Abstract: A velocity limiting device providing greater resistance to motion through a fluid in one direction than in the opposite direction. The device includes a toroidally shaped control member having a smooth generally conical surface on one side for low resistance movement through the fluid in the one direction. On its opposite side the control member is formed with at least one groove providing a concave surface spaced from which is an arrangement of vanes forming a jet for directing a stream of fluid into the groove upon movement in the opposite direction whereby the resultant increase in fluid turbulence increases resistance to rapid movement in this opposite direction.

Abstract: An hydraulic energy dissipater with multiple working ratios, of the telescopic type, comprising a member with a variable cross-section, penetrating into a bore provided on the bottom of a piston and into a chamber provided inside the rod of the piston, which controls, as a function of its position with respect to the bore, the passage of fluid between two working chambers, either through weakly loaded valves or through more strongly loaded valves. The invention is applied more especially to the damping of yaw movements of bogies of railway rolling stock.

Abstract: A piston assembly for a shock absorber includes a first set of one or more ports controlled by two valve mechanisms, a second set of ports controlled by a single valve mechanism, and a third set of ports uncontrolled by any valve mechanism. All three sets of ports conduct fluid during the compression and rebound strokes.

Abstract: A piston assembly for a shock absorber includes a first set of one or more ports, controlled by two valve mechanisms, which conduct fluid only during the rebound stroke of the piston. A second set of ports, controlled by a single valve mechanism, conducts fluid during all compression and rebound strokes. A third set of ports uncontrolled by any valve mechanism conducts fluid during all compression and rebound strokes.

Abstract: A hydraulic damping unit, particularly for use in artificial joints. The unit includes a cylinder housing having a screw-in bottom part. A hollow piston is guided in the housing and has on its jacket a shoulder which delimits with corresponding flanges on the inner wall of the housing two chambers of variable volume for storing a hydraulic liquid. A hollow throttling piston is guided in the main piston and is formed with an annular recess which communicates with respective variable volume chambers via passages passing through the jacket of the main piston at both sides of the shoulder. In the range of both passages, the bottom of the recess of the throttling piston is connected to the outer surface of the latter via a sloping annular surface which, depending on the relative position of the throttling piston to the main piston, adjusts the clearance of the passages to control the resistance to flow of the hydraulic liquid.

Abstract: A shock absorber including a casing, a piston rod having a portion in the casing, a piston head mounted on the piston rod for dividing the casing into chambers on opposite sides thereof, a piston head having a central bore therein having an inner peripheral surface which flares outwardly at opposite ends thereof, and a plurality of interspersed grooves and ridges on the piston rod within the bore for permitting flow of liquid between the chambers to thereby provide fluid amplification through the spaces between the inner peripheral surface of the piston head and the outer peripheral surface of the piston rod.

Abstract: The invention relates to a hydraulic shock absorber with two-way action, in which two pistons (18, 19), one for each direction of motion, act in a housing (1). The pistons (18, 19) are movable relative to each other in, or with, a pressure tube (6). Equalizing elements (4, 5) are provided at the ends. The pistons (18, 19) are each provided with a piston rod. The piston rods are provided with seals (38, 39) which are nearly completely relieved of pressure.

Abstract: A hydraulic shock isolator damping valve exhibiting variable damping depending on degree of valve extension is described which comprises a hydraulic cylinder defining closed fluid reservoirs at each end, a piston within the cylinder and interconnecting the structural members between which relative movement is damped, the piston having first and second axially spaced portions sized for slidably engaging the inner surface of the cylinder and including an intermediate third axial portion of reduced outer diametric size, the first and second portions each including a predetermined number of axial holes sized for displacement of fluid through the piston in response to movement of the piston through the fluid, and an annular member of outer diameter smaller than the first and second portions slidable on the third portion between confronting surfaces of the first and second portions, the annular member including a pair of confronting peripheral flanges, each including axial holes smaller in size and corresponding in

Abstract: A delayed restraint releaseable device utilized to restrain and controllably release the lower end of an inflating escape slide at a predetermined pressure, orientation and time. The device combines two distinct restraint mechanisms into one combination unit. The primary release is accomplished by means of shear pin or pins located at the first end of the device. Under normal conditions, the release is accomplished by shearing of the pin or pins under the load provided by the tied back inflating slide. The back-up release, in series with the primary release, occurs when the pressure of the reduced load causes a piston within the restraint to move against both a spring and captive fluid. As the piston moves, the fluid transfers through a precise sized orifice in the piston, from one side of the piston to the other. The piston moves eventually to a point at which the interlocking leg of the piston support shaft is released, thus allowing the ends of the mechanism to separate.

