Anti-scalping blade for rotary lawn mower
US5287686A · kind A · utility
Inventor
Key dates
| Filing date | Aug 14, 1992 |
| Grant date | Feb 22, 1994 |
| Priority date | — |
| Expiry date | Aug 14, 2012 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA01D34/73
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An improved blade member is shown for the type of rotary lawn mower that includes a shroud supported on wheels for horizontally traversing the surface of a lawn, a rotatably driven shaft extending downwardly at the horizontal center of the shroud for rotatably driving a blade assembly, and an opening in the upper part of the shroud for the exit of cuttings from the lawn. The blade member has a central section of circular configuration whose periphery is concentric to a center balance point, means for securing the driving shaft to the member at the center balance point, and three blade arms which are symmetrically circumferentially spaced about the central section and extend radially outwardly therefrom. Each blade arm has its forward side sharpened to form a cutting edge and has a portion of its width adjacent its rearward side inclined upwardly to create an air lift for lifting cuttings toward the exit port. Each of the cutting edges extends substantially the full length of the respective blade arm up to and adjacent the circular central section so that there is little or no dull edge of the blade arm adjacent the central section, and any tendency of the blade member to knock down…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.