Abstract: A retractable speed bump and a method for retracting a speed bump. The retractable speed bump may include a retractile element, a chassis, and a hydraulic mechanism. The hydraulic mechanism may include a hydraulic cylinder including a hollow cylindrical shape, a hydraulic piston including a solid cylindrical shape, a first connecting rod, an oil sealing member, a return spring, a spring retainer, and a floating gasket. Responsive to downward movement of the first connecting rod at a speed higher than a threshold, the hydraulic cylinder may prevent downward movement of the first connecting rod and responsive to downward movement of the first connecting rod at a speed lower than the threshold, the hydraulic cylinder may allow downward movement of the first connecting rod.

Abstract: A motor-vehicle shock absorber has a tube at least partially filled with damping liquid and extending, a piston rod axially shiftable inside the damper tube, and a piston connected to the piston rod and subdividing the damper tube into a piston rod-side working chamber and an opposite working chamber. An on-off control valve is axially movable inside the piston between a closed and an open position. A first soft-characteristic damping valve inside the piston through which the damping liquid may flow in both flow directions is connectable to a flow path of the damping liquid from one into the other working chamber through the control valve. A second hard-characteristic damping valve through which the damping liquid may flow in both flow directions is also provided in the piston.

Abstract: A residual pressure holding valve (1) for a hydropneumatic suspension strut (2) of a motor vehicle has a valve housing (3) with an air inlet (4) and an air outlet (5). A valve body (6) is arranged displaceably in the valve housing (3) and a valve element (7) is arranged displaceably in the valve body (6). Air pressure applied to the air inlet (4) can lift the valve body (6) off a valve body seat (8) of the valve housing (3) to allow air to flow past the valve body (6) to the air outlet (5). Air pressure applied to the air outlet (5) can lift the valve element (7) off a valve element seat (9) of the valve body (6) to allow air to flow past the valve element (7) to the air inlet (4).

Abstract: A shock absorber having a valve controlling the flow rate of fluid between a compression chamber and a rebound chamber in a housing and separated by a piston. The valve has an orifice component and a blocker component, one of which has a permanent magnet, and the other of which has a magnetically permeable material. Upon the application of sufficient fluid pressure, the blocker component is forced away from the orifice component, despite the magnetic bias that tends to attract the two structures. Because the magnetic force decreases as the two components are spaced farther apart, the shock absorber has excellent performance characteristics. Alternatively, a mechanical spring urges the blocker closed, and magnetic attraction between the blocker and a spaced opener mitigates the increased force of the compressed spring tending to close the valve.

Abstract: The invention relates to a device for damping compressive forces designed to be reversible also upon dynamic impact load. With the objective of achieving the lowest possible construction volume while simultaneously retaining favorable damping properties both upon static as well as dynamic compression, the device comprises a cylinder having a hydraulic chamber, a hollow piston, a valve arrangement and a separating piston, wherein the valve arrangement divides the hydraulic chamber into a front hydraulic chamber region and a rear hydraulic chamber region and the separating piston separates a head space from the front hydraulic chamber region. The valve arrangement comprises an eccentric hydraulic compartment connected to a transfer-flow area which is sealed by an eccentrically arranged multiplier valve.

Abstract: An end-stop damper including a damper body in the form of a cylinder, wherein a piston is guided so that it is displaceable in the cylinder receiving chamber. An air pressure is formed in the receiving chamber produces a braking force acting on the piston during its displacement. The receiving chamber includes at least one pressure reducing opening and the piston includes a bellows section which is actively connected to the cylinder according to pressure conditions in the receiving chamber. This invention substantially simplifies the structural design of the end-stop damper because the piston and the bellows section are connected to each other so that they are formed in one piece.

Abstract: A shock absorber having a valve controlling the flow rate of fluid between a compression chamber and a rebound chamber in a housing and separated by a piston. The valve has an orifice component and a blocker component, one of which has a permanent magnet, and the other of which has a magnetically permeable material. Upon the application of sufficient fluid pressure, the blocker component is forced away from the orifice component, despite the magnetic bias that tends to attract the two structures. Because the magnetic force decreases as the two components are spaced farther apart, the shock absorber has excellent performance characteristics. Alternatively, a mechanical spring urges the blocker closed, and magnetic attraction between the blocker and a spaced opener mitigates the increased force of the compressed spring tending to close the valve.