Abstract: A shock absorber having a casing and a piston with a piston head mounted thereon and located in a chamber within the casing containing fluid, an annular peripheral groove on the shock absorber head for mounting an annular turbulence inducing member having an L-shaped cross section which is slidable on the bottom surface of the groove from a passive position which it occupies when the piston head forces liquid from one side thereof to the other in a fluid amplification mode and which moves to an active position for creating turbulence within the groove during the rebound movement of the piston head.

Abstract: An improved all terrain cycle having a single front steerable wheel mounted on a pivotable frame having a steering stabilizer affixed thereto. The steering stabilizer is a damper assembly which has a piston held within a fluid filled cylinder linked to the frame of the cycle at one end and to the frame of the steering assembly at the other end. The resulting cycle is much easier to control because rapid movement of the handlebars which occurs when the front wheel hits rough terrain is effectively eliminated.

Abstract: The invention pertains to a boring tool for boring cylinder chambers of internal combustion engines without removing the engines from the vehicle chassis. A housing affixed to the engine block includes a rotatable driveshaft supporting a cutting tool whereby rotation of the driveshaft by an electric motor causes linear movement of the driveshaft to feed the tool. Tool advance is produced by a spiral groove pump defined upon a piston mounted on the driveshaft located within an oil-filled cylinder defined in the housing. A valved fluid passage located in the driveshaft piston selectively permits the pump to be bypassed for axial rapid traverse movement of the driveshaft and tool.

Abstract: A gas spring in which the piston rod is connected to a piston with a through-hole bored therethrough which is disposed in the cylinder filled with high pressure gas and oil and the spring action is effected by axial movement of the piston rod, characterized in that, when the piston rod is fully pushed into the cylinder, the oil reservoir formed within the cylinder is closed, yielding an ample sealing effect; and when the piston rod is fully pulled out of the cylinder, the high pressure gas can be filled along the piston rod into the cylinder without being hindered by the oil in the cylinder.

Abstract: A fluid-operated actuating device of the type including an actuating cylinder member, an axially movable actuating piston rod member, and actuating fluid connection means for introducing actuating fluid to and removing actuating fluid from the actuating cylinder member so as to adjust the relative axial position of the actuating cylinder and piston members and including structure for damping the movement of the piston rod member with respect to the cylinder member.

Abstract: A vortex flow hydraulic shock absorber for damping relative displacement of two components comprising a piston provided with a fluid passage therethrough including a pair of vortex chambers formed in a movable valve body disposed between a pair of resilient annular discs in a valve chamber in the piston. The valve body moves against the force of the resilient annular discs in response to an increase in the pressure difference of the working fluid on opposite sides of the piston to positions in which the fluid is permitted to bypass one or both of the vortex chambers as it traverses the piston, thereby varying the damping force of the shock absorber.

Abstract: A hydraulic damper includes a cylinder containing hydraulic liquid, a piston slidable in the cylinder and partitioning the interior of the cylinder into two liquid chambers, a passage formed through the piston to communicate the two liquid chambers, a piston rod connected to the piston and extending out of the cylinder, and a valve for controlling the liquid flow in the passage. The piston is axially displaceable relative to the piston rod by a limited amount, and the valve comprises an annular disc mounted on the piston rod and cooperating with one side surface of the piston when the piston abuts with the disc when the piston displaces in one direction and separating from the piston to form a clearance therebetween which acts as an inlet of the passage when the piston displaces in the opposite direction.

Abstract: A damping force generating mechanism in a hydraulic damper includes a housing containing therein oil and an oil chamber partitioning member such as a piston. The mechanism includes a communicating passage provided in the oil chamber partitioning member and defining an annular valve seat on one end thereof and an annular valve plate provided on one end of the communicating passage and being deflectable toward and away from the valve seat for permitting the oil to flow in the communicating passage in one direction. The plate valve consists of a plurality of mutually overlapping annular plates, and at least one of the annular plates is deflected in the direction separating from the valve seat by a projection member which also is one of the annular plates.

