Abstract: Disclosed is a frequency sensitive type shock absorber including a piston rod reciprocating an inside of a cylinder and having a connection passage therein; a piston valve mounted on the piston rod and having a plurality of compression and rebound flow paths penetrating up and down thereof, and partitioning the cylinder into compression and rebound chambers; and a valve assembly mounted on the piston rod to generate a damping force that changes with frequency during a rebound stroke; wherein the valve assembly comprises a housing coupled to the piston rod and having a pilot chamber in communication with the connection passage; a main retainer coupled to the piston rod and having a main chamber formed on an upper portion thereof in communication with the connection passage; a first pilot valve coupled to the piston rod and disposed between the housing and the main retainer to partition the pilot chamber and the main chamber; and a second pilot valve coupled to the piston rod and disposed above the pilot chambe

Abstract: A damper assembly comprises a housing disposed on a center axis and defining a fluid chamber for containing a working fluid. A piston is slidably disposed in the fluid chamber dividing the fluid chamber into a compression chamber and a rebound chamber. A piston rod attaches to the piston for moving the piston in the housing. The piston includes a first portion and a second portion defining a first perforation. An outer sleeve has an exterior surface and an interior surface and extends between the first portion and the second portion covering the first perforation. The piston includes a first entry valve and a second entry valve located in the piston and coupled to the piston for limiting the working fluid from flowing into the piston with the first entry valve being disposed adjacent the first portion and the second entry valve being disposed adjacent the second portion.

Abstract: A hydraulic shock-absorber comprises an outer cylindrical tube, an inner cylindrical tube defining with the outer cylindrical tube an annular chamber, a main piston slidably mounted in the inner cylindrical tube and dividing the inner volume of the inner cylindrical tube into an extension chamber and a compression chamber, both containing an incompressible damping fluid, a valve assembly mounted on a bottom wall of the inner cylindrical tube and comprising a first compression valve and a first intake valve, a cup-shaped body mounted in the inner cylindrical tube, inside the compression chamber, and an auxiliary piston rigidly connected to the main piston and configured to slide in the cup-shaped body at least during a final section of the compression phase of the shock-absorber.

Abstract: A rail brake damper includes a cylinder-piston arrangement. A damping device assigned to the piston comprises at least one damping valve having at least one piston channel, which passes through the piston, connecting the two operating chambers of the cylinder, and a closure element assigned to the piston channel. The closure element is spring pre-loaded with the effect of closing the piston channel and is acted on by the hydraulic pressure which prevails in the operating chamber facing away from the piston rod with the effect of opening the damping valve.

Abstract: An air spring for a motor vehicle or a driver's cab of a motor vehicle has a cover, a rolling piston and at least one air spring bellows. At least two damping devices are integrated into the air spring.

Abstract: A shock absorber having a main tube extends between a first end and a second end defining a fluid chamber therebetween. A main piston is slidably disposed in the fluid chamber dividing the fluid chamber into a compression chamber and a rebound chamber. A piston rod is attached to the main piston. A hydraulic compression stop including an additional piston is attached to the piston rod for movement therewith. The additional piston includes a body extending from the piston rod and defining a conduit extending along the center axis. An actuator is disposed in the conduit and attached to the body movable from a closed position to an open position during the compression stroke with the open position allowing fluid flow through the actuator and the conduit and the closed position preventing fluid flow through the actuator. The actuator includes a spring and a blocking member disposed in the conduit.

Abstract: A hydraulic damper includes a hydraulic compression stop arrangement having an insert including a bottom and a fixing member including a body. The bottom is attached to the body through a locking connection preventing axial movement of the insert and transferring pressure exerted on the insert to the fixing member and allowing the cavity of the insert to receive the additional piston during the compression stroke to provide an additional damping force. The body includes a locking plate and the bottom includes a locking yoke with the locking yoke being secured to the locking plate to define the locking connection. The fixing member includes a head and the locking plate extends radially outwardly from the head defining a recess extending about the center axis. The locking yoke, having an arcuate shape and an L-shaped cross section, extends axially outwardly from the bottom to engage the recess forming the locking connection.

