Height adjustment mechanism for lawn mowers

Claim 1

IN A POWER MOVER HAVING FORWARD AND REARWARD GROUND ENGAGING WHEELS, A LINKAGE SYSTEM INTERCONNECTING SAID FORWARD AND REARWARD GROUND ENGAGING WHEELS AND A CUTTER UNIT ASSEMBLY SUSPENDED FROM SAID LINKAGE SYSTEM; AND LINKAGE SYSTEM COMPRISING: A FORWARD BELL CRANK LEVER HAVING A FIRST ARM PAIR EXTENDING FORWARDLY OF SAID HOUSING WITH THE FORWARD WHEEL MEANS BEING MOUNTED ON THE FORWARD END OF SAID FIRST ARM PAIR, A SHORT ARM EXTENDING AT AN ANGLE FROM SAID FIRST ARM PAIR, A REARWARD BELL CRANK LEVER HAVING A SECOND ARM PAIR, EXTENDING REARWARDLY OF THE CUTER UNIT, SAID REAR WHEELS MEANS BEING MOUNTED ON THEREARWARDLY EXTENDING ENDS OF SAID SECOND ARM PAIR, A SECOND SHORT ARM RIGID WITH SAID SECOND ARM PAIR AND EXTENDING AT AN ANGLE THEREFROM IN A DIRECTION OPPOSITE TO THE DIRECTION IN WHICH SAID FIRST SHORT ARM EXTENDS, AN INTERMEDIATE LINK INTERCONNECTING THE SHORT ARMS OF SAID FORWARD AND REARWARD BELL CRANK LEVERS, SAID CUTTER UNIT ASSEMBLY NORMALLY CONSTRAINING SAID LINKAGE SYSTEM TO CAUSE SAID FORWARD AND SAID REARWARD WHEELS TO MOVE AWAY FROM EACH OTHER ALONG THE LONGITUDINAL AXIS OF THE CUTTER UNIT, CAM MEANS BETWEEN SAID LINKAGE SYSTEM AND SAID CUTTER UNIT FOR RESTRAINING LONGITUDINAL MOVEMENTS OF SAID WHEEL MEANS RELATIVE TO SAID CUTTER UNIT ASSEMBLY, SAID CAM COMPRISING AN ECCENTRIC SCALLOPED CAM PIVOTALLY MOUNTED ON SAID CUTTER UNIT, EACH SCALLOP OF SAID CAM HAVING AN EFFECTIVELY DIFFERENT RADIUS FROM THE PIVOTAL MOUNTING OF SAID SAM ON THE HOUSING, A THIRD ARM ON ONE OF SAID BELL CRANK LEVERS COOPERATIVELY ASSOCIATED WITH SAID CAM FOR ENGAGEMENT WITH ONE OF THE SCALLOPS ON SAID CAM, AND MEANS FOR ROTATING SAID SCALLOPED CAM TO MOVE A DIFFERENT ONE OF THE SCALLOPS THEREON INTO COOPERATIVE ASSOCIATION WITH SAID THIRD ARM AND EFFECT CLOCKWISE ROTATION OF ONE OF SAID BELL CRANK LEVERS IN COUNTERCLOCKWISE ROTATION OF THE OTHER OF SAID BELL CRANK LEVERS TO THUS ADJUST THE HEIGHT OF THE CUTTING UNIT ABOVE GROUND.