US2093959A - Carburetor - Google Patents

Description

I G. R. ERICSON Sept. 21, 1937.

CARBURETOR Filed March 30, 1933 2 Sheets-Sheet 1 G E O RGE R. ERICSQN IN VEN TOR FIG.

' ATTORNEY Patented Sept. 21, 1937 OARBURETOR George R. Ericson, St. Louis, Mo., assignor to Carter Carburetor Corporation, St. Louis, Mo., a corporation of Delaware Application March 30, 1933, Serial No. 663,431

20 Claims. (Cl. 123-119) This invention relates to carburetors, and more particularly to carburetors for automotive engines. In the construction of carburetors of this class it is important to keep the mixture passages as large as possible so as to provide maximum capacity for high speed, full load operation of the engine. At the same time the efficient vaporization of the fuel, particularly at low temperatures, depends on the introduction of the jet of fuel into an air stream moving at high velocity, a construction which obviously cannot be satisfied when an engine with a high capacity carburetor is operated at low speeds.

When starting and warming upsuch engines it is customary to greatly increase the ratio of fuel to air and depend on a high concentration of liquid fuel in. the mixing conduit and intake manifold in order to obtain a suitable mixture for combustion. In starting a motor at a temperature of zero Fahrenheit it is quite customary to use proportions of as much as 200 ounces of gasoline per hundred cubic feet of air, whereas only about '7 or 8 ounces of gasoline per hundred cubic feet of air are used when the motor isfully warmed up. It may be stated that the same mixture of '7 or 8' ounces of gasoline per hundred cubic cubic feet of air, if completely vaporized, would operate the engine almost as well at zero as it does at high temperatures. It will be obvious from these facts that much more gasoline is wasted in starting .and warming up than is actually used, and this. results in poor economy, washing of the lubricant from the cylinders of the engine, and dilution of the oil.

It is an object of this invention to provide a generally new and improved device for vaporizing as much as possible of the fuel supplied to the engine without interfering with the maximum capacity of the. carburetor for normal temperature, full speed and full load operation. The invention will be better understood upon reference to the following specification and. accompanying drawings, referring to which,

Figure 1 is a side elevation of a device constructed according to my invention with parts broken away and others shown in section.

Figure 2 is a sectional plan view of the carburetor taken along the line 2-2 of Figure 1.

Figure 3 is a side elevation of the device with parts broken away and others shown in section.

The reference numeral l indicates the main body member of a down draft carburetor having a flange 2 by means of which it is connected to the intake manifold 3 of an internal combustion engine. The intake manifold is surrounded by a heating device comprising a portion of the exhaust manifold indicated by the reference numeral 4.

The carburetor is provided with a conventional fuel reservoir 5 in which the fuel is maintained at a substantially constant level A-A by the float 6 and float valve 1. A conventional vent B for the float chamber is provided and fuel is supplied from the reservoir 5 to the mixing conduit 9 by means of the main nozzle H] and idling passages II in a manner well'understood. Other features of the carburetor, such as the accelerating pump, economizer, etc., are not shown, as they have no relation to the present invention.

The upper body member 12 of the carburetor carries an air inlet or choke valve l3 eccentrically mounted on shaft I 4 and urged toward the limit of its movement in either closing or opening di-' rections by means of spring l5 which is attached to a boss or anchor post l6 at one end and has the other end attached to the lever H. The lever I1 is fixed to the choke shaft l4 and is provided with a circular central or hub portion I8 which is notched at l9 to receive the latch 20. This latch is pivotallymounted on the member l2 by means of screw 2| and is yieldably held in contact with member l8 by means of spring 22 which is confined between the latch and a spring seat 23 on the member l2.

In order to control the valve IS in accordance with the temperature the lever H is connected by means of link 24, and lever 28 to a thermally controlled member 29. The member 29 forms the housing of a spiral coil bi-metallic thermo- 3. The housing 29 is rotatably mounted on the stud 3| and the arrangement of the thermostat 30 is such that housing 29 is rotated in a clockwise direction with respect to Figure 1 when the temperature increases and vice versa.

