US2362145A

US2362145A - Carburetor for internal-combustion engines

Info

Publication number: US2362145A
Application number: US429970A
Authority: US
Inventors: Mallory Marion
Original assignee: Individual
Current assignee: Individual
Priority date: 1942-02-09
Filing date: 1942-02-09
Publication date: 1944-11-07
Anticipated expiration: 1961-11-07

Description

Patented Nov. 7, 1944 CARBURETOR FOR INTERNAL-COMBUSTION ENGINES Marion Mallory, Detroit, Mich.

Application February 9, 1942, Serial No. 429,970

Claims.

This invention relates to a carburetor for internal combustion engines.

Many conventional carburetors are provided with so-called vacuum power jets. A vacuum power jet opens and closes a fixed fuel orifice and therefore does not vary the mixture in direct proportion to the load variations. For example, suppose the engine is working on the quarter load and it is necessary to have a slightly richer mixture, the conventional power jet which must be either closed or open, would open under these conditions and make the mixture just as rich for quarter load as it would for full load. In other words, the so-called vacuum power jet is all on or all oil.

The vacuum in the intake manifold of an internal combustion engine varies'in accordance with the load applied to the engine. When the vacuum is high the load is light and when the vacuum is low the load is heavy. It is the object of this invention to produce a carburetor which will increase the richness of the mixture as the load is increased and decrease the richness as the load is decreased.

In the conventional carburetor the idle jet operates independently of the main jet. When the engine is idling or operating at a very slow speed, the throttle of a conventional carburetor is practically closed and the car is operating entlrely on the idle jet because there is not enough air going through the venturi to cause the main jet to draw fuel out of the bowl. At this time the main jet is dry and there is no gasoline in the passageway leading to the main jet from the float bowl higher than the gasoline level in the bowl. If the throttle valve is now suddenly opened to, say, quarter open position, the vacuum in the manifold will drop and the idle jet will lean out or cease to feed. Due to the fact that time is required for the air flowing by the main jet or nozzle to pull the gasoline from float level to nozzle height, there is a delay in gasoline feeding which is known asthe "flat spot in the ordinary carburetor. While-driving a car this "flat spot" is evidenced by the fact that as the carburetor cross over from the idle jet to the main let the engine hesitates momentarily and then takes hold.

It is also an object of this invention to elimimate the so-called cross over or flat spot in the ordinary carburetor when shifting from the idle jet to the main jet. This object is accomplished by arranging the idle and main jets so that they are connected to the float bowl in series so that there is fuel or gasoline always passing the main jet even when the throttle is closed for idling so that the fuel level never drops back to the carburetor bowl fuel level as in the conventional carburetor.

The drawing is a cross sectional view showing my improved carburetor. I

The carburetor housing 2|) is provided with the usual passageway 2| therethrough including the venturi 22. The air inlet end of the carburetor is designated 23 and the fuel mixture outlet into the engine manifold is designated 24. The carburetor is provided with a butterfly throttle valve l adapted for manual operation in the .con'ventional manner and mounted upon shaft 25. The carburetor float bowl is designated 26. The nozzle bar 21 is provided with an orifice l which constitutes the main carburetor jet. One end of the nozzle bar 21 is connected with the float bowl through passageway iii and oriflce 6 which is controlled by a metering pin 4. The metering pin 4 is reciprocably mounted in the bore 28 in the float bowl housing in a conventional manner and its lower end is provided with a flat taper 5 which cooperates with orifice 6 to meter the fuel flowing from the float bowl to the nozzle.

The float bowl is also provided with a fuel outlet orifice II which is connected to oriflce I 3 by passageway l2. Orifice l3 opens into bore 28 adjacent orifice ii and also is controlled by metering pin 4. Orifice H is controlled by a needle valve I ll connected by bridge 29 with plunger 9. Plunger 9 is reciprocably mounted in bore 30 which communicates with fuel mixture outlet 24 on the engine side of throttle valve l by means of passageway 32. A compression spring 8 is mounted between the plunger 9 and seat 3| in the lower end of bore 30. Compression spring 8 tends at all times to raise plunger 9 and lift needle valve Ill from its seat on orifice I I.

The end of nozzle bar 21' opposite passageway l6 communicates through passageway ll with orifice 33 on the engine side of throttle valve I. A screw valve I5 is provided for regulating the idle mixtures passing through passageway N.

