Abstract: A shock absorber includes a hard side damping element that imparts a resistance to a flow of liquid moving between an extension side chamber and a compression side chamber, a solenoid valve configured to change an aperture area of a bypass passage that bypasses the hard side damping element and communicates with the extension side chamber and the compression side chamber, a soft side damping element provided in series with the solenoid valve in the bypass passage, and a tank connected to the compression side chamber. The hard side damping element includes an orifice and leaf valves provided in parallel with the orifice. The soft side damping element includes an orifice having a larger aperture area than the orifice.

Abstract: A motor vehicle chassis is provided having a base structure that can be hydraulically adjusted in level between a raised and a lowered position. A hydraulic adjuster is assigned to one of the two foot points of the corresponding suspension spring in each of the four wheel suspensions. At least two of the adjusters can be pressurized in parallel by a common hydraulic aggregate comprising a tank and a motor-pump unit and activated by a control unit. The at least two hydraulic adjusters that can be pressurized by the common hydraulic aggregate communicate hydraulically with the accumulator chamber of a spring-piston accumulator, which has at least one piston-position transmitter linked by signal transmission to the control unit.

Abstract: A front fork of a bicycle may include a suspension system that includes a damper. The damper may include a hollow tube with orifices that may be partially blocked by an adjustable blocker. A free end of the adjuster that adjusts the blocker may maintain its axial position in any rotational position. Ambient air may be introduced through a valve and retained in the suspension system. The suspension may include a mechanical spring in a chamber away from the valve that introduces the ambient air.

Abstract: A pneumatic automotive height adjuster assembly provides at least one bag removably connected to a vehicle having a frame. The at least one bag is configured to adjust a height of the frame. An air supply line has a supply end and a discharge end. The discharge end is in fluid communication with each of the at least one bag. The air supply is configured to provide air to inflate the at least one bag. A switch is in fluid communication with the supply end of the air supply line. The switch has a first discharge, a second discharge, and a switch input. A leveling valve is in fluid communication with the first discharge. The air supply line is in fluid communication with the second discharge. An air supply is in fluid communication with the leveling valve and the switch input.

Abstract: An active-passive dual mode switchable vehicle suspension system is provided. The suspension system includes a filter, a hydraulic pump, a one-way valve, a power takeoff, a servo valve, a suspension cylinder, an overflow valve, an energy accumulator, a reversing valve, a first pressure sensor, a second pressure sensor, a controller, an oil tank and a displacement sensor. Further related is a switching method for the active-passive dual mode switchable vehicle suspension system. When the active and passive dual-mode switchable vehicle suspension system is switched between modes, an oil pressure in the rodless cavity of the suspension cylinder and an oil pressure in the energy accumulator are adjusted to be equal in advance, so that the stable switching of the active-passive suspension system can be realized, and the vibration of the vehicle body is eliminated when the existing active-passive suspension system is switched.

Abstract: A hydraulic system for controlling a hydraulic circuit of a working machine is disclosed. The hydraulic system can include a first hydraulic cylinder assembly, a second hydraulic cylinder assembly, a third hydraulic cylinder assembly and a valve. When coupled to the first hydraulic cylinder assembly and the second hydraulic cylinder assembly, the third hydraulic cylinder assembly can be configured to control a flow of a hydraulic fluid between the first hydraulic cylinder assembly and the second hydraulic cylinder assembly to limit an extent of travel of the first piston and an extent of travel of the second piston.

Abstract: A snowmobile has a rear suspension assembly including front and rear suspension arms, first and second rear shock absorbers, a first sensor for sensing an angular position of the front suspension arm, a second sensor for sensing an angular position of the rear suspension arm, and a controller communicatively connected to the first and second sensors. A method of controlling the rear suspension assembly includes: sensing an angular position and/or an angular velocity of the front suspension arm; sensing an angular position and/or an angular velocity of a rear suspension arm; and determining a stroke and/or a piston velocity of the first rear shock absorber and/or the second rear shock absorber based on the angular position and the angular velocity of the front and rear suspension arms as sensed by the first and second sensors respectively.

