Patent ID: 7647913

Claim:
A portable, hand-held, combustion engine powered working machine comprising a tool unit ( 1 ) including a rotatable working tool ( 3 ), and a machine unit ( 2 ) including an internal combustion engine ( 11 ), an assembly ( 16 ) for supplying air and fuel to the engine, and an air cleaning system, which comprises a filter assembly ( 10 ) including at least two filters ( 84 , 85 ), referred to as pre-filter ( 84 ) and main filter ( 85 ), for cleaning the air that shall be supplied to the engine, wherein the pre-filter is accommodated in an upper filter chamber ( 86 ) between a top cover ( 83 ) and a pre-filter bottom ( 9 ), and the main filter is accommodated in a lower filter chamber under the pre-filter bottom, said lower filter chamber being defined by the underside of the pre-filter bottom, a second filter bottom ( 125 ) at a distance from the pre-filter bottom, and a closed, circumferential wall ( 120 ) between the pre-filter bottom and the second filter bottom, said closed, circumferential wall forming a downwards directed protrusion on the underside of the upper filter bottom, the second filter bottom ( 125 ) forms a shelf on a bracket ( 79 ), carrying said assembly ( 16 ) for supplying air and fuel to the engine.