Abstract: A damping valve for a vibration damper includes a damping valve body with separate passage channels. The outlet orifices of the passage channels for a flow direction are connected to one another via a groove, which is covered by at least one valve disk and is bounded radially by at least one annular web on the radially inner side with respect to the center axis (A) of the damping valve and at least one annular web on the radially outer side with respect to the center axis (A) of the damping valve. The radially outer web has at least one first portion in which the support is configured as area support for the valve disk, and the radially outer web has at least one second portion in which the support is configured as line support for the valve disk.

Abstract: A hydraulic device includes a tubular housing containing a rod to which a plunger is rigidly secured that separates an upper chamber and a lower chamber both filled with a hydraulic fluid such that the plunger and the rod move together in a relative manner axially inside the tubular housing, thereby moving the hydraulic fluid from one chamber to the other and varying the volumes thereof. The hydraulic device further includes a spring that operates under compression resisting the movement of the plunger in one direction when the plunger moves toward a maximum extension position of the hydraulic device. The hydraulic device also includes an open elastic ring, the ends of which define an adjustable intermediate passage for the hydraulic fluid in order to adjust damping at the end of maximum extension of the hydraulic device and in other relative positions.

Abstract: A device having two glands leading a piston rod the glands being located at one side of a piston, whereas an inner gland divides the chamber inside the closed cylinder into a working chamber limited axially by an inner surface of a bottom and into a lubricating chamber limited axially by the inner surface of the outer gland. The working chamber has a flow zone shaped as the cylinder with its inner diameter increased, placed adjacent to the inner gland, as well as the compression zone, whereas the inner diameter of the cylinder is slidingly fitted with the outer diameter of the piston.

Abstract: A hydraulic shock absorber includes a cylinder, a piston ring, a first valve seat forming an extension side oil path, a first valve opening and closing the extension side oil path, a second valve seat forming an inner-side channel through which oil flows separately from a flow of the oil causing the first valve to open the extension side oil path, a second valve opening and closing the inner-side channel, a spool provided to press the second valve toward the inner-side channel, a base member holding the spool, and an axially-movable free piston forming a back pressure chamber communicating with the inner-side channel and that houses the oil between the spool and the base member.

Abstract: A hydraulic damping cylinder for a prosthetic knee joint, including a housing, a cylinder chamber in the housing and filled with a hydraulic fluid, and a piston arranged in the cylinder chamber and movable by a piston rod. In the housing there are provided at least two separate receiving chambers, which are of different size and are connected to the cylinder chamber by fluid ducts, for hydraulic fluid displaced from the cylinder chamber during a piston movement. The receiving chambers are each separated, by a diaphragm, from a compression chamber filled with a compressible fluid that forms an energy store. Upstream of the larger receiving chamber, there is connected a throttle device which forms a flow resistance for the hydraulic fluid flowing into the receiving chamber so that the hydraulic fluid can be distributed to the two receiving chambers in a manner dependent on speed of the piston movement.

Abstract: A damping device comprises a piston that partitions an interior of a cylinder into first and second working chambers. A flow-rate-dependent damping force generating element connects the first and second working chambers. A first pressure chamber and a second pressure chamber divided by a free piston are formed integrally with the piston. A first connecting passage connects the first working chamber and the first pressure chamber, and a second connecting passage connects the second working chamber and the second pressure chamber. By providing a relief valve that allows fluid to flow from the first working chamber into the second working chamber, an increase in the generated damping force during a high speed operation of the piston can be suppressed, regardless of a vibration frequency of the piston.

Abstract: Provided is a piston valve of a shock absorber which can achieve both an effect of varying an attenuation force according to a pressure and an effect of varying an attenuation force according to a frequency region. The piston valve includes: a main valve unit coupled to a lower end of a piston rod formed with an orifice hole, to divide an inside of a cylinder into an extension chamber and a compression chamber, the main valve unit generating an attenuation force according to a difference of pressure between the extension chamber and the compression chamber; and a frequency sensitive valve unit installed at one side of the main valve unit and configured to generate an attenuation force according to a frequency of hydraulic fluid delivered through the orifice hole of the piston rod, wherein the frequency sensitive valve unit is installed within the main valve unit.

Abstract: A bicycle fork leg including a pressurized gas chamber functioning as a shock absorber and a piston adjacent to the bicycle fork leg. A movable compression rod which moves toward the piston when a force is imparted to the bicycle leg. A rubber or compliant member within the piston. The movable compression rod coming in contact with the compliant member to reduce low amplitude high frequency shocks.

