US3612021A - Carburetor fuel level control - Google Patents

Abstract

A carburetor for an internal combustion engine for a vehicle such as an automobile is provided with a mechanism for preventing the fuel level in the carburetor from getting too high or too low thereby preventing flooding, hard starting and reduction of efficiency of fuel consumption as well as keeping PCV valve cleaner.

Description

United States Patent [72] Inventor Ralph R. Ross Box 4554, Midland, Tex. 7970] [21] Appl. No. 847,264 [22] Filed Aug. 4, 1969 [45] Patented Oct. 12, 1971 [54] CARBURETOR FUEL LEVEL CONTROL 4 Claims, 3 Drawing Figs.

[52] U.S.Cl 123/119 B, 123/198 [51] Int. Cl F021 9/00, F02b 77/00 [50] Field of Search 123/136, 1 19 B, 198 C [56] References Cited UNITED STATES PATENTS 1,404,152 1/1922 Kettering 123/136 C'AR8UR r 702- FUEL AREA VA L V5 LEEDEQ LINE 2@ NEEDLE 10/1963 MacPherson -3,105,471 123/119 3,177,858 4/1965 Vanderpoel 123/119 3,303,836 2/1967 Burleigh i 123/198 FORElGN PATENTS 606,050 11/1934 Germany...; 123/136 Primary Examiner-Mark M. Newman Assistant Examiner-Ronald B. Cox Attorney-Marcus L. Bates SOLENOID SW/ICl-l VALVE 2O Fl/EL LINE (/EL PUMP 2 10M 6A5 TANK CARBURETOR FUEL LEVEL CONTROL SUMMARY OF THE INVENTION In my invention, a solenoid switch valve is disposed as close to the fuel inlet of the carburetor as possible. When the ignition switch is off, this valve closes and eliminates any fuel pressure developed by the fuel pump from being applied to the float in the carburetor. When the ignition switch is-on, the

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a detail view of a portion of the structure of my invention;

FIG. 2 is a diagrammatic side view of my invention; and

FIG. 3 is another view of my invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 of the drawings discloses a duct which is flow connected to an air cleaner 12. The air cleaner is supported by a carburetor 14 in the usual manner, and both the carburetor and air cleaner can take on several different forms. The remaining end portion of the duct 10 extends through the firewall of the vehicle and into close proximity of an air condition (not shown) so as to enable cold, moist air from the air conditioner to be ingested into the air cleaner.

In FIG., 2, fuel from the vehicle gas tank (notshown) is pumped by fuel pump 16, through strainer 18, and to the sole noid-actuated valve 20. The fuel continues to flow through the needle valve 22, where the main flow continues into the float chamber or fuel area 24 of the carburetor, while a small por- -tion is diverted into and along the illustrated bleeder line 26.

Fuel line 26 therefore forms a fuel flow path to the PCV valve 28.

As seen illustrated-in FIG. 3, the ignition switch 30 is electrically connected to a switch 32, which may be conveniently hidden from viewwithin the vehicle structure. Switch 32 is electrically connected in seriesrelationship to switch 34 so that when either of the switches 30 or 32 is moved to the opened'circuit position, current flow from switch 34 to the solenoid valve 20 is precluded.

The switch 34 is preferably a microswitch which is actuated by the illustrated upstanding free depending end of float 36, which is located within the carburetor float bowl in the usual manner. The float 36 contacts switch 34 so as to energize the before-mentioned solenoid switch valve 20 as the float rises to a predetermined height within its float chamber.

It will be noted that needle valve 22 meters a predetermined quantity of fuel through bleeder line 26 and into the inlet portion of PCV 28 so long as fuel is flowing through valve 20. Accordingly, vapor or air which may be formed in the fuel line between the carburetor and the fuel pump will be directed to the PCV valve thereby avoiding vapor lock of the fuel flow system.

