Abstract: A hydraulic apparatus is used in an industrial vehicle. The apparatus has a hydraulic cylinder interposed between a vehicle frame and an axle swingably coupled to the frame. A passage connects a first chamber with a second chamber defined by a piston in a cylinder case. The piston is movable based on differential pressure in the chambers. A cylinder rod selectively extends and retracts in respect with the cylinder case to absorb a swinging motion of the axle. The passage is selectively open and closed based on at least one of a traveling state and a loading state of the vehicle. The piston has a first surface defining the first chamber and a second surface defining the second chamber. The first surface has an area equal to that of the second surface.

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 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.

Abstract: A load limiting apparatus for a vehicle safety restraint belt is inserted in the force path between a mounting for a seat belt and a vehicle occupant. The load limiting apparatus has a vessel which contains fluid. The fluid is moved from one part of the vessel to another through a valve having a tapering profile to decrease the open area of a constriction as a function of the deceleration of the vehicle in a crash. Ideally the load limiting is self regulating and the force absorbed increases with increasing crash severity.

Abstract: An externally adjustable dampening control for a shock absorber provides the ability to adjust the hardness and softness of the ride near the normal curb/ride height, and still give strong resistance, and hence control, when the piston moves beyond the intermediate region. The adjustable dampening control includes a bypass for permitting fluid to bypass the piston when the piston is within an intermediate region of the cylinder corresponding to the normal curb/ride height of the shock. The bypass includes a valve body extending longitudinally along a portion of the hollow cylinder and defining a flow passage having first and second longitudinally spaced ports opening to cylinder and defining a flow passage having first and second longitudinally spaced ports opening to the internal chamber. Resistance to piston movement can be adjusted by rotating a knob to move a second piston into and out of the flow passage, thereby adjusting the amount of fluid that can flow through the bypass flow passage.

Abstract: The present invention relates to a semi-active damper controlled by a control circuit including a direct control loop made up of an inverse model of the damper. The inverse model of the damper determines an ideal value for an electrical current i.sub.th for controlling a compression controlled-restriction valve and an expansion controlled-restriction valve on the basis of a measured value for a relative speed y between the two ends of the damper and on the basis of a force reference value Fc. The semi-active damper of the invention is applicable as a transverse secondary suspension for a passenger rail vehicle.

Abstract: A shock absorber has a cylinder with a piston and piston rod arrangement in the cylinder. Working medium can be guided in different flow paths via shim stacks for the purpose of obtaining different dampings based on the position of the piston. The piston arrangement can have a piston supporting shim stacks. One or more further shim stacks are arranged in a unit which is separate from the cylinder. In at least one of the shock absorber strokes, the working medium can be conveyed via the shim stack(s) in the unit separate from the cylinder.

Abstract: A vibration damper with variable damping force, including a cylinder, a piston and a piston rod arranged in the cylinder so as to be axially movable, an adjustable damping valve connected between the piston rod and the cylinder, and controlled as a function of a spring deflection path, a device for controlling the adjustable damping valve, and additional damping valves arranged to have a damping effect on the piston independent of the controlling device.

Abstract: A pair of combined accumulator and control devices for interconnected suspension units having a simplified construction and wherein unequal displacement of fluid from the associated suspension units will cause an increase in the effective damping of the suspension unit having the greatest fluid displacement.

Abstract: A shock absorber includes the typical fluid valving in the piston and in the base valve assembly which is designed to provide a firm damping characteristic for the shock absorber. A stepper valve assembly includes a bypass fluid passage between the upper working chamber and the reserve chamber which when opened provides a soft damping characteristic during an extension movement of the shock absorber. The stepper valve assembly also includes a bypass fluid passage between the lower working chamber and the reserve chamber which when opened provides a soft damping characteristic during a compression movement of the shock absorber. The stepper valve assembly selectively opens and closes the bypass fluid passages to adapt the shock absorber to changing vehicle conditions.