Abstract: A hinge module connected between a first body and a second body of an electronic device is provided. The hinge module includes a hinge connecting the first and the second bodies, a linking rod, and a sleeve pivoted to the second body. The linking rod has a first end connected to the first body and a second end slidably coupled into the sleeve. When the first and the second bodies are rotated by the hinge module, the first body drives the linking rod such that the second end slides in the sleeve and drives the sleeve to rotate relative to the second body. Inner wall of the sleeve has at least one interfering section. When the second end moves onto the interfering section, the linking rod is interfered to the sleeve, such that the first body is supported by the hinge module and opened relative to the second body.

Abstract: A shock absorber has a pressure tube with a piston assembly slidably disposed within the pressure tube and attached to a piston rod. The piston assembly divides the pressure tube into an upper working chamber and a lower working chamber. The piston assembly includes a frequency dependent valve assembly attached to the piston rod which defines a housing attached to the piston rod and a piston disposed within the housing. The piston moves within the housing to control the fluid flow through a bypass fluid passage that bypasses the piston assembly.

Abstract: In a hydraulic shock absorber 10 in which a piston rod 14 is inserted into an oil chamber 27 of a cylinder 13 provided in a damper case 11, and a damping force generating device 40 is provided between a piston side oil chamber 27A and a rod side oil chamber 27B of the cylinder 13, an outer flow path 13C communicating the piston side oil chamber 27A and the rod side oil chamber 27B is provided around the oil chamber 27 of the cylinder 13 in the damper case 11, and an oil reservoir chamber 32 is provided around the oil chamber 27 of the cylinder 13 in the damper case 11 and the outer flow path 13C.

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 cylinder apparatus includes a flow path which is provided in a valve member and through which a fluid circulates when a rod is moved; a disk valve which opens and closes the flow path; and a spring member which presses the disk valve in an axial direction. The spring member includes a first spring which comes into contact with the disk valve in a state in which the disk valve closes the flow path, and a second spring which comes into contact with the disk valve in a state in which the disk valve opens the flow path.

Abstract: A bicycle shock absorber and methods for differentiating between rider-induced forces and terrain-induced forces includes a first fluid chamber having fluid contained therein, a piston for compressing the fluid within the fluid chamber, a second fluid chamber coupled to the first fluid chamber by a fluid communication hose, and an inertial valve disposed within the second fluid chamber. The inertial valve opens in response to terrain-induced forces and provides communication of fluid compressed by the piston from the first fluid chamber to the second fluid chamber. The inertial valve does not open in response to rider-induced forces.

Abstract: Shock absorber comprising a piston inside which a sleeve is present which can be operated separately from the piston. This sleeve is provided with through-flow conduits which can cooperate with apertures, which are fitted at a vertical distance, of a part of the piston in order to provide an auxiliary flow when the piston is displaced in the cylinder. Such auxiliary flow enters into a chamber which is delimited by one or more spring plates which act on a sleeve which loads the main valve against opening when it is pressed down by the spring plate. By filling the chamber with fluid, the load applied on the sleeve by the spring plate is reduced and the load on the main valve decreases, as a result of which the latter opens more readily.

Abstract: The invention relates to a hydraulic damper (1), in particular for the suspension system of a motor vehicle comprising a tube (2) filled with working liquid, inside of which a slidable piston assembly (3) is placed.

Abstract: A flow-control passive valve controls flow of fluid between an upstream space at high pressure and downstream space at low pressure. The valve comprises a valve body in fluid communication with the upstream and downstream spaces and within which are defined first and second spaces. A movable member is slidably received in a body chamber, and a force is applied to the member tending to keep it in a given “non-working” position. Metering discs meter the flow from the upstream to downstream space through the body and comprise first, second, and third fixed restrictors and first and second variable restrictors. Pressure in the first space is lower than that in the upstream space via a pressure drop through the first fixed restrictor while pressure in the second space is variable between the pressure in the first space and that in the downstream space depending on the position of the member.

