Abstract: Removeable cutters are mounted at each end of a rotary lawn mower blade, which cutters can be removed and reinstalled with replacements easily and quickly without the use of tools. The replaceable cutters are each held in place by a positive locking arrangement, including a safety lock that is manually released by the user. During operation of the mower, the centrifugal force of the rotating blade further locks the cutters in place so that it is virtually impossible for them to become separated from the blade. The replaceable cutter unit also may include an air deflecting vane that aids in creating a suction action to pull the grass to an erect position and enhance the discharge of the grass clippings.

Abstract: A rotary lawnmower blade that includes cutting edges on removable cartridges which can be replaced without the use of tools. The blade is hollow in design with air inlets that pick up high volumes of air as the blade rotates, compress the air and discharge it at an increased velocity to aid in discharging the grass clippings and other debris. The blade also is designed to increase the suction action of the blade as it rotates in order to make the grass more erect and also pick up the grass clippings more effectively. Also included in the design is an unique method of attaching the blade to the engine drive shaft so as to minimize damage if the blade strikes a solid object.