Patent ID: 8025272

Claim:
An air spring and damper unit for vehicles, comprising at least two pressure spaces filled with compressed air as a first and a second working space, a damper piston separating the first working space and the second working space from each other, a bellows at least partially delimiting one of the first and second working spaces, a first set of flow ducts inside the damper piston controlling a first flow direction from the first working space to the second working space and a second set of flow ducts controlling a second flow direction from the second working space to the first working space, each of the first and second set of flow ducts comprising a first, a second, a third, and a fourth flow duct, wherein a first controllable throttle valve is arranged in the first flow duct of the first set of flow ducts and is designed as a pilot-controlled main valve which opens in the first flow direction and which can be acted upon from the second working space with a control pressure, and the second set of flow ducts comprising a second controllable throttle valve disposed in the first flow duct of the second set of flow ducts, the second controllable throttle valve being designed as a pilot-controlled main valve opening in the second flow direction and controllable with a control pressure from the first working space, the damper piston having a piston axis, each of the throttle valves having an axis and movement direction in parallel relationship to each other and perpendicular to the piston axis, wherein the damper piston is a rotationally symmetrical piston axially movable inside a rotationally symmetrical housing and with a rear side located at a head end of a piston rod, one of the working spaces being arranged on a piston front side opposite the piston rod and the other one of the working spaces is arranged on the piston rear side, wherein in both sets of flow ducts the axis and movement direction of the respective main valve is perpendicular to the piston axis, the axis and movement direction of a respective non-return valve in the respective second flow duct is perpendicular to the piston axis and coaxial to the main valve, and a respective control valve for controlling a pilot pressure of the respective main valve has an axis and direction of action perpendicular to the piston axis and parallel to or in the axial direction of the respective main valve.