Inventors:
William R. Phillips - Sacramento CA
Assignee:
Crow, Lytle, Gilwee, Donoghue, Adler and Weineger - Sacramento CA
International Classification:
B27G 1900
Abstract:
An apparatus and method for the prevention of injury to the operator of a chain saw, which saw includes on-off actuating means, a housing, an engine within said housing, a guide bar, connected to the housing, a cutting chain carried by said bar, said engine having a drive shaft operably connected thereto, and to a centrifugal clutch, a flywheel, gear means meshed in driving engagement with said cutting chain and said flywheel, said clutch engageable with said flywheel for driving said cutting chain, a brake system for slowing the speed of the flywheel to a stop during operation of the saw, and a secondary brake to prevent the re-engagement of the clutch with the flywheel while the on-off actuating switch is on. The brake becoms operative as a result of an electromechanical sensing of a kickback condition, as does the secondary brake.
The method includes providing an electro-mechanical sensing of a kickback, and providing a self-energizing braking of the flywheel, and preventing the re-engagement of the clutch with the flywheel.