Mower blade assembly for a lawn mower

Abstract

A mower blade assembly for a lawn mower, the assembly comprising a blade bar adapted to be rotated by the output shaft of the lawn mower, and a cutter blade subassembly secured to each of the opposite ends of the blade bar. Each cutter blade subassembly comprises a thin spring steel cutter member preferably of rectangular shape and preferably having a thickness in the range 0.010 to 0.025 inch. The preferred rectangular shape of the cutter blade provides four cutting edges, only one of which is used at a given time, but which may be used interchangeably by repositioning the cutter blade relative to the subassembly. The cutter blade is detachably sandwiched between the blade bar and an interchangeable propeller lift cap having an upwardly inclined end portion at the trailing end thereof relative to the direction of rotation of the blade bar. The propeller lift cap serves the dual function of (1) helping to retain the cutter blade in position on the blade bar; and (2) by means of its upwardly inclined end portion of providing a propeller action which lifts the grass before it has been cut to facilitate cutting of the grass, and also of lifting the cut grass to move it toward the discharge outlet of the lawn mower. The easy interchangeability of the propeller lift cap permits substitution of a propeller lift cap having an inclined end portion of different angular inclination and, hence, having more or less propeller lifting action, since different grass conditions require different lift; for example, wet spring grass requires more lift than dry fall grass.