Patent ID: 6491005
Filing Date: 2002-12-10
Classification: F02B,F02F

Abstract:
A cylinder assembly for a two-stroke engine including an engine for a portable handheld work apparatus including a chain saw, brushcutter and cutoff machine, the two-stroke engine including a piston, the cylinder assembly comprising:a cylinder having a cylinder wall defining a cylinder bore surface and a cylinder axis; said cylinder wall and said piston conjointly delimiting a combustion chamber in said engine; an outlet formed in said cylinder wall for conducting combustion gases away from said combustion chamber; a plurality of transfer channels for conducting operating means to said combustion chamber for operating said engine; a first one of said transfer channels having a first transfer window opening into said combustion chamber near said outlet to form an outlet-near transfer window; a second one of said transfer channels having a second transfer window opening into said combustion chamber remote from said outlet to form an outlet-remote transfer window; said first and second transfer channels being open channels directed radially outwardly; a cover mounted on said cylinder to cover said channels; said first and second windows having respective outlet-remote frame surfaces extending approximately parallel to said cylinder axis and facing toward said outlet viewed in the peripheral direction of said cylinder bore surface; said outlet-remote frame surfaces lying in respective mutually parallel pull planes; said first transfer window also having an outlet-near frame surface; said outlet-near and said outlet-remote frame surfaces of said first transfer window lying in respective first planes which intersect in said combustion chamber; said second transfer window also having an outlet-near frame surface; and, said outlet-near and said outlet-remote frame surfaces of said second transfer window lying in respective second planes which also intersect in said combustion chamber.