Provided is a vibration-proof structure capable of more effectively reducing rotational vibration of a rotating body during a cutting operation. According to a configuration of the structure, inside a main body of the rotating body, there are provided a plurality of shaft members arranged along a longitudinal direction of a rotation axis of the rotating body and at least one layer of multiple tubular members fitted over the shaft members and arranged coaxially with the rotation axis along the longitudinal direction of this rotation axis; and a boundary position between the shaft members adjacent each other in the longitudinal direction and a boundary position between the tubular members adjacent each other in the longitudinal direction are set as different positions along the longitudinal direction.

An anti-vibration damper for tools for machining of metallic work pieces is provided. For improving the damping in order to be more effective under rough includes a vibration damping device received in a hollow cylindrical space of a tool member. The vibration damping device includes a plurality of rotationally symmetrical stacked on top of each other to form a stack. A part of mutually facing upper and lower surfaces of adjacent members is spaced at a distance from each other by elastically deformable elements. The outer diameter of the stack is smaller than the inner diameter of the hollow cylindrical space of the tool member, thereby providing a cylindrical gap, which is substantially filled with spherical balls, wherein clear gap width between the inner diameter of the hollow cylindrical space and the common outer diameter of the stack deviates from any integer sum of the ball diameters.

A cutting tool holder has a holder body and a vibration damping weight assembly. The holder body has first and second side surfaces, and a top surface extending there between, and a cutting portion located at a front end of the holder body at the top surface thereof. A weight aperture opens out to the first and second side surfaces and has an aperture inner surface. A weight assembly is located within the weight aperture, having a first weight portion with a through hole, a second weight portion with a threaded hole, a damping ring located along the aperture inner surface, and a fastening member configured to connect together and urge the first and second weight portions towards one another, such that the contact surface of each weight portion presses against the damping ring, within the weight aperture.

A milling cutter with at least one peripheral cutting edge 4 disposed on its periphery, the peripheral cutting edge 4 being configured as a profile of spaced-apart teeth 7 that forms a so-called cord; wherein each of the teeth 7looking from the flute in a direction opposite to the cutting direction onto the cutting edge portionforms a cutting edge portion SK composed of several different radii, i.e. of at least one larger radius R1 forming the predominant part of the cutting edge portion of the respective tooth 7 and a smaller radius R2, which is preferably immediately adjacent thereto on both sides.

A rotary cutting tool includes a tool body including a chip flute portion having a plurality of helical chip flutes separated by lobes. In one aspect, a tunable vibration absorber assembly is disposed within a cavity formed in the chip flute portion. In another aspect, the tunable vibration absorber assembly is disposed within a cavity of a replaceable cutting head. In each aspect, the tunable vibration absorber assembly includes at least two tunable absorber masses, a resilient material between the one or more absorber masses and the cavity, and one or more connecting members for preventing relative angular displacement of the one or more tunable absorber masses. The at least two tunable absorber masses are suspended only by the resilient material, thereby enabling the tunable vibration absorber assembly to be tuned to a desired frequency for suppressing torsional vibration of the rotary cutting tool during a cutting operation.

A rotary cutting tool includes a tool body including a shank portion and a cutting portion adjoining the shank portion. The cutting portion has a plurality of blades separated by helically twisted flutes. A tunable vibration absorber is disposed within an internal cavity formed in the cutting portion and has a shape that follows the helically twisted flutes. The tunable vibration absorber includes an absorber mass and a resilient material disposed between the absorber mass and an outer wall of the internal cavity. In one aspect, the tunable vibration absorber is tuned to a desired frequency by selecting the mechanical properties of the absorber mass and the resilient material. In another aspect, the tunable vibration absorber is tuned by controlling a pressure of fluid within a main internal fluid cavity disposed within the tunable vibration absorber.

A rotary cutting tool includes a tool body including a shank portion and a cutting portion adjoining the shank portion. The cutting portion has a plurality of blades separated by helically twisted flutes. A tunable vibration absorber is disposed within an internal cavity formed in the cutting portion and has a shape that follows the helically twisted flutes. The tunable vibration absorber includes an absorber mass and a resilient material disposed between the absorber mass and an outer wall of the internal cavity. In one aspect, the tunable vibration absorber is tuned to a desired frequency by selecting the mechanical properties of the absorber mass and the resilient material. In another aspect, the tunable vibration absorber is tuned by controlling a pressure of fluid within a main internal fluid cavity disposed within the tunable vibration absorber.

A tool (T) is provided with: a shaft-like tool body (11) having a first end portion (11a) extending along a central axis line (Ot) and attached to a main shaft, and a second end portion (11b) on an opposite side to the first end portion (11a); and a fore end portion (12) connected to the second end portion (11b) of the shaft-like tool body (11). The fore-end portion (12) includes a central portion (13) including a fore-end face (17) of the tool (T), and a plurality of blade portions (14) protruding radially outward from the central portion (13). A cutting blade of each blade portion (14) includes a main cutting blade (15) adjacent to the fore-end face (17). The main cutting blade (15) includes an outline that forms an angle of 30-150 degrees with respect to the central axis line (Ot) in a cross-sectional view including the central axis line (Ot).

A tool holder, for a tool assembly, comprising a tubular element having a cavity and a central axis; a damping mass arranged within the cavity and movable radially with respect to the central axis and relative to the tubular element; an adapter having a rear part fixed to the tubular element, and a front part for connection to an end effector of the tool assembly, the rear part comprising an opening, and the damping mass is at least partly received in the opening with a radial clearance; and an elastic element positioned between the adapter and the damping mass, the elastic element being arranged to support the damping mass and to damp radial vibrational movements of the damping mass relative to the tubular element, and the elastic element comprising a front surface substantially perpendicular to the central axis and a rear surface substantially perpendicular to the central axis.

A cutting tool is rotatable about an axis line, and includes a main body portion, a cutting insert, and a plurality of anti-vibration members. The main body portion has an inner circumferential surface and an outer circumferential surface opposite to the inner circumferential surface. The cutting insert is attached to at least one of the inner circumferential surface and the outer circumferential surface. Each of the plurality of anti-vibration members is provided at the main body portion. Each of the plurality of anti-vibration members includes a weight member composed of a material having a specific gravity larger than a specific gravity of a material of the main body portion.