Abstract: A suspension unit for a front fork of a vehicle includes an annular tube. The first tube defines a compression chamber and a damping chamber. A damper includes a first valve allowing gas to variably flow from the compression chamber to the damping chamber and a second valve allowing gas to flow from the damping chamber to the compression chamber. An external adjuster allows a rider to adjust the first valve to improve ride conditions.

Abstract: A milling machine is disclosed. The milling machine may have a frame, first and second tracks connected to a first end of the frame, a third track connected to a second end of the frame, and a milling drum attached to the frame. The milling machine may have first, second, and third actuators connecting the frame and the first, second, and third tracks, respectively. Each actuator may adjust a height of the frame relative to a respective one of the first, second, and third tracks. The milling machine may include a damper assembly attached to each of the first and second actuators. The damper assembly may have an accumulator connected to a respective one of the first and second actuators and a control valve for controlling a flow of fluid between the accumulator and the respective one of the first and second actuators.

Abstract: A method for operating a motor vehicle with a chassis arrangement having at least two vibration dampers. A body control is carried out at least partially with the vibration dampers. The chassis arrangement further has at least one stabilizer. During transverse accelerations below a threshold acceleration the stabilizer contributes to the body control less than the vibration dampers and contributes more than the vibration dampers from the threshold acceleration upward.

Abstract: A vehicle control device includes a spring mechanism configured to connect a sprung member and an unsprung member of a vehicle, generate a spring force according to a relative displacement between the sprung member and the unsprung member, and be able to variably control the spring force, and a damping mechanism configured to connect the sprung member and the unsprung member, generate a damping force for damping a relative motion between the sprung member and the unsprung member, and be able to variably control the damping force, wherein the spring mechanism and the damping mechanism are controlled based on a first physical quantity relating to a sprung vibration of the vehicle and a second physical quantity relating to an unsprung vibration of the vehicle.

Abstract: A harvesting machine includes a frame carrying at least one harvesting mechanism and a lightening device of the harvesting mechanism. The lightening device includes second hydraulic jacks articulated on the frame and on the harvesting mechanism and connected by hydraulic circuits to first hydraulic jacks so as to be able to be actuated by the first hydraulic jacks and to hydropneumatic accumulators.

Abstract: A control arrangement for a hydropneumatic suspension system and a hydropneumatic suspension system are provided. The control arrangement has a pressure supply connection, a return connection, a piston chamber connection adapted to be connected to the piston chamber of a suspension cylinder of the hydropneumatic suspension system, an annular chamber connection adapted to be connected to the annular chamber of the suspension cylinder, and at least one controllable valve arrangement comprising a plurality of switch positions via which the pressure supply connection and the return connection are connectable to the piston chamber connection and the annular chamber connection. The annular chamber connection is in flow connection with the return connection via a pressure-limiting line having a hydraulically controllable pressure-limiting element. The pressure-limiting element has a control input adapted to be acted upon via a control line by a control pressure which is limitable to a predefinable pressure limit.

Abstract: Methods and apparatus for regulating the function of a suspension system are disclosed herein. Suspension characteristics often contribute to the efficiency of a suspended system. Depending on the desired operating parameters of the suspended system, it may be desirable to alter the functional characteristics of the suspension from time to time in order to maintain or increase efficiency. The suspension hereof may be selectively locked into a substantially rigid configuration, and the damping fluid may be phase separated and/or cooled to increase damping rate during use (or offset rate degradation). The suspension hereof may generate power usable to achieve any or all of the foregoing or to be stored for use elsewhere in the suspended system or beyond.

Abstract: A suspension system can include an air spring, an air reservoir external to the air spring, and a flow control device which variably restricts flow of air between the air spring and the air reservoir. Flow between the air spring and the air reservoir may be permitted in response to compliance of the suspension system, and the air spring can have an internal air volume at least 2½ times as great as a volume of the air reservoir. The flow control device may permit flow between the air spring and the air reservoir in response to a predetermined pressure differential level across the flow control device. Multiple air reservoirs can be internal to an axle, and can be isolated from each other in the axle.

