Abstract: The invention is directed to a method for controlling the level of a vehicle body of a motor vehicle with a level control system having a plurality of actuator elements with which the level of the vehicle body can be lowered by discharging an actuating fluid from the actuator elements. The level control system includes a control unit. A first level of the vehicle body is determined relative to a reference point directly before a discharge operation. A discharge operation of the vehicle body is initiated when the first level lies above a pregiven level. After initiating a discharge operation, a check is made in the control unit as to whether the vehicle body has lowered from the first level in accordance with an input. The discharge operation is interrupted when the vehicle body has not lowered from the first level in accordance with the input.

Abstract: Filling valve for a gas bag installed in a space bounded by rigid walls, where the forces of a liquid medium, which is under pressure and which flows into and out of this space, act on this space. The gas bag serves as a compensation space, is filled with gas, and can be filled through a filling valve, which has an access channel aligned with an opening in the rigid wall. The access channel is located in a connector part connected to the gas bag, the connector part also being connected to a guide part resting against the inside surface of the rigid wall, the access channel being in effective connection with the opening in the rigid wall via this guide part.

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

Abstract: The invention provides a damper assembly (10) comprising a housing (12) defining an inner chamber (22, 24) having a damping fluid disposed therein. A piston rod (14) is slidably retained by the housing (12), and at least partially extends into, the chamber (22, 24). A piston (18) is disposed at a first distal end (21) of the piston rod (14) and strokes inside the housing (12). The piston (18) defines a first chamber (22) and a second chamber (24) within the housing (12) and includes at least one aperture (26) for allowing damping fluid to flow between the first (22) and second (24) chambers. An actuator (30) is disposed within the piston (18) for varying the flow of damping fluid through the aperture (26) between the first (22) and second (24) chambers within the housing (12). The piston rod (14) includes an inner bore (16) that receives pressurized air from an external source for communicating pneumatic control signals to the actuator (30).

Abstract: Improved adjustable shock absorbers comprising a cylinder, a piston movable within said cylinder, a source of hydraulic or pneumatic fluid, a pump, means connecting said source to supply fluid through said pump to said cylinder, valve means operable from the driver's seat for regulating the flow of fluid from said source to said cylinder, damper means located within said cylinder for controlling oscillation of said piston, said cylinder and piston being connected between the axle and frame of said vehicle to regulate the ground clearance and ride stiffness of said vehicle.

Abstract: An integral one-piece end plate and bracket combination is formed of a high strength plastic and is mounted in an airtight sealing engagement with an open end of a flexible elastomeric sleeve which forms the fluid pressure chamber of an air spring. The end plate includes a semi-circular wall which extends perpendicular to a longitudinal axis of the air spring and a semi-circular opening. The bracket includes an upstanding wall perpendicular to the semi-circular wall of the end plate and a half dome-shaped wall, which together with the upstanding wall, forms an auxiliary fluid chamber which is in fluid communication through the semi-circular opening with the main fluid chamber of the flexible sleeve. The upstanding wall includes attachments for securing the bracket and end plate to a support structure which aligns with a longitudinal axis of the air spring.

Abstract: A gas spring device includes a pressure adjustor having an actuator mechanism which regulates the rate of discharge through a pressure-release valve in equal bursts small enough to permit precise adjustment of the internal working pressure of the gas spring. Manually turning the actuator mechanism provides a consistent application of intermittent inertial force to the gas spring pressure-release valve so that resultant equal bursts provide a controlled release of pressure, even from imprecise manual operation. The chance of over-bleeding is eliminated since the mechanics of the actuator mechanism provides a single metered burst of released gas regardless of how quickly or slowly it is turned, thus the size of the burst is not dependent on the operator's skill. Because the adjustor mechanism is integrated directly into the device, it is compact and does not interfere with other surrounding mechanical structures.

