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. 27, 2001
Filed:
Jul. 28, 1999
Bernhard Dürr, Stuttgart, DE;
Karl-Heinz Klöpfer, Winnenden, DE;
Andreas Stihl AG & Co., Waiblingen, DE;
Abstract
The invention relates to a drive unit of a portable handheld work apparatus such a motor-driven chain saw having an internal combustion engine. The crankshaft of the engine drives a tool of the work apparatus and a fan wheel. The fan wheel is held within a fan housing on a drive pin of the crankshaft. A crankcase is rigidly connected to a cylinder of the engine and is made of a metal material. The crankcase is configured of two parts and the axis of the crankshaft lies in the partition plane of the crankcase housing parts which can be connected to each other. A metallic chassis of the drive unit includes a crankcase sump as one of the crankcase halves and has a flange surface lying essentially perpendicularly to the crankshaft axis. The flange surface is at least defined in sections by the free-lying end of the crankcase sump. In this way, the weight and the manufacturing costs of the work apparatus are reduced. The fan housing is made of plastic and is attached to and lies against the flange surface with its housing base.