Abstract: A damping valve arrangement for a vibration damper includes a damping valve body, which has at least one through-flow opening for the damping medium, and at least one valve disk which at least partly covers the through-flow openings under the influence of a closing force. The damping valve arrangement includes at least one spring element which has at least one supporting portion axially supported at another structural component part of the damping valve arrangement, and at least one spring portion disposed at a distance from the supporting portion and which introduces a spring force into the valve disk at least indirectly, wherein the spring force of the spring element is directed counter to the closing force acting on the valve disk, and wherein the spring force of the spring element is less than the closing force of the valve disk.

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 valve assembly for a shock absorber includes a valve body defining a fluid passage. A valve disc engages the valve body to close the fluid passage. A fulcrum disc engages the valve disc at a first position and a second position radially outward from the first position. The fulcrum disc is designed such that the second position is closer to the valve body. In one embodiment, the fulcrum disc is concave with respect to the valve body.

Abstract: A shock absorber has a compression valve assembly which functions during a compression stroke, a rebound valve assembly which functions during a rebound stroke and a velocity sensitive valve which is in series with one or both of the compression valve assembly and the rebound valve assembly. The compression valve assembly, the rebound valve assembly and the velocity sensitive valve can be incorporated into a piston assembly, a base valve assembly or both.

Abstract: A shock absorber has a compression valve assembly which functions during a compression stroke, a rebound valve assembly which functions during a rebound stroke and a velocity sensitive valve which is in series with one or both of the compression valve assembly and the rebound valve assembly. The compression valve assembly, the rebound valve assembly and the velocity sensitive valve can be incorporated into a piston assembly, a base valve assembly or both.

Abstract: A shock absorber includes a first passage and a second passage to which a working fluid flows out from one chamber in a cylinder by movement of a piston, a damping valve installed on the first passage and configured to regulate a flow of the working fluid caused by sliding of the piston to generate a damping force, a back pressure chamber applying an internal pressure to the damping valve in a closing direction of the damping valve, a back pressure chamber inflow oil passage introducing the working fluid from one chamber into the back pressure chamber, a pressure chamber provided in-between on the second passage, and a free piston installed in the pressure chamber so as to freely slide in the pressure chamber.

Abstract: A shock absorber has a compression valve assembly which functions during a compression stroke, a rebound valve assembly which functions during a rebound stroke and a velocity sensitive valve which is in series with one or both of the compression valve assembly and the rebound valve assembly. The compression valve assembly, the rebound valve assembly and the velocity sensitive valve can be incorporated into a piston assembly, a base valve assembly or both.

Abstract: An active suspension system for a vehicle including at least one fluid operated ram having a cylinder and a main piston mounted therein for reciprocating movement, control means for controlling an equilibrium position of the piston in the ram in response to lateral acceleration of the vehicle in order to counter the effects of body roll of the vehicle, and wherein the ram includes shock absorbing means for permitting rapid movement of the piston from the equilibrium position when operating fluid in the ram is subjected to transient increases in pressure.

Abstract: A damping device for a two-wheeled vehicle having a first and a second damper chamber which are coupled to one another through a flow connection. The flow connection includes at least one flow valve provided with a damping channel. A magneto-rheological fluid is provided in the damping channel of the flow valve wherein the flow valve includes at least one magnetic device such that the damping channel of the flow valve can be exposed to a magnetic field of the magnetic device. The flow valve further includes at least one spring device. The magnetic device of the flow valve is provided on a valve piston and the valve piston is received in a deflection chamber to resiliently deflect counter to a spring force of the spring device such that the magnetic field of the magnetic device effective in the damping channel depends on the resilient deflection of the valve piston.

Abstract: A shock absorber has a compression valve assembly which functions during a compression stroke, a rebound valve assembly which functions during a rebound stroke and a velocity sensitive valve which is in series with one or both of the compression valve assembly and the rebound valve assembly. The compression valve assembly, the rebound valve assembly and the velocity sensitive valve can be incorporated into a piston assembly, a base valve assembly or both.

Abstract: A rod acceleration reducing mechanism is provided in a bottom-side oil chamber in an inner tube. The rod acceleration reducing mechanism includes a housing having a cylindrical accommodating casing screwed onto a fastening bolt of a bottom valve and a cap, a free piston displaceably fitted in the housing to define variable chambers at vertically opposite sides thereof, and elastic disks applying an elastic resistance to the displacement of the free piston. The variable chambers formed in the housing are variable in volume in response to pressure changes in the bottom-side oil chamber and the reservoir chamber. Thus, rod vibration can be generated by the rod acceleration reducing mechanism to reduce generation of rapping noise during running of the vehicle.

