Patent ID: 8631780

Claim:
A power cutter powered by a single cylinder internal combustion engine, the power cutter comprising: a tool unit having at least one working tool, which can be rotated about an axis of rotation, and preferably having a tool guard; a drive unit comprising a single cylinder internal combustion engine, the engine comprising an engine cylinder with cylinder bore having a cylinder bore centerline, a piston, a crankshaft with at least one crank web and a crankshaft axis of rotation, a crankcase, a muffler and a flywheel, the crankshaft running in a counter clockwise direction as seen towards the flywheel; a cutter arm attached to the drive unit in its inner end and its outer end carrying the tool unit, a centerline of the cutter arm essentially follows a connection line between the axis of rotation of the tool and the axis of rotation of the crankshaft; the crank web/s are arranged to counterbalance approximately a half piston weight and the flywheel is arranged so that it gives a radially outwards acting unbalance force FB during engine rotation, and FB is provided at a flywheel angle in a clockwise direction in relation to the cylinder bore centerline when the piston is in a top dead center position, and the flywheel angle is larger than 20° but smaller than 110° in order to at least minimize or reduce cutter arm bending stress.