Torsion bar spring draft sensing means for implement hitch mechanism

Claim 1

IN A TRACTOR HAVING POWER LIFT MEANS FOR RAISING AND LOWERING A VEHICLE-BORNE IMPLEMENT, AND ACTUATOR MEANS FOR CONTROLLING THE OPERATION OF SAID LIFT MEANS, THE COMBINATION, COMPRISING: TUBULAR MEANS SUPPORTABLY MOUNTED BY THE TRACTOR FOR ROTATIVE MOVEMENT AND DISPOSED TRANSVERSELY THEREOF; AN ELONGATED BAR POSITIONED WITHIN SAID TUBULAR MEANS AND HAVING ONE END THEREOF ANCHORED AGAINST ROTATION RELATIVE TO THE TRACTOR AND THE OTHER END CONSTRAINED FOR ROTATIVE MOVEMENT WITH SAID TUBULAR MEANS AND BEING RESILIENTLY YIELDABLE UPON TORSIONAL STRESSING IN ANY DIRECTION OF ROTATION; IMPLEMENT-CONNECTING DRAFT MEANS HAVING A PAIR OF ELEMENTS SPACED APART LENGTHWISE OF AND RESPECTIVELY CONNECTED TO END PORTIONS OF SAID TUBULAR MEANS FOR TORSIONALLY STRESSING THE ATTACHED BAR IN RESPONSE TO IMPLEMENT DRAFT LOADS; CRANK ARM MEANS EXTENDING FROM A MIDPORTION OF AND CONSTRAINED FOR ROTATION WITH SAID TUBULAR MEANS; AND SENSING MEANS INTERCONNECTED BETWEEN SAID CRANK ARM MEANS AND THE ACTUATOR MEANS AND OPERATIVE FOR TRANSMITTING MOVEMENTS OF SAID TUBULAR MEANS TO THE ACTUATOR MEANS FOR EFFECTING OPERATION OF THE POWER LIFT MEANS.