Abstract: In a damping force control type hydraulic shock absorber, the flow path area of a port is changed by moving a spool according to an electric current supplied to an actuator, and thus the flow path area of a passage between cylinder upper and lower chambers is directly changed, thereby controlling orifice characteristics. Moreover, the pressure in a pilot chamber is changed according to the resulting pressure loss so as to change the valve opening pressure of a disk valve, thereby controlling valve characteristics. This enables the damping force characteristic control range to be widened. The pilot chamber is formed by the side wall of a valve member, the disk valve, a seal disk, and a seal member, also, the seal member has no sliding portion. It is therefore possible to minimize the leakage of hydraulic fluid and to obtain stable damping force characteristics. It is also possible to minimize variations in damping force with temperature changes.

Abstract: A double-acting hydraulic cylinder for use in an exercising apparatus to provide a resistance to a user of the exercising apparatus is disclosed.

Abstract: A vibration damper having a pressure tube in which a piston with a piston rod is located so that the piston can move axially. The pressure tube is divided into upper and lower working chambers. The upper working chamber is connected by a hydraulic connection to the oil sump of an equalization chamber. The vibration damper also has at least one damping valve in the piston at least for the direction of flow from the upper working chamber to the lower working chamber, a port valve between a connection opening in the upper working chamber and the oil sump, a non-return valve in a bottom valve body which connects the lower working chamber with the equalization chamber and at least one additional damping valve in addition to the piston valve(s). In the insertion direction, the additional damping valve produces a damping which occurs as a function of the volume flow distribution.

Abstract: The present invention relates to a semi-active damper controlled by a control circuit including a direct control loop made up of an inverse model of the damper. The inverse model of the damper determines an ideal value for an electrical current i.sub.th for controlling a compression controlled-restriction valve and an expansion controlled-restriction valve on the basis of a measured value for a relative speed y between the two ends of the damper and on the basis of a force reference value Fc. The semi-active damper of the invention is applicable as a transverse secondary suspension for a passenger rail vehicle.

Abstract: A gas charged monotube strut carries the accumulator outside the damper's cylinder tube and within the strut mount. A substantially direct flow path is provided between the damper and the accumulator through the damper's piston rod. Air to oil separation is maintained by a gas cup and a low profile of packaging is provided.

Abstract: A piston connected to a piston rod is slidably mounted in a cylinder, and a lower cylinder chamber is connected to a reservoir. An extension side passage for communicating an upper cylinder chamber with the lower cylinder chamber and a compression side passage for communicating the cylinder chamber with the reservoir are provided with disc valves, respectively, behind which extension side and compression side back pressure chambers are formed. The extension side back pressure chamber is communicated with the upper and lower cylinder chambers through a fixed orifice and ports. The compression side back pressure chamber is communicated with the lower cylinder chamber and the reservoir through a fixed orifice and ports. By rotating a shutter, flow areas of the ports are changed to adjust orifice features and pressures in the extension side and compression side back pressure chambers are changed to adjust valve features.

Abstract: A hydraulic damper has a first oil chamber, a second oil chamber, a communication mechanism defining a communication oil passage, the first and second oil chambers communicating with each other through the communication oil passage, and a damping force adjusting mechanism for varying a cross-sectional area of the communication oil passage to adjust damping forces. The damping force adjusting mechanism includes an adjusting rod having an end disposed in a portion of the communication oil passage, the adjusting rod being movable toward and away from the communication oil passage to vary the cross-sectional area of the communication oil passage, an eccentric cam rotatably disposed in engagement with an opposite end of the adjusting rod, and a rotary actuator for rotating the eccentric cam to move the adjusting rod toward and away from the communication oil passage to adjust the damping forces.

