A cutter holder structure comprises a cutter arbor and a connecting shaft having a tapered section at one end thereof. One end of the tapered section is formed with a first inner screw hole, and another end of the tapered section is formed with a second inner screw hole. The connecting shaft further has a horizontal positioning hole that penetrates through the connecting shaft. Two ends of the positioning hole are formed with cylindrical holes. A reduced hole is defined between the cylindrical holes. A nut has a third inner screw hole at one end and an axial hole at another end. The nut further has a horizontal countersink hole and a horizontal fourth inner screw hole. An eccentric distance is defined between a center of the countersink hole and a center of the fourth inner screw hole. A screw is inserted through the countersink hole and locked into the fourth inner screw hole.

A positioning device positions a tool holder (12, 14, 16, 18) on a tool turret (6) of a machine tool by positioning pins (10). The positioning pins are secured to the tool turret (6) and engage with receptacles (40) on the tool holder (6) when the tool holder (12, 14, 16, 18) is attached to the tool turret (6). 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). 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).

A screwing tool includes a tool head and a tool shaft having an external thread. A first support section is disposed between the tool head and the external thread, and a second support section is disposed between the external thread and a free end of the tool shaft. The second support section has radially outwardly projecting supporting elements that are disposed at a distance from each other in the circumferential direction.

A chuck mechanism of the present invention includes multiple master jaws placed movably in a radial direction on a front surface of a chuck body, and top jaws each detachably attached to front surfaces of the top jaws. Each master jaw and each top jaw have a raised portion and a recessed portion engageable with each other. Each of the raised and recessed portions has conical surfaces formed by part of a conical body. Each top jaw has a gripping surface formed by part of a circular columnar body. Upon work gripping, the center axes of the conical surfaces on a gripping side among the conical surfaces of each master jaw and each top jaw and the center axis of the gripping surface are all coincident with a rotation axis of the chuck body.

The present invention relates to the field of industrial cutting machines and cutting tools therefore. In one particular aspect the present invention relates to a method and system for quickly changing cutting tools in computer controlled cutting machines, in a first aspect of embodiments described herein there is provided a mechanism for retaining a cutting tool of a cutting machine, the mechanism having a longitudinal axis substantially perpendicular to a cutting surface, the mechanism comprising a mount associated with the cutting machine, a holder for a cutting tool, a retaining device for removably attaching the holder to the mouth, wherein the retaining device is adapted to bias the holder in the direction of the longitudinal axis.

In a general aspect, a machining tool includes a diamond crystal having a working section configured to machine a workpiece. The machining tool includes a body and a shank extending from the body. The shank defines a cylindrical slot outside the body. The machining tool includes an assembly carried by the shank. The assembly includes a cylindrical pin that resides in the cylindrical slot. The assembly also includes a diamond crystal secured to an end of the cylindrical pin. The diamond crystal has a curved perimeter that defines a working section, which contacts a workpiece during operation of the machining tool. The shank is adapted to allow rotation of the cylindrical pin within the cylindrical slot to modify the working section.

The illustrative embodiment of the present invention uses a tangible three-dimensional structure as a fiducial mark, which structure is, at least partially, tolerant of dimensional variations in the article. The illustrative embodiment uses three such tangible three-dimensional structures: (1) a portion of a tangible conical surface, (2) a portion of a tangible spheroidal surface, and (3) a portion of a tangible pyramidal surface.

A cutting insert has a multi-stage columnar shape with an insert central axis as a center, the cutting insert including: a head portion having a circular cutting edge with the insert central axis as a center, a shaft portion disposed on a lower side of the head portion in an insert axial direction along the insert central axis and having a smaller outer diameter dimension than the head portion; a step portion configured to connect the head portion and the shaft portion; and an index portion disposed over a part of the step portion and a part of the head portion and recessed inward in an insert radial direction from an outer peripheral surface of each of the step portion and the head portion, in which a plurality of the index portions are arranged in an insert circumferential direction, and each of the index portions has a planar alignment surface.

To provide a cutting insert that readily fragmentizes chips, and that has excellent durability.

At least a cutting part of a cutting insert is formed of a sintered compact. The sintered compact includes a chip breaker that is a recessed portion in which a partial region of a cutting part upper surface is depressed downward. The chip breaker includes a downward inclined surface, an upward inclined surface, a jutting portion that juts out along a first axial line that passes through a distant end of a cutting edge, and a stepped surface that adjoins the jutting portion in a Y axis direction orthogonal to the first axial line. An upper end of the jutting portion is formed at a height of an upper stage. The stepped surface is formed at a height of an intermediate stage at a part closest to the first axial line.

A chamfer tool includes a main body, a driving shaft and a plurality of milling members. The main body, which rotates along an axis, has an inner surface and an outer surface located on opposite sides thereof; wherein the main body further has a plurality of mounting portions, each of which is connected to the inner surface and outer surface. The driving shaft is fixed to the main body to drive the main body to rotate. Each of the milling members has a first blade and a second blade, wherein the milling members are mounted on the mounting portions of the main body with the first blades protruding from the outer surface of the main body and the second blades protruding from the inner surface of the main body.