The operation of the device is as follows: When the throttle valve I is moved towards an open position, lever 2 fixed on shaft 25 and connected with metering pin 4 by link 3, raises the metering pin upwardly thereby permitting more fuel to flow through oriflce B and to orifice I in nozzle bar 21. At idle position of throttle I. the manifold vacuum is sufliclently high so that orifice H is closed by needle valve M, as shown in the drawing. II the throttle is opened wide enough, which calls for a greater power demand on the engine, the vacuum in the manifold will decrease to such a point that compression spring I will raise plunger 9 and needle valve Ill. As soon as needle valve ill is lifted from orifice ll, fuel will flow through passageway l2 and out of orifice l3. The fiat taper of the metering pin 4 will meter the fuel flowing from orifice l3 the same as it meters the fuel flowing into orifice 6, that is, the higher the metering pin 4 is raised the wider the fiat taper 5 of the metering pin 4 will open orifices 6 and I3 and increase the flow of fuel therethrough. Gasoline will pass downwardly from orifice l3 into orifice 6 and under these conditions orifice 6 will receive gasoline from two directions, namely, from both above and below the orifice 5 through the clearance or groove provided between the flat taper 5 of the metering pin and the side wall of the bore 28. This enrichens the mixture when the throttle valve is opened far enough to cause the vacuum in the manifold to drop low enough so that the compression spring 8 will raise plunger 9 and lift needle valve Ill 05 orifice H. Thus, the device increases the richness of the mixture in proportion to the increase in the load applied to the engine and decreases the richness of the mixture in proportion to the decrease in load of the engine.

As long as the engine is operating, gasoline will be flowing upwardly past the fiat taper 5 of the metering pin to orifice 6, but gasoline will fiow from orifice Hi to orifice i only at the time, as above explained, a richer mixture is necessary. The fuel drawn through orifices l3 and 6 is metered by pin 4. Needle valve Ill does not meter the fuel fiowing out of orifice l3.

When the throttle valve l is in idle position, as shown in the drawing, and the engine is idling, the vacuum is high at orifice 33 and causes fuel to be drawn from the bowl through passageway l6, nozzle bar 21, passageway H and orifice 33 into the manifold. Orifice I now plays the role of an air bleed and orifice 33 is the idling jet. As the throttle is opened wider and wider from idle position, the velocity of the air through the venturi 22 starts pulling on orifice l and it ceases to be an air bleed and becomes the main jet. Thus, as long as the engine is operating gasoline is always passing by or out of orifice 1. If the engine is operating at a slow speed and the air velocity through the venturi is low, there is gasoline passing'through the nozzle bar 21 by orifice I even though orifice I acts at this time as an air bleed. Hence, in shifting from idle to full or part load throttle position, there is no fiat spot" because there is at all times fuel at orifice I.

I claim:

1. In a carburetor for an internal combustion engine having a passageway therethrough, a throttle valve in said passageway, a fuel bowl, a conduit leading from the fuel bowl to the passageway, a metering pin for metering the fiow of fuel out of said bowl into the inlet end of said conduit, means positively connecting the metering pin and the throttle valve for coincidental operation whereby an increasing amount of fuel is metered from the fuel bowl as the throttle valve opens and a decreasing amount of fuel is metered from the fuel bowl as the throttle valve closes, a second conduit leading from the fuel bowl to an orifice adjacent the fuel inlet end of the first conduit. said metering pin having a tapered face adjacent said orifice in the inlet end of said first conduit for controlling and metering the flow of fuel out of the second conduit into the inlet end of the first conduit and also for metering the fipw of fuel out of said bowl into said inlet end of said first conduit, a valve for controlling the fiow of fuel from the bowl into the second mentioned conduit, and means controlled by the pressure existing in the intake manifold for operating said second mentioned valve whereby when the intake manifold pressure reaches a predetermined point higher than idling pressure the second mentioned valve opens and the fuel mixture is enriched by additional flow of fuel from the fuel bowl through said second conduit and orifice.

2. In a carburetor for an internal combustion engine having a passageway therethrough including a venturi, a throttle valve in said passageway on the engine side of said venturi, a fuel bowl, a conduit having an inlet end in said fuel bowl and leading from the fuel bowl to the venturi, a metering pin for meteringthe fiow of fuel out of said bowl, means positively connecting the metering pin and the throttle valve for coincidental operation whereby an increasing amount of fuel is metered from the fuel bowl as the throttle valve opens and a decreasing amount of fuel is metered from the fuel bowl as the throttle valve closes, a second conduit leading from the fuel bowl to an orifice adjacent the fuel inlet end of the first conduit, said metering pin having a shape adjacent said orifice and the inlet end of said first conduit whereby an increasing clearance between said metering pin and said orifice and inlet end of said first conduit is produced as the throttle valve opens, the said clearance between the metering pin and inlet end of said first conduit being always greater than the clearance between the metering pin and said orifice whereby said metering pin controls and meters the flow of fuel out of the second conduit into the inlet end of the first conduit and also for metering the flow of fuel out of said bowl into the inlet end of said first conduit, a valve for controlling the flow of fuel from the bowl into the second mentioned conduit, and means controlled by the pressure existing in the intake manifold for operating said second mentioned valve whereby when the intake manifold pressure reaches a predetermined point higher than idling pressure the second mentioned valve opens and the fuel mixture is enriched by additional fiow of fuel from the fuel bowl through said second conduit and orifice.