Abstract: A semi-active vibration damping assembly for suppressing structural vibrations. The damping assembly includes a double rod hydraulic cylinder having a first fluid chamber and a second fluid chamber interconnected by a valve assembly. The hydraulic cylinder being connected within the framework of the structure and motion sensors being attached to the structure to measure movement of the structure and pressure sensors being disposed in the first and second chambers to measure the pressure differential between each chamber. In response to the motion and pressure data and the compressibility of the fluid, a controller outputs a control signal to the valve assembly in accordance with a control logic to vary the flow rate of the fluid between the first and second chambers and thereby vary the elastic deformation of the fluid and the amount of elastic energy stored in the fluid.

Abstract: A semi-active vehicle suspension system employing a shock absorber whose damping characteristics are variable under the control of a signal representing one or more conditions of the vehicle. The system employs a coaxially arranged valve pair to provide one or two fluid flow paths between a chamber of the shock absorber and a reservoir. Two of such coaxial valve pairs may be used in tandem to control both chambers of the shock absorber in an inverse relationship. Both of the tandem pairs may be controlled by a single spool which is controlled by a single control signal.

Abstract: The present invention is directed to a damping force adjustable hydraulic shock absorber including a cylinder filled with a hydraulic fluid, a piston slidably mounted within the cylinder to divide the interior of the cylinder into two chambers, and a piston rod having one end connected to the piston and the other end extending out of the cylinder. A damping force generating mechanism is provided to communicate between the two chambers and to generate a damping force. A communication passage for communicating one of two chambers in the cylinder with the other chamber and a valve are provided in the communication passage and are adapted to generate the damping force by opening in response to one way flow of the liquid. The shock absorber has a valve opening pressure adjusting mechanism having a back pressure chamber communicating with an upstream portion of the communication passage with respect to the valve.

Abstract: A nonadjustable shock absorber that can accommodate for variations in weight, and propelling force, and to provide a specific deceleration or reaction force. The shock absorber provides dual function metering that combines soft contact dampening with the self compensating ability to decelerate a wide range of weights. The shock absorber includes a low pressure zone, a hydraulic cylinder having a high pressure zone chamber, a piston in said cylinder for movement under a shock load through a predetermined stroke length, a fluid pathway metering control means, having four fluid metering pathways of which the first three fluid metering pathways are approximately linear spaced apart, for controlling high pressure fluid escaping from the high pressure zone chamber into the lower pressure zone, ahead of the piston as the piston moves from an initial position in response to a shock load through a total stroke to a final position, to create five control zones during the compression of the shock absorber.

Abstract: A hydraulic, adjustable vibration damper for motor vehicles, with a damping piston fastened to a piston rod, which damping piston divides the work cylinder into two chamber halves filled with damping fluid, has a bypass located parallel to the valves of the damping piston. In the bypass there is at least one valve which reacts as a function of the pressure, and to control the bypass, there is a device to adjust a control body, which control body can be pressurized in the closing direction by a pressure medium. Between the pressure medium and the control body there can be an axially movable pressure intensifier which is sealed on its circumference, whereby corresponding to the pressure intensifier there can be an additional spring force which acts in the direction opposite to that of the pressure medium.

Abstract: A controllable hydraulic vibration absorber is disclosed whose power cylinder and a tube defines a connecting duct which affords a balance of volume between both power chambers of the vibration absorber and a balancing chamber which is formed between the tube and an external tube disposed coaxially with it. The controllable vibration absorber valve affords variations of the vibration absorbing power and allows a flow through it in one direction only and is arranged between the connecting duct and the balancing chamber so as to be integrated as to its action in a valve assembly which is constituted by a non-return valve and by a switching valve. The switching valve is inserted between the second power chamber and the connecting duct.