Abstract: A hydraulic damper includes a cylinder, a piston working in the cylinder and partitioning the interior thereof into two liquid chambers, two valve discs provided respectively on opposite end surfaces of the piston, two sets of passages opening respectively in opposite end surfaces of the piston to cooperate with respective valve discs, and an orifice communicating permanently the two liquid chambers. A restricting member is provided to change the effective area of the orifice in response to the direction of the liquid flow passing through the orifice.

Abstract: A shock absorber comprises a cylinder and a piston rod passing through at least one end of the cylinder. A piston unit is mounted on the piston rod and divides the cavity within the cylinder into two working chambers. A damping fluid is contained within the cylinder. The working chambers are interconnected across the piston unit by first and second branch flow passages arranged in parallel. First and second flow valves are associated with these first and second flow passages, respectively, and operate to dampen movement of the piston rod in at least one direction in dependency on the velocity of movement. The first branch passage flow valve is normally open and closes only when a predetermined velocity of movement is exceeded. The second branch passage flow valve is normally closed and opens only when the pressure differential between the working chambers exceeds a predetermined value. Closing of the first branch passage flow valve increases the damping effect.

Abstract: A shock absorber is provided with a relief valve within a thrusting piston. The relief valve defines a vortex chamber therein and is movable in response to the pressure difference between a high pressure chamber and a lower pressure chamber. The valve is movably urged toward an initial position by a set spring which defines the set pressure of the shock absorber.

Abstract: Single tube vehicle suspension strut with built-in shock absorber in which the piston rod is formed from tubing that provides a reservoir for shock absorber fluids and further featuring this type piston valving with the deflecting spring discs and cooperating metering pin construction which can readily reduce high pressure build-up and which can be adjusted to provide ride and level control. This unit can be used to provide a leveling feature with the gas spring in the piston tube operatively connected to suitable controls for pressurized gas and exhaust.

Abstract: A hydraulic damper comprising a tube with a bottom end thereof closed for containing hydraulic oil therein, a piston slidably fitted in the tube and partitioning the tube into upper and lower chambers which are filled with oil, a piston rod having one end thereof being secured to the piston by a hollow nut having a cavity opening to the lower chamber therein which is located on the side of lower chamber and the other end thereof projecting to the outside through a rod guide and sealing member which are fixed to the upper end of the tube and which seal the upper end of the tube, a pressurized gas chamber provided on the side of the lower chamber for compensating the changed volume of the piston rod within the tube, a first communicating path provided in the piston for communicating the upper and lower chambers, a second communicating path which serves to communicate the upper and lower chambers via the cavity provided in the hollow nut and which is provided in the piston rod on the side of the piston and the h

Abstract: A shock absorber is disclosed having an outer cylinder closed at one end thereof, a hollow inner cylinder closed at one end and opened at an another end thereof, the open end being inserted in the outer cylinder, a guide member for guiding the inner cylinder slidably in the outer cylinder, a member for generating a damping force, the damping force generating member being connected to the open end of the inner cylinder, and having an orifice for throttling flow of hydraulic fluid from a chamber in the outer cylinder to a chamber in the inner cylinder, the orifice being in a central portion of the inner cylinder, and a plate-like stop provided between the inner cylinder and the damping force generating member for retaining the damping force generating member against the damping force within a predetermined range, the stop having an aperture greater than the orifice.

Abstract: A combined shock absorber and suspension device, particularly for a vehicle, comprises a suspension whose function is to elastically support the weight of a vehicle and a double-effect shock absorber which comprises an energy dissipation brake. The combined shock absorber and suspension device is either oleopneumatic or hydropneumatic. The device includes two telescopically slidable tubes which are each blocked at one end and open at the other end, the respective open ends of the tubes adapted to be inserted into one another to achieve a telescopically slidable motion. Each of the tubes can comprise an oil reservoir, the two reservoirs being separated by a piston attached to a free end of the interior one of the tubes. The piston includes at least one permanently open bleed bore. This bore is adapted to work during both compression and expansion of the device.

