Abstract: A machining apparatus including a rotating shaft disposed rotatably about an axis thereof, an eccentric rotating member supported by the rotating shaft rotatably about an axis thereof which is offset from the axis of the rotating shaft, at least one cutting tool which is supported by the eccentric rotating member such that each cutting tool is rotated with the eccentric rotating member and such that the cutting edge of each cutting tool is offset from the axis of the eccentric rotating member, and a rotating device supported by the rotating shaft, for rotating the eccentric rotating member relative to the rotating shaft, and thereby changing the cutting edge position of each cutting tool in the radial direction of the rotating shaft.

Abstract: An indexing device wherein a rotary member which is supported by a support member such that the rotary member is rotatable about its axis and axially movable between a first position thereof and a second position thereof is rotated by a rotational drive mechanism having a one-way clutch, in increments of a predetermined angle, and wherein the rotary member is prevented by a stopper mechanism from being rotated past the predetermined angle due to inertia while being placed in the first position, and is precisely positioned by a positioning mechanism while being placed in the second position.

Abstract: A holder for a rotary cutting tools has a holder body fixed to a spindle of a machine tool. A rotatable shaft concentric with the holder body and having a tool-mounting portion at one end thereof is coupled at its other end portion to the holder body to receive torque from the holder body. The rotatable shaft is so mounted as to be radially displaceable and inclinable relative to the holder body. A positioning member is fixedly disposed on the machine tool body radially outwardly of the spindle. A cylindrical casing disposed radially outwardly of and rotatably engaged with the rotatable shaft such that the casing and the shaft are rotatable relative to each other, the casing being engageable with the positioning member for accurate positioning thereof by the positioning member, and thereby positioning the rotatable shaft.

Abstract: A tool holder for holding a rotary cutting tool, attachable to a spindle of a machine tool, has a holder body fixed to the machine spindle. A rotatable shaft having a tool-mounting portion is coupled to the holder body such that the shaft is axially and radially displaceable relative to the holder body. A positioning member is fixedly disposed on the machine tool body radially outwardly of the machine spindle. A casing is disposed radially outwardly of the rotatable shaft such that the casing and the rotatable shaft are rotatable relative to each other, the casing being engageable with the positioning member to accurately position the rotatable shaft when the holder body is fixed to the machine spindle. A guide bushing is fixedly supported at one axial end portion of the casing remote from the holder body.

Abstract: A multi-spindle unit for holding and rotating a plurality of rotary cutting tools has a unit body fixed to a first spindle of a machine tool, a rotatable shaft concentric with the unit body, and a plurality of secondary spindles each having a tool mounting portion at one end thereof. The rotatable shaft is coupled at one end portion to the unit body for receiving a torque from the holder body, the rotatable shaft being displaceable relative to the holder body. A rotation transmitting mechanism is provided to transmit a rotary motion of the rotatable shaft to the secondary spindles. A positioning member is fixedly disposed radially outwardly of the first spindle, and a cylindrical casing is disposed radially outwardly of the rotatable shaft such that the casing and the shaft are rotatable relative to each other. The casing is engageable with the positioning member for positioning thereof by the positioning member, and thereby positioning the secondary spindles.

Abstract: An end milling tool having an elongate body which has two flutes defining two elongate lands extending generally in an axial direction of the body. The two lands have first and second flute surface each facing in a direction of rotation of the end mill. The end mill carries at least two peripheral-cutting inserts for peripheral milling, an inner drilling insert for cutting a radially inward portion of a hole, and an outer drilling inserts for cutting a radially outward portion of the hole, each insert being replaceable and of a generally flat configuration having a back face held in contact with the appropriate surface of the body, and a front face opposite to the back face and including a cutting edge. The peripheral-cutting inserts are disposed in a staggered manner alternately in the first and second flute surfaces, such that the first flute surface carries the peripheral-cutting insert which is nearest to the end face of the body.