Vehicle-supported three-point coupling and position responsive fluid blocking device therefor

A vehicle-supported three-point coupling assembly for coupling an implement to one end of said vehicle, wherein said coupling assembly comprises:

• a rectangular frame assembly fixedly mounted to said vehicle, said frame assembly including a pair of vertically extending sides, a pair of horizontally extending sides interconnecting said vertically extending sides and supporting a yoke for receiving an end of a thrust bar;
• a cross-bar assembly including a pair of traction bars pivotally connected to vertically extending support brackets at one end and extending horizontally away from said vertically extending brackets, said support brackets pivotally connected to said vertically extending sides, said support brackets further being interconnected by a tubular bar, said traction bars supporting at a remaining end thereof an implement holding means, whereby said cross-bar assembly including said traction bars can pivot in a vertical direction pivoting said implement holding means;
• first and second screw adjustment means each connecting one of said vertically extending brackets to a respective one of said traction bars, said screw adjustment means determining the angular relationship between said cross-bar assembly and said brackets;
• a fluid operated jack assembly connected to said vehicle and to said support brackets;
• conduit means supplying an operating fluid to and from said jack assembly;
• a shutter block means for blocking fluid flow through said jack assembly, said shutter block means having an actuator responsive to a predetermined relative position of said support bracket with respect to said vehicle;
• and
• valve means for controlling the direction of fluid flow through said conduit means and said jack assembly, whereby said cross-bar assembly moves vertically until said support bracket arrives at said predetermined relative position with respect to said vehicle.