Abstract: A rod guide is press-filted to an inner periphery of an outer cylinder and to an inner periphery of an inner cylinder. A rod seal is provided at an inner periphery of a cover member for covering the outer cylinder to seal between a piston rod and the cover member. Space between the rod seal and the rod guide is formed as a hydraulic fluid reservoir chamber. Further, a lip seal is integrally formed on an outer periphery of the rod seal. The lip seal is set so as to separably abut a valve seat surface of the rod guide. One side surface of the lip seal is provided with a plurality of radially extending hydraulic fluid grooves spaced from each other in a circumferential direction. With this arrangement, a valve opening pressure of the lip seal can be kept small regardless of size of interference of the lip seal. Thus, air removability is improved.

Abstract: A fluid damped shock absorber comprises an outer tube having a closed end and an open end, and a damper tube disposed within the outer tube. An inner tube is axially slideable within the outer tube and has a closed end and an open end. A sealing piston is attached to the inner tube to provide a seal between the inside of the outer tube and the outside of the damper tube. A sealing device is attached near the open end of the outer tube to provide a seal between the outside of the inner tube and the outer tube. A regulation valve is fixed to the damper tube in a sealed arrangement with the outer tube. The regulation valve is located between the closed end of the outer tube and the sealing piston. The regulation valve is configured to regulate fluid flow of a damping fluid between the outer tube and the damper tube upon axial movement of the inner tube within the outer tube.

Abstract: A shock absorber includes a valve assembly with a low speed oil flow circuit and a mid/high speed oil flow circuit. Both circuits control fluid flow through the valve assembly in the same direction. The low speed oil flow circuit is tunable in order to provide low speed damping to improve both the vehicle control and handling. The tuning of the low speed oil flow circuit is accomplished by supporting a low speed valve disc on a chordal edge at a position radially inward of its outer edge to control the rate at which the low speed oil flow circuit opens. The valve assembly of the present invention can be located within either a base valve assembly or a piston valve assembly.

Abstract: In an embodiment, the present invention provides a damping device that comprises a bladder that has an exterior surface and an interior surface, with the interior surface defining a chamber which stores a compressible fluid and a valve that is attached to the interior surface of the bladder. In an embodiment, the damping device contains a bladder that can be constructed from one or more of the following materials: urethane, neoprene, Viton, Nitrile, buna rubber, or silicon. The bladder is constructed to minimize the distance between the interior surface and the exterior surface. In an embodiment, the damping device contains a valve that can be constructed from one of the following materials: steel, brass, aluminum, or composite. The valve includes a stem that has threads for attaching a nut and a flange for attaching the valve to the interior surface of the bladder. The flange is contoured to maintain the axial location of the bladder within the damping device.

Abstract: A modular blow-off base valve is provided for a vehicle twin tube damper in which a valve body is inserted into the end of an inner damper tube. The valve body has a central opening into which is inserted a valve cage assembly. The valve cage assembly includes a valve cage tubular member having a blow-off valve opening which is pressed into the central opening. A valve stem forming a valve seat with the blow-off valve opening is biased into a closed position by a helical spring seated against the underside of the valve stem at one end and a spring retainer fastened to the bottom of the valve cage at its other end. An annular bleed disc, intake disc and washer disc fit over the tubular member and cover rebound openings in the valve body. When the valve cage assembly is placed into the valve body's central opening, the washer disc biases the intake disc into sealing engagement with the rebound openings in the valve body.

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 valve regulates fluid displacement in a damper assembly, for example, displacement of hydraulic fluid in a sealed shock absorber. The valve is placed between a portion of fluid at one pressure and regulates the passage of fluid through an aperture or passage to a portion of fluid at a lower pressure by a blocking member which moves to obstruct the aperture in accordance with a desired level of damping. The blocking member is, or is driven by, an electroactive device, such as a bimorph actuator formed of ferroelectric material.