Abstract: An improved shear-type pressure relief device is provided which is useful in conjunction with pressure chambers requiring relief when system pressures exceed a predetermined level, such as in the shock absorbing piston and cylinder assemblies of present day vehicle bumpers. The relief device is preferably in the form of an integral, metallic body including a flange in engagement with a pressure chamber wall adjacent a relief opening, with a projection extending into the opening. The juncture between the flange and projection is advantageously very sharp (having a radius of less than about 0.020 inches) and the device is designed to shear upon experiencing high system pressures for relief purposes. In the case of vehicle bumpers the shear device is located on the shiftable, bumper-mounted piston thereof, and circumscribes the usual stationary, tapered, frame-mounted, flow-restricting rod.

Abstract: Disclosed is a liquid metering valve unit, particularly for water. The unit uses a dash-pot mechanism filled with metering liquid such as water, silicone oil or a mixture of water and glycerine. The dash-pot mechanism is a closed system. The unit comprises a sleeve member having an axial bore and a transverse bore communicating with the axial bore. One end of the axial bore connects to a liquid supply and the transverse bore connects to an outlet. A valve stem in the axial bore is slidable between an open position and a closed position in which a resilient seat washer seals the end of the axial bore. A spring biasses the stem toward the closed position and the stem can be manually moved to the open position. Movement of the stem to the closed position is controlled by a dash-pot mechanism or regulating means comprising a cup washer secured to the stem and disposed within a liquid-filled chamber betwen the stem and sleeve.

Abstract: An oleopneumatic suspension with variable throttle orifices, particularly for aircraft landing gear comprising a rod (1) enclosing a pneumatic spring (2) and being fixed with respect to a piston (4) sliding in a cylinder (3), two valves (6) and (7) with permanent throttle orifices, the valve (6), which is of greater cross-section, throttling in the compression phase and the valve (7), which is of lesser cross-section, throttling in the extension phase, the suspension comprising in addition a throttle device, the section of whose orifice varies in dependence on the position and the direction of displacement of the piston (4) in the cylinder (3) so that over a given distance around a predetermined equilibrium position the orifices ensuring throttling in the compression and extension phases are of cross-sections respectively greater than the corresponding orifices over the remainder of the distance covered by the piston (4) in the cylinder (3).

Abstract: An improved air/oil shock absorber (16) especially adapted for aircraft landing gears (11) is provided whereby the rate of strut (14) compression is programmed separately for the landing impact and for rollout after the landing. During the landing impact, increased tail clearance is achieved by temporarily delaying the last few inches of compression. After the aircraft rotates on to the nose landing gear, the shock absorber (16) slowly compresses to its static position where it then functions in a conventional manner. The shock absorber assembly (16) may be oriented in any position with respect to the aircraft (10) by virtue of two internal air/oil separator pistons (24 and 29).

Abstract: A shock absorber including a piston assembly dividing a cylinder into a rebound chamber and a compression chamber, the piston assembly including fluid control bleed orifices of a size to permit flow therethrough during a relatively slow long amplitude movement of the piston assembly in either direction, normally closed valves for controlling the flow of fluid between the chambers during relatively fast long amplitude movements of the piston assembly, and a normally open valve assembly operable (1) to permit relatively unrestricted flow of hydraulic fluid between the chambers during a relatively rapid short amplitude movement of the piston assembly in either direction and (2) to move into a closed position (a) during a relatively slow long amplitude movement of the piston assembly in either direction so as to permit the bleed orifices to control the resultant fluid movement between the chambers and (b) during a relatively rapid long amplitude movement so as to permit the normally closed valves to control the r

Abstract: Preferably, a ski or like member contacting the ground suspends a snowmobile frame or chassis via vertical telescoping tubes defining a variable volume chamber. A hollow piston rod fixed to an end cap at one end of one of the telescoping tubes bears at its opposite end and slidable within the other cylinder, a damping piston. The damping piston bears a plurality of orifices for permitting restricted flow of hydraulic liquid to opposite sides of the piston and between chamber sections separated by the damping piston. The hollow rod opens at the end bearing the piston, directly to one chamber section, and bars at least one radial port adjacent its opposite end opening to the other chamber section with the port being closed off by an expandable O-ring functioning as a check valve. A given mass of hydraulic fluid is supplied to the chamber, and the chamber is gas pressurized.

Abstract: An improved buffer for small arm weapons utilizes a pair of fluid containing reciprocating chambers to attenuate recoil forces by limiting fluid flow in relation to chamber travel between the pair. In the second chamber of the pair a flow control element moves in the direction of a restricting member when the fluid pressure drop through the flow control element reaches a predetermined point. The flow restricting member limits fluid flow through the flow control element when the flow control element travels to a point proximate the flow restricting member. Fluid flow in the opposite direction is substantially unrestricted by the flow restricting members.

