A cutter holder has a body and a damping assembly. The damping assembly is contained inside the body. The damping assembly has a central damping pole and six auxiliary damping poles. The six auxiliary damping poles are arranged around the central damping pole. The body has a specific weight. The central damping pole has a specific weight larger than the specific weight of the body. Each one of the six auxiliary damping poles has a specific weight larger than the specific weight of the body. The damping assembly is utilized to reduce vibrations caused by machining.

A boring bar for a non-rotating boring tool includes an elongated body configured for attachment to a support structure of a metal cutting machine and arranged to carry a tool part provided with a cutting element. At least two electrically controlled vibration actuators are arranged for active vibration damping of the boring bar. Each actuator includes a moveably arranged damping mass configured to generate vibratory forces in parallel with a working axis of the actuator that is perpendicular to a center axis of the damping mass. Each actuator is a single-axis actuator having one single working axis, wherein the actuators are arranged with their working axes angularly offset from each other. The actuators are arranged in a longitudinal series in the elongated body with the center axis of the damping mass of each actuator coinciding with a longitudinal axis of the elongated body.

A tool body includes a damping apparatus for damping vibrations in a machining tool having, besides the tool body, a member with at least one cutting edge to be secured to the tool body. The damping apparatus is arranged in an internal room of the tool body and includes a damper mass body with an axial bore and a central tube extending through the bore and which is rigidly secured to the damper mass body inside the through bore. A central tube is also at both ends thereof rigidly connected to a tool body fixed part and the central tube is made of a material with a spring property allowing the damper mass body to oscillate in the internal room perpendicularly to the longitudinal extension of the central tube.

A tool body includes a damping apparatus having a damper mass body with an axial through bore and a central tube received in the through bore and surrounded by a cavity. An elastic element is arranged on each side of the damper mass body and provided with two socket-like portions extending axially through a central hole of two disc-like members clamping the elastic element therebetween. The socket-like portions project in a rest state of the elastic element extend axially beyond the respective axially directed side of the respective disc-like member and are in an assembled state of the tool body compressed for sealing the cavity with respect to the exterior.

A damping apparatus is provided for damping vibrations of a tool-holding apparatus during machining of a workpiece. The damping apparatus comprises a damping body having two ends on which a respective damping device is arranged, which comprises a bearing pin rigidly connected to the damping body and a bearing bush that surrounds the bearing pin in the circumferential direction. An annular space filled with a damping fluid is arranged between the bearing pin and the bearing bush, which annular space is sealed in the axial direction by two elastically deformable sealing rings. The two sealing rings each comprise first and second abutment regions as well as a resilient intermediate region arranged therebetween. The first abutment region is bonded to the bearing pin and the second abutment region is bonded to the bearing bush. The intermediate region is elastically deformable relative to the bearing pin and the bearing bush.

An elongated tool holder has a tool anti-vibration component constituting a mass housing portion provided with an enclosed interior cavity, and an anti-vibration arrangement occupying the enclosed interior cavity. The anti-vibration arrangement includes two vibration absorbing masses disposed within the holder cavity and elastically suspended therein by at least three resilient suspension members contacting an inwardly facing cavity wall surface. The two vibration absorbing masses are made from different materials and have different lengths. A cutting tool is provided with the tool holder.

An elongated tool holder includes a mass housing portion having a housing peripheral surface, an outer sleeve having a sleeve hole wall surface, and an anti-vibration arrangement. An elongated groove is formed in one of the housing peripheral surface and the sleeve hole wall surface. In an assembled state of the tool holder, the groove, which is located at a common interface of the housing peripheral surface and the sleeve hole wall surface, forms a groove coolant channel. The groove coolant channel forms part of an overall tool holder coolant channel which is spaced apart from the anti-vibration arrangement, and thus isolates the coolant from the anti-vibration arrangement. A cutting tool incorporates the tool holder.

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 boring bar with electrodynamic actuators is for counteracting vibrations and machine tool provided with such a bar. The boring bar includes a wall, an internal recess and a longitudinal axis. The boring bar has a first electrodynamic actuator with coil windings associated with a moving mass and a spring assembly that are arranged to define a first actuation direction perpendicular to the longitudinal axis of the boring bar. A second electrodynamic actuator has coil windings associated with a moving mass and a spring assembly that are arranged to define a second actuation direction perpendicular to both the first actuation direction and the longitudinal axis of the boring bar. The actuators allow counteraction of the vibrations in the directions perpendicular to the longitudinal axis of the bar. The longitudinal axis also defines the boring direction.

To make it possible for bores (16) that are in line with one another to be efficiently worked by means of a boring bar (2), the boring bar has a main body (10) with an axis of rotation (R) and a number of cutting elements (12, 12A) at intervals from one another in the axial direction (4) and also guiding elements (14) for guiding the main body (10) in a guiding bore (16A). The guiding elements (14) are kept at a distance from the axis of rotation (R) equivalent to a guide radius (r1). The main body (10) is divided into a functional region (19) and an eccentric region (10), wherein the cutting elements (12, 12A) and the guiding elements (14) are arranged such that they are distributed around the main body (10) over an angular range (a) of less than 180°. Furthermore, the circumferential side (22) of the main body (10) can be passed eccentrically through a respective bore (16, 16A) of which the unworked tube radius (r2) is less than the guide radius (r1).