The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 06, 2007
Filed:
Oct. 17, 2005
Hans Nickel, Weissach, DE;
Hans Nickel, Weissach, DE;
Andreas Stihl AG & Co. KG, Waiblingen, DE;
Abstract
A device that controls the engine speed of an internal combustion engine of a hand-held power tool has a protective control unit. The engine has an ignition control unit for controlling the ignition timing relative to a crank angle of a crankshaft based on the crankshaft speed and also has a centrifugal clutch driven by the crankshaft that begins to engage when a first engine speed is surpassed and is fully engaged when a second engine speed is reached. The protective control unit is activated within an engine speed range between the first and second engine speeds and monitors a dwell time of the actual engine speed within the engine speed range. When a predetermined dwell time of the actual engine speed is surpassed, the protective control unit intervenes in the combustion process and corrects the engine speed to a value that is outside of the engine speed range.