Abstract: A shock strut is disclosed. The shock strut may include a shock strut cylinder, a shock strut piston that is slidably disposed within the shock strut cylinder, a metering pin, and a percolation seal configured to restrict a flow of liquid between the shock strut cylinder and the shock strut piston.

Abstract: A method to analyze a rack with riveted joints is provided. The method includes importing a computer aided design (CAD) model of a rack and finding all annular edges in the CAD model with a predefined parameter. The method further includes gathering coordinates of nodes on the found annular edges, calculating average coordinates for the nodes of each found annular edge and identifying the average coordinates as a center point for each found annular edge. The method also includes identifying pairs of proximal center points and, for each pair of proximal center points, connecting the nodes on the found annular edges with the corresponding center point with rigid constraints and generating a beam element connecting the proximal center points in accordance with the rigid constraints.

Abstract: A hydraulic cylinder retarder includes a hydraulic cylinder mechanism, a hydraulic oil conveying mechanism and a hydraulic oil valve mechanism. A piston component of the hydraulic cylinder mechanism is connected to a transmission device. Resistance to the piston movement of the hydraulic cylinder mechanism is generated by the hydraulic oil conveying mechanism and the hydraulic oil valve mechanism, so as to reduce the operation speed of the transmission device.

Abstract: A shock absorber has a first pressure tube and a second pressure tube. A first piston is disposed within the first pressure tube and a second piston is disposed within the second pressure tube. Movement of the first and second pistons within their respective pressure tubes control both damping characteristics for the shock absorber and stiffness for the shock absorber. Valving in the pistons and/or external valving associated with each pressure tube generates both the damping characteristics and the stiffness.

Abstract: A frequency unit valve is provided. In the frequency valve, a free piston reciprocates within a housing where a sub-valve is mounted in a lower portion. Variable frequency units installed above and under the free piston provide a damping characteristic by selectively opening or closing a passage when a frequency of a piston rod is in a high-frequency region and a low-frequency region. Accordingly, the vehicle ride comfort is maximally improved.

Abstract: A stabilizing device for axles of vehicles, such as motor vehicles, trailers, semi-trailers, or the like, including a hollow cylinder unit, which comprises a hollow cylinder containing a fluid therein, a piston unit with a piston which is arranged in the hollow cylinder and divides the hollow cylinder into at least two chambers, wherein the piston unit can slide relative to the hollow cylinder unit in that said piston unit can be moved from an original position to a deflected position, a pre-tensioning device which tensions the piston unit in the direction of the original position, and a control or regulating device which controls or regulates the fluid flow into/out of the chambers.

Abstract: Yaw damper for damping yaw motions between two vehicle parts. This includes in the customary manner a piston part and a cylinder part, wherein that piston part is provided with a piston which divides that cylinder part into two chambers. Between these two chambers, connecting lines are present. The embodiment of these connecting lines determines the damping characteristic which governs the motion between the piston and the cylinder part. Especially for vehicle parts which move at higher speeds and/or high frequencies, such as train sets, it is desirable to provide a damper which is as stiff as possible. For this purpose, the present invention proposes the installation of pumping elements which, as far as possible, increase the pressure in the chambers which are formed by the piston in the cylinder part. Preferably, this construction is realized such that this pressure automatically decreases at lower speeds and/or low frequencies.

Abstract: The invention relates to a suspension arrangement (1) for—loading-bearing and resilient wheel support in a motor vehicle, having at least one spring cylinder (2) with a piston (6) which is guided in a cylinder (4) such that it can be moved relative to the latter and which, on one side, has a piston rod (8) guided out of the cylinder (4) in the outward direction. The piston (6) separates, within the cylinder (4), a cylindrical working chamber (12) from an annular chamber (14), which encloses the piston rod (8). On the side of the working chamber (12), in order to generate a load-bearing spring force (F), the piston (6) acts counter to a working pressure (pA) of an elastically compressible, in particular pneumatic spring medium (FM). The piston rod (8) is telescopically variable in length via an additional spring cylinder (16), the additional spring cylinder (16) being subjected at least to a counterpressure (pG; pG1, pG2) of an elastically compressible, in particular pneumatic opposing spring medium (GM).

