Abstract: An active vehicle suspension includes a strut comprising a piston working in a cylinder and movable to compensate for unexpected road inputs to the suspension and for inputs generated by the driver, such an inertial force introduced by braking or cornering. At times when the piston is being moved by the road and driver inputs to compress the strut excess hydraulic fluid is fed from the strut to an accumulator where it is temporarily stored at high pressure and later released back to the strut when it is desired to increase the length of strut. Thus some, and sometimes all, of the energy needed to extend the strut can be supplied by the accumulator rather than a pump. This save energy. The piston has unequal areas and a system of spool valves is provided to control the flow of fluid between the strut, accumulator, and pump.

Abstract: A road vehicle suspension unit particularly suited for the front wheels of a front wheel drive vehicle has an outer subframe consisting of a double-wishbone structure which supports the road wheel and is mounted on a rigid inner subframe so as to accommodate vertical road wheel movement, which is strongly opposed by a spring or damper device. The inner subframe is mounted on the vehicle chassis or body by forward and rear resilient mountings such that horizontal wheel movement also is strongly opposed but with provision for some rearward movement of the wheel by turning of the subframe about an axis through the forward mounting.