Hand-held power tool

US8863705B2 · kind B2 · utility

Assignee

• Andreas Stihl AG & Co. KG · DE

Inventors

• Niels Kunert · Sindelfingen, DE
• Michael Grether · Waiblingen, DE

Key dates

• Filing date: Sep 6, 2011
• Grant date: Oct 21, 2014
• Expiry date: Feb 9, 2033

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02B2075/025
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A hand-held power tool has a two-stroke engine with a cylinder with combustion chamber and a piston disposed therein that drives a crankshaft supported in a crankcase. In at least one piston position, crankcase and combustion chamber are connected by a transfer passage. An air passage supplies in at least one piston position combustion air to the transfer passage. A mixture passage for fuel/air mixture is provided. Air and mixture passages in operation are at least partially connected to each other. Part of the mixture passage is formed in a carburetor where a fuel port opens into the mixture passage. The mixture passage opens into the crankcase with a piston-controlled mixture inlet having a width in circumferential direction of the cylinder. Upon upward piston stroke the mixture inlet is connected to the crankcase with a portion of the width before a connection of air passage and transfer passage is established.