Abstract: A seismic shock isolator and method of strengthening structures against seismic shock. The shock isolator includes a cylinder having a damping chamber and an accumulator chamber and a piston movable into the damping chamber. The damping chamber can contain compressible liquid or incompressible liquid. The piston has a damping head and a first control orifice, and the accumulator chamber is separated from the damping chamber by a wall having a second control orifice having a higher exponent than the first control orifice. Movement of the piston into the damping chamber creates a combination of damping and stiffening having a spring component. When the isolator has compressible liquid therein, the spring and stiffening is produced by a compression of the liquid. When the isolator contains an incompressible liquid, the stiffening and spring component are obtained by a yielding of a column which movably supports the wall which divides the damping chamber from the accumulator chamber.

Abstract: A suspension system with at least one hydraulic spring strut. At least a portion of the hydraulic medium is displaced into a hydropneumatic spring reservoir during the compression movement of the spring strut, and that portion of the hydraulic medium flows back into the spring strut during the expansion movement. At least the expansion flow is conveyed through the flow path of a damping valve and damped due to the fact that the flow path is continuously closed and reopened in an alternating fashion by means of a valve element once a expansion flow is present. The valve element is bypassed via a bypass which is constructed in such a way that a pressure compensation between the sections of the flow path arranged on both sides of the valve element is ensured in the static condition in which essentially no flow is present; and that the bypass essentially loses this pressure compensation function in the dynamic condition in which a flow is present.

Abstract: In an oscillation damper with bypass between an annular working chamber and a compensating chamber, a shut-off valve is provided in the bypass. The shut-off valve is on the one hand exposed to the pressure in the annular working chamber and on the other hand to the pressure in a control chamber which is constructed directly adjacently to a valve shut-off element of the shut-off valve and is supplied by a throttle section with the pressure in the annular working chamber. The control chamber is constructed with a control chamber outlet. This control chamber outlet is opened or closed selectively by a cross section dimensioning module.

Abstract: A damping force control type hydraulic shock absorber has a piston that has main hydraulic fluid passages and valve mechanisms and also has a piston rod connected thereto. One side of the cylinder of the shock absorber is provided with a damping force control mechanism having a guide member and a shutter, which open and close a bypass passage, and a valve mechanism that generates damping force by controlling the flow of hydraulic fluid through the bypass passage. Damping force characteristics are changed by rotating the shutter with a rotary actuator. Since the damping force control mechanism is provided on the side of the cylinder and the piston is provided with only the main hydraulic fluid passages and the valve mechanisms, the size of the piston assembly is relatively small. Accordingly, the stroke of the piston rod can be increased.

Abstract: In the case of a vibration damper with a by-pass (32, 32a) between an annular working chamber and a compensating chamber (28), there is in the by-pass (32, 32a) a shut-off valve assembly (36) with a valve shut-off element (42) and a valve seat (40b). The valve shut-off element (42) is for its part subject to the pressure (p.sub.1) in a first section (32) of the by-pass and on the other to the pressure (p.sub.2) in a control chamber (48). The cross-section of a control chamber outlet (46c) can be controlled by an outlet cross-section dimensioning device (52). The shut-off valve assembly (36) is so constructed that at maximum control chamber outlet cross-section the valve shut-off element (42) begins to be lifted off the valve seat (40b) when the throughflow rate through the control chamber outlet (46c) amounts to at least 0.2 times the total throughflow rate through the shut-off valve assembly (36) which becomes adjusted to a damper velocity of 1 m/sec.

Abstract: A casing for a vibration damper of a motor-vehicle comprises a container tube and a side tube with the side tube axis being substantially transverse to the container tube axis. The side tube is shaped such as to accommodate a bypass valve the opening and closing of which effects a variation of the damping behaviour of the vibration damper. The side tube is made from a side tube preproduct which has a bottom wall and a contact face adapted to the radially outer circumferential surface of the container tube. The side tube is positioned on the radially outer circumferential surface of the container tube by positioning the contact face onto the radially outer circumferential surface of the container tube. Hereupon, the side tube is fastened by welding to the container tube along the circumference of the contact face. Hereupon, a connection passage is made between a cavity of the side tube and a cavity of the container tube.

