Arrangement in a chain saw
US4920649A · kind A · utility
6Cited by
8References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 16, 1989 |
| Grant date | May 1, 1990 |
| Priority date | — |
| Expiry date | Feb 16, 2009 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16D2129/12
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
When kick-backs occur on chain saws the cutter bar (36) is subjected to heavy forces, especially in the longitudinal direction. By putting in a piezo-electric crystal (37) at the cutter bar attachment in a place where the forces occur at kick-backs it can be effected that the crystal generates an electric impulse at sudden force changes, while the normally imposed screw powers do not give any signal. In this way it is possible to let the crystal trigger a mechanism (15) which releases the chain brake (14, 15) in an electrical way.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.