Hydraulic systems

In an hydraulic system of the kind having an hydraulic actuator, an hydraulic power supply, an hydraulic circuit operative to supply hydraulic power to and from the actuator, and an electrical drive unit operative to control operation of the hydraulic circuit, the improvement wherein the hydraulic system includes a balanced seated valve connected in said circuit, said valve including a housing having an opening, an outlet, a valve seat disposed between said opening and said outlet, a valve member operative to seal on said seat and prevent flow between the opening and the outlet, and a fluid passage between opposite sides of the valve seat so that fluid pressure acting on the valve member is substantially balanced, said valve including a solenoid operative to engage and displace the valve member away from said valve seat, and the system including a connection between said electrical drive unit and said solenoid, said electrical drive unit being operative to supply a progressively varying voltage to said solenoid such that said valve member is displaced gradually between a fully open position away from said valve seat and a fully closed position in sealing engagement with said valve seat during at least a part of the time that the voltage is progressively varied so that flow of fluid through the valve between the opening and the outlet is varied and the acceleration of the actuator is reduced.