Abstract: A bicycle shock absorber and methods for differentiating between rider-induced forces and terrain-induced forces includes a first fluid chamber having fluid contained therein, a piston for compressing the fluid within the fluid chamber, a second fluid chamber coupled to the first fluid chamber by a fluid communication hose, and an inertial valve disposed within the second fluid chamber. The inertial valve opens in response to terrain-induced forces and provides communication of fluid compressed by the piston from the first fluid chamber to the second fluid chamber. The inertial valve does not open in response to rider-induced forces.

Abstract: A bicycle shock absorber and methods for differentiating between rider-induced forces and terrain-induced forces includes a first fluid chamber having fluid contained therein, a piston for compressing the fluid within the fluid chamber, a second fluid chamber coupled to the first fluid chamber by a fluid communication hose, and an inertial valve disposed within the second fluid chamber. The inertial valve opens in response to terrain-induced forces and provides communication of fluid compressed by the piston from the first fluid chamber to the second fluid chamber. The inertial valve does not open in response to rider-induced forces.

Abstract: A floating piston valve includes an annular valve body having a fluid passing hole formed therein, a pair of upper and lower valve discs respectively mounted on upper and lower sides of the valve body to generate damping force, a pair of upper and lower tripod type leaf valve springs respectively mounted on upper and lower sides of the upper and lower valve discs, and a pair of upper and lower coupling supports coupled to the valve body respectively at upper and lower sides of the upper and lower tripod type leaf valve springs. Each of the coupling supports includes an annular support section and a coupling section at least partially formed on an outer edge of the annular support section and is fastened to the valve body through a portion of an outer edge of the valve body.

Abstract: A shock absorber has a compression valve assembly which functions during a compression stroke, a rebound valve assembly which functions during a rebound stroke and a velocity sensitive valve which is in series with one or both of the compression valve assembly and the rebound valve assembly. The compression valve assembly, the rebound valve assembly and the velocity sensitive valve can be incorporated into a piston assembly, a base valve assembly or both.

Abstract: There is provided a vibration isolator in which a restriction passage for causing a main fluid chamber and a sub-fluid chamber to communicate with each other is changed over to one of a first restriction passage and a second restriction passage according to a change in the frequency of vibrations in a short period of time, and the size of the isolator is made small efficiently. A plunger member 78 closes an orifice opening 74 when being moved to a closing position against the urging force of a coil spring 90 by the fluid pressure in a pressurization space 130, and opens the orifice opening 74 when being returned to an opening position by the urging force of the coil spring 90. For the orifice opening 74, the opening ratio R between the transverse opening width along the axial direction and the longitudinal opening width along the circumferential direction is set in the range of 2?R?25, further preferably 5?R?20.

Abstract: An amplitude selective shock absorber includes a cylinder, a piston rod axially movable within the cylinder, a stationary piston valve fixedly mounted on the piston rod to divide a space of the cylinder into a rebound chamber and a compression chamber, a floating piston valve mounted on the piston rod to be movable in an axial direction in the rebound chamber, a stopper secured to the piston rod above the floating piston valve, and frustoconical leaf springs disposed between the floating piston valve and the stationary piston valve and between the floating piston valve and the stopper, respectively.

Abstract: A hydraulic valve includes a main body, a valve body, a piston, a valve sleeve, a spool and a resilient energy storage member. The valve body and the piston are disposed within the main body. The valve body defines a first chamber, a second chamber, and a cylindrical passage connecting the first chamber and the second chamber. The valve sleeve is moveably disposed in the cylindrical passage. The spool is moveably disposed within the bore of the valve sleeve. The resilient energy storage member may be disposed between the valve sleeve and valve spool. The resilient energy storage member is compressed as pressure is induced in one of the first chamber or the second chamber such that the valve sleeve and the spool move relative to one another so that at least a portion of the shaped aperture is exposed to the first chamber or second chamber to allow a proportional amount of hydraulic fluid to flow between the first chamber and the second chamber.

