Automatic line trimmer head
US5109607A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 12, 1990 |
| Grant date | May 5, 1992 |
| Priority date | — |
| Expiry date | Oct 12, 2010 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA01D34/4162
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A line trimmer head 10 for a vegetation cutter having an automatic line feed mechanism which replenishes the line 19 as a result of changes in centrifugal force. The line trimmer head 10 comprises a reel housing 14 which rotates with a shaft 12. A spool 18 containing a supply of line 19 is located within the housing 14. An indexer cam 16 is journaled on the shaft 12 and is axially and rotatably shiftable with respect to the shaft 12. The indexer cam 16 is periodically axially shifted and rotated by a reduction in the centrifugal force applied by the line 19 to the spool 18. A spring 20 is provided to bias the indexer cam 16 axially relative to the housing 14 away from an interlocked posiiton. In the interlocked position, the indexer cam 16 and housing 14 are interlocked together so that the spool 18, indexer cam 16, housing 14 and shaft 12 rotate together. The indexer cam 16 is shifted axially to cause the indexer cam 16 to be disengaged from the housing 14 allowing the spool 18 and indexer cam 16 to rotate relative to the housing 14. As the spool rotates a predetermined incremental amount relative to the housing, an increment of line 19 is fed from the spool 18. Centrifugal force …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.