Abstract: A gas spring of the piston-and-cylinder type in which the two compartments of the cylinder cavity, separated by a piston assembly, are connected by a first passage. A valve arrangement on the piston assembly defines a second passage between the compartments and closes in response to movement of the piston assembly away from a terminal position in the cylinder while opening in response to movement of the piston assembly towards the terminal position. Releasable locking structure carried in part by the cylinder and in part by the piston assembly cooperates to close the first passage when the piston assembly approaches the terminal position, thereby to hold the piston assembly in such terminal position.

Abstract: A piston is biased by a valve so as to decrease the volume of a chamber just before seating of the valve on the valve seat and brakes and slows up movement of the valve towards the valve seat by compressing a hydraulic fluid in the chamber and forcing out the hydraulic fluid from the chamber through a hole at a limited flow rate.

Abstract: The valve is mounted within the piston of a hydraulic shock-absorber for a vehicle suspension system. An axial rod attached to the piston is surrounded by a passageway and fitted with a moving element consisting of an elastically deformable washer which moves between two end positions defined by stops. In one end position, the cross-sectional area permits free flow of the operating fluid between the wall of the passageway and the washer. In the other end position, the passageway is throttled and the flow is limited in respect of a fluid pressure below a predetermined threshold value. In the throttling position the washer is capable of undergoing elastic deformation in respect of a fluid pressure above the threshold value in order to increase the flow cross-section.

Abstract: An automatic-locking damping unit designed to prevent damage to pipelines exposed to violent shaking. The unit is characterized by the presence of a compensating chamber provided in the inner cavity of the cross-head; this chamber communicating with the inner space of the unit via two valves and nozzles. The invention is of interest to designers of hydraulic equipment.

Abstract: A thermal timer valve for temperature-dependent operation of accessory devices of a fuel mixture preparation system of a combustion engine. The valve has a membrane chamber acted upon by intake pipe or manifold negative pressure. The membrane is connected to a rod which on one end has a valve closure element and on the other end a piston located in an oil chamber. The oil chamber may have an adjustable overflow channel. A disk check valve may be associated with the piston. Also there may be an overflow channel with a compensation chamber.

Abstract: A hydraulic shock absorber of the type having a cylinder and a piston with axial passages therethrough. The piston is mounted to slide within the cylinder. Valve plates having orifices therethrough are provided to control flow through the axial passages of the piston. Certain of the valve plates are situated to operate together with a variable effective orifice on the downstream side of the axial passages and to act with a fixed effective orifice as check valve plates when the flow is reversed. The composite valve thus defined offers a smooth and properly sloping velocity-resistance curve. The shock absorber also includes a foot valve assembly controlling flow between the interior of the cylinder and an annular oil reservoir outside the cylinder. The foot valve assembly may have two check valves for controlling flow through two sets of foot valve passages or it may employ a check valve spring which changes from a "V" shape to a flat shape to cover orifices in a check valve plate.

Abstract: A hydraulic snubber device and more particularly, a snubber adapted to be interposed between a bolster and a side frame member and being operative to provide a first damping rate when the railway car is operating on tangent track and at equilibrium speed on super elevated track and to provide a second relatively higher damping rate when the railway car is operating on super elevated track at low speed and in all instances of severe rocking.

Abstract: A gas-operated absorber includes a piston and cylinder unit wherein axially extending grooves of a predetermined length are provided on the inner surface of the cylinder to vary the dampening effect during the expansion stroke of the piston. The piston expansion movement is braked as the piston moves away from the grooves during its expansion stroke, and through holes in the piston head permit passage of gas therethrough during the expansion stroke although, when the piston moves away from the grooves, a flexible lip on the piston completely closes the holes to effect further braking. Additional holes are also provided in the piston head through which the gas may pass throughout the expansion stroke.

Abstract: A method for filling gas into a cylinder having a rod slidably extending from one end thereof. The method involves the steps of forming a reduced diameter portion in the rod at a position adjacent to the inner end thereof, locating the rod at the position of maximum extension so as to form a gas filling passage between the reduced diameter portion and an annular seal ring, filling a high pressure gas into the cylinder, moving the rod inwardly to close the gas filling passage, and deforming a portion of the cylinder to form a stop restricting the outward movement of the rod.