Abstract: A vehicle damper includes a valve having of an imperforate, deflectable variable orifice disk with an outer periphery that is only partially clamped against a valve seat, during low velocity operation of the damper, by a variable orifice support disk having an outer periphery that is not coextensive with the outer periphery of the variable orifice disk. The portion of the outer periphery of the variable orifice disk that is not clamped against the valve seat deflects away from the valve seat during low velocity operation of the damper, in response to force on the variable orifice plate generated by pressure of fluid in flow apertures closed off by the variable orifice plate, to provide a variable orifice for fluid flow through the valve and digressive performance of the damper. The valve may take the form of a compression or rebound valve on the piston of the vehicle damper, or a base valve in a dual tube damper.

Abstract: A piston rod is guided in an axially movable manner within a cylinder filled with a damping medium, and a piston is arranged on the piston rod, which piston divides the cylinder into a working space on the piston-rod side and a working space remote from the piston rod. The two working spaces are connected to each other by at least one flow passage which is activated as a function of the axial position of a valve body, which is prestressed in the opening direction by a spring, the valve body being movable onto a valve seat surface into the closed position as a function of dynamic pressure and at least reducing the passage cross section of the at least one flow passage. The piston has a valve seat surface on which the valve body comes to bear with a conical closing surface in the maximally closed position.

Abstract: A hydraulic pressure brake device includes a master cylinder, a brake operating member, a master piston, a booster, a first auxiliary piston, a pressure transmitting chamber, a valve device, and a second auxiliary piston. The hydraulic pressure brake device further includes an output member and a rod. The output member is provided in the booster for transmitting the boosting power generated by the booster to the first auxiliary piston when the movement of the master piston is assisted by the booster. The rod is provided in the second auxiliary piston for transmitting the operating force applied to the brake operating member to the valve device and for opening the valve device when the movement of the master piston is not assisted by the booster.

Abstract: A gas spring includes an outer tube; a base plate; a head plate; an inner tube mounted to extend between the head plate and the base plate; a piston/rod assembly mounted to reciprocate vertically in the inner tube between a retracted, compressed position and an extended, rest position; a valve ring coaxially mounted around the rod to reciprocate between the main piston and head plate; a primary gas chamber; a relief chamber; seals for preventing fluid flow from the primary and relief chambers; a passageway providing communication between the primary gas chamber and relief chamber; and, valve apparatus for controlling fluid flow between the primary and relief chambers. The valve apparatus operates to open and close the fluid flow as a function of the position and direction of travel of the piston/rod assembly.

Abstract: A self-positioning cushioning device adapted to be mounted in the end of a rail car sill includes a hydraulic cylinder and yoke. A piston rod extends from the cylinder and is joined to one end of a yoke. The other end of the yoke is joined to a rail car coupler through a drawbar. A preloaded stack of elastomer pads is confined in a pocket in the yoke between a pair of stop plates which extend laterally of the yoke to engage stops during movement of the yoke, rod and piston in response to buff and draft impacts. The cylinder is filled with pressurized hydraulic fluid which maintains the piston in a central neutral position with the stop plate adjacent to coupler held against stops on the rail car sill. Buff impacts are cushioned first by the cylinder and at the end of the stroke by both the cylinder and the spring. Draft impacts are cushioned by both the cylinder and the spring.

Abstract: A vibration damper with variable damping force, includes a cylinder filled with damping medium and in which a piston fastened to a piston rod axially moveably therein. The piston divides the working cylinder into two working spaces. The damping force for the directions of rebound and compression are influenced by nonretum valves acting in the respective directions. A damping valve of variable damping action is additionally provided in series with each of the nonreturn valves so that the damping valve is active in both the rebound and compression directions.

Abstract: A single absorber includes a valve assembly with a low speed valving system and a high speed valving system. Both systems control fluid flow through the respective valve assembly for fluid flow in the same direction. The low speed valving system is independently tunable in order to provide low speed damping to improve both vehicle control and handling. The independent tuning of the low speed valving system allows the optimization of the low speed valving system in relation to the high speed valving system as well as independent tuning of the high speed valving system in relation to the low speed valving system. The independent tuning of the two systems allow the achievement of a smooth transition between the two systems. The two valving systems can be incorporated into a piston assembly for an extension stroke, a base valve assembly for a compression stroke or both.

