Apparatus for controlling the attitude of tractor mounted equipment

Claim 1

A VEHICLE-MOUNTED ROAD GRADER COMPRISING A CHASSIS, A ROAD SURFACING ELEMENT, A FRAME MOUNTED ON SAID CHASSIS, SAID ELEMENT MOUNTED ON SAID FRAME, AN ARTICULATED MOUNTING FOR SAID FRAME ON SAID CHASSIS, MEANS TO ADJUST SAID FRAME AND ELEMENT IN A HORIZONTAL AND IN A VERTICAL PLANE TRANSVERSE TO THE LONGITUDINAL AXIS OF SAID CHASSIS, SAID MEANS INCLUDING A FLUID-ACTUATED ACTUATOR CONNECTED TO SAID FRAME, A FLUID CONNECTION TO SAID ACTUATOR, AND A VALVE MOUNTED ON SAID FRAME IN SAID FLUID CONNECTION TO VALVE FLUID TO ACTUATE SAID ACTUATOR, SAID VALVE INCLUDING A VALVE MEMBER TO CONTROL THE PASSAGE OF FLUID TO SAID ACTUATOR, A PENDULUM AND A PENDULUM PIVOT, A PENDULUM PIVOT MOUNTING ON SAID FRAME AND ANGULARLY DISPLACEABLE ON SAID FRAME ABOUT SAID PENDULUM PIVOT AXIS, A FLEXIBLE CONNECTION BETWEEN SAID VALVE MEMBER AND SAID PENDULUM FOR MOVEMENT OF SAID VALVE MEMBER WITH A FORCE RESPONSIVE TO THE ANGULAR DISPLACEMENT OF SAID ELEMENT ABOUT SAID PIVOT AXIS, SAID ACTUATOR MOVING SAID FRAME TO OPPOSE VARIATIONS IN ANGULAR DISPLACEMENT OF SAID ELEMENT.