Abstract: An air chamber (53) of a damping force adjusting mechanism (49) disposed in a hydraulic shock absorber (3) of a damping force adjusting type communicates with an air chamber (7) of an air spring through a tubular path (57). A free piston (51) is transferred in accordance with the pressure of the air chamber and a spool (46) is transferred to shift a damping force. The damping force presents a soft characteristic both on the extending side and on the retracting side in a usual status, presents a hard characteristic on the extending side and a soft characteristic on the retracting side when the pressure of the air chamber is high, and presents a soft characteristic on the extending side and a hard characteristic on the retracting side when the pressure of the air chamber (7) is low. The damping force can be obtained, which approximates the damping force control on the basis of a so-called sky-hook theory.

Abstract: The invention relates to a pneumatic spring system (1) comprising at least the following components, specifically: a pneumatic spring cover (2) and a pneumatic spring piston (4), which are arranged opposing each other; a pneumatic spring bellows (3) made of elastomer material, which connects the pneumatic spring cover (2) and the pneumatic spring piston (4) with each other with the use of fasteners (8), whereby the bellows is capable of rolling off on the outer wall of the piston (5) with formation of an internal chamber (6) of the pneumatic spring having an elastic volume; as well as a connection (7) for ventilating and evacuating the internal chamber (6) of the pneumatic spring. The pneumatic spring system is equipped with a pressure-sensitive connection system which reacts to pressure in a way such that in the evacuated condition, the pneumatic spring cover (2) and the pneumatic spring piston (4) are connected with each other, whereby the connection is released again in the operating conditions, i.e.

Abstract: An automatic pneumatic control system for the air springs of a semi-trailer air-ride trailing beam-type axle/suspension system. A plurality of conduits and valves of the control system pneumatically interconnect one or more sources of compressed air, the vehicle parking brakes and the suspension air springs. The control system incorporates a vented two-position two-way pilot valve for controlling inflation and deflation of each air spring. The valve closes when air pressures in a pair of control system sensor lines differ, thereby enabling complete or nearly complete deflation of the air spring it controls before the parking brake is set, thereby minimizing or eliminating the problems of trailer drop and walk during loading of an empty trailer, heretofore caused by complete or nearly complete deflation of the air springs only after the parking brakes are already set.

Abstract: A level control system for a motor vehicle having a vehicle body includes a plurality of air springs which can be filled or discharged with pressurized air to control the level of the vehicle body. A first control apparatus controls the functions of filling and discharging the air springs in dependence upon the level of the vehicle body. A communications channel interconnects the first control apparatus to a second control apparatus. A switch triggers an additional function in the level control system and this switch is movable between a first switching state and a second switching state. The switch is connected to the second control apparatus and the second control apparatus functions to transmit a signal sequence via the communications channel to the first control apparatus when the switch is transferred from the first switching state into the second switching state. The first control apparatus operates to carry out the additional function when the first control apparatus receives the signal sequence.

Abstract: A hydraulic circuit controls a doubling acting cylinder of a vehicle suspension to provide load leveling and shock absorption functions. A set of solenoid valves control the application of pressurized hydraulic fluid from a supply line to the cylinder and from the cylinder to a tank return line to raise and lower the vehicle for load leveling. The chambers of the cylinder are interconnected by a parallel arrangement of a check valve, orifice and a relief valve. Another parallel arrangement of a check valve, orifice and a relief valve couples the cylinder to an accumulator. These parallel arranged components enable the doubling acting cylinder to function as a passive shock absorber. A lock-out valve is provided in the preferred embodiment a to defeat the shock absorber operation and provide a very stiff suspension.

Abstract: An air suspension for a vehicle includes at least one air spring per wheel at at least one vehicle axle, one pump, at least one accumulator, and one circuit arrangement for connecting these units, the pressure side of the pump being connected to the accumulator or the air springs. To form a closed compressed-air system, the intake side of the pump is connected via at least one valve to the accumulator or the air springs, and at least the air-guiding interior pump chambers between the intake side and the pressure side of the pump have a pressure-tight design. The air suspension system requires comparably low energy consumption and small unit volume at a high level of efficiency.

