A vehicle stabilization system including a frame; a wheel; a control arm connected to the frame and the wheel; a fluid spring connected to the frame and the control arm; a stabilizer connected to the frame and operable between a retracted and extended position; a reservoir; and a fluid manifold connected to the fluid spring and the chamber, fluidly coupling the spring interior and stabilizer chamber to the reservoir interior. A vehicle stabilization method including maintaining an orientation of the vehicle frame, coupling the frame to a support surface using a stabilizer by introducing a fluid to a chamber of the stabilizer, and retracting a wheel by reducing a quantity of fluid within a fluid spring coupling the wheel to the frame.

An air suspension system is provided with air spring devices, a pressure accumulation tank, a compressor device that supplies compressed air at least to the pressure accumulation tank, and that includes an electric motor, a pump device, and a dryer, and a control device that performs a vehicle height increase control, a vehicle height decrease control, an air suction control, and a regeneration air discharge control. The control device performs a heat accumulation control, by actuating the pump device with the communication between the compressor device and the air spring devices being blocked, supplying the compressed air discharged through the dryer to the pump device to be circulated, and accumulating heat of compression of the compressed air in the dryer, to regenerate the dryer.

An air suspension system which includes the ability to adjust the working air volume, pressure, and spring rate of one or more air springs to reduce or eliminate various types of vehicle oscillations. Switchable or variable volume air spring assemblies have the ability to change air spring volumes, which results in changes in air spring rates, and therefore changes in normal loads applied to each wheel. Changes in wheel normal loads change wheel traction (slip) and vehicle dynamics (pitch, roll, yaw displacement, rate and acceleration). The spring rate of one or more of the air spring assemblies is adjusted automatically when a vehicle oscillation is detected. This vehicle oscillation is calculated from the raw vehicle signals, or another vehicle module may detect the oscillation and send a command to the air suspension module to change the spring rates. This changes the natural frequency of the vehicle, dampening the oscillation.

A method for operating a pressure control system having a multi-stage compressor includes providing a multiply compressed pressure medium by the multi-stage compressor for filling a pressure medium reservoir or pressure medium chambers of the pressure control system. Providing the multiply compressed pressure medium includes (i) providing, by a first compression stage, a pre-compressed pressure medium and additionally compressing, at least by a second compression stage, the pre-compressed pressure medium, and/or (ii) introducing an already-compressed charging pressure medium into an intermediate volume between the first compression stage and the second compression stage of the multi-stage compressor and further compressing the charging pressure medium at least by the second compression stage. The charging pressure medium simultaneously passes via a control line to a control input of a shut-off valve that interacts with the first compression stage, such that a charging pressure of the charging pressure medium predefines a control pressure.

A method for operating a pressure control system having a multistage compressor. The method comprises providing a pressure medium compressed multiple times by the multistage compressor in order to fill a pressure medium reservoir or pressure medium chambers of the pressure control system, by performing (i) providing, by a first compression stage, a precompressed pressure medium and additionally compressing the precompressed pressure medium via a second compression stage, and/or (ii) introducing, into an intermediate volume between the first compression stage and the second compression stage of the multistage compressor, an already compressed charge pressure medium and compressing, by the second compression stage, the charge pressure medium again. An intermediate pressure of the precompressed pressure medium conveyed into the intermediate volume is limited by an overpressure valve interacting with the first compression stage. The overpressure valve is configured to open if the intermediate pressure exceeds a limit value.

An emergency egress system for a multi-passenger vehicle such as a school bus (10) includes a housing (30) that operatively supports a ramp (34) in movable connection therewith. Opening an emergency exit door (18) of the bus causes a housing door (24) to open and the ramp to move outwardly from a retracted position toward an extended position. Opening the emergency exit door also causes the suspension of the bus to be automatically lowered to place the emergency exit opening (16) closer to the ground (166).

A method for operating a pressure control system having a multistage compressor includes providing, by the multistage compressor, a pressure medium that has been compressed multiple times in order to fill a pressure medium reservoir or pressure medium chambers of the pressure control system. The providing the pressure medium involves providing, by a first compression stage, a precompressed pressure medium and additionally compressing, via a second compression stage, the precompressed pressure medium, and/or introducing an already compressed charge pressure medium into an intermediate volume between the first compression stage and the second compression stage of the multistage compressor and further compressing, by the second compression stage, the charge pressure medium. The charge pressure medium simultaneously passes, via a control line, to a control input of a shut-off valve that interacts with the first compression stage, such that a charge pressure of the charge pressure medium predefines a control pressure.

An air spring includes a sleeve, a jounce bumper, and a bump cap. The sleeve defines a chamber. The jounce bumper is fixed relative to the sleeve in the chamber. The bump cap is moveable relative to the jounce bumper from a first position to a second position in contact with the jounce bumper. The jounce bumper includes a valve moveable by the bump cap to a closed position when the bump cap moves to the second position.

A regulator for establishing outlet fluid pressure. The regulator includes a valve body having a fluid pressure inlet in selective fluid communication with a fluid pressure outlet. A pilot pressure inlet is formed in the valve body and in fluid communication with a source of pilot pressure. Valving structure in the valve body establishes outlet fluid pressure as a function of pilot pressure. First adjustable structure within the valve body may establish a minimum outlet fluid pressure threshold without regard to pilot pressure. Second adjustable structure within the valve body may establish outlet fluid pressure offset relative to pilot pressure.

An air management system and method are provided. The system includes a pressurized air source. A manifold block is coupled to the pressurized air source and includes a plurality of suspension valves in fluid communication with the pressurized air source and each defines a suspension orifice of a first diameter for controlling air flow to and from a plurality of air springs. A manifold pressurization valve is in fluid communication with the plurality of suspension valves and the pressurized air source and defines a manifold pressurization orifice of a second diameter that is less than the first diameter of the suspension orifice for opening under high pressure to allow pressurized air into the manifold block. An electronic control unit controls the manifold pressurization valve and the plurality of suspension valves to equalize a high pressure differential across the plurality of suspension valves from the plurality of air springs.