Fuel metering device for internal combustion engine

Claim 2

In a carburetor for an internal combustion engine, the combination of: a. a housing providing a mixing passage adapted to have air drawn therethrough by the engine; b. movable venturi plates pivotally mounted on parallel axes spaced apart and adjacent the walls upstream of said mixing passage; c. throttle means in said housing movably mounted downstream of said mixing passage; d. a fuel chamber; e. a fuel discharge spray bar extending laterally across said mixing passage having an axis parallel to the pivot axes of said venturi plates and fixedly mounted immediately below the venturi plates when in a closed position, said bar having a plurality of spaced apart fuel discharge openings; f. a fuel pickup arm pivotally mounted in said fuel chamber and having an opening therein in fluid communication with said fuel discharge spray bar, said opening moving in an arcuate path within said fuel chamber; g. means interconnecting said movable venturi plates and said pickup arm for concurrent pivotal movement thereof; and h. ramp means in said fuel chamber variably spaced from said pickup arm opening so as to cooperate therewith to provide a non-linear variable fuel metering clearance at different arcuate positions of said pickup arm, said clearance increasing with arcuate movement of said pickup arm to a position corresponding to an increased opening of said venturi to maintain the air-fuel mixture ratio substantially constant.

Claim 3

The carburetor of claim 1 wherein said means interconnecting said movable means defining a variable venturi and said pickup arm comprises mechanical linkage for rotating said pickup arm in direct proportion to movement of said movable means.

Claim 4

The carburetor of claim 2 wherein said linkage comprises a gear train.

Claim 5

The carburetor of claim 1 including electrically operated valve means for admitting fuel under pressure into said fuel chamber and switch means operable by said movable means defining a variable venturi for preventing energization of said electrically operated valve means when said variable venturi is closed.

Claim 6

The carburetor of claim 4 including manually operable, normally closed switch means for preventing energization of said electrically operated valve means.

Claim 7

A carburetor for an internal combustion engine comprising: a. a housing including a mixing passage through which air is drawn; b. variable venturi plates pivotally mounted on parallel axes in the upstream end of said mixing passage for movement from a position at which the free ends of said plates are substantially in contact so as to entirely close said mixing passage to an open position at which said plates are substantially removed from the air flow passage; c. pivotally mounted throttle means mounted at the downstream end of said mixing passage; d. a fuel supply chamber; e. a hollow fuel discharge spray bar extending entirely across said mixing passage having an axis parallel to the pivotal axes of said venturi plates and fixedly mounted immediately below said venturi plates so as to be in close proximity to the free edge of said plates when said plates are partially open, and including a plurality of fuel discharge openings; f. a tubular shaft rotatably mounted within said hollow spray bar and having openings in communication with the interior of said spray bar; g. a fuel pickup arm pivotally mounted in said fuel supply chamber and having a passage therein in fluid communication at one end with said tubular shaft and having an inlet opening at its other end; h. means interconnecting said variable venturi plates and said fuel pickup arm for concurrent pivotal movement; and i. ramp means in said fuel chamber variably, non-linearly spaced from said pickup arm opening so as to cooperate therewith to provide a varying fuel metering clearance upon movement of said arm, said clearance increasing in proportion to increased opening of said variable venturi plates.

Claim 8

A carburetor for an internal combustion engine comprising: a. a housing including a mixing passage through which air is drawn; b. variable venturi plates pivotally mounted on parallel axes in the upstream end of said mixing passage for movement from a position at which the free ends of said plates are substantially in contact so as to entirely close said mixing passage to an open position at which said plates are substantially removed from the air flow passage; c. pivotally mounted throttle means mounted at the downstream end of said mixing passage; d. a fuel supply chamber; e. a hollow fuel discharge spray bar extending entirely across said mixing passage having an axis parallel to the pivotal axes of said venturi plates and fixedly mounted immediately below said venturi plates so as to be in close proximity to the free edge of said plates when said plates are partially open, and including a plurality of fuel discharge openings; f. a tubular shaft rotatably mounted within said hollow spray bar and having openings in communication with the interior of said spray bar; g. a fuel pickup arm pivotally mounted in said fuel supply chamber and having a passage therein in fluid communication at one end with said tubular shaft and having an inlet opening at its other end; h. means interconnecting said variable venturi plates and said fuel pickup arm for concurrent pivotal movement; and i. ramp means in said fuel chamber variably, non-linearly spaced from said pickup arm opening so as to cooperate therewith to provide a varying fuel metering clearance upon movement of said arm, said clearance increasing in proportion to increased opening of said variable venturi plates.

Claim 9

A carburetor for an internal combustion engine comprising: a. a housing adapted for mounting to an intake manifold having an elongated mixing passage through which air is drawn and fuel is discharged; b. a pair of venturi plates each mounted on a shaft, said plates being pivotable toward each other, said shafts being spaced apart, parallel and positioned in the upstream end of said mixing passage; c. throttle means movably mounted in the downstream end of said mixing passage; d. a fuel discharge spray bar fixedly mounted in said mixing passage below said venturi plates and above said throttle means and having an axis parallel to said venturi plate shafts and having a plurality of lateral fuel discharge openings; e. a fuel pickup arm pivotally mounted in a fuel supply chamber, said arm having a fuel passage in communication with said fuel discharge spray bar at one end and an inlet opening at the other end moving in an arcuate path within said fuel chamber adjacent a ramp in said chamber variably and non-linearly spaced from the pickup arm inlet opening so as to cooperate therewith to provide a variable fuel metering clearance at different arcuate positions of said pickup arm; and f. means interconnecting said venturi plates and said pickup arm for coordinated concurrent pivotal movement of said arm whereby the clearance between said arm inlet opening and said ramp increases with increasing opening of said venturi so as to control the air-fuel mixture ratio.

Claim 10

A carburetor for an internal combustion engine comprising: a. a housing adapted for mounting to an intake manifold having an elongated mixing passage through which air is drawn and fuel is discharged; b. a pair of venturi plates each mounted on a shaft, said plates being pivotable toward each other, said shafts being spaced apart, parallel and positioned in the upstream end of said mixing passage; c. throttle means movably mounted in the downstream end of said mixing passage; d. a fuel discharge spray bar fixedly mounted in said mixing passage below said venturi plates and above said throttle means and having an axis parallel to said venturi plate shafts and having a plurality of lateral fuel discharge openings; e. a fuel pickup arm pivotally mounted in a fuel supply chamber, said arm having a fuel passage in communication with said fuel discharge spray bar at one end and an inlet opening at the other end moving in an arcuate path within said fuel chamber adjacent a ramp in said chamber variably and non-linearly spaced from the pickup arm inlet opening so as to cooperate therewith to provide a variable fuel metering clearance at different arcuate positions of said pickup arm; and f. means interconnecting said venturi plates and said pickup arm for coordinated concurrent pivotal movement of said arm whereby the clearance between said arm inlet opening and said ramp increases with increasing opening of said venturi so as to control the air-fuel mixture ratio.

Claim 11

The carburetor of claim 7 additionally including temperature responsive resilient means biasing said venturi plates towards their closed position with variable force in opposition to the force due to the pressure differential across said plates tending to move said plates to the open position.