Control valve system for a power shift transmission for agricultural and industrial tractors

Claim 1

IN A TORQUE DELIVERY DRIVELINE FOR A VEHICLE ADAPTED TO DELIVER DRIVING TORQUE FROM AN ENGINE TO A VEHICLE TRACTION MEMBER, A DRIVING SHAFT, A DRIVEN SHAFT, MULTIPLE SPEED RATIO GEARING COMPRISING RELATIVELY MOVABLE GEAR ELEMENTS DEFINING PLURAL TORQUE DELIVERY PATHS BETWEEN SAID DRIVING SHAFT AND SAID DRIVEN SHAFT, A PAIR OF POWER INPUT GEAR ELEMENTS, A FORWARD-DRIVE FLUID PRESSURE OPERATED FRICTION CLUTCH BETWEEN SAID DRIVING SHAFT AND A FIRST ONE OF SAID POWER INPUT GEAR ELEMENTS TO DEFINE IN PART A FORWARD POWER FLOW PATH THROUGH SAID GEARING, A FLUID PRESSURE OPERATED REVERSE CLUTCH BETWEEN SAID DRIVING SHAFT AND A SECOND POWER INPUT ELEMENT OF SAID GEARING, A FLUID PRESSURE SOURCE, A CONDUIT STRUCTURE INTERCONNECTING SAID PRESSURE SOURCE AND EACH OF SAID CLUTCHES INCLUDING SEPARATE BRANCH PORTIONS EXTENDING TO EACH CLUTCH, A MANUAL CONTROL VALVE MEANS SITUATED IN AND PARTLY DEFINING SAID CONDUIT STRUCTURE FOR SELECTIVELY DISTRIBUTING PRESSURE FROM SAID PRESSURE SOURCE TO EACH OF SAID BRANCH PORTIONS WHILE EXHAUSTING THE OTHER BRANCH PORTION, A HYDROMECHANICAL INTELOCK HAVING AT LEAST ONE PRESSURE-OPERATED INTERLOCK PLUNGER, AN INTERLOCK ELEMENT MOVABLE TRANSVERSELY WITH RESPECT TO THE PATH OF MOVEMENT OF SAID CONTROL VALVE MEANS, SAID INTERLOCK ELEMENT INHIBITING MOTION OF SAID CONTROL VALVE MEANS WHEN IT ASSUMES ONE POSITION AND MOVABLE OUT OF REGISTRY WITH SAID CONTROL VALVE MEANS WHEN IT ASSUMES ANOTHER POSITION, A MECHANICAL CONNECTION BETWEEN SAID PLUNGER AND SAID INTERLOCK ELEMENT FOR OPERATING THE LATTER, A SOURCE OF PRESSURE SIGNAL THAT IS PROPORTIONAL IN MAGNITUDE TO THE DRIVING SPEED OF SAID DRIVING MEMBER, AND A HYDRAULIC CONNECTION BETWEEN SAID SIGNAL SOURCE AND SAID PLUNGER FOR ACTUATING THE LATTER TO A POSITION WHEREIN MOTION OF SAID CONTROL VALVE MEANS IS INHIBITED WHEN THE PRESSURE SIGNAL EXCEEDS A PREDETERMINED VALUE.