Patent attributes
A scavenging carburetor having an improved relationship between scavenging air flow and fuel-and-air flow to an engine over its range of operating conditions. The carburetor has a butterfly throttle valve and a plug-type scavenging valve. Levers are attached to support shafts of the valves and are connected to each other by a connecting rod so as to synchronize movement of the valves. Because of the different opening angle versus open area properties of the two valves, the supply of the scavenging air is minimized over a low speed range of the engine so as to achieve a stable low speed operation and a stable acceleration from idle conditions and a relatively large amount of scavenging air is supplied over a high speed range of the engine for the given amount of fuel-and-air mixture that is supplied. Therefore, the fuel-and-air mixture supply and scavenging air supply is better matched to the requirements of a particular engine than was possible with conventional combinations of valves.
