Abstract: The invention relates to a fuel system of a portable handheld work apparatus driven by an internal combustion engine. The fuel system includes a fuel tank (2), a fuel pump, a fuel line (4) leading from the fuel tank (2) to the fuel pump and a first suction head (5) which is disposed at an end (7) of the fuel line (4) at the fuel tank. At least a second suction head (6) is arranged within the fuel tank (2) and is connected in the fuel line (4) in series ahead of the first suction head (5). The second suction head (6) has an external suction surface which is formed by a porous covering (9). The porous covering (9) delimits a suction space. A guide is arranged in the suction space which guides the through-passing fuel flow at least approximately along the entire inner surface of the porous covering (9).
Abstract: A liquid dosing apparatus comprises a tank (8) to be repeatedly filled with liquid to an upper level; a float (24) adapted to rise in the tank concurrently with the filling thereof and, each time the upper level has been reached, to be wholly or partly filled with liquid so as to sink in the tank, thus actuating a draining siphon (15) which drains the tank to a lower level; and a float siphon (27) draining the float (24) so that this will float again when the liquid level rises after the tank has been drained. The actuating of the draining siphon (15) by the float (24) is achieved by the provision of a chamber (13) which communicates with the tank (8) so as to be filled with liquid when the tank (8) is being filled, an inlet (20) of the draining siphon (15) being connected to the chamber (13). The sinking movement of the float (24) reduces the amount of liquid in the chamber (13), the liquid being pressed into the inlet (20) of the draining siphon for actuating the latter.