A torque splitting device (12) capable of use in a four wheel drive road vehicle has two coupled epicyclic differential devices providing the two outputs and connected respectively with a torque input shaft (30), which may be driven by a vehicle gearbox and a control shaft (35). The control shaft is driven from the input shaft (35) by way of an infinitely variable ratio drive means comprising a fixed displacement hydrostatic motor (51) coupled with a variable displacement hydrostatic pump (50) which is controlled by signals from a control unit (60). The unit (60) may be responsive to signals representing vehicle control and/or experience.

A vibration control apparatus for vehicles to be installed on the vehicle wherein a vehicle body is supported on a truck through springs and damping mechanisms, for suppressing the vibrations of the vehicle body and enhancing the riding quality of the vehicle, comprising a vibration detector which detects the vibration of the vehicle body, a compensator circuit which compensates the detection output of the vibration detector and produces a control output for suppressing the vibration of the vehicle body, a fluid operating mechanism which controls the relative displacement between the vehicle body and the truck and which is connected to the vehicle body on one side and to the truck on the other side, a fluid control device which controls the fluid operating mechanism by the use of the control output produced by the compensator circuit, and damping control means to suppress the damping function of the damping mechanism upon sensing the state under which the vibration of the vehicle body is suppressed by the fluid operating mechanism.

An electronic controlled fluid suspension system in which a change in a vehicle attitude is expected in advance by an advance control means responsive to a driving state detected by a driving state detection means, and the current vehicle attitude is feedback-controlled by a feedback control means. The shares of the advance control amount and the feedback control amount are calculated by a share determination means so that final control amount is determined based on the shares. Fluid flow to and from the fluid suspension is controlled by a fluid flow control means in response to the final control amount. In such control system, the advance control and the feedback control are smoothly switched, which results in improved maneuverability and stability of the vehicle.

A two-stage aircraft gear. The landing gear includes a cantilever landing gear whose lower end is attached to a trailing arm (or articulated) landing gear. The cantilever gear is a collapsible piston-cylinder assembly, and the trailing arm gear also has a shock absorber connected between a fixed portion of the trailing arm gear and the movable wheel support arm. When landing, the load imposed is first absorbed by the trailing arm landing gear. After the trailing arm gear has been fully compressed, the cantilever gear begins to compress. The cantilever and trailing arm landing gear can be combined to provide the desired performance. The landing gear static position can be designed to be in the static load curve of the first component, allowing the aircraft to be stably supported and yet difficult to overturn. Adjustable orifice plates contained within one or both of the cantilever and articulated stages can be controlled as a function of the vertical descent velocity and/or distance. If desired, differential pressure measurements within the two stages can be used to give the landing gear any desired damping and/or landing gear extension characteristic.

A seat suspension includes a device which is responsive to a sensor which detects the condition of the road surface being traversed by the vehicle in a manner to produce relatively hard suspension characteristics when the vehicle is running on a rough road and softer characteristics when traversing a road having a smooth surface. The suspension of the vehicle if equipped with variable hardness type shock absorbers can be controlled in parallel with the seat suspension to improve the ride. Additional sensors which sense parameters such as acceleration, braking, steering angle, vehicle speed etc., can be used to control the setting of the seat suspension in addition to the basic road condition control.