Patent application number | Description | Published |
20080265476 | Self-pumping hydropneumatic spring strut with internal level control - Self-pumping hydropneumatic spring strut includes a working cylinder divided into first and second working spaces by a working piston carried on a hollow piston rod; a high pressure chamber and a low pressure chamber partially filled with hydraulic damping medium, the high pressure chamber having a gas cushion and being connected to the second working space; and a piston pump including a pump rod extending into the hollow piston rod, the pump rod having a bore connected to the low pressure chamber, an end provided with a suction valve inside the hollow piston rod, and a deregulating opening, which is closable as a function of position of the working piston in the working cylinder. An adjustable damping valve located outside the external tube has a first flow connection connected to the first working space, and a second flow connection connected to the second working space and the high pressure chamber. | 10-30-2008 |
20080314708 | Piston-cylinder unit - Presented is a piston-cylinder unit. The piston-cylinder unit includes an outer tube defining a cavity, a working cylinder disposed in the cavity of the outer tube and filling only a portion of the cavity. The unfilled portion of the cavity is a compensating space. The compensating space is divided into an area filled with a damping medium and an area filed with a gas. The piston-cylinder unit further includes a piston rod that includes a damping piston. The piston rod is disposed in the working cylinder and has freedom of axial movement, and is configured to displace the gas. The piston-cylinder unit further includes a reservoir that has a variable volume configured for actuating the compensating space. | 12-25-2008 |
20090000469 | Piston-cylinder unit - A piston-cylinder unit configured to provide a level adjustment function based on internal pressure includes a working cylinder, a piston rod, a working piston mounted on the piston rod, and fastening elements coupled to the piston rod and the working cylinder. Each fastening element is configured to attach to a chassis or a vehicle body. One of the fastening elements is mountable with freedom of axial movement relative to the piston rod or the working cylinder and includes a cylindrical bore and a chamber disposed between the cylindrical bore and an end surface of the piston rod or a journal of the working cylinder. The end surface of the piston rod or the journal includes a first effective pressure-actuated cross-sectional area approximately the same as a second effective pressure-actuated cross-sectional area of the piston rod. The first and the second cross-sectional areas are actuated by system pressure. | 01-01-2009 |
20090033009 | Self-pumping hydropneumatic spring-damper unit - A self-pumping hydropneumatic spring-damper unit with internal leveling control is provided. The spring-damper unit has an oil-filled work cylinder under pressure by gas cushions. A damping piston is displaceable in the work cylinder and arranged at the end of a hollow piston rod whose hollow space serves to receive a pump by means of a pump rod fastened to the work cylinder. Damping medium is sucked out of a reservoir space when the piston rod moves outward and is conveyed into the work space when the piston rod moves inward. The pump rod has a control opening and, at a distance therefrom, an outlet bore for pressure equilibrium between work spaces in the work cylinder. At least one pressure-dependent throttle point is provided in the pump space between the high-pressure and low-pressure gas cushions. A first flow connection in the pump rod provided with at least one check valve connects the low-pressure gas cushion to the pump space. A second flow connection having the throttle point is connected to the work space by the outlet bore. | 02-05-2009 |
20090065991 | Self-Pumping Hydropneumatic Spring Strut - A self-pumping hydropneumatic spring strut with internal leveling control, particularly for motor vehicles, has an outer tube having an oil-filled high-pressure work space in the work cylinder, which high-pressure work space is under pressure by at least one gas cushion which is arranged in a high-pressure chamber and acts as a spring, a second work space on the piston rod side, and a piston which is supported by a hollow piston rod and which is axially displaceable in the work cylinder in a sealed manner, a piston pump which is driven by the spring movement of the vehicle and pumps oil out of a low-pressure chamber into the work space connected to the high-pressure chamber and which comprises a pump rod and a pump cylinder which is formed by the hollow piston rod, and the high-pressure chamber can be connected to the atmosphere by a flow connection which is arranged in the piston rod guide and has a closing element. The piston rod is sealed in the piston rod guide by means of at least two seals which are arranged one behind the other axially. A flow connection extends from between two adjacent seals into the low-pressure chamber. The flow connection is acted upon by a check valve which passes damping medium only in direction of the low-pressure chamber. | 03-12-2009 |
20100011578 | Check Valve - A check valve includes a housing, a bore, and a liftably movable valve body which is spring-loaded at least after a small axial travel of the valve body and tightly contacts a valve seat. The bore is constructed as a stepped bore, the bore section of smaller diameter having the valve seat, and the bore section of larger diameter receiving the liftably movable valve member. A ball which is held captive by a holding element arranged in the bore is provided as valve body. The valve seat has a contour corresponding to the valve body in the area of the contact surface of the valve body. | 01-21-2010 |
20110240424 | Vibration Damper with Integrated Level Control - A vibration damper with integrated level control includes a cylinder in which a hollow piston rod with a piston outfitted with damping valves is guided so as to be axially movable. The piston divides the cylinder into a workspace on the piston rod side and a workspace remote of the piston rod. The workspace on the piston rod side is limited at the end by a piston rod guide, and the workspace remote of the piston rod is connected to a pump space by at least one connection opening in a separating wall. The separating wall supports a hollow rod on which the piston slides and controls the pump operation of the vibration damper. A compensation space receives the damping volume displaced by the piston rod due to a dynamic load, and the piston rod guide is guided in the cylinder so as to be movable axially, and the connection opening in the separating wall is outfitted with a valve that opens in the direction of the work space remote of the piston rod. | 10-06-2011 |
20120273311 | ADJUSTABLE DAMPING VALVE DEVICE FOR A VIBRATION DAMPER - Damping valve device for a vibration damper, including an actuator that acts on a preliminary stage valve body of a preliminary stage valve. The preliminary stage valve body is arranged in a pre-loading line with a main stage valve body of a main stage valve. The lifting path of the main stage valve body is proportional to the lifting path of the preliminary stage valve body, and the damping characteristic of the damping valve device is influenced by a valve spring arrangement. The preliminary stage valve body controls an adjustable spring compressor that determines the pre-loading of a main stage valve spring is part of the valve spring arrangement. | 11-01-2012 |