The carburetor is provided with a conventional throttle valve 32 mounted on shaft 33 and controlled by any suitable means such as the lever 34. In the walls of the body member I a pair of shafts 35 and 36 are mounted. These shafts are each made in two sections in the present modification for convenience of assembly, but it will be understood that the sections are concentric and operate together. A pair of valve portions 31 and 38 are mounted on the shafts 35 and 36 and are connected together by gear segments 39 and 40. While I have in this instance mounted the throttle 32 anterior to the revaporizing valves 31 and 38, these valves may also, in some installations be mounted anterior to 5 the throttle.

The whole assembly comprising shafts 35 and 36, valves 31 and 38 and segments 39 and 40 is freely operable to open or close the valves 31 and 38 by movement of a lever 26 which is rigidly fixed to the shaft 35. In operation the rotation of the valves is limited however to an opening or closing movement of approximately 90 by means of blank portions 4| formed at the ends of the segments 39 and 40. Two similar conformations 42 on valves 31 and 38 cooperate when these valves are closed to produce a formed nozzle for directing and increasing the velocity of, the flow of mixture at this point when the valves are closed. The lever 26 is connected to the link 24 by means of spring 25 which has one end attached to lever 26 and the-other to an eye 21,

formed in link 24 as indicated in Figure 1.

In operation when the motor is cold the choke valve [3 and also the valves 31 and 38 will have been moved to closed position by a thermostat 30 and throttle 32 will have been set in partially open position by any suitable means. I

While the motor is being cranked the valves I3, 31 and 38 remain in substantially closed position and large quantities of fuel and some air will be drawn through the carburetor in such a manner that the fuel and air will flow together through the formed nozzle 42 at high velocity, thereby vaporizing a substantial portion of the fuel. When the engine starts the fiow of mixture will pull valves I3, 31 and 38 open to some extent against the resistance of the thermostat, thereby reducing the ratio of fuel to air but still maintaining a high velocity of fuel and air between 40 the edges of the valves 31 and 38. Each of these valves being tilted towardsthe center, the greater part of the fuel will be discharged between the edges of these valves in a thin, fiat spray, which is so fine that it does not readily recondense.

In this manner the vaporization of the fuel is very substantially increased and engines may be started with a fuel to air ratio much less than that previously required.

I claim:

1. In a carburetor, means forming a mixing conduit having air and fuel inlets, and a mixture outlet, a valve mounted in said mixture outlet to control the flow of mixture therethru and a heat responsive device for biasing said 55 valve toward closed position when the temperature is low.

2. In a carburetor, means forming a mixing conduit having air and fuel inlets, a valve in said conduit posterior to said inlets, and means 60 for controlling said valve in accordance with both heat and suction.

conduit having air and fuel inlets and a mixture outlet, a pair of swinging valve members in said outlet, and means responsive to both heat and suction for operating said valve members.

6. In a carburetor, means forming a mixing conduit, having air and fuel inlets and a mixture outlet, a pair of substantially semi-circular valve members mounted in said mixture outlets, said valve members having their adjacent edges constructed and arranged to provide a formed nozzle when said valve members are in closed or substantiallyclosed position, said valves being eccentrically pivoted and connected together for simultaneous operation, and a heat responsive device operatively connected to one of said valves.

7. In a carburetor, means forming a mixing conduit having an air inlet and a mixture outlet, a choke valve controlling said air inlet, a throttle for said mixing.conduit, valve means mounted in said mixing conduit posterior to said throttle, heat responsive means for urging said valve means toward closed position when the temperature is low, said valve means being openable in response to suction, and heat responsive means for closing said choke valve whenthe temperature is low.

8. In a carburetor, means forming a mixing conduit having an air inlet and a mixture outlet, a choke valve controlling said air inlet, a throttle valve for said mixing conduit, valve means mounted in said mixing conduit posterior to said throttle, heat responsive means for holding said valve in closed position when the temperature is low, said valve being openable in response to suction or increase of temperature, and heat responsive means tending to close said choke valve when the temperature is low, said choke valve being openable in response to suction.

9. In an internal combustion engine, a carburetor having a passage for conveying fuel and air from said carburetor to said engine, a thermosuction operated valve for causing the fuel and air to flow through a restricted path when the temperature is low and a thermosuction operated valve for restricting the admission of air when the temperature is low.