Abstract: A method and apparatus for a vehicle shock absorber comprising a main damper cylinder, a first reservoir and a second reservoir. One embodiment includes a first operational mode where both reservoirs are in fluid communication with the cylinder. In a second operational mode, only one reservoir communicates with the cylinder during fluid evacuation from the cylinder. In each mode, rebound from either or both reservoirs may travel through a single, user-adjustable metering device.

Abstract: In a vehicle-height adjustment apparatus of a motorcycle having the hydraulic jack attached to the damper, damping force characteristics of a damper are stabilized, the influence of the charged gas pressure of an oil reservoir chamber is eliminated, and the sealing performance of a hydraulic jack is reduced. In the vehicle-height adjustment apparatus of a motorcycle, a back pressure chamber is provided on a side opposite to a jack chamber, with a plunger being interposed therebetween inside a hydraulic jack, and this back pressure chamber is communicated with a hydraulic chamber inside a damper tube.

Abstract: A shock absorber for a vehicle having a damper and a first and second springs mounted coaxially around the damper and a preload adjuster for partially compressing at least one of the springs independently of the compression stroke. In one embodiment the preload adjuster is remotely controllable. In another embodiment the shock absorber includes an additional mechanism for preloading at least one of the springs.

Abstract: A control arrangement for a hydropneumatic suspension system and a hydropneumatic suspension system are provided. The control arrangement has a pressure supply connection, a return connection, a piston chamber connection adapted to be connected to the piston chamber of a suspension cylinder of the hydropneumatic suspension system, an annular chamber connection adapted to be connected to the annular chamber of the suspension cylinder, and at least one controllable valve arrangement comprising a plurality of switch positions via which the pressure supply connection and the return connection are connectable to the piston chamber connection and the annular chamber connection. The annular chamber connection is in flow connection with the return connection via a pressure-limiting line having a hydraulically controllable pressure-limiting element. The pressure-limiting element has a control input adapted to be acted upon via a control line by a control pressure which is limitable to a predefinable pressure limit.

Abstract: An auxiliary axle suspension system for a motor vehicle is disclosed wherein a pair of hydraulically operated actuators position and force the auxiliary axle to help support the vehicle. And gas springs are provided that allow the actuators to extend and retract over a wide range of hydraulic operating pressure and thereby allow the auxiliary axle to adjust to a wide range of road grade differences between the auxiliary axle wheels and the wheels of the axles that normally support the vehicle without incurring significant gas and hydraulic pressure fluctuation and while isolating shock forces on the auxiliary axle wheels from the vehicle.

Abstract: An air suspension system of a tandem axle assembly for a trailer includes a front axle air spring configured to be coupled to a front axle assembly of the tandem axle assembly and a rear axle air spring configured to be coupled to a rear axle assembly of the tandem axle assembly. The air suspension system further includes an air reservoir in fluid communication with the front axle air spring and the rear axle air spring and a ratio valve in fluid communication with the air reservoir, the front axle air spring, and the rear axle air spring. The ratio valve is positioned between the air reservoir and the front axle air spring. Further, the ratio valve is selectively operable to send a lesser amount of air from the air reservoir to the front axle air spring than to the rear axle air spring.

Abstract: The embodiments of the invention are directed to a method and apparatus for improvement in the function of dampers used on mobile vehicles such as recreational vehicles. The main function of current dampers (sometimes called shock absorbers) is to extract energy from the suspension system of a moving vehicle by forcing liquid through a system of valves internal to the damper. This invention adds two more functions. One is to lock the suspension so it cannot move when the vehicle is stationary. The second additional function is to level the chassis of the vehicle with respect to the gravity field.

