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:
Nov. 24, 2009
Filed:
Aug. 14, 2007
Wolfgang Layher, Besigheim, DE;
Georg Maier, Stetten, DE;
Christine Halle, Ebersbach/Fils, DE;
Arno Kinnen, Fellbach, DE;
Uwe Theimer, Frickenhausen, DE;
Wolfgang Layher, Besigheim, DE;
Georg Maier, Stetten, DE;
Christine Halle, Ebersbach/Fils, DE;
Arno Kinnen, Fellbach, DE;
Uwe Theimer, Frickenhausen, DE;
Andreas Stihl AG & Co. KG, Waiblingen, DE;
Abstract
The absolute crankshaft angle of an internal combustion engine of a hand-held power tool is to be determined. The engine has a cylinder with a combustion chamber delimited by a piston that drives a crankshaft in a crankcase. The crankcase is connected by a transfer passage to the combustion chamber and the transfer port of the transfer passage is piston-controlled. Ignition takes place at an adjusted crankshaft angle. The energy supply unit of the engine is driven by the crankshaft and provides electric energy for ignition. The crankshaft angle is determined in that a signal generator is provided as an energy supply unit and generates an alternating voltage signal caused by a crankshaft revolution. An operating pressure signal of the engine is detected by a pressure sensor. The output signals of the pressure sensor and of the signal generator are linked with one another for determining the absolute crankshaft angle.