Abstract: A suspension system for a vehicle includes a plurality of spring assemblies, each spring assembly including, in combination, a coil spring and an air spring arranged around a common central axis, and being mounted above the rear axle of the vehicle. A method for improving a vehicle's ride, handling, and load-carrying capability includes providing the foregoing suspension system for which respective coil springs are positioned within respective housings; partially inflating respective air springs thereby causing respective coil springs to partially collapse into their housings when improvement to the ride is desired in combination with improvement in load-carrying ability; and completely inflating respective air springs thereby causing respective coil springs of the plurality of spring assemblies to substantially completely collapse into their housings when maximum load-carrying ability is desired.

Abstract: A composite suspension system for a vehicle includes a mechanical suspension system supporting the body of the vehicle with respect to an axle and a pneumatic suspension system to selectively provide support for the body relative to the axle. Under heavy loads, the pneumatic suspension system may be inflated to support the body relative to the axle. When not under heavy loads the pneumatic suspension system may be deflated so as not to interfere with the support provided by the mechanical suspension system. A control system regulates a compressor connected to the pneumatic suspension system to inflate the same. The control system also regulates access of the pneumatic suspension system to a vacuum source to deflate the same.

Abstract: A composite suspension system for a vehicle includes a mechanical suspension system supporting the body of the vehicle with respect to an axle and a pneumatic suspension system to selectively provide support for the body relative to the axle. Under heavy loads, the pneumatic suspension system may be inflated to support the body relative to the axle. When not under heavy loads the pneumatic suspension system may be deflated so as not to interfere with the support provided by the mechanical suspension system. A control system regulates a compressor connected to the pneumatic suspension system to inflate the same. The control system also regulates access of the pneumatic suspension system to a vacuum source to deflate the same.

Abstract: A supplemental suspension system for a vehicle having a rear axle and a leaf spring suspension system including a pair of leaf springs mounted over respective ends of the rear axle, the supplemental suspension system including a lower support member which is positioned above the rear axle, which extends between respective leaf springs of the pair of leaf springs, and which is fixedly mounted to respective leaf springs of the pair of leaf springs; and a plurality of spring assemblies which are mounted above the rear axle, each spring assembly of the plurality of spring assemblies being composed of, in combination, a coil spring and an air spring arranged around a common central axis and attached by a retainer, wherein the plurality of spring assemblies are supported by the lower support member.

Abstract: A roll correction system for use in a vehicle including a body, wheels, and a suspension coupling the body to the wheels includes a roll correction apparatus hydraulically actuated by a hydraulic signal indicative of a roll direction. A hydraulic signal source provides the hydraulic signal conditioned to indicate a roll position in response to a first steering direction. A countersteer correction element maintains the condition of the hydraulic signal to indicate the roll direction in response to countersteer in a second steering direction opposite the first steering direction as would occur, for example, in a skid.

Abstract: An anti-roll system for turn compensation in a vehicle generates a differential hydraulic signal in which a pressurizing potential corresponds to a first curve direction and a complementary return hydraulic potential. The system includes a pair of rear wheel cylinder and piston assemblies and a pair of front wheel cylinder and piston assemblies. A hydraulic circuit is connected to conduct the pressurizing potential to move the pistons in a first rear wheel cylinder and piston assembly and a first front wheel cylinder and piston assembly, while conducting the return signal to move the pistons in second front wheel cylinder and piston assembly and a second rear wheel cylinder and piston assembly. A hydraulic conductor directly connects corresponding ends of the rear wheel cylinder and piston assemblies to provide a hydraulic conduction between those assemblies in response to conduction of the differential hydraulic signal.

Abstract: The invention concerns a tilt correction system with at least one pair of cylinder and piston assemblies which are hydraulically operated. The extent of tilt correction is limited by grooves internal to the cylinders of the assemblies which short hydraulic potentials once the pistons of the assemblies have moved from a rest position to a position adjacent the grooves. A preferable arrangement includes connecting each assembly between an anti-roll bar and an axle.