Abstract: An air suspension system for a multi-axle vehicle having air bags (4,5; 6,7; 8,9; 10,11; 44 to 49) supporting either side of the axles (2,3; 41 to 43), including separate air lines (18 to 25; 50 to 55) respectively connecting each air bag to a level control valve (16,17; 56,57) via manifolds (26,27; M) and air lines (28,29; 54,55) to independently control air supply to the bags on either side, the separate air lines being of the same size and length to ensure that substantially the same volume of air is supplied to each bag to improve the responsiveness and stability of the system.

Abstract: The present disclosure provides a hitch suspension system that reduces a transfer of energy (e.g., provides a smoother ride) between two bodies hitched together, such as between a towing vehicle and a towed vehicle/trailer. In an embodiment, the suspension system includes a hydraulic cylinder with an extendable rod in fluid communication with a fluid pump. A control valve is fluidly coupled between the hydraulic cylinder and the fluid pump and is configured to adjust an extension length of the rod. Additionally, a variable orifice that adjusts resistance to extension and retraction of the rod is fluidly coupled between the hydraulic cylinder and the control valve. A first fixed restrictive element is fluidly coupled in series with the variable orifice to dissipate energy ad the rod extends and a second fixed restrictive element is fluidly coupled in series with the variable orifice to dissipate energy as the rod retracts.

Abstract: Improved mount and bearing height adjustable air suspension shock absorber devices, apparatus, systems and methods, for use with sport utility vehicles(SUVs) such as Range Rovers®, and the like. Air lines run through an upper mount into an upper opening of an inflatable and deflatable airbag. The airlines have not external lines such as the nylon type tubing used in the prior art, and are not prone to failure which occurs more frequently with the external tubing air lines. Inflating and deflating the air springs/airbags (bladders) allows for the shock absorbers in the devices to be adjusted to different riding conditions over different types of terrains giving the rider a customized ride over different types of on road and off-road terrains. An internal air line machined into the head of the air suspension device provides a direct passageway for compressed air to pass into and out of the airbag without using external tubes.

Abstract: System to control the trim of motorcycles with three or four wheels, the motorcycle having two couples of front and rear wheels, or one front wheel and a couple of rear wheels, or a couple of front wheels and one rear wheel.

Abstract: A suspension device has in- and out-configurations for use with a vehicle, including means for damping and/or spring action, the damping and/or spring action being controllable, wherein the controllability of the damping and/or spring action includes a locked or substantially locked state in the out-configuration. A method of using the suspension device with a vehicle is also provided.

Abstract: A multiple ride height control apparatus for an air suspension system having an air spring to be installed between a frame/body and a suspension arm in order to adjust the ride height, by filling and exhausting a compressed air, said apparatus comprises a mechanical leveling valve for controlling a filling and exhausting said compressed air by adjusting its mounting angle, being rotated clockwise and counterclockwise; and a valve driver for rotating said mechanical leveling valve to the direction of filling and exhausting said compressed air; and a controller for controlling the operation of said valve driver.

Abstract: A hydraulic system for lowering the ride height of a vehicle includes at least one hydraulic shock mounted to the suspension of the vehicle. Each of the hydraulic shocks has a floating bearing in the hydraulic shock, and an inlet. The inlet is hydraulically connected to a central manifold that is adapted to move fluid into and out of the hydraulic shock for moving the floating bearing in each of the hydraulic shocks. When the floating bearing is moved in the hydraulic shock, the hydraulic shock shortens thereby lowering the ride height of the vehicle.

Abstract: A closed ride control system for vehicles by which a vehicle body is suspended with respect to at least one vehicle axle and which includes the following components: pressure medium chambers which are connected via branches to a pressure medium line, a compressor, an air dryer which is arranged in a pressure medium line, a pressure medium reservoir which is connected via the compressor to the pressure medium chambers, and a non-return valve arranged in the pressure medium line between an outlet of the air dryer and the directional valve in order to connect the outlet of the air dryer to the pressure medium reservoir.

