Aerodynamic trimmer head for use in flexible line rotary trimmers
US8918999B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 2011 |
| Grant date | Dec 30, 2014 |
| Priority date | — |
| Expiry date | Aug 29, 2033 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA01D34/4165
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An aerodynamic trimmer head assembly for use in flexible line rotary trimmers including a trimmer head having a curvilinear upper head surface and a shroud having a curvilinear portion extending over the head surface. A plurality of ribs extend downwardly and forwardly in the direction of rotation between the head surface and shroud defining a plurality of channels extending between portions of the upper head surface and shroud along curvilinear paths defined by the ribs. The channels define inlet openings in an upper portion of the shroud and outlet openings about the lower end portion thereof. During rotation of the head and shroud, air is drawn downwardly about the drive mechanism, through the channel inlets, into and through the channels and outwardly therefrom at a forward inclination about the line projecting from the housing thereby cooling the drive mechanism of the rotary trimmer and reducing aerodynamic drag on the line.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.