A method and apparatus for machining an internal surface of a differential case. A lathe having a turret and a pair of spindles are in electrical communication with a programmable computer. Integrally connected to the turret is a cutter gripper assembly that is selectively grippingly engageable with a cutter. A differential case is mounted horizontally within a mount assembly on a tabletop of the lathe. Once the cutter gripping assembly engages the cutter, the turret moves toward the differential case until the cutter is in a start position within the hollow portion of the case aligned with openings in a first and second tubular portion of the case and the pair of spindles. The pair of spindles then drivingly engage the cutter and the cutter machines a first and second internal machining surface as the cutter moves from a first cutting position to a second cutting position.

A turning tool for internal turning of a metal work piece having a rear end, an opposite forward end and a longitudinal center axis extending therebetween. The first nose cutting edge includes a first radially distal point having an associated first rake face and separates and connects a first forward cutting edge and a first rearward cutting edge. A second nose cutting edge of the turning tool includes a second radially distal point having an associated second rake face and separates and connects a second forward cutting edge and a second rearward cutting edge. The second radially distal point is positioned ahead of the first radially distal point. The first forward cutting edge forms an acute first entering angle, the second forward cutting edge forms an obtuse second back clearance angle, and the second rearward cutting edge forms an acute second entering angle.

A turning tool for internal turning of a metal work piece having a rear end, an opposite forward end and a longitudinal center axis extending therebetween. The first nose cutting edge includes a first radially distal point having an associated first rake face and separates and connects a first forward cutting edge and a first rearward cutting edge. A second nose cutting edge of the turning tool includes a second radially distal point having an associated second rake face and separates and connects a second forward cutting edge and a second rearward cutting edge. The second radially distal point is positioned ahead of the first radially distal point. The first forward cutting edge forms an acute first entering angle, the second forward cutting edge forms an obtuse second back clearance angle, and the second rearward cutting edge forms an acute second entering angle.

The present invention includes a tool magazine (10) storing a plurality of tools (T), a turret (3) to which a plurality of tools (T) are attached, and a tool changer (20) changing a tool (T) attached to the turret (3) for a tool (T) stored in the tool magazine (10). The tool changer (20) has two tool grippers for gripping tools (T) and replaces tools (T) attached to the turret (3) with one another using the two tool grippers based on tool information stored in a tool information storage (43) under control by a tool change control unit (42).

A control method of superimposition processing in an NC machine tool comprises providing at least one tool rest that performs machine processing to workpieces respectively held on a plurality of spindles, providing respective processing programs for performing respective machine processing to the workpieces held on the respective spindles, and inserting superimposition control program for performing superimposition processing during one of the respective processing programs is running. The superimposition processing is performed so that, during an operation of performing machine processing to a workpiece held on one of the plurality of spindles by one of the plurality of tools, the other operation of performing machine processing to a workpiece held on another one of the plurality of spindles by another one of the plurality of tools is superimposed.

An adjustable angle toolholder comprising a shank and an adjustable head is provided. The shank has a first end and a second end. The first end is adapted to be held in a machine, such as a lathe. The second end includes a fixed plane oriented parallel to a lengthwise direction of the shank. The fixed plane includes an arcuate face at a distal end of the fixed plane. The head has a fixed plane that mates with the fixed plane of the shank. The fixed planes of the shank and head include a pivot hole through which a pivot bolt passes. The pivot bolt allows adjustment of the head through a wide range of angles relative to a lengthwise direction of the shank, while the fixed planes maintain a position of a centerline of a cutting tool constant with respect to a centerline of the shank. The fixed plane of the shank may be on a centerline of the shank.

In a machine tool having a tool carrier (1) that comprises at least one receptacle (4) for a tool holder (3) for driven or stationary tools a tool change device is provided that comprises gripping means (370) for gripping the tool holder (3) at the housing (7) or at part (71) connected with the housing (7). In addition to the gripping means the tool change device comprises a device for actuating the fastening means that are configured for attachment of the tool holder at the tool carrier.

A tooling exchange mechanism and a machine tool having the tooling exchange mechanism, in which a load applied to a turret is reduced when exchanging a tooling in the machine tool, are provided with a pressing member 210 of a tooling detachment unit 200 that presses the rear end of a tooling holding unit 100 to be able to release the retracted state of a tool holder Th of a tooling T by a tool holder holding portion 150 of the tooling holding unit 100, and a locking lever 220 of the tooling detachment unit 200 engageable with an engaging projection 112a formed on the rear end side of the tooling holding unit 100.

A tooling exchange mechanism and a machine tool having the tooling exchange mechanism, in which a load applied to a turret is reduced when exchanging a tooling in the machine tool, are provided with a pressing member 210 of a tooling detachment unit 200 that presses the rear end of a tooling holding unit 100 to be able to release the retracted state of a tool holder Th of a tooling T by a tool holder holding portion 150 of the tooling holding unit 100, and a locking lever 220 of the tooling detachment unit 200 engageable with an engaging projection 112a formed on the rear end side of the tooling holding unit 100.

A positioning device for positioning a tool holder (12, 14, 16, 18) on a tool turret (6) of a machine tool by means of positioning pins (10), which are secured to the tool turret (6) and which engage with receptacles (40) on the tool holder (6) when the tool holder (12, 14, 16, 18) is attached to the tool turret (6), is characterized in that at least one of the receptacles of the tool holder (6) is formed by a sleeve (40), with which the assignable positioning pin (10) engages in the mounted state while contacting the inner circumferential surface (58) of the sleeve (40), and in that the inner circumferential surface (58) is part of an expanding part (56), which, when the pin (10) engages, expands elastically and flexibly away from the pin (10).