Abstract: Apparatus for automatic tool changing, such apparatus being situated between the lathe rest and the stationary tool magazine of the lathe. The total changing apparatus contains a basic support frame which can move parallel to the axis of the lathe spindle; a transport unit for following cross-traverse on the support frame, a two-seat tool magazine, and a mechanism for straight-lined translation of the tool units. The basic support frame contains a brace structure and a beam. The brace structure extends along a guideway towards the body of the lathe, while the beam acts as a guideway for the transport unit. The two-seat tool magazine includes a slide fixed to the transport unit; it can move along the beam of the support frame together with the transport unit, as well as independently. It also contains two seats for tool units, rigidly fastened to the slide.

Abstract: Tool holder for use with machine tools, the tool holder having two aligned cylindrical bores of different diameters, separated by a circumferential groove, which is in communication with a hole through the body of the tool holder through which hydraulic fluid can be supplied. The cylindrical shank of the tool has correspondingly two cylindrical surfaces of different diameters with conical shoulders, one of which is in the end of the shank, while the other connects the cylindrical surfaces. The relaxed diameters of both stepped holes in the tool holder are smaller than the diameters of both cylindrical surfaces of the cylindrical shaft of the tool, the tool shank being press fitted into the tool holder.