Two-fuel carburetor

Claim 2

In a carburetor for an internal combustion engine, an intake conduit, a pair of separate liquid chambers each having an outlet below the normal liquid level therein, separate normally open metering valves respectively controlling said outlets responsive to fuel requirements of the engine, a shut-off valve separate from said metering valves controlling one of said outlets independently of the respective metering valve, means controlling said shut-off valve responsive to engine temperature to maintain said shut-off valve closed during cold starting of the engine when the engine temperature is below a predetermined value and to open said shut-off valve during normal operation of the engine when the engine temperature equals or exceeds such predetermined value, and separate passage means connecting said outlets to the intake conduit and having discharge means thereinto at a level above the liquid level in said chambers.

Claim 3

In a carburetor according to claim 1, a choke valve in the intake portion of said mixture conduit openable and closable in accordance with engine temperature, said shut-off valve control means being solely responsive to movements of said choke valve between closed and opened positions to maintain said shut-off valve closed whenever said choke valve is closed and to open said shut-off valve when said choke valve is opened.

Claim 4

In a carburetor according to claim 2 each said chamber outlet having a calibrated orifice and each said metering valve comprising a pin movable axially in the respective orifice, said shut-off valve being a sleeve slidably mounted on the associated metering pin, said shut-off valve control means comprising resilient means biasing said shut-off valve downwardly into seated sealing engagement with said one chamber outlet and a linkage connecting said shut-off valve to said choke valve and arranged to lift said shut-off valve out of seated sealing engagement with said one chamber outlet when said choke valve is moved from closed to opened position.

Claim 5

In a carburetor according to claim 3, said metering pins being operatively connected to each other for operation in unison.

Claim 6

In a carburetor according to claim 4, a cross bar connecting the upper ends of said metering pins, an upright cylinder formed in the fluid chamber wall structure, a plunger vertically slidably received in said cylinder and secured to said cross bar intermediate said metering pins, a spring biasing said plunger upwardly, and a vacuum connection between said cylinder and the intake conduit for operating said metering pins in accordance with suction conditions in said mixture conduit.

Claim 7

In a carburetor according to claim 5, a primary Venturi centrally disposed in said mixture conduit with its throat slightly above the liquid level in said fluid chambers, said passage means having their discharge ends in the throat of said primary Venturi.

Claim 8

In a carburetor according to claim 6, means for transmitting hot air from a source outwardly of the carburetor into the primary Venturi, whereby to effect vaporization of the liquids discharged into the Venturi through said separate passages.

Claim 9

In a carburetor according to claim 1, a throttle valve in said intake conduit posterior to said liquid discharge means, an idling port in said intake conduit posterior to said throttle valve, and additional passage means connecting said idling port solely to said other outlet whereby to provide communication during idling solely between said intake conduit and the liquid chamber served by said other outlet.

Claim 10

In combination with an internal combustion engine having an intake manifold and an exhaust manifold, an intake conduit communicating with said intake manifold, a pair of liquid chambers for storing respectively gasoline and a liquid other than gasoline, each of said chambers having an outlet below the normal liquid level therein, separate normally open metering valves respectively controlling said outlets responsive to fuel requirements of the engine, a shut-off valve separate from said metering valves controlling the outlet from the chamber containing liquid other than gasoline independently of the respective metering valve, means controlling said shut-off valve responsive to engine temperature to maintain said shut-off valve closed during cold starting of the engine when the engine temperature is below a predetermined value and to open said shut-off valve during normal operation of the engine when the engine temperature equals or exceeds such predetermined value, and separate passage means connecting said outlets to the intake conduit at a level above the liquid level in said chambers, a primary Venturi centrally disposed in said intake conduit and having its throat slightly above the liquid level in said chambers, said separate passage means terminating in said primary Venturi, a thin wall heat exchange tube extending lengthwise through the exhaust manifold substantially throughout the entire length thereof, and a hot air transmitting tube communicating directly with the upper end of said primary Venturi and connected at its opposite end to said thin wall tube, whereby to transmit hot air from said thin wall tube to said primary Venturi for effecting vaporization of the gasoline and other liquid discharged into the primary Venturi through said separate passages.

Claim 11

In combination with an internal combustion engine having an intake manifold and an exhaust manifold, an intake conduit communicating with said intake manifold, a pair of liquid chambers for storing respectively gasoline and a liquid other than gasoline, each of said chambers having an outlet below the normal liquid level therein, separate normally open metering valves respectively controlling said outlets responsive to fuel requirements of the engine, a shut-off valve separate from said metering valves controlling the outlet from the chamber containing liquid other than gasoline independently of the respective metering valve, means controlling said shut-off valve responsive to engine temperature to maintain said shut-off valve closed during cold starting of the engine when the engine temperature is below a predetermined value and to open said shut-off valve during normal operation of the engine when the engine temperature equals or exceeds such predetermined value, and separate passage means connecting said outlets to the intake conduit at a level above the liquid level in said chambers, a primary Venturi centrally disposed in said intake conduit and having its throat slightly above the liquid level in said chambers, said separate passage means terminating in said primary Venturi, a thin wall heat exchange tube extending lengthwise through the exhaust manifold substantially throughout the entire length thereof, and a hot air transmitting tube communicating directly with the upper end of said primary Venturi and connected at its opposite end to said thin wall tube, whereby to transmit hot air from said thin wall tube to said primary Venturi for effecting vaporization of the gasoline and other liquid discharged into the primary Venturi through said separate passages.

Claim 12

In combination with an internal combustion engine according to claim 9, an air cleaner mounted on the inlet end of said intake conduit and an air conduit connecting said air cleaner and the inlet end of said thin wall tube, whereby to provide clean air thereto.