Abstract: A controllable hydraulic vibration absorber is disclosed whose power cylinder and a tube defines a connecting duct which affords a balance of volume between both power chambers of the vibration absorber and a balancing chamber which is formed between the tube and an external tube disposed coaxially with it. The controllable vibration absorber valve affords variations of the vibration absorbing power and allows a flow through it in one direction only and is arranged between the connecting duct and the balancing chamber so as to be integrated as to its action in a valve assembly which is constituted by a non-return valve and by a switching valve. The switching valve is inserted between the second power chamber and the connecting duct.

Abstract: A variable dashpot for motor vehicles. It comprises a vibration-suppressing piston-and-cylinder mechanism. The cylinder contains displacement fluid. The piston divides the cylinder into two displacement compartments. The piston has a piston rod attached to it. The piston is provided with pressure-dependent valves that vary the level of vibration suppression. The vibration-suppression valve system has two vibration-suppressing valves (2) accommodated in alignment in a cylindrical valve housing (1). Each vibration-suppressing valve consists of an axially displaced electromagnetic plunger (5 or 6) that operates in conjunction with at least one outlet (3 or 4) and of at least one pressure-sensitive valve (7 or 8) on stream parallel or in alignment with the plunger.

Abstract: In a vibration damper for a motor vehicle a flow path connecting a working chamber of the cylinder with a damping behavior control unit is confined by a flow path tube surrounding the cylinder. The flow path tube is provided adjacent its axial end portions with bead-shaped grooves accommodating respective sealing rings. These sealing rings are according to an illustrated example of the invention in engagement with an external surface of the cylinder. The bead-shaped grooves are obtained by non-cutting machining.

Abstract: A suspension system for motor vehicles is disposed between body (1) and wheel (2) and is provided with a damper (4) with integrated resonance dampers (40, 48) for improved insulation of transmission of road unevenness to the body. The resonance damper is formed in that the casing (40) of the damper (4) forms a moving mass m.sub.40 between the body (1) and the wheel (2), the casing being connected to the wheel via a spring (48) harmonized with the mass m.sub.40. The pistons (41, 42) of the damper are connected via piston rods (43, 44, respectively) to the body (1) and the wheel (2), respectively.

Abstract: Hydraulic adjustable vibration damper with a work cylinder, a piston fastened to a piston rod and dividing the work cylinder into two work chambers, at least one additional tube coaxially surrounding the work cylinder and at least one controllable damping valve installed in a stationary and sealed manner on the side of the vibration damper. For the proper and easy installation of the damping valve on the outer tube of the vibration damper, the damping valve is centered and held in a sealed manner by a centering ring in a hole in the tube, whereby the fastening is achieved by means of a screw fitting running through the hole of the centering ring.

Abstract: A hydraulic suspension damper includes a fluid-filled cylinder divided into first and second fluid chambers by a reciprocating piston. A bypass valve assembly includes a first pressure responsive valve assembly in fluid connection with one of the fluid chambers and a second pressure responsive valve assembly in fluid connection with the other fluid chamber. The pressure responsive valve assemblies direct fluid to an unidirectional electromechanical valve assembly. Operation of the bypass valve assembly permits independent control of fluid during compression and rebound strokes of the damper.

Abstract: The shock absorber comprises a working cylinder (3) in which a piston (1) integral with a rod (2) defines two chambers (7, 8). In accordance with the invention, a rotary solenoid valve is placed in an end piece closing the working cylinder so as to control the circulation of the damping liquid between one chamber (7) and a reservoir (10). The solenoid valve comprises a passage (18, 22, 19) for the liquid between this cheer and this reservoir and closing devices (21, 21', 21", 21"') for the selective throttling of the passage. The closing devices are integral with a rotor (27) mounted on a bearing (33), opposite a stator (26) forming part of a magnetic circuit (25, 26, 27) excited by an electric coil (24). Air gaps extending parallel to the axis of rotation of the rotor (27) are formed between the stator and the rotor. Feeding the coil (24) brings about the rotation of the rotor (27) and the closing devices ( 21) integral with the latter, in order to cause the throttling of the passage to vary.

