from above, is used to supply the spindle heads for transfer to the exchange unit (15). The exchange unit (15) grips the spindle heads from the side. By pivoting the exchange arm (16) over 90 DEG , the spindle head is pivoted to a position in front of the machine stand (10) and thus can be taken over by the vertical carrier (12).