Abstract: A suspension system for a vehicle tandem axle has air springs positioned adjacent the ends of the trailing and lead axles of the tandem axle. Pairs of air springs on each side of the vehicle are pneumatically connected to form a common reservoir. Displacement of the ends of the lead and trailing axles of the tandem axle are averaged to provide a controlling input to air spring pressurization controllers provided for each pair of air springs.

Abstract: A vehicle suspension system (1) which provides roll control comprises a pair of hydraulic actuators (2, 3) mounted at wheels on opposite sides of the vehicle chassis, each hydraulic actuator (2, 3) being connected between the wheel and the chassis. Each hydraulic actuator (2, 3) has a fluid filled variable volume fluid chamber (8, 9) defined by a cylinder (4, 5) and piston (6, 7), one part being connected to the wheel and the other part to the chassis. An hydraulic accumulator (12, 13) is connected to each fluid chamber via a fluid transfer line (14, 15) to act as a spring with damping means being provided by a flow restrictor orifice (10, 11). A pump (16) communicates via fluid transfer lines (14, 15) between both hydraulic actuator fluid chambers (8, 9) through a control valve (19) which is operable to isolate both chambers (8, 9) from each other and from the pump (16) or to selectively connect one chamber (8, 9) to an inlet (17) of the pump (16) and the other chamber (8, 9) to an outlet of the pump (16).

Abstract: A number of embodiments of suspension systems for vehicles having at least two wheels, each of which is independently suspended by a system including a respective shock absorber. The shock absorbers may be generally conventional in nature but are interconnected by a system that includes an accumulator and a flow control so as to provide a damping for vehicle characteristics that is independent of the individual damping of each wheel's shock absorber. The systems also provide constructions so that both the vehicle and individual wheel damping can be independently controlled to permit the use of smaller shock absorbers.

Abstract: A vehicle height adjust control apparatus and method prevents interference between a vehicle and a road surface due to a vehicle height reduction caused by an occupant or load added during a stop of the vehicle and minimizes unnecessary or ineffective operation of actuators while the vehicle is stopped with a brake pedal depressed. The apparatus has a vehicle sensor for detecting a vehicle speed, and a brake switch for detecting a brake pedal depressing operation. When the vehicle is stopped and the brake pedal is depressed, a microcomputer maintains a normal determination condition for starting a vehicle height adjustment to raise the vehicle body, but prevents a vehicle height reducing adjustment from lowering the vehicle body or uses a severe determination condition for starting a vehicle height reducing adjustment, thereby restricting the vehicle height adjustment only in the reducing direction.

Abstract: An X type hydro-pneumatic vehicle suspension system has diagonally opposite wheel support cylinders cross connected rod side to bore side to make a pair of discrete hydraulic circuits for each pair of diagonally opposite wheels of the vehicle. Each discrete circuit has two gas charged accumulators, one near the front and one near the rear. The gas chambers of accumulators in the two pairs of discrete hydraulic circuits are connected in a variety of ways to equalize pressures between the pairs of circuits.

Abstract: A vehicle roll stabilizing system uses front and rear stabilizer assemblies (23, 24) which each use a stabilizer bar (24) and a hydraulic ram (33, 35) to resist vehicle roll. Selector valves (43, 44) select pressure from a pump (36) or return hydraulic oil to a reservoir (37) according to 4 modes, two of which the selector valve is in an on and an off condition, respectively. A diverter valve (73) operates to control the pump pressure in proportion to lateral acceleration to provide an actuator effort which resists roll during vehicle cornering. This effort is provided up to a limit equivalent to a lateral acceleration of approximately 0.4 g after which roll is allowed to increase, either by keeping the pump pressure (and hence effort) constant or by increasing the pump pressure at a reduced rate.

Abstract: An arrangement for vertically adjustably supporting an individual wheel carrier disposed by way of control arms or an axle beam on the body of a motor vehicle. An actuator is fastened on the vehicle body, constructed as a hydraulic motor with at least one pressure space. The actuator has a swivellable actuating shaft which acts upon the wheel carrier, its control arms or the axle beam, by way of a linkage which contains at least one lever arm. The lever arm, upon which the hydraulic actuator acts directly, is designed as a mechanical spring. Also, at least one loaded pressure space of the actuator is hydraulically connected by way of at least one return valve, with a less loaded or unloaded pressure space or a return flow. As an alternative or in addition to the return valve, the loaded pressure space can be connected to a hydraulic accumulator.