Automatic valve control mechanisim for tractor mounted loaders

Claim 1

IN A TRACTOR MOUNTED LOADER HAVING A BUCKET SUPPORTED ON LIFT ARMS AND ADAPTED TO BE RAISED BY A HYDRAULIC JACK PIVOTALLY CONNECTED TO THE TRACTOR, A VALVE FOR DIRECTING FLUID TO SAID JACK UPON MOVEMENT OF THE VALVE AWAY FROM A NEUTRAL POSITION TO RAISE THE BUCKET, DETENT MEANS TO HOLD THE VALVE IN ITS BUCKET-RAISING POSITION, AND MEANS TO OVERRIDE THE DETENT MEANS AND RETURN THE VALVE TO ITS NEUTRAL POSITION WHEN THE BUCKET REACHED A PREDETERMINED HEIGHT, SAID LAST NAMED MEANS INCLUDING A VALVE ATUATING LEVER, A CONTROL ROD, MEANS ACTUATING SAID CONTROL ROD BY THE PIVOTAL MOVEMENT OF SAID JACK, MECHANICAL LINKAGE BETWEEN SAID ACTUATING LEVER AND SAID VALVE, AND MEANS OPERABLE BY THE ACTUATION OF SAID CONTROL ROD UPON RAISING OF THE BUCKET TO A PREDETERMINED HEIGHT TO BRING THE CONTROL ROD INTO FORCIBLE CONTACT WITH THE ACTUATING LEVER TO ACTUATE THE SAME AND OVERRIDE THE DETENT MEANS AND RETURN THE VALVE TO ITS NEUTRAL POSITION TO HOLD SAID BUCKET AT SAID PREDETERMINED HEIGHT.