Abstract: A hydraulic control system for high flow applications in motor vehicles, in particular for active wheel suspensions and active steering arrangements, includes at least one passive high flow valve which is controlled hydraulically by at least one low flow valve.

Abstract: A wheeled loading machine includes a body mounting a loading arm, a ground engaging structure including a front axle which carries a front pair of ground engaging wheels and a rear axle which carries a rear pair of ground engaging wheels, the loading arm being mounted at a position towards a rear of the machine for up and down movement about a generally horizontal axis, and the loading arm extending forwardly beside a cab which is mounted at one side of the body, to an outermost end which is beyond a front of the body, and the loading arm having at its outermost end a mounting for a loading implement and the arm being extendible to vary the length of the loading arm, and each axle being suspended from the body by a respective suspension, each of the ground engaging wheels being drivable by an engine of the machine through a mechanical transmission, and the machine including a braking system for braking each wheel, the braking system including a brake control system which provides a brake anti-locking function

Abstract: An air suspension system for a multi-axle vehicle having air bags (4,5; 6,7; 8,9; 10,11; 44 to 49) supporting either side of the axles (2,3; 41 to 43), including separate air lines (18 to 25; 50 to 55) respectively connecting each air bag to a level control valve (16,17; 56,57) via manifolds (26,27; M) and air lines (28,29; 54,55) to independently control air supply to the bags on either side, the separate air lines being of the same size and length to ensure that substantially the same volume of air is supplied to each bag to improve the responsiveness and stability of the system.

Abstract: A shock absorbing system includes an air container, a power source to supply a high-pressure air into the air container, a plurality of shock absorbers each provided with at least one air spring, a central controller including a plurality of control units each connected between the air container and a respective one of the shock absorbers, and a drive unit to control operation of the central controller in a wireless way. Thus, each of the shock absorbers can be lifted to lift the chassis of the car so as to prevent the chassis from being worn out or broken due to a violent hit when the car passes a rugged road and can be lowered to lower the chassis of the car so as to enhance maneuverability of the car.

Abstract: A roll control system comprising a front torsion bar; a front first hydraulic actuator attached to the front torsion bar; a rear torsion bar; a rear first hydraulic actuator attached to the rear torsion bar; and control means connected to the hydraulic actuators and controlling the operation thereof on detection of a predetermined vehicle condition; wherein each hydraulic actuator comprises a first fluid chamber and a second fluid chamber; wherein the control means comprises a source of fluid pressure, a fluid reservoir, a pressure control valve fluidly connected between the pressure source and the reservoir, two pressure relief valves each having two positions to selectively fluidly connect the fluid chambers of the hydraulic actuators either to the pressure source or to the fluid reservoir, and a directional valve fluidly connected between the pressure relief valves and the fluid chambers of the hydraulic actuators; wherein the pressure relief valves and the directional valve are positioned on detection of

Abstract: The invention relates to a road-building machine whose left front wheel (4) or caterpillar, right front wheel (6) or caterpillar, left rear wheel (8) or caterpillar and right rear wheel (10) or caterpillar are connected to the road-building machine chassis by means of an actuating element and are height-adjustable with respect to the road-building machine frame. According to said invention, different actuating elements are rigidly connected to the road-building machine chassis and forcedly coupled to each other in such a way that the left front wheel (4) or caterpillar and the right rear wheel (10) or caterpillar are height-adjustable in the same direction and with respect to the right front wheel (6) or caterpillar and the left rear wheel (8) or caterpillar are adjustable in the opposite directions. The all wheels (4, 6, 8, 10) or caterpillars are equally height-adjustable.

Abstract: A method and apparatus for a low-profile suspension system, which provides coarse and fine suspension control to an object supported by the low-profile suspension system. Coarse suspension is provided to adaptively control a position of the object through pneumatic support devices. Pneumatic pressure is adaptively increased in the pneumatic support devices to support an increasing weight of the object, while pneumatic pressure is adaptively decreased in the pneumatic support devices to support a decreasing weight of the object. Fine suspension control is provided through rotational actuation of a shock absorbing device through a right-angle gear drive. By rotationally actuating the shock absorbing device, a range of stroke of the shock absorbing device along a vertical direction is minimized. Position equalization control is further provided to maintain a position of the object along an axis that is orthogonal to the coarse and fine suspension axis.

