Abstract: A vehicle suspension system includes a hydraulic anti-roll mechanism in which a pair of suspension arms (10a, 10b), on opposite sides of the vehicle, are mounted to the vehicle body pivots (16a, 16b). A pair of hydraulic struts (22a, 22b) are connected between the suspension arms and the body (14). The struts are asymmetrically mounted so that one is inboard of its suspension arm pivot and the other is outboard of its suspension arm pivot. The two lower chambers of the struts (22a, 22b), through which the connecting rods (32) of the pistons extend, are hydraulically interconnected, and so are the two upper chambers.

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: A vehicle air suspension can be controlled between a Standard setting of ride height and a lower, Kneel, setting. Movement to or from the Kneel setting is frozen if a door is opened or if the footbrake is applied. Alteration to the Kneel setting is prevented except when the vehicle is stationary. The suspension reverts to the Standard ride height if the vehicle is driven off or the handbrake is released. Movement of the suspension to or from a lower or higher setting is carried out sequentially to prevent headlamp dazzle. If the vehicle becomes partly supported by direct contact between the chassis and the ground (belly-out) this is detected by monitoring signals to ride height control valves and by providing a controlled re-inflation and balancing of the air springs.