Carburetor

Claim 2

A multibarrel carburetor connected to supply a fuel mixture to at least one intake manifold of an internal combustion engine, said carburetor having at least one primary induction passage and at least one larger secondary induction passage, a primary choke plate mounted in said primary induction passage for movement between opened and choking positions, a secondary choke plate mounted in said secondary induction passage for movement between opened and choking positions, a temperature-responsive member having actuating means connected to said choke plates to move them to choking positions in response to temperatures below a predetermined minimum and to open the choke plates in response to temperatures above said minimum, engine-operation-responsive means connected to urge the primary choke plate open during choked operation, a yieldable device in the connection of the actuating means with the primary choke plate to allow said primary choke plate to be moved toward opened position by said engine-operation-responsive means, the connection between the actuating means and the secondary choke plate being relatively non-yielding as compared with the primary choke plate connection to hold the secondary choke plate in less open position when the engine-operation-responsive means moves the primary choke plate toward open position.

Claim 3

The combination of claim 1 in which there is only one primary induction passage and its cross-sectional area is not more than about one-eighth of the total cross-sectional area of all induction passages.

Claim 4

The combination of claim 1 in which there is only one primary induction passage and its cross-sectional area is not more than about one-eighth of the total cross-sectional area of all seCondary induction passages, the primary induction passage is connected to supply an unchoked combustion mixture having an air-fuel ratio at least as high as about 14.5 to 1, and the primary induction passage has a venturi-operated fuel jet connected to supply to that passage all idle fuel as well as fuel for all other operating modes.

Claim 5

A multibarrel carburetor as in claim 1 in which the engine-operation-responsive means includes an unsymmetrical pivot mounting for the primary choke plate to cause that plate to be urged toward open position by the movement of air into the carburetor.

Claim 6

A multibarrel carburetor as in claim 4 in which the engine-operation-responsive means includes an unsymmetrical pivot mounting for the secondary choke plate to cause that plate to be urged toward opened position by the movement of air into the carburetor.

Claim 7

A multibarrel carburetor as in claim 1 in which the engine-operation-responsive means includes a suction head with a suction connection for the suction downstream of the throttle in the primary induction passage, the head being connected to the actuating means for the primary choke plate to urge said plate toward open position in response to said suction.

Claim 8

A multibarrel carburetor as in claim 6 including a second suction head with a suction connection for the suction upstream of the throttle in the secondary induction passage, the second head being connected to the actuating means for the secondary choke plate to urge the last-mentioned plate toward open position in response to suction at the last-mentioned source.

Claim 9

The combination of claim 6 and further including limit means defining a maximum choke opening position for the suction head and temperature-responsive adjustment elements are connected to the limit means to gradually reduce that maximum as the choking temperature decreases.

Claim 10

The combination of claim 8 in which the temperature-responsive adjustment elements are connected to modulate the suction in the suction head.

Claim 11

The combination of claim 8 in which the primary induction passage is connected to supply an unchoked combustion mixture having an air-fuel ratio at least as high as about 14.5 to 1.

Claim 12

The combination of claim 10 in which the primary induction passage has a venturi-operated fuel jet connected to supply to that passage all idle fuel as well as fuel for all other operating modes.

Claim 13

The combination of claim 10 in which the suction head has a maximum choke opening position, and temperature-responsive adjustment elements coact with the suction head to gradually reduce that maximum as the choking temperature decreases.