Abstract: A vehicle roll control system for a vehicle having a pair of front wheels and a pair of rear wheels each rotatable on an axle, comprising a front hydraulic actuator attached to the front torsion bar; a rear hydraulic actuator attached to the rear torsion bar; and control means connected to the front and rear hydraulic actuators and controlling the operation thereof on detection of a predetermined vehicle condition; wherein each front and rear hydraulic actuator comprises a housing, a piston making a sealing sliding fit inside the housing to define a first fluid chamber and a second fluid chamber, and a piston rod connected to the piston and extending through the second fluid chamber and out of the housing; wherein the control means acts on detection of the predetermined vehicle condition to apply a fluid pressure to the first fluid chambers of the front and rear hydraulic actuators and to apply a fluid pressure to the second fluid chambers of the front and rear hydraulic actuators; and wherein the control mea

Abstract: Complementary suspension device applicable between the hydro-pneumatic suspension systems of at least two wheels of a vehicle, which transfer the forces originating in said wheels to the aforementioned complementary device by means of displacement, and/or decanting, of the fluids of said suspension systems through the corresponding conduits, said device comprising two fluid distribution units connected in parallel by means of each joint conduit, between the hydro-pneumatic suspension systems of at least one pair of vehicle wheels, in such a way that for each pair of wheels the first distribution unit is capable of allowing the intake of fluid through the joint conduit with the suspension system of one of the wheels and, at the same time, lets fluid exit through the joint conduit with the suspension system of the other wheel, whereas the second unit only allows the intake of fluid through the joint conduits with the two suspension systems at the same time.

Abstract: A suspension system includes first and second wheel carriers, a stabilizer having a first end and a second end, the stabilizer being coupled to the wheel carriers, a first cylinder/piston unit being arranged between the first end of the stabilizer and the first wheel carrier and a second cylinder/piston unit being arranged between the second end of the stabilizer and the second wheel carrier. Each cylinder/piston unit is a double-acting cylinder/piston unit and the two cylinder/piston units are cross-connected.

Abstract: The present invention relates to a suspension device for the load-bearing and resilient support of a wheel in a motor vehicle. The device comprises at least one spring cylinder with a piston which is guided in a manner moveable relative to it in a pressure cylinder. A driving device converts pivoting movement of a wheel oscillating-crank supporting arm, which movement oscillates about an oscillating-crank axis into the relative movements between the pressure cylinder and the piston. The piston acts counter to an elastically compressible spring medium in order to produce a load-bearing supporting spring force. The driving device is designed as a gearwheel mechanism.

Abstract: The invention relates to a gas pressure shock absorber for vehicle chassis having a damper tube (1) and a piston rod (3) which supports a working piston (2) and is disposed in a reciprocally moveable manner in the damper tube (1), wherein a first partial volume (1a) of the inner space of the damper tube (1) can be filled with a damping fluid and a second partial volume (1b) of the inner space of the damper tube (1) can be filled with a gas, and wherein the gas pressure shock absorber has a device for regulating the vehicle level, which is actuated by the introduction of a gas under pressure into the inner space of the damper tube (1).

Abstract: A vehicle subassembly includes first and second hydraulic cylinders each having an upper chamber and a lower chamber. A fluid circuit is hydraulically connected to the first and second hydraulic cylinders and includes a valve movable between a first position where the upper chamber of the first hydraulic cylinder and the lower chamber of the second hydraulic cylinder are hydraulically connected and the lower chamber of the first hydraulic cylinder and the upper chamber of the second cylinder are hydraulically connected, and a second position where the upper chamber and the lower chamber of the first hydraulic cylinder are hydraulically connected and the upper chamber and lower chamber of the second hydraulic cylinder are hydraulically connected. A control unit is operable to position the valve in at least one of the first position and the second position based on an operating variable of the vehicle.