3. In a carburetor for an internal combustion engine having a. passageway therethrough. a throttle valve in said passageway, a fuel bowl, a conduit leading from the fuel bowl to the passageway, a metering pin having a tapered end for metering the fiow of fuel out of said bowl into the conduit. means positively connecting the metering pin and the throttle valve for coincidental operation whereby an increasing amount of fuel is metered from the fuel bowl as the throttle valve opens and a decreasing amount of fuel is metered from the fuel bowl as the throttle valve closes, a. second conduit leading from the fuel bowl to an orifice adlacent the fuel inlet end of the first conduit, the tapered end of said metering pin being positioned opposite the said orifice and the inlet end of the first conduit and controlling and metering the fiow of fuel out of the second conduit and also controlling and metering the flow of fuel out of said bowl into the inlet end of said first conduit into the inlet end of the first conduit, a valve for controlling the flow of fuel from the bowl into the second mentioned conduit, and

means controlled by the pressure existing in the intake manifold for operating said second mentioned valve whereby when the intake manifold pressure reaches a predetermined point higher than idling pressure the second mentioned valve opens and the fuel mixture is enriched 4. In a carburetor for an internal combustion engine having a passageway therethrough including a venturi, a throttle valve in said passageway on the engine side of said venturi, a fuel bowl, a conduit leading from the fuel bowl to the venturi, a metering pin having a. tapered end for metering the fiow of fuel out of said bowl into the conduit, means positively connecting the metering pin and the throttle valve for coincidental operation whereby an increasing amount of fuel is metered from the fuel bowl as the throttle valve opens and a decreasing amount of fuel is metered from the fuel bowl as the throttle valve closes, a second conduit leading from the fuel bowl to an orifice adjacent the fuel inlet end of the first conduit, the tapered end of said metering pin being positioned opposite the said orifice and the inlet end of the first conduit and controlling and metering the flow of fuel out of the second conduit and also controlling and metering the flow of fuel out of said bowl into the inlet end of said first kondult into the inlet end of the first conduit, a. valve for controlling the flow of fuel from the bowl into the second mentioned conduit, and means controlled by the pressure existing in the intake manifold for operating said second mentioned valve whereby when the intake manifold pressure reaches a predetermined point higher than idling pressure the second mentioned valve opens and the fuel mixture is enriched. v

5. In a carburetor for an internal combustion engine having a passageway therethrough including a venturi. a throttle valve in said passageway on the engine side of said venturi, a fuel how], an opening in a wall of said fuel bowl having its lower end communicating with the interior of the fuel bowl, a metering pin in said opening, means positively connecting the metering pin with the said throttle valve for coincidental operation whereby an increasing amount of fuel is metered from the fuel bowl as the throttle valve opens and a decreasing amount of fuel is metered from the fuel bowl as the throttle valve closes, a conduit leading from the said opening to the venturi, said conduit having an orifice at each end, said metering pin metering the flow of fuel out of said opening through the orifice into said conduit, the other orifice of said conduit serving as a fuel jet, a second conduit leading from the fuel bowl into the said opening at a second orifice adjacent the fuel inlet orifice of the first mentioned conduit, said metering pin having a beveled face adjacent said second orifice and the inlet orifice of the first mentioned conduit for controlling and metering the flow of fuel out of the second conduit into the said opening and thence into the first mentioned conduit and also for controlling and metering the flow of fuel from the fuel bowl into said first mentioned conduit, and pneumatic means for controlling the flow of fuel from the bowl into the second mentioned conduit controlled by the pressure existing in the intake manifold whereby when the intake manifold pressure reaches a predetermined point higher than idling pressure the second mentioned orifice opens and the fuel mixture is enriched.

MARION M ALLORY.

CERTIFICATE OF CORRECTI ON.

Patent No. 2,562,115.

MARION MALLORY November 7, 19%.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

0nd column, lot and of the first conduit" Page 2, sec- 111195 and 7 claim 5, strike out the words "into the inand insert the same after the syllable "duit' and before "and" in line 71, same claim; page 3, first column, lines 26 to 28 inclusive, claim 14.,

strike out the words "and also controlling and meter-ing the flow of fuel out of said bowl into the inlet end of said first conduit and insert the same after in line 28, some claim;

"conduit" and before the comma and that the said Letters Patent should be read with this correction therein that the some may conform to the record of the case in the Patent Office.

Signed and scaled this 10th day of A ril, A. o. 1915.