Abstract: The present actuator includes an inner cylinder closed at one end by an end cap and concentrically mounted in a reservoir tube. A fluid reservoir is formed between the inner cylinder and the reservoir tube. A piston is slidably mounted in the Y inner cylinder, dividing an interior volume of the inner cylinder into first and second chambers. A hollow piston rod is secured at its lower end to the piston and extends beyond the inner cylinder. A separator tube is mounted on the end cap and extends through the piston and into the piston rod to provide a fluid conduit from the reservoir to an external source of controlled pressurized fluid.

Abstract: A vibration damper assembly is provided which includes a first attachment element or bracket for securing the damping mechanism to a first component, the vibrations of which are to be damped. A visco-elastic spacer is secured to the element or bracket at one end, and to a cylinder of a piston/cylinder assembly at its other end. A piston is slidably received in the cylinder with a predetermined clearance between the peripheral surface of the piston and the cylinder wall. A piston rod extending from the piston and the opposite end of the cylinder is received within a housing of a viscous damping device, the piston rod having a plurality of discs mounted thereon in predetermined, spaced relationship. An interior wall of the housing is also formed with a plurality of disc-like surfaces projecting toward the radial center of the housing, with aligned apertures therein to accommodate the piston rod.

Abstract: The invention relates to a shock absorber comprising a main body and a rod-piston, with the rod-piston being retracted when the landing gear is down and extended when the landing gear is up. The main body comprises, in succession, three chambers that are separated by associated partitions, and that comprise: a first hydraulic chamber in which the rod-piston slides freely; a chamber in which a separator piston slides, delimiting a second hydraulic chamber; and a chamber in which another piston slides, delimiting both a third hydraulic chamber and a chamber containing gas under high pressure. Communication means are provided between said chambers together with two associated electrically controlled valves enabling corresponding fluid connections to be selectively established.

Abstract: Magnetorheological (MR) fluid dampers are optimized. Dimensional relationships involved in the flow of magnetic flux are related to an operational parametric ratio of magnetic flux density in the fluid to the flux density in the steel. A magnetic valve is utilized to change the flow parameters of the MR fluid and, hence, the operational characteristics of the damper. Several embodiments depicting improved piston designs, including spool as well as toroidal configurations, are disclosed. In addition, both single and twin-tube housing designs are presented.

Abstract: A shock absorber damping system including at least one cylinder including a compensation chamber which is made to communicate with a pressure source. Thus the load-bearing capacity of the shock absorber can additionally be arbitrarily adjusted and varied within wide limits, independently of a damping of the shock absorber.

Abstract: An adjustable vibration damper for motor vehicles has a cylinder containing a damping fluid, an axially-movable piston rod projecting into the cylinder in a sealed manner, and a damping piston fastened to the piston rod to divide the cylinder into two work chambers, whereby a damping valve equipped with an axially movable valve body and a valve seat controls the effective cross section of a damping passage. For this purpose, the valve body, starting from its pressurized end surface, has at least one constant throttle cross section running toward the back side of the valve body, and an additional throttle passage running in the outflow direction, whereby a pilot control element for regulating flow through the additional throttle passage is located in a recess inside the valve body.

Abstract: A hydraulic shock absorber for a vehicle includes a cylinder tube through which a piston is slidably displaced to define upper and lower chambers, a reservoir tube surrounding the cylinder tube to define a reservoir chamber, a piston rod guide member mounted in a first end portion of the cylinder tube which guides a stroke of a piston rod to which the piston is attached, a valve assembly, provided in a second end portion of said cylinder tube, for restricting fluid flow among the upper chamber, the lower chamber, and the reservoir chamber to create damping force during bounding and rebounding strokes of the piston, a seal provided in an end portion of the reservoir tube for sealing between the piston rod and the reservoir tube, and a fluid passage communicating between the valve assembly and the reservoir chamber. The fluid passage directing leak fluid from the seal of the piston rod guide member to the reservoir chamber.

