Steering system for four-track snow vehicles

Claim 1

IN A FOUR-TRACK VEHICLE CHASSIS WHICH INCLUDES A FRAME, FRONT AND REAR FIFTH WHEELS MOUNTED ON THE FRAME FOR ROTATION ABOUT VERTICAL AXES, FRONT AND REAR TRACK UNITS MOUNTED ON THE CORRESPONDING FIFTH WHEELS, AND A STEERING SYSTEM MOUNTED ON THE CHASSIS AND CONNECTED TO THE FIFTH WHEELS; SAID STEERING SYSTEM EMBODYING A HYDRAULIC RAM CONNECTED BETWEEN THE FRAME AND THE FRONT FIFTH WHEEL TO TURN THE SAME, ANOTHER HYDRAULIC RAM CONNECTED BETWEEN THE FRAME AND THE REAR FIFTH WHEEL TO TURN THE SAME, A HYDRAULIC PUMP ON THE FRAME, CONDUITS EXTENDING BETWEEN BOTH ENDS OF BOTH RAMS AND THE PUMP, MANUALLY ACTUATED MEANS INTERPOSED IN THE CONDUITS TO CONTROL THE FLOW OF HYDRAULIC FLUID THERETHROUGH TO ONE END OR THE OTHER OF THE RAMS AND HAVING A NEUTRAL POSITION, MANUALLY CONTROLLED MEANS NORMALLY PREVENTING THE FLOW OF SUCH FLUID TO THE REAR RAM, AND A LOCK VALVE INTERPOSED IN THE CONDUITS BETWEEN THE REAR RAM AND THE LAST NAMED MEANS AND ARRANGED TO PREVENT ANY FLUID FLOW FROM THE REAR RAM WHEN THE CORRESPONDING TRACK UNIT HAS BEEN MOVED TO A PREDETERMINED POSITION AND SAID MANUALLY ACTUATED MEANS IS IN A NEUTRAL POSITION.