Anti-scalping device for rotary lawn mowers

Claim 1

IN A POWER MOWER COMPRISING, IN COMBINATION, A SUBSTANTIALLY HORIZONTAL OPEN BOTTOM HOUSING, FRONT AND REAR MEANS SUPPORTING SAID HOUSING IN A PREDETERMINED ELEVATION WITH RESPECT TO THE GROUND OVER WHICH THE MOWER IS TO OPERATE, A ROTARY CUTTER BLADE OPERABLE ON A SUBSTANTIALLY VERTICAL AXIS INSIDE SAID HOUSING, AND POWER OPERATED DRIVE MEANS FOR TRANSMITTING DRIVE TO SAID CUTTER BLADE, THE IMPROVEMENT WHICH CONSISTS IN A VERTICAL DRIVE SHAFT THAT IS IN FLOATING RELATION TO SAID HOUSING AN DRIVE MEANS BUT PROVIDES THE DRIVING CONNECTION BETWEEN SAID CUTTER BLADE AND DRIVE MEANS IN ANY POSITION UP OR DOWN FROM A PERVIOUS POSITION WITHIN A PREDETERMINED RANGE OF ADJUSTABILITY OF SAID CUTTER BLADE RELATIVE TO SAID HOUSING AND INDEPENDENTLY OF SAID HOUSING SUPPORT MEANS, AND A ROTARY GROUND ENGAGING CUP-SHAPED SPACER ELEMENT FIXED IN CONCENTRIC RELATION TO AND UNDER SAID CUTTER BLADE AND SHAFT TO TURN THEREWITH AND ADAPTED TO RAISE OR LOWER SAID CUTTER BLADE AND SHAFT IN RESPONSE TO UNEVENNESS IN THE CONTOUR OF THE GROUND OVER WHICH THE MOWER IS MOVED.