10. In an internal combustion engine, a mixture supply conduit, a vaporizing valve mounted in said supply conduit, said valve being so formed as to leave a small open passageway in the center of the conduit even when the valve is closed, fuel supply means in said conduit anterior to said vaporizing valve, a manually operable throttle between said fuel supply means and said vaporizing valve, said vaporizing valve being operable in response to suction, a choke valve anterior to said fuel supply means, and a connection between said choke valve and said vaporizing valve.

11. The combination with the fuel mixture passageway of an internal combustion engine, of an unbalanced valve therein adapted to be opened by suction of the engine, and thermostatic means offering yieldable resistance to such opening while the engine is cold.

12. The combination with the fuel mixture passageway of an internal combustion engine, of an unbalanced valve therein adapted to be opened by suction of the engine, and a control rod operable in one direction to positively close the valve and in the other direction to release the valve for control by the engine suction.

13. In a charge forming device for internal combustion engines, means forming a conduit having an air inlet at one end and adapted to be connected to the inlet port of the engine at the other end, a choke valve at the inlet end of said conduit, a suction operated fuel nozzle posterior to said choke valve, a'manually operable throttle posterior to the fuel nozzle and a vaporizing valve posterior to said throttle, and connections between said vaporizing valve and said choke valve.

14. In a charge forming device for internal combustion engines, means forming a conduit having an air inlet at one end and adapted to be connected to the inlet port of the engine at the other end, a choke valve at the inlet end of said conduit, a suction operated fuel nozzle posterior to said choke valve, a manually operable throttle posterior to the fuel nozzle and a vaporizing valve posterior to said throttlefa connection between said vaporizing valve and said choke valve, and a heat responsive device for controlling said vaporizing valve and said choke valve.

15. In a charge forming device for internal combustion engines, means forming a conduit having an air inlet at one end and adapted to be connected to the inlet port of the engine at the other end, a chokevalve at the inlet end of said conduit, a suction operated fuel nozzle posterior to said choke valve, a manually operable throttle posterior to the fuel nozzle and a vaporizing valve posterior to said throttle, and a connection between said vaporizing valve and said choke valve, at leastone of said valves being constructed and arranged to be directly acted on by suction.

16. In a charge forming device for internal combustion engines, means forming a conduit having an air inlet at one end and adapted to be connected to the inlet port of the engine at the other end, a choke valve at the inlet end of said conduit, a suction operated fuel nozzle posterior to said choke valve, a manually operable throttle posterior to the fuel nozzle and a vaporizing valve posterior to said throttle, a; connection between said vaporizing valve and said choke valve, at

aoaaoae 7 iii least one oi said valves being constructed and arranged to be actedon directly by suction, and a heat responsive device for moving said valves toward closed position.

17. In an internal combustion engine,.a fuel mixture supply device comprising conduit means having air and fuel inlets, a choke valve controlling said air inlet, a vaporizing valve mounted in said conduit means between said throttle valve and the engine, said fuel inlet and said conduit means being located between said vaporizing valve and said choke valve, a throttle valve mounted in said conduit means between said vaporizing valve and said choke valve, a connection between said choke valve and said vaporizing valve,and means including a heat responsive device for operating said choke valve and said vaporizing valve toward closed position when the temperature is low and toward open position when the temperature is high.

18. In an. internal combustion engine, an intake passage, suction operated valve means for controlling the admission of fuel mixture to said intake passage, and a heat responsive device for influencing the operation of said valve.

19. In an internal combustion engine, an intake passage, a carburetor for supplying fuel mixture to said intake passage, a manually controlled throttle for said carburetor, flow controlled valve means mounted posterior to said throttle for controlling the flow of fuel mixture to said engine, and a heat responsive device for influencing the operation of said valve means.

20. In an internal combustion engine, an intake passage, a suction-operated valve for controlling the admission of fuel mixture to said passage, and means" yieldingly resisting opening of 4 said valve, said means being affected by the heat of the engine to vary the efifect of said means upon said valve.

GEORGE R. ERICSON.

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