Patent ID: 6401673
Filing Date: 2002-06-11
Classification: F02B

Abstract:
A two-stroke engine including an engine in a portable handheld work apparatus, the two-stroke engine comprising:a cylinder having a cylinder wall; a piston mounted in said cylinder to undergo a reciprocating movement along a stroke path between top dead center and bottom dead center during operation of said engine; said cylinder and said piston conjointly delimiting a combustion chamber; a crankcase connected to said cylinder; a crankshaft rotatably mounted in said crankcase; a connecting rod connecting said piston to said crankshaft to permit said piston to drive said crankshaft as said piston reciprocates in said cylinder; at least one transfer channel connecting said crankcase to said combustion chamber; said transfer channel having a first end defining an entry window opening into said combustion chamber and a second end opening into said crankcase; an air filter having an air filter housing defining a clean space; a choke throttle unit for conducting essentially fuel-free air from said air filter; an air channel connected to said transfer channel for supplying said essentially fuel-free gas flow thereto from said choke throttle unit; a mixture-preparation unit for supplying an air/fuel mixture; said mixture-preparation unit being mounted downstream of said air filter; an inlet channel downstream of said mixture-preparation unit for conducting said air/fuel mixture into said crankcase; said choke throttle unit including: an independent choke housing defining a choke channel communicating with said air channel; and, a throttle element adjustably mounted in said choke channel; and, said choke housing being attached to said air filter housing and said choke channel being connected to said clean space of said air filter upstream of said choke element.