Arrangement in a motor saw
US4656985A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1985 |
| Grant date | Apr 14, 1987 |
| Priority date | — |
| Expiry date | Jun 17, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
Upon a kick-back of a motor saw, energy is transferred from the rotating parts of the engine into energy which generates the kick-back. This causes a tremendous decrease of the r.p.m. of the engine. In the saw there is an electronic control comprising a timer which measures the r.p.m. of the engine. During certain intervals the difference in r.p.m. is computed with respect to previous intervals and if the r.p.m. has decreased more than a predetermined value, a sensor in the electronic control emits a signal which releases an electrically controlled chain brake for stopping the chain.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.