Abstract: Shock absorber comprising a piston inside which a sleeve is present which can be operated separately from the piston. This sleeve is provided with through-flow conduits which can cooperate with apertures, which are fitted at a vertical distance, of a part of the piston in order to provide an auxiliary flow when the piston is displaced in the cylinder. Such auxiliary flow enters into a chamber which is delimited by one or more spring plates which act on a sleeve which loads the main valve against opening when it is pressed down by the spring plate. By filling the chamber with fluid, the load applied on the sleeve by the spring plate is reduced and the load on the main valve decreases, as a result of which the latter opens more readily.

Abstract: An amplitude sensitive damper apparatus that is provided with an amplitude sensitive valve unit may include a plug coupled to a piston rod to form a spring groove with the piston rod in a predetermined section, a spool member configured and dimensioned to cover the spring groove and slidably coupled to the piston rod to move up and down along the piston rod, wherein the spool member includes a supporting portion that protrudes toward the piston rod from a middle portion of an inner surface of the spool member, upper and lower elastic members that are mounted inside the spring groove to support the supporting portion of the spool member upwards and downwards respectively along the piston rod, and an amplitude sensitive valve that is integrally mounted on an outer surface of the spool member to generate a damping force when the spool member is moving.

Abstract: A shock absorber comprises a first passage (2a, 2b) and a second passage (15) connecting a first fluid chamber (41) and a second fluid chamber (42). A throttle (12, 14) narrows an inflow of fluid to the first passage (2a, 2b) according to an applied displacement pressure. The displacement pressure includes a fluid pressure in one of the two fluid chambers (41, 42) and a pressure that depends on a velocity of the fluid flow through the throttle (12, 14). A spring (25, 29) biases the throttle (12, 14) in the opposite direction to narrow the fluid flow. The second passage (15) comprises a pair of orifices (16a, 17a). By exerting a pressure between the pair of orifices (16a, 17a) on the throttle (12, 14) in the opposite direction to narrow the fluid flow, the spring load required of the spring (25, 29) is reduced.

Abstract: A damping valve for a vibration damper includes a guide sleeve which slides on the piston rod of a vibration damper. An annular damping valve body which is provided with at least one through-opening is fixed axially by positive engagement on the guide sleeve, and the through-opening is covered at least partly by at least one valve disk which is biased by at least one closing spring which is supported at its end at a spring plate connected to the guide sleeve. The damping valve body and a spring plate which is constructed separate from the guide sleeve form a compression chain between two axially spaced stops of the guide sleeve.

Abstract: A damper device includes a cylinder body and a piston body. At least one of the cylinder body and the piston body is attached to an article subject to damping so that the damping is applied to a movement or a relative movement of the article subject to the damping. The damper device has a run-through hole formed in an inner recess part of the cylinder body facing the piston body, and a stopper body having a shaft part, which is inserted into the run-through hole. A dimension of insertion of the shaft part of the stopper body into the run-through hole changes by a change of pressure caused by a movement of the piston body.

Abstract: A damping valve (10) resists a flow of fluid from a first fluid chamber (41) to a second fluid chamber (42) which are separated by a piston (1). A partitioning member (24, 27-29, 52) partitions an inflow space (A, B) of a passage (2) in the first fluid chamber (41). A spool (17, 31, 51) decreases a flow cross-sectional area of a flow path from the first fluid chamber (41) into the inflow space (A, B) according to a differential pressure between the fluid chambers. By ensuring a gap between the outer circumference of the valve disk (1) and the partitioning member (24, 27-29, 52) which permanently allows fluid to flow from the first chamber (41) into the inflow space (A, B), the damping force characteristic in a high speed region of piston displacement can be set independently of the damping force characteristic in other regions.

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 vibration damper with amplitude-selective damping force includes a piston rod carrying a piston arrangement axially movably arranged in a cylinder and dividing the cylinder into two working spaces. A flow connection is present between the working spaces and controlled by an axially movable switching ring which cooperates with a working surface which faces the ring to define a pilot opening cross section. A bypass channel with at least two connecting openings to the flow connection is provided hydraulically in parallel to the flow connection. At least one connecting opening upstream of each of two stop surface of the switching ring. A check valve arrangement separates the bypass channel and the flow connection from each other in the different flow directions as a function of the movements of the piston rod, the check valve arrangement having two check valves which close in opposite directions.