Husqvarna Ab

Magnus Ottosson

Bo P Carlsson

Mikael Larsson

Pär Martinsson

Rikard Rydberg

Fredrik Lindström

A fuel supply system for small two-stroke internal combustion engines for e.g. chain saws, line trimmers and similar hand-held power-tools including a diaphragm carburetor () equipped with a purging system () or priming system () for facilitating starting of the engine (). Downstream of the diaphragm (), the carburetor has a fuel valve () with a fuel cavity (), which when the valve is not closed being connected via a fuel conduit () to a fuel nozzle () in a main air passage () in the carburetor. The purging system or priming system including a fuel line (), which is provided with a manually operated pump () and is connected between a fuel tank () and either the fuel cavity () or the fuel conduit ().

Carburetor system for a carburetor engine

The invention concerns a method for controlling the fuel supply to an internal combustion engine at start-up. The fuel supply system can be set in at least two start modes, a lean mode and a rich mode, and the selection of mode is based on an evaluation of a previous start attempt or successful run. The invention also concerns a carburetor () having a fuel supply system including a main fuel path () with an actively controlled fuel valve () and an idling fuel path () branching off from the main fuel path () downstream of the valve (). The fuel supply system further includes a start fuel line () starting upstream (FIG.) or downstream (FIG.) of the fuel valve () and ending in at least one start fuel outlet near and downstream of a choke valve.

Method for controlling the fuel supply to an internal combustion engine at start-up and a carburettor

The invention concerns a method for controlling the fuel supply to an internal combustion engine at start-up, the engine having a fuel supply system. The invention also concerns a carburetor having a fuel supply system including a main fuel path connecting a diaphragm controlled regulating chamber to a main outlet in the region of the venturi section, the main fuel path including an actively controlled fuel valve, and an idling fuel path branching off from the main fuel path downstream of the valve and ending in at least one idling outlet in the region of a throttle valve, the fuel supply system further including a start fuel line starting upstream or downstream of the fuel valve and ending in at least one start fuel outlet to the intake channel.

Method for controlling the fuel supply to an internal combustion engine at start-up and a carburetor

The invention relates to a carburetor assembly () for a two-stroke internal combustion engine, the assembly comprising a main intake passage () accommodating a throttle valve (), an additional air passage () accommodating an additional air valve (), a pivotable air valve lever () turning together with the air valve (), and an interlock lever () turning together with the throttle valve (). The interlock lever () is configured to be settable in an interlocked pivotal position, in which the throttle valve () is open to a certain degree in order to provide a start gas position of the throttle valve (), wherein the interlock is arranged to be released if the interlock lever () is pivoted further in the opening direction of the throttle valve (). The assembly further comprising a pivotable trigger lever () responsive to e.g. pulling of a throttle trigger and being operatively connected to the air valve lever (). The pivotable trigger lever () is operatively connectable to the interlock lever () or a member that moves with the interlock lever () via an abutting engagement at predetermined relative positions of the trigger lever () and the interlock lever (). Further, the trigger lever () is arranged to permit the interlock lever () to pivot away from the abutting engagement in the opening direction of the throttle valve () at least to an offset angle ( ) relative to the trigger lever (), such that the interlocked lever () can be set in the interlocked position without affecting the pivotal position of the trigger lever ().

Carburetor assembly

A fixture configured to file a chain of a chain saw. The fixture includes at least one pair of flanges, wherein each of the flanges has a first end and a second end. Further, a first connecting portion connects the flanges at their first ends, and a second connecting portion connects the flanges at their second ends. Further, the first connecting portion includes a pair of counter holds configured to provide area contact with a guide bar of the chain saw. The fixture also includes a cam portion pivotally coupled to the second connecting portion, wherein the cam portion and at least one of the counter holds simultaneously secure the fixture to the guide bar.

Growing community of inventors

Norrahammar, Sweden

Magnus Ottosson