Abstract: A suspension system for a vehicle (3) comprises a gas spring accumulator (6) pneumatically connected (7) to a system accumulator (8). The suspension system further comprises a gas throttle valve (9) arranged to restrict the pneumatic connection (7) between the gas spring accumulator (6) and the system accumulator (8), such that only a limited mass flow which is greater than zero is allowed in the pneumatic connection (7).

Abstract: An air suspension system includes a first transfer pipe having one end communicating with the outside, the first transfer pipe being constructed such that air flows through the first transfer pipe; a filter mounted adjacent to the one end of the first transfer pipe to filter out foreign matter from the air; a compressor mounted on the first transfer pipe, such that the compressor is located adjacent to the filter, to compress the air; a dryer mounted on the first transfer pipe, such that the dryer is located adjacent to the compressor, to dry the air; an exhaust pipe extending from the first transfer pipe between the compressor and the dryer; an exhaust valve mounted on the exhaust pipe to control the flow of the air; a second transfer pipe communicating with the other end of the first transfer pipe; a control unit connected to the second transfer pipe, the control unit being constructed such that the high and low of the control unit are controlled by the pressure of the air; and a storage unit connected to t

Abstract: The present invention concerns embodiments of a portable fluid-transporting system for mounting on a land-driven vehicle, such as a loader, and methods for their use. In an illustrated embodiment, a fluid-transporting device includes at least one fluid container, or tank, that is mountable to and completely removable from a vehicle. The container is configured to be carried by the vehicle such that at least a portion of the container is supported in front of the forward end of the vehicle. In particular embodiments, the container is generally U-shaped and includes a forward-container portion and first and second side-container portions extending from respective ends of the forward-container portion.

Abstract: A suspension system dampens motion between two components of a vehicle, such as the wheels and the chassis. An assembly of a cylinder and a piston is connected to both components. The piston defines first and second chambers in the cylinder and has a shaft with an end surface exposed to pressure within a third chamber of the cylinder. A first accumulator is connected to the first chamber by a first accumulator valve and a second accumulator valve connects a second accumulator to the second chamber. A damping valve alternately connects the third chamber to either the second chamber or a fluid tank wherein that connection defines the stiffness of the suspension system and is made in response to force acting on the suspension system. A load leveling circuit also is described.

Abstract: A pneumatic suspension system for a vehicle includes pneumatic bellows connectable by means of a valve arrangement to at least one other component of the pneumatic suspension system in order to selectively increase or decrease the amount of compressed air therein. The other component contains at least one volume. Undesirable changes in the amount of compressed air inside the pneumatic bellows arising as a result of pressure compensation are avoided or reduced to a non-disruptive level by a return valve between the valve arrangement and the volume which prevents compressed air from flowing between the pneumatic bellows and the volume in one direction of flow.

Abstract: An arrangement is provided in which the durability of an operation changing means is improved when this means is provided to the suspension mechanism in a suspension structure for a work vehicle. A maximum position (A1) and minimum position (A2) of the operation of the suspension mechanism are detected, and an intermediate position (B1) between the maximum and minimum positions (A1) and (A2) is detected. When the intermediate position (B1) departs from the target range (H1), the operation of the suspension mechanism is changed to the body raising side or body lowering side so that the intermediate position (B1) moves toward the target range (H1).

Abstract: A shock absorber comprises first and second axially aligned cylinders (11, 21) each having a liquid filled prison chamber (12, 22), an axially displaceable piston (13, 23), received in the piston chamber (12, 22), and dampeners (14, 24) for dampening axial displacement of the piston (13, 23) through the liquid in the piston chamber (12, 22). A piston rod (1) axially extends between and into the first and second cylinder piston chambers (12, 22). The first and second axial ends (1a, 1b) of the piston rod (1) are connected to the first and second cylinder pistons (13, 23), respectively.