Abstract: A carburettor for an internal combustion engine, which includes a duct connectable to a combustible charge inlet of the engine; a butterfly valve pivotally mounted within the duct and connectable to a throttle linkage of the engine to permit control of airflow through the duct; and a housing provided exteriorly of the duct, the housing having an inlet adapted for connection to a fuel source, an outlet passage leading into the duct, and at least one valve means intermediate the inlet connection and the outlet passage for regulating fuel flow into the duct.

Abstract: A carburettor for an internal combustion engine, which includes a duct connectable to a combustible charge inlet of the engine and having opposed internal wall portions which are parallel, a regulatable fuel inlet for feeding fuel into the duct, and a vacuum inducing vane within the duct and upstream of the fuel inlet, the vacuum inducing vane being biased towards a closed position to impede airflow through the duct and being displaceable against the bias by airflow through the duct, thereby, during operation, to create a negative pressure downstream of the vacuum inducing vane.

Abstract: A carburetor has a manually adjustable control to simultaneously change fuel flow rates from the power valve and accelerator pump circuits to compensate for altitude changes varying the air density and thereby the air/fuel ratio of the mixture flowing from the carburetor.

Abstract: A carburetor comprising a body, means to secure the body to an engine, a barrel rockably mounted in the body and means for rocking said barrel means defining a passage extending through the body and the barrel to an engine which passage can be restricted by rotation of the barrel relative to the body, the part of the passage through the body and the barrel being tapered down to the trailing edge of the barrel, the barrel having a fuel passage way defined therein extending from a tapering slot in the circumferential edge of the barrel to an opening adjacent said trailing edge of the barrel, which opening always communicates with said passage extending through said body and said barrel in all operative positions of the barrel, the tapering slot being adjacent a hole extending through the body and leading to a fuel control valve so that movement of the barrel alters the cross section of said tapering slot presented to said hole to meter the quantity of fuel to be passed through said tapering slot.

Abstract: In a four-barrel carburetor, a pair of plain tube primary mixture conduits each has a main well receiving fuel through a main jet controlled by a metering rod which is positioned by a vacuum responsive piston. An auxiliary fuel passage receives fuel both through an auxiliary jet controlled by a metering rod positioned by a vacuum responsive piston and through a supplementary jet controlled by a metering rod positioned by an ambient pressure responsive bellows. A pair of transfer passages respectively connect the auxiliary fuel passage to the main wells.

Abstract: A carburetor comprising a throttle valve operated control valve controlling the supply of fuel to an air valve operated control valve discharging directly into the carburetor air duct.

Abstract: In a carburetor having a two-stage power valve and an off-idle air bleed, a lean air-fuel mixture may be supplied when it is desirable to operate in a lean mode for optimizing an exhaust gas oxidizing reactor while a rich air-fuel mixture may be provided when it is desirable to operate in a rich mode for optimizing an exhaust gas reducing converter. In the rich mode means comprising a selectively energizable solenoid control closes the off-idle air bleed and opens the first stage of the power valve thereby enriching both off-idle and open throttle air-fuel mixtures. The power valve is also operated by an induction pressure responsive piston, and at high induction pressures both stages may be opened during lean mode operation and the second stage may be opened during rich mode operation for wide open throttle enrichment.