Abstract: A valve and a shock absorber based on electrorheological liquids A valve and a shock absorber are described which are based on electrorheological liquids and which contain a valve aperture between two chambers, wherein the boundary faces of the valve aperture consist of electrically conductive material and are insulated from each other, and which comprise a source of high voltage, each of the voltage terminals of which can be connected to one of the boundary faces, with the characterising feature that the valve aperture has a meander-shaped cross-section.

Abstract: A suspension unit for mounting an axle to the body of an automobile or a handle-bar to the fork of a bicycle or motorcycle. A pair of pistons (15, 29) operate in tandem in separate chambers (17, 31) having a compressible gas in spaces (21, 35) on one side of the piston and an uncompressible hydraulic fluid in spaces (19, 31) on the other side of the piston. One of the pistons (15) responds to external disturbances (caused by e.g. road bumps) to drive the other piston (29) against the compressible gas which responds resiliently to return the pistons to normal intermediate placements, thereby maintaining or recovering proper height of the automobile or′cycle parts. The hydraulic fluid spaces are communicated via constrictor passage to provide suitable dynamic dampening.

Abstract: A device, e.g. a pressure regulator, for realizing an opening and/or closing function in connection with the force-velocity curves of the device incorporates two parts which work away from and towards each other at different velocities and accelerations, e.g. slide and housing. The parts work with a stroke and determine, in dependence upon the present size of the stroke, the passage of a fluid by way of a restrictor function realized by the parts. At least the one part (the slide) is subjected to force on both its sides. The restrictor function is made up of at least two part-restrictors which can be simultaneously actuated by a respective stroke and thereupon vary, preferably successively, their restrictor sizes differently from each other in dependence upon the respective stroke size. In the restrictor function, a passage of fluid is herein obtained which produces a smooth curve shape in the introductory and concluding part of the respective opening or closing function.

Abstract: A damper piston assembly includes a rod, a piston, a rivet disk, and a spring. The piston surrounds the rod between a riveted end and a longitudinal stop of the rod. The piston includes a valve assembly having a valve body with an orifice extending therethrough. The rivet disk surrounds the rod and has an opening for fluid communication with the orifice. The rivet disk is longitudinally secured between the piston and the riveted end of the rod. The spring is positioned in compression longitudinally between the rivet disk and the longitudinal stop of the rod.

Abstract: The flow of a hydraulic fluid between connecting ports caused by sliding movement of a piston in a cylinder is controlled by a fixed orifice and the flow path area determined by ports that is varied by a spool, thereby directly controlling orifice characteristics. At the same time, the pressure in a pilot chamber is changed by the pressure loss between the ports to change the valve opening pressure of a main valve, thereby controlling valve characteristics. An orifice passage is provided in parallel to the ports. Thus, when the flow path area determined by the ports is restricted, variations in the flow path area attributable to machining accuracy or the like can be absorbed by the flow path area of the orifice passage provided in parallel to the ports. Therefore, stable “hard” damping force characteristics can be obtained.

Abstract: The flow of a hydraulic fluid caused by sliding movement of a piston in a cylinder is controlled by a disk valve and extension- and contraction-side main valves, thereby generating damping force. By controlling the valve opening pressures of the disk valve as a pressure control valve with respect to extension- and compression-side valve seats with a proportional solenoid actuator, damping force can be directly controlled independently of the piston speed. Moreover, the pressures in pilot chambers are changed to control the valve opening pressures of the extension- and compression-side main valves. Because the disk valve is placed between the extension- and compression-side valve seats, it is possible to simultaneously select different damping force characteristics for the extension and compression sides.