Abstract: Vibration damper comprising a cylinder in which a piston rod is guided with freedom of axial movement, where the piston rod cooperates with a piston arrangement comprising a first, stationary piston and at least one additional piston, which is supported on the piston rod with freedom of axial movement against the elastic force of at least one restoring spring, where the cylinder is divided by the stationary piston and by the minimum of one axially movable piston into a working space on the side of the piston facing the piston rod, a working space on the side of the piston facing away from the piston rod, and a working space between the two pistons, where valve-equipped through-openings control a connection between the working spaces, and where the axial movement of the minimum of one axially movable piston is limited by a hydraulic pressure stop.

Abstract: A force control strut including a housing having first and second ends and an internal chamber, a rod member having an inner end reciprocally movable inside the housing and along the internal chamber, a guide member forming a bushing allowing reciprocation of the rod member in the housing, a bottom plug fixed in the internal chamber, a guide piston secured to an inner end of the rod and slidable along an inner surface of the internal chamber, a first coil spring positioned between the guide piston and one end of the housing to bias the rod member in a given direction in the housing, a first external connector fixed to the rod member, a second connector fixed to the bottom plug, and a damper that includes a plunger reciprocally mounted in a force controlling passageway inside the rod member and movable in a passageway of the rod member.

Abstract: A shock absorber comprises first and second axially aligned cylinders (11, 21) each having a liquid filled prison chamber (12, 22), an axially displaceable piston (13, 23), received in the piston chamber (12, 22), and dampeners (14, 24) for dampening axial displacement of the piston (13, 23) through the liquid in the piston chamber (12, 22). A piston rod (1) axially extends between and into the first and second cylinder piston chambers (12, 22). The first and second axial ends (1a, 1b) of the piston rod (1) are connected to the first and second cylinder pistons (13, 23), respectively.

Abstract: A frequency-dependent damper incorporates a compensated piston assembly to reduce the amount of static push-out force. The piston rod is a hollow rod with a compensator being disposed within the hollow portion of the piston rod. The piston rod is a hollow rod with a compensator being disposed within the hollow portion of the piston rod. The compensator is attached to the pressure tube of the damper such that the compensator slides within the piston rod during stroking of the shock absorber. The compensated piston assembly reduces the difference in cross-sectional area between the upper and lower surfaces of the piston.

Abstract: A suspension unit used in a pull type shock application is disclosed, whereby a main shaft passes completely through a damping fluid so that the shock absorber fluid is not compressed when the shock shaft is displaced. The shaft also acts on a compression spring by an additional piston on the shaft. A cylindrical outer housing provides two distinct air chambers. The pressurization of these air chambers alters the spring rate, preload of the suspension, and vehicle ride height.

Abstract: A prosthetic knee device having a hydraulic cylinder with a piston and a gas cylinder. A connecting element extends outwardly from the piston and passing through a gas cylinder. A bottom portion of the gas cylinder is adapted for slidable engagement with the hydraulic cylinder. A plunger is fixedly connected to the hydraulic cylinder. An outer periphery of a plunger is adapted for slidable engagement with the interior surface of the gas cylinder, so as to form an operational chamber within the gas cylinder between the bottom portion thereof and the plunger. The operational chamber is responsive to the movement of the prosthetic knee device.

Abstract: A shock absorber comprises first and second axially aligned cylinders (11, 21) each having a liquid filled piston chamber (12, 22), an axially displaceable piston (13, 23) received in the piston chamber (12,22), and means (14, 24) for dampening axial displacement of the piston (13,23) through the liquid in the piston chamber (12, 22). A piston rod (1) axially extends between and into the first and second cylinder piston chambers (12, 22). The first and second axial ends (1a , 1b) of the piston rod (1) are connected to the first and second cylinder pistons (13, 23) respectively.

Abstract: A dampening apparatus for dampening an actuating member over a wide array of temperatures. The present invention provides a fluid filled housing having a first chamber, a second chamber, and a passageway therebetween. A first piston is slidably received within the first chamber for movement from a pre-actuated position to an actuated position. A second piston is slidably received within said second chamber for movement from said pre-actuated position to said actuated position. A spring disposed within the second chamber biases the second piston toward said passageway and maintains a constant level of fluid pressure within the housing regardless of the temperatures of the fluid. An exhaust port is in communication with the second chamber wherein the second piston is disposed between the passageway and the exhaust port in the pre-actuated position, and wherein the exhaust port is located between the passageway and the second piston in the actuated position to allow the fluid to escape through the exhaust port.

