Patent · US Expired

Arrangement in a motor saw

US4656985A · kind A · utility

3Cited by
5References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 17, 1985
Grant dateApr 14, 1987
Priority date
Expiry dateJun 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.