Apparatus and system for controlling the air-fuel ratio supplied to a combustion engine

A carburetor for a combustion engine, comprising carburetor body means, induction passage means formed in said body means, variably positionable throttle valve means for controlling the rate of motive fluid through said induction passage means and into said engine, fuel reservoir chamber means carried by said body means, main fuel metering system means communicating generally between said fuel reservoir chamber means and said induction passage means, said main fuel metering system means comprising modulating valve means carried by said body means and effective to be variably positioned in order to thereby controllably alter the rate of metered main fuel flow through said main fuel metering system means to said induction passage means, and fluid pressure responsive motor means carried by said body means and operatively connected to said modulating valve means, said fluid pressure responsive motor means comprising fluid pressure chamber means and pressure responsive movable wall means, said pressure responsive wall means being effective to variably position said modulating valve means in response to the magnitude of an actuating fluid pressure applied to said fluid pressure responsive wall means, said fluid pressure chamber means being effective for receiving actuating fluid pressure and in turn causing said actuating fluid pressure to be applied to said fluid pressure responsive wall means, said modulating valve means comprising orifice means and a valve member cooperating with said orifice means to variably define therebetween an effective fuel metering area, said pressure responsive wall means comprising pressure responsive movable diaphragm means, said valve member being operatively connected to said diaphragm means for movement therewith, said fluid pressure chamber means comprising a chamber partly defined by said diaphragm means, and further comprising first spring means at least partly situated generally in said chamber and operatively engaging said diaphragm means, and second spring means situated generally externally of said chamber and operatively engaging said valve member, each of said first and second spring means being effective to urge said valve member in a direction resulting in an increase in said effective fuel metering area.

A carburetor for a combustion engine, comprising carburetor body means, induction passage means formed in said body means, variably positionable throttle valve means for controlling the rate of motive fluid through said induction passage means and into said engine, fuel reservoir chamber means carried by said body means, first fuel metering system means communicating generally between said fuel reservoir chamber means and said induction passage means, second fuel metering system means communicating generally between said fuel reservoir chamber means and said induction passage means, said first fuel metering system means comprising first modulating valve means carried by said body means and effective to be variably positioned in order to thereby controllably alter the rate of metered fuel flow through said first fuel metering system means to said induction passage means, said second fuel metering system means comprising second modulating valve means carried by said body means and effective to be variably positioned in order to thereby controllably alter the rate of metered fuel flow through said second fuel metering system means to said induction passage means, first fluid pressure responsive motor means carried by said body means and operatively connected to said first modulating valve means, said first fluid pressure responsive motor means comprising first chamber means and first pressure responsive movable wall means, said first pressure responsive wall means being effective to variably position said first modulating valve means in response to the magnitude of an actuating fluid pressure applied to said first pressure responsive wall means, and second fluid pressure responsive motor means carried by said body means and operatively connected to said second modulating valve means, said second fluid pressure responsive motor means comprising second chamber means and second pressure responsive movable wall means, said second pressure responsive movable wall means being effective to variably position said second modulating valve means in response to the magnitude of an actuating fluid pressure applied to said second fluid pressure responsive wall means, said first and second chamber means being effective for receiving actuating fluid pressure and in turn causing said actuating fluid pressure to be applied to said first and second pressure responsive wall means.

A carburetor for a combustion engine, comprising carburetor body means, induction passage means formed in said body means, variably positionable throttle valve means for controlling the rate of motive fluid through said induction passage means and into said engine, fuel reservoir chamber means carried by said body means, idle fuel metering system means communicating generally between said fuel reservoir chamber means and said induction passage means, main fuel metering system means communicating generally between said fuel reservoir chamber means and said induction passage means, said main fuel metering system means comprising modulating valve means carried by said body means and effective to be variably positioned in order to thereby controllably alter the rate of metered main fuel flow through said main fuel metering system means to said induction passage means, fluid pressure responsive motor means carried by said body means and operatively connected to said modulating valve means, said fluid pressure responsive motor means comprising fluid pressure chamber means and pressure responsive movable wall means, said pressure responsive wall means being effective to variably position said modulating valve means in response to the magnitude of an actuating fluid pressure applied to said fluid pressure responsive wall means, said fluid pressure chamber means being effective for receiving actuating fluid pressure and in turn causing said actuating fluid pressure to be applied to said fluid pressure responsive wall means, said modulating valve means comprising orifice means and a valve member cooperating with said orifice means to variably define therebetween an effective fuel metering area, said pressure responsive wall means comprising pressure responsive movable diaphragm means, said valve member being operatively connected to said diaphragm means for movement therewith, said fluid pressure chamber means comprising a chamber partly defined by said diaphragm means, first spring means at least partly situated generally in said chamber and operatively engaging said diaphragm means, and second spring means situated generally externally of said chamber and operatively engaging said valve member each of said first and second spring means being effective to urge said valve member in a direction resulting in an increase in said effective fuel metering area.