GB1526519A - Cutter disc assembly for rotary lawn mower - Google Patents

Abstract

1526519 Lawn mowers ROPER CORP 25 Aug 1976 [8 Sept 1975 18 Aug 1976] 35376/76 Heading A1F A cutter disc assembly for a rotary lawn mower having a vertical shaft comprises a disc 20, preferably made of plastics, having a central portion 21, a peripheral portion 23, a number of radially aligned resilient plastics cutter pins 33 held in cantilever mountings adjacent their heads 35 to extend radially across and outwardly of the peripheral portion 23; the pins being of tapered construction and/or being provided with curved support means 41 to smoothly distribute curvature in the pin when deflected by an obstruction in use; the pins being capable of bending to a position where they are wholly protected by the peripheral portion, Fig. 11 (not shown). The pin may be tapered and may be inclined so that its tip 38 is below the level of the cutter disc. Vents (61, 63) Fig. 4a (not shown) in the central portion cause an updraft of air. In alternative embodiments the pins 130 are held in flared grooves 137-139 in the underside of the peripheral portion 123, Fig. 12, and the grooves have a ceiling 147 connected by a rib 157 to the centre of the disc, the ribs being provided for reinforcement and to cause a turbulent air current. The ceilings hold the pins in their inclined positions and to dampenout oscillation; the curved walls 142, 143 of the grooves serve to distribute curvature in the pins both on bending backwards after striking an obstruction and on subsequent forward bending, Fig. 16. The pins, which may have non-circular cross-sections, e.g. cruciform Fig. 26, may be located by passing through two depending annular walls 122', 122", Fig. 14, or may be held in two saddles 122', 122" Fig. 20. A floor below the pins may also be provided, Figs. 32-34 (not shown).