Power steering for articulated vehicles

Claim 1

IN COMBINATION, A VEHICLE COMPRISING FIRST AND SECOND FRAME SECTIONS, MEANS PIVOTALLY INTERCONNECTING SAID FRAME SECTIONS ON A STEERING AXIS FOR RELATIVE STEERING ARTICULATION THEREBETWEEN TO EITHER SIDE OF STRAIGHT-AHEAD STEERING ALIGNMENT OF SAID FRAME SECTIONS, A FLUID PRESSUREOPERATED STEERING JACK INCLUDING RELATIVELY RECIPROCABLE PISTON AND CYLINDER MEMBERS, MEANS OPERATIVELY CONNECTING SAID JACK BETWEEN SAID FRAME SECTIONS TO ARTICULATE THE LATTER RELATIVE TO EACH OTHER A RELATIVELY CONSTANT AMOUNT THROUGHOUT THE ENTIRE STEERING RANGE OF SAID FRAME SECTIONS IN RESPONSE TO EACH CHANGE OF A GIVEN AMOUNT IN THE LENGTH OF SAID JACK TO PROVIDE A RELATIVELY CONSTANT MECHANICAL ADVANTAGE FOR SAID JACK IN ARTICULATING SAID FRAME SECTIONS ABOUT SAID STEERING AXIS, SAID MEANS INCLUDING A PAIR OF LINKS, ONE OF SAID LINKS PIVOTALLY CONNECTED TO THE FIRST FRAME MEMBER ABOUT A FIRST PIVOT AXIS, THE OTHER OF SAID LINKS PIVOTALLY CONNECTED TO THE SECOND FRAME MEMBER ABOUT A SECOND PIVOT AXIS, MEANS INTERCONNECTING SAID LINKS ABOUT A THIRD PIVOT AXIS, AND MEANS FOR SELECTIVELY SUPPLYING OPERATING FLUID UNDER PRESSURE TO THE OPPOSITE ENDS OF SAID CYLINDER, RESPECTIVELY, TO STEER SAID VEHICLE IN OPPOSITE DIRECTIONS.