Patent ID: 6314922
Filing Date: 2001-11-13
Classification: B25F,B27B,F02B,F02M,Y02T

Abstract:
A hand-held working tool comprising:an engine housing (17);an inter combustion engine (2) arranged in said engine housing (17) and comprising a crankshaft (4) and air filter device (18, 19, 20);a tool (41) driven by said crankshaft (4) of said internal combustion engine (2);a fan housing (6) attached to said engine housing (2) and having an air inlet;a fan wheel (5) arranged in said fan housing (6);said fan wheel (5) driven by said crankshaft (4) of said internal combustion engine (2) to supply cooling air, sucked in through said air inlet, to said internal combustion engine (2);said fan housing (6) having a bottom (7) extending radially to said crankshaft (4), wherein said bottom (7) is positioned directly adjacent to said internal combustion engine (2) and said crankshaft (4), such that said fan housing (6) has a minimal axial depth;said bottom (7) and a side of said fan wheel (5) facing said bottom (7) defining a chamber (10) in said fan housing (6);said bottom (7) having a combustion air outlet (11);a combustion air channel (9, 9u, 9s) connecting said combustion air outlet (11) to said air filter device (18, 19, 20);said combustion air outlet (11) axially supplying combustion air from said chamber (10) through said combustion air channel (9, 9u, 9s) into said air filter device (18, 19, 20) of said internal combustion engine (2);said fan housing (6) having a channel wall (8, 8u, 8s) having a bottom portion (8s) connected to a face of said bottom (7) remote from said fan wheel (5) and covering said bottom (7) partially to form a double-walled bottom, wherein said combustion air channel is provided at an end face portion (9s) of said fan housing (6), said combustion air channel (9, 9u, 9s) defined by said bottom (7) and said portion (8s).