Abstract: The present invention relates generally to front suspension fork assemblies for bicycles, and provides an improved suspension fork comprising an adjustable compression system for quick and easy adaptation to various types of terrain. The front suspension fork of the present invention comprises a pair of rigidly connected parallel fork legs, with each fork leg having at its bottom end a dropout for connection to the axle of a wheel. Each fork leg further comprises a shock absorber positioned therein and comprising a helical coil spring to urge expansion of the sliding tubes, flow dampers, and damping fluid within the cavities of the sliding tubes to dampen the movement of the sliding tubes in compression and expansion. Each flow damper comprises a flexible shim which opens in compression or expansion to increase the flow of damping fluid. Varying the flexibility of the shims also varies the damping effect of the shock absorber.

Abstract: A base valve assembly fore regulating the flow of fluid through a twin tube fluid vehicle damper is provided. The base valve assembly has opposing compression and rebound surfaces. Inner and outer annular seats extend from the compression surface and define an annular channel therebetween. At least one fluid passageway connects the annular channel and the rebound surface for providing fluid communication therebetween. A connector secures a blow-off valve to the cylinder end. The blow-off valve has a hollow cylindrical portion with a flange extending transversely from an end thereof. The flange is adjacent the annular seats when the blow-off valve is in a closed position. The blow-off valve is movable from the closed position to an open position away from the compression surface. A helical spring is interposed between the connector and the blow-off valve for biasing the blow-off valve to the closed position.

Abstract: A valve assembly for a fluid vehicle damper having a cylinder with a valve body is provided. The valve body has an outer surface adjacent to an interior wall of the cylinder and includes first and second opposing surfaces. The valve body defines first and second fluid chambers within the damper, which are adjacent to the first and second surfaces, respectively. Inner and outer annular seats extend from the first surface and define an annular channel therebetween. At least one fluid passageway is connects the annular channel and second surface for providing fluid communication therebetween. A high speed bypass valve assembly is attached to the valve body and is movable between an open position and a closed position adjacent to the annular seats. An orifice disc is interposed between the annular seats and the high speed bypass valve assembly for providing low speed bypass of fluid from the second chamber to the first chamber when the high speed bypass valve assembly is in the closed position.

Abstract: A passive damping for a shock absorber is disclosed. The shock absorber includes a working chamber, and a piston disposed in the working chamber. The piston includes a primary bypass valve for defining an upper fluid portion and a lower fluid portion. A piston rod is connected to the piston and extends through the top portion of the working chamber. A variable bypass assembly is disposed between a first fluid chamber and a second fluid chamber. The variable bypass assembly includes at least one bypass aperture for providing communication of damping fluid between the first and second fluid chambers. The variable bypass assembly also includes a passive control member for varying the size of the bypass aperture, and biasing structure for normally retaining the passive control member in a position which maximizes the size of the bypass aperture.

Abstract: A piston-type rail retarder includes a shock absorber having a cylinder defining a cavity between a pair of end walls. A piston rod extends axially through one of the end walls, and a piston is mounted on the piston rod between the end walls so as to divide the cavity into first and second working chambers containing a damping fluid. A first array of passages extends through the piston and communicates between the first and second chambers, and a sprung valve assembly is provided for obturating the first array of passages in the event of the velocity of the piston rod relative to the cylinder exceeding a predetermined value. The first valve mechanism includes a valve plate and a spring for biasing the valve plate into an open position. An array of restricted orifices extend through the valve plate and communicate directly with the corresponding array of first passages when the valve plate is closed.

Abstract: The flow of a hydraulic fluid caused by sliding movement of a piston is controlled through a sub-disk valve, a main disk valve and a disk valve to generate damping force. A coil is energized to urge a plunger in the valve closing direction against spring force from a spring, thereby adjusting the relief pressure of the disk valve and thus controlling the damping force. The pressure in a back-pressure chamber varies according to the relief pressure of the disk valve. Thus, the valve opening pressure of the main disk valve is also adjusted. An abrupt input is absorbed by relieving the pressure from the back-pressure chamber by deflection of the disk valve. Because “soft” damping force characteristics, which are often used, are maintained with a small electric current, the power consumption can be reduced.