Patent ID: 7013850

Claim:
A two-stroke engine including a two-stroke engine in a portable handheld work apparatus, the two-stroke engine comprising: a cylinder defining a cylinder bore and a longitudinal axis; a piston mounted in said cylinder to undergo a reciprocating movement along said longitudinal axis; 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; an inlet for fuel and an outlet for conducting exhaust gases away from said combustion chamber; at least one transfer channel; a piston window formed in said piston; said combustion chamber being connected to said crankcase via said piston window and said transfer channel at pregiven positions of said piston along said longitudinal axis; a transfer window opening into said combustion chamber and a transfer opening opening into said crankcase; said transfer channel communicating with said combustion chamber via said transfer window and communicating with said crankcase via said transfer opening; said transfer opening and said transfer window opening into said cylinder bore in a region thereof traversed by said piston; and, said transfer opening being not yet closed by said piston while moving toward said crankcase while said transfer window to said combustion chamber begins to open and shortly after said transfer channel is opened to said combustion chamber, said transfer channel is closed to said crankcase by the further downwardly moved piston.