Claim 14

A multibarrel carburetor having at least one primary induction passage and at least one larger secondary induction passage, a primary choke plate mounted in said primary induction passage for movement between opened and choking positions, a secondary choke plate mounted in said secondary induction passage for movement between opened and choking positions, a temperature-responsive actuator connected to both of said choke plates to move them to choking positions in response to temperatures below a predetermined minimum and to open the choke plates in response to temperatures above said minimum, a yieldable device in the connection between the temperature-responsive actuator and the primary choke plate to allow said primary choke plate to be moved toward opened position by said engine-operation-responsive means, the connection between the temperature-responsive actuator and the secondary choke plate being relatively non-yielding as compared with the primary choke plate connection to hold the secondary choke plate in less open position when the engine-operation-responsive means moves the primary choke plate toward open position, the primary choke plate being unbalanced, means holding that plate oriented in an air intake for movement toward open position by air moving through that intake at speeds above idle, engine-operation-responsive mEans with a suction connection for the suction downstream of the throttle, said engine-operation-responsive means being connected to the temperature responsive actuator to limit the cold closing of the plate when said suction is appreciable, and temperature-responsive elements connected to said engine-operation-responsive means to gradually lower the closing limit as the temperature diminishes, the connections from the temperature-responsive actuator and said engine-operation-responsive means to the choke plate including one-way connection means enabling the actuator and said enginge-operation-responsive means to move the plate but also permitting the plate to be independently opened wide by the air-intake notwithstanding the actuator and said engine-operation-responsive means.

Claim 15

A multibarrel carburetor having at least one primary induction passage and at least one larger secondary induction passage, a primary choke plate mounted in said primary induction passage for movement between opened and choking positions, a secondary choke plate mounted in said secondary induction passage for movement between opened and choking positions, a temperature-responsive actuator connected to both of said choke plates to move them to choking positions in response to temperatures below a predetermined minimum and to open the choke plates in response to temperatures above said minimum, a yieldable device in the connection between the temperature-responsive actuator and the primary choke plate to allow said primary choke plate to be moved toward opened position by said engine-operation-responsive means, the connection between the temperature-responsive actuator and the secondary choke plate being relatively non-yielding as compared with the primary choke plate connection to hold the secondary choke plate in less open position when the engine-operation-responsive means moves the primary choke plate toward open position, the primary choke plate being unbalanced, means holding that plate oriented in an air intake for movement toward open position by air moving through that intake at speeds above idle, engine-operation-responsive mEans with a suction connection for the suction downstream of the throttle, said engine-operation-responsive means being connected to the temperature responsive actuator to limit the cold closing of the plate when said suction is appreciable, and temperature-responsive elements connected to said engine-operation-responsive means to gradually lower the closing limit as the temperature diminishes, the connections from the temperature-responsive actuator and said engine-operation-responsive means to the choke plate including one-way connection means enabling the actuator and said enginge-operation-responsive means to move the plate but also permitting the plate to be independently opened wide by the air-intake notwithstanding the actuator and said engine-operation-responsive means.

Claim 16

A carburetor having two barrels and an automatic choke system for both barrels, said system including an unbalanced choke valve in one barrel, means holding the valve oriented in an air intake for movement toward open position by air moving through that intake at speeds above idle, a temperature-responsive actuator connected to the valve to move it to choking position when the temperature is below a predetermined minimum, engine-operation-responsive means with a suction connection for the suction downstream of the throttle, said engine-operation-responsive means being connected to the temperature-responsive actuator to limit the cold closing of the valve when said suction is appreciable, and temperature-responsive elements connected to said engine-operation-responsive means to gradually lower the closing limit as the temperature diminishes, the connections from the temperature-responsive actuator and said engine-operation-responsive means to the choke valve including one-way connection means enabling the actuator and said engine-operation-responsive means to move the valve but also permitting the valve to be independently opened wide by the air-intake notwithstanding the actuator and said engine-operation-responsive means.

Claim 17

A carburetor having two barrels and an automatic choke system for both barrels, said system including an unbalanced choke valve in one barrel, means holding the valve oriented in an air intake for movement toward open position by air moving through that intake at speeds above idle, a temperature-responsive actuator connected to the valve to move it to choking position when the temperature is below a predetermined minimum, engine-operation-responsive means with a suction connection for the suction downstream of the throttle, said engine-operation-responsive means being connected to the temperature-responsive actuator to limit the cold closing of the valve when said suction is appreciable, and temperature-responsive elements connected to said engine-operation-responsive means to gradually lower the closing limit as the temperature diminishes, the connections from the temperature-responsive actuator and said engine-operation-responsive means to the choke valve including one-way connection means enabling the actuator and said engine-operation-responsive means to move the valve but also permitting the valve to be independently opened wide by the air-intake notwithstanding the actuator and said engine-operation-responsive means.