Abstract: The air spring is comprised of a flexible airsleeve, a retainer, and a main piston. The airsleeve is secured at one end by the retainer and at the opposing end by the main piston. A hollow restraining piston extends from the retainer and into the main piston. The restraining piston acts as a lateral stabilizer, over extension restraint and height control. The hollow region in the restraining piston communicates through at least one passage with an air chamber formed between the airsleeve and the outer surfaces of the restraining piston and the main piston. Fluid is admitted to or exhausted from the air spring through a valve which functions relative to the displacement of the restraining piston and the main piston.

Abstract: The present invention provides a bellows type air spring, which includes a bellows body, and first and second end members. The bellows body has a generally hollowed cylindrical shape with upper and lower open ends and a longitudinal axis extending between the upper and lower open ends. The bellows body also defines therein an air chamber for receiving the air, thereby allowing the bellows body to be expanded and contracted along the longitudinal axis. The first end member is disposed in the lower open end for sealing the same, and defines therein a through hole for receiving a body of a shock absorber. The second end member is disposed in the upper open end for sealing the same, and defines therein a through hole for receiving a retractable rod of the shock absorber.

Abstract: Hydraulic mounts which include a body member, a partition, a diaphragm and a base member are placed on an apparatus for supporting the body member loosely assembled with the partition, diaphragm and base member. A head member engages the body member and the base member in temporary fluid sealing relationship while air is evacuated from internal chambers of the mount and hydraulic fluid is flowed into the chambers. The head member may then be moved away from the base member and a final assembly of the mount provided by crimping a peripheral upper edge of the body member in forcible engagement with the base member, the partition and the diaphragm. The mount may include spaced apart projections to allow fluid to flow between the partition and the body member during the air evacuation and fluid fill process.

Abstract: A gas spring for a steerable vehicle wheel includes bellows that are supported at one end on a roll-off surface on a wheel carrier, a suspension element, or a part connected therewith, and are fastened at another end on a spring can. The spring can has an inlet opening to which a pressure hose or a pipe is connected. The pressure hose or pipe is arranged in a loop at least in an area above the bottom of the spring can and, during rotating movements of the spring can, is elastically deformed at least in that area.

Abstract: Level adjustment device for vehicles with air springs 8a through 8d, by which a vehicle body is furnished with suspension on at least one vehicle axle, which includes the following: a source of compressed air 2, which, for the purpose of filling air springs 8a through 8d, can be connected to air springs 8a through 8d via an air dryer 4, the air dryer 4, for the purpose of filling the air springs, is connected on one side to air springs 8a through 8d through a check valve 6 that is open to air springs 8a through 8d, each air spring 8a through 8d, for the purpose of emptying them, can be connected through the air dryer 4 and through a pneumatically controlled first distribution valve 10 to the atmosphere, wherein the pneumatic control input 38 of this distribution valve 10 is then impinged through a second controllable distribution valve 12 with the pressure in air springs 8a through 8d against a restoring force 50 acting on the pneumatic control input 38, the pneumatic control input 38 of the pneumatically co

Abstract: A fluid spring assembly. The spring assembly preferably includes a body that slidably supports a piston that is attached to a piston rod. The piston serves to define a fluid chamber within the body that is charged with a pressurized fluid medium. The piston is retained within the body by a rigid retainer member. A biasing member is provided between the retaining member and the piston for resisting the force generated by the fluid medium within the fluid chamber.

Abstract: A vibration control system utilizes a liquid spring filled with a compressible liquid. In its most general embodiment, the vibration control system minimizes the transmission of vibration between a first mass and a second mass, i.e. vehicle frame/vehicle cabin, structure/ground, machinery/platform. The liquid spring can be either a passive or an active system. An active system utilizes a second volume of compressible fluid. A passive system only uses a single volume of fluid. Further, the liquid spring can provide either spring force or both spring and damping forces. Alternatively, a single volume liquid spring can be utilized in conjunction with a conventional damper.

