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US 4,152,833 AGranted
Chain saw braking mechanism
AssigneeCrow, Lytle, Gilwee, Donoghue, Adler and Weineger
InventorWilliam R. Phillips
Life of this patent
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AssigneeCrow, Lytle, Gilwee, Donoghue, Adler and Weineger
InventorWilliam R. Phillips
Estimating the term…
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.
In a chain saw having a housing, and an engine in said housing, an activation means for the engine, a chain bar connected to said housing, a cutting chain operably carried by said chain bar;
In a chain saw having a cutting chain operatively connected to a flywheel, and a drive shaft of a motor connected to a centrifugal clutch, said clutch being engageable with said flywheel upon energization of said motor to drive said chain, the invention comprising an improved sensing and activation means for a brake system to stop said flywheel, comprising:
A chain saw includes a trigger, actuating means, a housing, a motor within said housing, a guide bar for a cutting chain connected to the housing, a chain carried by said bars, said engine having a drive shaft operably connected thereto, a centrifugal clutch connected to said drive shaft, a flywheel, gear means meshed in driving engagement with said cutting chain, an electromechanical activation means for a brake system, said means being automatically operable by a kick back of the chain saw, a brake system including a first brake means to slow down and stop said flywheel, and a second brake means engageable with said clutch as a replacement for said flywheel, and said system being self-energized.
Dependencies are inferred from the claim text.