Automatic head for a line trimmer
US5060384A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 6, 1990 |
| Grant date | Oct 29, 1991 |
| Priority date | — |
| Expiry date | Dec 6, 2010 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA01D34/4162
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An automatic line trimmer head 10 including a housing 11 containing a rotor 12 which controls rotation of a spool 16 relative to the housing in a stepwise fashion which is actuated by centrifugal force. Centrifugal force acts upon a radially expansible annular member 14 which is disposed between the housing 11 and the rotor 12. The spool 16 contains a supply of line 18 and is attached to the rotor 12 for rotation with the rotor. A shaft extends through the housing 10, rotor 12 and spool 16. The rotor 12 is biased by a helical spring 24 toward an upper plane of rotation. The radially expandable annular member 14 shifts the rotor 12 to a lower plane when centrifugal force expands the annular member 14. Teeth 54 extending radially outwardly from an outer edge 56 of a circular disk portion 50 of the rotor 12 contact an upper set of stop blocks when the circular disk portion 50 is in the upper plane. The teeth 54 contact a lower set of stop blocks 42 when the circular disk portion 50 is in the lower plane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.