Abstract: A vehicle is carried by a number of supporting members, such as wheels. Movement between the supporting members and the vehicle body is controlled by respective dampers. Several interrelationships between and among the dampers are disclosed. A flow regulator is provided to augment damping forces under a variety of operating conditions.

Abstract: A novel and improved magnetorheological (MR) damper charging system is provided which simply and effectively substantially minimizes MR fluid leakage during a MR damper assembly process thereby minimizing cleanup and reducing costs. The damper charging system includes a charging body having a bore for receiving damper components and damper fluid, at least one inlet formed in the charging body for delivering fluid to the bore, and a magnetic field generating assembly mounted at the inlet and operable in an energized state to generate a magnetic field across the inlet to cause MR fluid in the inlet to experience a MR effect sufficient to prevent leakage flow through and from the inlet. An inlet valve is mounted on the charging body for controlling flow of fluid through the inlet into the bore.

Abstract: An apparatus and a method of making an automatic temperature compensating gas spring strut, the method comprising providing an outer cylinder having opposite ends with one end closed and the other end apertured to permit movement of the strut therethrough; nesting an inner cylinder within the outer cylinder with radial space therebetween, the inner cylinder being apertured at opposite ends; partitioning the space between said cylinders into a first chamber adjacent the closed end of the outer cylinder and a second chamber remote from such closed end; inserting a piston in sliding, sealing relation with the interior of the inner cylinder, the piston having a piston rod extending from said piston and sealingly out through the aperture of the outer cylinder; after injecting a high pressure, non-condensing gas in the first chamber, inserting a measured quantity of solid carbon dioxide (“dry ice”) in the second chamber at ambient conditions and closing said second chamber while sealingly allowing movem

Abstract: A seat assembly for accommodating vibrations imparted thereto including a seat having a bottom surface, a frame including a base secured to a fixed surface and a support member extending upwardly therefrom. A substantially rigid pivot member is provided which includes a forward portion and a rearward portion. The pivot member being pivotally secured to the frame at a pivot point disposed on the pivot member between the forward portion and the rearward portion, and the forward portion being pivotally secured to the seat, the pivot member permitting the seat to move relative to the fixed surface. A biasing device is included which extends between the frame and the rearward portion of the pivot member to accommodate the movement between the seat and the frame.

Abstract: The invention is directed to an air spring arrangement having a device for making ultrasonic distance measurements. An ultrasonic sensor, which is built into an air spring (2) for making measurements, can be disturbed when high frequency sonic oscillations occur when filling and venting the air spring. An air supply line (8) is disposed between the air spring (2) and a source of compressed air (30). To prevent the above disturbing frequencies, the air supply line (8) includes an air connecting pipe stub (10) which is lined with a net-shaped layer (16) on its inner wall surface. The layer (16) is preferably a plastic mesh. The filaments (18) of the mesh-shaped layer (16) are slightly inclined to the longitudinal center axis (28) of the pipe stub (10).

Abstract: A gas spring has a casing defining a chamber constructed to be filled with a gas under pressure, a piston rod received in the chamber for reciprocation between extended and retracted positions and having a free end projecting beyond the casing, a gas fill passage formed in the casing and through which pressurized gas is admitted into the chamber and a filler valve disposed in the fill passage to selectively permit the flow of gas through the fill passage. The filler valve has a body with a passage formed therethrough, a valve seat defined in the passage between opposed ends of the body and a poppet received in the passage and engageable with the valve seat to selectively permit gas flow through the filler valve and hence through the fill passage of the gas spring casing. The filler valve body preferably has mechanical threads formed in its exterior and constructed to be mated with complementary threads in the gas fill passage to firmly and releasably hold the filler valve within the fill passage.