The invention relates to an industrial truck comprising

a chassis (6),
a mast (8) arranged on the chassis (6) in an upright position, a load-carrying apparatus (36), which has at least one load-receiving means (42) for receiving a load that is to be transported,
a support structure (9) that supports the load-carrying apparatus (36) on the mast (8) and can be moved, together with the load-carrying apparatus (36), upwards and downwards on the mast (8), and comprising
a device (54) for reducing vibrations,
wherein the device (54) for reducing vibrations has at least one additional mass body (60), which is supported by the mast (8) or the components connected thereto and is not constantly rigidly coupled to the mast (8) or the support structure (9) or the load-carrying apparatus (36), but is movably mounted by means of a bearing arrangement (62) such that it is movable relative to the mast (8) in response to mast vibrations, in particular to mast vibrations having horizontal vibration components, in order to counteract mast vibrations.

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.

The invention relates to a vibration elimination system, comprising a shielding plate (2) for a motor component, at least one vibration elimination element (10) that is fastened to the shielding plate (2), wherein each vibration damping element (10) comprises a spring-mass system that is capable of vibration, the spring force and mass of which are dimensioned such that said spring-mass system is matched to a predetermined vibration frequency of the shielding plate (2).

The invention relates to a vibration elimination system, comprising a shielding plate (2) for a motor component, at least one vibration elimination element (10) that is fastened to the shielding plate (2), wherein each vibration damping element (10) comprises a spring-mass system that is capable of vibration, the spring force and mass of which are dimensioned such that said spring-mass system is matched to a predetermined vibration frequency of the shielding plate (2).

An electromagnetic actuator including: an outer housing member wherein outer peripheral edges of lid members are fixed respectively to opposite axial sides of the outer tubular member; an inner axial member elastically-connected to the outer housing member by plate springs at opposite axial sides thereof such that central portions of the plate springs are attached to the inner axial member, while outer peripheral edges of the plate springs are clamped and fixed between the outer tubular member and the respective lid members; a stator and a mover having electromagnetic oscillation force between them securely-assembled to the outer housing member and the inner axial member; and integrally-formed seal rubber and stopper rubber provided at inner faces of the lid members to seal a fixation part to the outer tubular member and to cushion strike of the inner axial member against the lid members, respectively.

An electromagnetic actuator including: an outer housing member wherein outer peripheral edges of lid members are fixed respectively to opposite axial sides of the outer tubular member; an inner axial member elastically-connected to the outer housing member by plate springs at opposite axial sides thereof such that central portions of the plate springs are attached to the inner axial member, while outer peripheral edges of the plate springs are clamped and fixed between the outer tubular member and the respective lid members; a stator and a mover having electromagnetic oscillation force between them securely-assembled to the outer housing member and the inner axial member; and integrally-formed seal rubber and stopper rubber provided at inner faces of the lid members to seal a fixation part to the outer tubular member and to cushion strike of the inner axial member against the lid members, respectively.

A building element includes a sheet of a rigid material and at least one nonlinear energy sink including a blade with two end parts and a nonlinear spring function intermediate part, a mass fixed to the nonlinear spring function intermediate part of the blade, and a fixing element allowing the two end parts of the blade to be fixed to a solid support in such a way that the nonlinear spring function intermediate part can oscillate about its position of equilibrium or its positions of equilibrium. The nonlinear energy sink is fixed rigidly to the sheet by the fixing element. The building element can be contained in a partition wall. Additionally, such an energy sink or building element can be used for reducing the acoustic transparency of a wall.

A building element includes a sheet of a rigid material and at least one nonlinear energy sink including a blade with two end parts and a nonlinear spring function intermediate part, a mass fixed to the nonlinear spring function intermediate part of the blade, and a fixing element allowing the two end parts of the blade to be fixed to a solid support in such a way that the nonlinear spring function intermediate part can oscillate about its position of equilibrium or its positions of equilibrium. The nonlinear energy sink is fixed rigidly to the sheet by the fixing element. The building element can be contained in a partition wall. Additionally, such an energy sink or building element can be used for reducing the acoustic transparency of a wall.

In one embodiment, a vibration control apparatus is provided having a pair of face sheets with a core material in between. The core material comprising a positive stiffness material. A stack comprising a positive stiffness structure in series with a negative stiffness structure is located between the pair of face sheets, in parallel with the core material. The stack may be embedded in the core material. Various embodiments may include multiple stacks in parallel with each other. In some embodiments, the stack may include multiple positive stiffness structures in series with multiple negative stiffness structures. The multiple positive stiffness structures and negative stiffness structures may be interleaved.

A machining unit for a machine tool includes a carrier head base, which on its rear side includes a carriage. The carriage can be coupled to axis guides and is longitudinally displaceable. The machining unit further includes a spindle carrier head held pivotably on the carrier head base. The spindle carrier head has a spindle with a tool holder. The carrier head base is provided with a damping unit. The disclosed machining unit provides increased precision of a machine tool. The machining unit may be incorporated in a machine tool.