Abstract: A piston arrangement for a shock absorber. A piston rod has a piston mounted on it, the piston being axially non-displaceable with respect to the piston rod. The piston has flow channels through which a damping medium may flow when the piston is axially displaced in the shock absorber. There are two valves for controlling the flow of medium when the piston is moved in opposite axial directions, respectively, each of which valves has a valve element that opens against a spring force, depending on the direction of axial movement of the piston and therefore on the direction of flow of the medium. This closure element of one of the valves includes a disc while the closure element of the other valve includes a sleeve which surrounds the piston rod. The sleeve has a flange which is exposed to the pressure of the medium when the valve is opened. This piston rod itself has a region of reduced diameter, part of which region is in axial alignment with the disc. The sleeve and disc form a space between themselves.

Abstract: In a shock strut for an aircraft landing gear having inner and outer elongated telescoping tubes and a primary orifice selected and designed to attenuate the load level to a certain design condition which is compatible with the aircraft's structural threshold up to a certain overload sink speed, a load attenuating valve which opens when the design velocity is exceeded. The load attenuating valve includes secondary orifices held closed by a tension fuse which ruptures and opens the orifices in parallel to the primary orifice for additional flow, thus keeping the pressure drop across the orifices to an acceptable level so as to permit full stroking of the strut. In this way, as much energy as possible is absorbed before the load is transmitted to the aircraft on failure.

Abstract: An improved plunger type solenoid comprises a solenoid coil, a plunger to be attracted into the solenoid coil, a piston directly or indirectly connected to the plunger and a cylinder filled with oil for containing the piston. The piston is subject to the pressure of the oil, such that the speed of movement of the plunger is widely controlled.

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

Abstract: A damping force generating device in a hydraulic shock absorber having at least two oil spaces therein and an oil space partitioning member on which the damping force generating device is mounted including an annular resilient valve disc controlling oil flow flowing thereacross in the opposite directions in response to the extension and compression strokes of the shock absorber. A second annular resilient disc is disposed overlapping the valve disc for delaying the valve opening time in either direction of the oil flow.

Abstract: A simplified but highly efficient fluid-amplified liquid spring shock absorber is provided by incorporating a plurality of DeLaval nozzles in the piston head or dashpot head of a shock absorber.

Abstract: A telescopic hydraulic shock absorber in which a valve for controlling downward flow through the piston is formed by a spring disc valve sealing against a seat on the underside of the piston, and a valve for controlling upward flow through the piston is formed by a spring disc valve located between the piston and the first-mentioned disc valve. Apertures are formed in the first-mentioned disc valve to permit the upward flow, and the second disc valve seals these apertures when closed. A single set of passages through the piston is provided to accommodate both upward and downward flows.

Abstract: A shock absorber for a motor vehicle suspension includes a piston construction having flow control valving that becomes more restrictive during the life of the shock absorber to compensate for the reduction in friction damping in the suspension during usage. The piston valving includes a flow passage surrounded at one of its ends by an annular land that forms a valve seat. A valve element is urged to a closed position against the seat by the cumulative force of a primary spring and a secondary spring. The secondary spring provides a spring force countering the force of the primary spring but is constructed to progressively take a permanent set after repeated cycling whereby the cumulative force of the two springs urging the valve element to a seated condition will increase during the service life of the shock absorber.

Abstract: A pneumatic suspension element of the piston-and-cylinder type in which the escape of compressed gas from the cylinder cavity is prevented by a liquid in a portion of the cylinder cavity through which the piston rod passes. The compressed gas and liquid are introduced into the cylinder cavity through resiliently sealed gaps about the piston rod and/or through a porous partition separating the liquid-filled cavity portion from the gas-filled portion.

Abstract: A pneumatic shock absorber for use in a suspension has a cylinder and a piston with a piston stem mounted in the cylinder for reciprocation, the piston stem and the cylinder being connected to different relatively movable parts of the suspension. A communication is established between the two chambers which the piston separates in the housing, which communication is controlled so as to determine the rate of flow of the pneumatic medium therethrough and thus the extent and speed of reciprocation of the piston relative to the housing. A valve arrangement controls the pressure of the pneumatic medium in the interior of the housing.