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:
Apr. 29, 2008
Filed:
Jul. 28, 2006
Eberhard Schieber, Backnang, DE;
Heinrich Leufen, Schwaikheim, DE;
Mohamed Abou-aly, Waiblingen, DE;
Hans Nickel, Weissach, DE;
Heiko Rosskamp, Adelberg, DE;
Jörg Schlossarczyk, Winnenden, DE;
Eberhard Schieber, Backnang, DE;
Heinrich Leufen, Schwaikheim, DE;
Mohamed Abou-Aly, Waiblingen, DE;
Hans Nickel, Weissach, DE;
Heiko Rosskamp, Adelberg, DE;
Jörg Schlossarczyk, Winnenden, DE;
Andreas Stihl AG & Co. KG, Waiblingen, DE;
Abstract
An ignition circuit is for an internal combustion engine in a handheld portable work apparatus. A combustion chamber () is configured in the cylinder () of the engine () which is delimited by a piston () driving a crankshaft (). A pole wheel () revolves with the crankshaft () and is assigned to an induction loop (). The pole wheel periodically changes the magnetic flux in the induction loop. An ignition capacitor () is charged by a charge coil () of the induction loop and is discharged via a discharge circuit () via an ignition coil (). The ignition coil is connected to a spark plug () projecting into the combustion chamber. For achieving a powerful ignition spark, the discharge of the ignition capacitor is prevented by an rpm evaluation circuit () when the rpm curve () exhibits an rpm change (Δn) which exceeds a pregiven threshold value.