Abstract: A piston and rod subassembly is reciprocally mounted in a piston tube subassembly. A transfer tube is concentrically mounted in the rod and is in fluid communication with a pressurized source of fluid. A solenoid valve subassembly provides real time damping of relatively high frequency inputs by opening and closing a bypass channel formed in the actuator. Relatively low frequency inputs are actively controlled as fluid passes to and from the pressurized source of fluid. An outer body tube includes a fluid trapping chamber to prevent leakage from the actuator.

Abstract: A hydraulic damper includes an internal accumulator for storing and dissipating energy resulting from a fluid pressure spike inside the damper. A housing is mounted on a piston rod above a reciprocable piston. A compressible medium is stored in the housing. A valve assembly controls the flow of fluid into and out of the accumulator. When a sudden fluid pressure rise occurs, the medium compresses to store the energy. When the pressure rise dissipates, fluid exits the accumulator as the medium expands.

Abstract: A semi-active hydraulic damper includes a solenoid valve assembly for controlling fluid flow through a bypass channel. A blow-off valve assembly is provided in series with the solenoid valve assembly to provide low-level damping when the bypass channel is open.

Abstract: An electro-rheological controlled shock absorber for use on motor vehicles is disclosed. The shock absorber employs a fluid filled cylinder, a piston member traveling in the cylinder, and an electro-rheological valve controlling the passage of fluid through the cylinder. In one embodiment of the present invention, the electro-rheological valve is placed in a by-pass passage to control the flow of fluid therethrough. In another embodiment of the present invention, the electro-rheological valve is placed in the piston to control the flow of fluid. The present invention is well adapted for use with all forms of shock absorbers.

Abstract: A shock absorber of the linear deceleration type in which the housing includes a forward reduced diameter threaded portion and a fixed flange at the rear end of the housing. This arrangement combines the advantages of the primary type of shock absorber and the fixed flange type of shock absorber and allows the invention shock absorber to be mounted in a wide variety of work situations with the mounting in each situation providing a positive position of the shock absorber relative to the mounting structure so that the shock absorber may be exchanged without fear of losing the precise positioning of the shock absorber relative to the object to be decelerated and with the mounting in each situation allowing the ready provision of a stop member to accurately position the component being stopped and to assure that the shock absorber will not bottom out internally.

Abstract: A monoflow shock absorber is provided with a blow off valve which provides the principal flow restriction during both extension and compression of the shock absorber. The force biasing the blow off valve closed is controlled by a control piston which is connected to the blow off valve plate by a rigid, solid rod. The piston responds to a pressurized control fluid, the pressure of which is selected by a high speed pressure regulating device such as a servo valve. This system provides high speed adjustment of the damping force of the shock absorber, substantially independently of the stroking speed of the shock absorber. The shock absorber includes a cylinder in which a working piston moves, and the cylinder is closed at one end with an inner cylinder head assembly made up of a body and a cap, which define a manifold therebetween.

Abstract: A hydraulic damper for a suspension system comprises a fluid-filled inner cylinder mounting a reciprocating piston and piston rod. The piston divides the interior of the inner cylinder into upper and lower chambers. A reservoir tube surrounds the inner cylinder and forms a reservoir in the interior volume between the reservoir tube and the inner cylinder. A base valve assembly permits the return of fluid into the lower chamber from the reservoir. A pair of concentric tubes are mounted between the inner cylinder and the reservoir tube and provide a one-way laminar flow path for fluid exiting the upper chamber of the inner cylinder and entering the reservoir. The length and the spacing of the concentric tubes can be varied to provide a preselected damping force.