Abstract: An actuation arrangement for movable components on vehicles, particularly for trunk lids or hoods, doors, vehicle tops and top covers, including at least one hydraulic cylinder (1) pivotably coupled to a cylindrical pivot pin (11) on the vehicle and/or on the movable vehicle component, and having at least one line (1) for the pressure medium in at least one working chamber (6, 9) of the hydraulic cylinder.

Abstract: A braking- and damping device, in particular for movable pieces of furniture, having a fluid-cylinder (1) in which two pistons (2, 5) are arranged in linearly displaceable manner. A piston (2) is displaceable over a piston rod (3). Arranged between the two pistons (2, 5) is an elastically deformable sealing member, which, when damping occurs, is deformed by being squeezed between the two pistons (2, 5) and pressed against the cylinder wall (7).

Abstract: A shock absorber is made with a bleed function and preferably a non-return valve function associated with the bleed function. The shock absorber has a cylinder (3) and, working in the latter in working medium and arranged on a piston rod (4), a piston arrangement. The latter comprises at least two first and second pistons (5, 6) arranged at a distance from one another on the piston rod. At least one piston (5) can, in connection with an end position, be introduced into a first space so as, depending on its position in or at the space, to bring about a modified or varied damping force relative to when the piston is located outside the space. The piston rod (4) is provided with an inner second space (15) which is arranged so as to contain said bleed and/or non-return valve function. Additionally or alternatively, the piston (6) working outside the first space is provided with a member performing a bleed function and with any associated non-return valve function.

Abstract: A fluid regulating device includes a valve housing formed with a piston receiving chamber that has a piston member slidingly and sealingly disposed therein to divide the piston receiving chamber into a volume-variable gas compartment filled with pressurized gas and a volume-variable fluid compartment. A regulator receiving chamber has a large-diameter rod receiving section, and a small-diameter fluid channel with a rate control section that is aligned with and that extends from the rod receiving section. The fluid channel interconects fluidly the rod receiving section and the fluid compartment.

Abstract: A speed controlling hydraulic dampener comprises a tubular housing defining a closed cylindrical chamber for containing a hydraulic fluid. The chamber containing two separate pistons and piston rods that extend through sealed openings in the ends of the housing. The second piston is spring-biased. First and second orifices are provided in the wall of the housing which are connected by a tubular passageway. A special seal arrangement cooperates with the first piston rod and with the wall of the housing defining the cylindrical chamber. This seal includes a third orifice extending longitudinally therethrough and cooperating with this orifice is a flow-controlling needle valve that can be used to adjust the rate of flow of hydraulic fluid from a first portion of the chamber through the first orifice, the tubular passageway and the second orifice to a zone between the first and second pistons.

Abstract: The invention is related to a tie device for use between two structural elements (10, 20) of a civil engineering structure, such as, for example a bridge. The tie device allows the two structural elements to be displaced relative to each other during slow movements, and prevents the two structural elements from being displaced relative to each other during rapid movements. In one embodiment of the invention, the tie device comprises a cylinder (30) which is stationary relative to the first structural element (10), and which defines two chambers (31, 32) that contain a fluid and that are interconnected via an orifice (39). The cylinder (30) includes a wall (33) that separates the two chambers. Each chamber is defined at its end remote from the wall (33) by moving pistons (37, 38) that are secured to the second structural element (20).

Abstract: A method and apparatus for structural deflection control, as well as associated sequential controls that are based on new control laws. The apparatus of this invention is of relatively low cost and performs better than prior art devices. The essence of the invention is to adjust the dynamic parameters (mass, damping, stiffness coefficients of the structure and/or input forcing coefficients) adaptive to input dynamic loads, by using the new devices and the suggested control laws. In so doing, the structure performs an adaptive function to effectively counter the effects induced by multi-directional external excitations. The required control power can be nil, or many times lower than prior art active control devices, and the effectiveness can be equivalent or even better than the current state-of-the-art active controls. The devices used by the apparatus of this invention can readily be manufactured for immediate application in structures, buildings and contents, and other constructed facilities.

Abstract: A valve actuator employs a torsion spring type clutch to engage and disengage a drive motor and an output shaft. The torsion spring normally engages and is connected to a gear which may be engaged by a dog to cause disengagement of the clutch. The output shaft carries a pinion which is engaged with a rack carried on a piston which is slidable in a closed fluid containing cylinder. The piston includes an axial passageway with a metering orifice therein which smoothes the operation of the actuator and provides positive stops for the output shaft with a minimization of impact between the piston and the ends of the cylinder.