Abstract: A vibration damper includes a cylinder within which a piston is slidably received thereby defining compression and rebound chambers. The piston has a bore with a valve seat through which fluid flows between those chambers. A poppet selectively engages the valve seat and forms a pilot chamber an opposite side of the poppet from the valve seat. The greater pressure within the compression or rebound chambers is applied by a first logic arrangement to the pilot chamber and a pilot spool control a fluid flow between the pilot chamber and a pressure cavity in the piston body. A second logic arrangement connects the pressure cavity to either the compression and rebound chamber which has the lesser pressure. A solenoid that moves the pilot valve element to control pressure in the pilot chamber and thus the amount that the poppet moves to allow fluid flow through the piston.

Abstract: A shock absorber has an outer tube, an inner tub, a piston rod, a piston and a damping device. The inner tube is slidably inserted into the outer tube and has an inner space with an inner diameter. The piston is securely mounted on the piston rod, is slidably held inside the inner tube to divide the inner space of the inner tube into two segments and has at least one channel. The damping device has a plug and a sleeve. The plug is securely attached to the piston and has a diameter. The sleeve is securely mounted in the inner tube and has an inner diameter. The diameter of the plug is smaller than the inner diameters of the inner tube and the sleeve. The inner diameter of the sleeve is smaller than that of the inner tube.

Abstract: A shock absorber with a shock absorber body having a cylinder. A piston is moveably guided in a receiving space of the cylinder. When the piston is moved, an air pressure generated in the receiving space exerts a braking force that acts on the piston. For air pressure reduction, the receiving space has at least one opening that produces an air-carrying connection between the receiving space and the environment. The shock absorber body has a simple design if the piston or the cylinder contains a receptacle into which an insert piece is inserted in a frictionally engaging fashion and if the opening is positioned between the insert piece and the wall of the receptacle that is touched by the insert piece.

Abstract: The invention relates to a device for adjusting the pressure in the chambers of a hydraulic jack comprising a hollow valve seat extending substantially longitudinally between two end sections, the body of the valve seat being connected to a source of pressurised fluid, each of the end sections of the valve seat being linked to a chamber of the hydraulic jack and adapted to receive a valve allowing to control the refilling with hydraulic fluid of said chamber of the jack, characterised in that a valve return spring is placed inside said valve seat and in that each of the ends of said valve return spring is attached to one of said valves.

Abstract: A shock absorber for a radio control model includes a cylinder and a piston reciprocally received in the cylinder. The piston has an annular groove defined in the periphery thereof and dividing the piston into an upper portion and a lower portion. At least two first holes are defined in the upper portion and communicates with the annular groove. At least one second hole is defined in the lower portion and communicates with the annular groove. At least one of the second hole co-axially aligns with a corresponding one of the at least two first holes and the number of the first hole is greater than that of the second hole. At least one stopper is received in the piston between the first hole and the second hole that align with each other for selectively closing the first hole and the second hole.

Abstract: A shock absorber is provided that includes a shock absorber body defining a cavity that is at least partially filled with hydraulic fluid. A piston is slidably arranged within the body and separates the cavity into rebound and compression fluid chambers. A rod is secured to the piston and includes first and second portions that are respectively adjacent to the rebound and compression chambers. A fluid passageway extends between the first and second portions to fluidly connect the rebound and compression chambers. In this manner, fluid is permitted to flow through the rod to provide damping characteristics in addition to those damping characteristics typically provided by the piston. A valve assembly, which may include a one-way check valve, is arranged within the passageway for controlling the flow of fluid between the rebound and compression chambers through the passageway. Preferably, the rod includes a longitudinal bore having an adjustable plunger arranged therein.

Abstract: A fluid regulating device includes a regulator housing that confines a valve receiving chamber and a fluid chamber filled with hydraulic fluid. The regulator housing is formed with a fluid opening that is in fluid communication with the valve receiving chamber and that is connected fluidly to a fluid port of a hydraulic cylinder device. A pneumatic cylinder device includes a cylinder housing with a piston member slidingly and sealingly disposed therein to divide the same into a volume-variable pressurized gas compartment and a volume-variable fluid compartment which is in fluid communication with the fluid chamber via a fluid aperture. A regulating valve unit is disposed in the valve receiving chamber to control flow rate of the hydraulic fluid between the fluid opening and the fluid chamber.

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 relates to adjustable stop-wagon retarders with locking function for wagons at high speed and disposal methods thereof, which are suitable for railway marshaling yards or rail lines where it is required to prevent wagons from running away, which are hydraulic equipment of no external energy source to automatically regulate wagon's speed and disposal methods of such equipment. The stop-wagon retarder is characterized in that a uni-directional return unit comprising a sealing valve plate and adjustable throttle valve, and a locking control valve composing of switch valve and positioning unit are mounted in the piston assembly, which make the returning speed and the locking speed for wagon at high speed adjustable, thus the aim of setting the retarder with different control levels and thresholds according to the wagon speed is realized.