A tamping unit includes tamping tines and a squeezing drive for squeezing the tamping tines. A vibration exciter has an outer cylinder and an inner cylinder. The inner cylinder is disposed coaxially to a cylinder axis and is mounted for displacement in an axial direction along sliding or gliding surfaces in the outer cylinder. A ring-shaped recess is provided between the two sliding or gliding surfaces which are spaced from one another in the axial direction. A spacer ring, which subdivides the ring-shaped recess into two fluid channels, is connected selectively to the inner or outer cylinder. The fluid channels are spaced from one another relative to the axial direction. The two fluid channels can be hydraulically actuated alternatingly by feed lines for vibration excitation.

The invention relates to a track maintenance machine having a tamping unit for tamping sleepers of a track lying in a ballast bed, including a tool carrier which is mounted for vertical adjustment on an assembly frame and on which tamping tools are arranged so as to be squeezable towards one another, wherein the tool carrier is coupled to a vertical adjustment drive actuated by means of a control device. In this, a control circuit is set up for controlling a lowering motion of the tool carrier, the control circuit including a controller, a setting device for the vertical adjustment drive and a measuring device for recording the lowering motion. With this, it is possible to provide an optimal course for the lowering motion.

The invention relates to a track maintenance machine having a tamping unit for tamping sleepers of a track lying in a ballast bed, including a tool carrier which is mounted for vertical adjustment on an assembly frame and on which tamping tools are arranged so as to be squeezable towards one another, wherein the tool carrier is coupled to a vertical adjustment drive actuated by means of a control device. In this, a control circuit is set up for controlling a lowering motion of the tool carrier, the control circuit including a controller, a setting device for the vertical adjustment drive and a measuring device for recording the lowering motion. With this, it is possible to provide an optimal course for the lowering motion.

A tamping unit of a machine for simultaneously tamping at least two sleepers of a track, positioned one following the other with regard to a longitudinal direction of the machine, includes inner tamping tines provided for simultaneous immersion into the same sleeper crib and, arranged at either end, a respective outer tamping tine. Each tamping lever mounted on an assembly frame for pivoting about a pivot axis is connected to a squeeze drive. Each squeeze drive is mounted on a common eccentric shaft having an eccentricity with respect to an axis of rotation. The eccentricity causing vibrations of the inner tamping tine is configured differently as compared to the eccentricity causing vibrations of the outer tamping tine.

A tamping unit of a machine for simultaneously tamping at least two sleepers of a track, positioned one following the other with regard to a longitudinal direction of the machine, includes inner tamping tines provided for simultaneous immersion into the same sleeper crib and, arranged at either end, a respective outer tamping tine. Each tamping lever mounted on an assembly frame for pivoting about a pivot axis is connected to a squeeze drive. Each squeeze drive is mounted on a common eccentric shaft having an eccentricity with respect to an axis of rotation. The eccentricity causing vibrations of the inner tamping tine is configured differently as compared to the eccentricity causing vibrations of the outer tamping tine.

A tamping assembly for a track tamping machine comprises a carrier guided in a height-adjustable manner with respect to a tamping assembly frame along guides, on which carrier pairs of tamping tools formed as oscillating levers are pivotably mounted, the tamping tools of which can be oppositely driven by an oscillation drive and can be hydraulically adjusted relative to one another, said tamping tools being intended for introduction into a ballast bed. To reduce the number of required drives, several of the tamping tools are combined into tamping units with a compartment between them engaging around a rail and are mechanically connected to each other, and each oscillating lever is associated with a tamping unit and an adjusting drive, wherein the guides, especially the guide rods, act directly on the respective carrier and run in fixed guides of the tamping assembly frame.

A tamping assembly for a track tamping machine comprises a carrier guided in a height-adjustable manner with respect to a tamping assembly frame along guides, on which carrier pairs of tamping tools formed as oscillating levers are pivotably mounted, the tamping tools of which can be oppositely driven by an oscillation drive and can be hydraulically adjusted relative to one another, said tamping tools being intended for introduction into a ballast bed. To reduce the number of required drives, several of the tamping tools are combined into tamping units with a compartment between them engaging around a rail and are mechanically connected to each other, and each oscillating lever is associated with a tamping unit and an adjusting drive, wherein the guides, especially the guide rods, act directly on the respective carrier and run in fixed guides of the tamping assembly frame.

In a tamping unit for tamping sleepers of a track, both squeezing drives of a tamping tine pair are articulatedly connected to a common connecting carrier. A vibration exciter fastened to the tine carrier is connected to the connecting carrier, likewise fastened to the tine carrier, for transmission of tamping tine vibrations from the connecting carrier to the squeezing drives and the tamping tines.

The invention relates to a tamping assembly for tamping sleepers of a track, including a tamping unit having oppositely positioned tamping tools mounted on a vertically adjustable tool carrier, the tamping tools being coupled in each case via a squeezing drive to a vibration drive, wherein each tamping tool comprises a pivot lever rotatable about a pivot axis and at least one tamping tool mount for accommodating at least one tamping tine. In this, a first squeezing drive is coupled directly to the vibration drive and articulatedly connected to a first pivot lever, and a second squeezing drive is coupled to the vibration drive via a separate coupling unit and articulatedly connected to a link, mounted on the tool carrier, as well as to a second pivot lever. In this manner, the tamping unit can be configured in a very compact way with squeezing drives being arranged one below the other, wherein forces and momentums occurring during operation can be easily controlled.

The invention relates to a tamping assembly for tamping sleepers of a track, including a tamping unit having oppositely positioned tamping tools mounted on a vertically adjustable tool carrier, the tamping tools being coupled in each case via a squeezing drive to a vibration drive, wherein each tamping tool comprises a pivot lever rotatable about a pivot axis and at least one tamping tool mount for accommodating at least one tamping tine. In this, a first squeezing drive is coupled directly to the vibration drive and articulatedly connected to a first pivot lever, and a second squeezing drive is coupled to the vibration drive via a separate coupling unit and articulatedly connected to a link, mounted on the tool carrier, as well as to a second pivot lever. In this manner, the tamping unit can be configured in a very compact way with squeezing drives being arranged one below the other, wherein forces and momentums occurring during operation can be easily controlled.