Patent ID: 7373906
Filing Date: 2008-05-20
Classification: F02B

Abstract:
1. A power tool comprising: a working tool; a two-stroke engine driving the working tool; the two-stroke engine comprising a cylinder and a piston reciprocating within the cylinder in a direction of a longitudinal cylinder axis, wherein the cylinder has a combustion chamber delimited by the piston; the two-stroke engine comprising a crankcase and a crankshaft rotatably supported in the crankcase about an axis of rotation, wherein the piston drives with a connecting rod the crankshaft; the two-stroke engine having one or more transfer passages connecting the crankcase to the combustion chamber in at least one position of the piston; the two-stroke engine comprising a mixture passage supplying a fuel/air mixture, wherein the cylinder has a mixture intake that is connected to the mixture passage and is piston-controlled; wherein the combustion chamber has an exhaust port provided within the cylinder; wherein the two-stroke engine has a transverse plane dividing the cylinder parallel to the longitudinal cylinder axis into a first half and a second half, wherein the longitudinal cylinder axis is located within the transverse plane; wherein the exhaust port and the mixture intake are arranged on the first half of the cylinder; wherein the axis of rotation of the crankshaft extends transversely to the transverse plane; wherein the two-stroke engine has an air passage that supplies combustion air, wherein the cylinder has an air intake and the air passage is connected to the air intake, wherein the air intake is arranged on the second half of the cylinder; wherein the two-stroke engine has a center plane dividing the exhaust port, wherein on either side of the center plane at least one of the one or more transfer passages is arranged; wherein the one or more transfer passages each have a transfer port opening into the combustion chamber, wherein the piston has a piston recess, and wherein the air passage is connected through the piston recess in at least one position of the piston to at least one of the transfer ports of the one or more transfer passages.