Those skilled in the art, having studied the drawings and read the foregoing portion of this disclosure, will now realize that the fuel pump forces fuel to flow from the gas tank, through the fuel strainer, and to the solenoid switch valve 20. As the float within the carburetor fuel bowl is lowered, switch 34 will assume the "off" position, thereby causing the solenoid-actuated valve to assume the opened position, and permitting fuel to flow through the valve 20 and on to the usual float-actuated valve associated with the fuel float of the carburetor, where the level within the bowl is maintained between some maximum andminimum predetermined value. At the same time, needle valve 22 bypasses a finite quantity of fuel through bleeder line 26 and into the upstream portion of PCV valve. This action maintains the PCV valve in operative working order since it is from time to time flushed with fresh gasoline. As the fuel level within the float rises, the float shaft of member 36 contacts switch 34, thereby providing the solenoid valve with a source of current, and moving the lastnamed valve to the closed position. This action precludes flow of fuel from the fuel pump to the fuel bowl or to the PCV valve. Accordingly, flooding of the carburetor with excess fuel is avoided. Examples where carburetors of the prior art inadvertently overflow is exemplified by centrifugal action as the vehicle negotiates a curve, sudden acceleration or deceleration of the vehicle, debris and gum deposits accumulating under the float-actuated metering valve, and improper adjustment of the float relative to the float valve.

Another desirable attribute and unexpected result of the present invention lies in the avoidance of flooding ,the'intake manifold with raw fuel when the engine is deenergized. Heretofore, when the ignition switch is turned off, fuel remaining under the diaphragm of the fuel pump will continue to be delivered to the carburetor float bowl until the spring associated with the diaphragm pump has relaxed. This causes a substantial amount of fuel to be forced into the carburetor bowl, where the fuel overflows into the intake manifold.

' Should it be desired to immediately start the engine, the mixture-is far too rich and difficulty will be experienced in restarting the engine. The small amount of fuel flowing to the PCV valve flows through PCV valve into intake manifold to be burned with fuel. The air-fuel mixture flowing through the PCV valve contains sufficient air to compensate for the small amount of raw fuel being received by the PCV valve from the needle valve. Also this small amount of fuel will help keep the PCV valve cleaner. Wire from ignition switch to switch G" could be interrupted with a hidden switch (location known to car owner or driver) and by turning the hidden switch off after turning ignition switch off would prevent a quick car thief from getting any distance (only as far as amount of fuel that was in carburetor would run the engine).

The fuel level contained within the carburetor will not stay consistent at all times, regardless of the correctness of the float adjustment nor how well the needle and seat are designed within the carburetor. Should the fuel level in the carburetor rise higher than desired, the driver usually fails to notice the reflected changes in engine performance associated by abnormally rich air-to-fuel ratios, even at normal driving speed, and especially at high driving speeds. There are drivers who realize that the fuel level in the carburetor is excessively high at low engine speeds.

Fuel pump pressure, engine temperature and weather temperature as well as foreign matter (a small grain of sand, and, sometimes, the solid additives the petroleum companies put into the fuel) causes the needle and seat in a carburetor to improperly close, and will let the carburetor fuel level rise too high.

In order to render the action of the float and plunger switch 34 extremely responsive, the solenoid-actuated valve 20 should be located as close as possible to the carburetor. This expedient increases the response rate brought about by the action of the float engaging the microswitch. Otherwise, an excessively long fuel line may act as a surge tank to thereby decrease the response of the vehicle engine with respect to the action of the solenoid-actuated valve. Furthermore, should the valve 20 be located far away from the carburetor, the likelihood of vapor lock is increased. By locating the bypass or the bleeder line adjacent to the carburetor and in close proximity to the valve 20, the fuel will be maintained at a constant level within the carburetor and the likelihood of vapor lock decreased.

Having thus described this invention what is asserted as new 1. In an internal combustion engine having a carburetor connected to an intake manifold, a float chamber associated with the carburetor, a float in the float chamber, a float-actuated valve, a source of fuel, and a PCV valve flow connected between the crankcase and manifold of the engine, the improvement comprising:

a solenoid-actuated valve, switch means, a bleeder line; means, including a fuel pump, for causing fuel to flow from the source of fuel to the float chamber;

means including a fuel flow line for conducting the flow of fuel from the fuel pump, through the solenoid-actuated valve, to the float-actuated valve, and to the carburetor fuel bowl;

means by which said bleeder line is flow connected to the fuel line at a location downstream of the solenoid valve and upstream of the fuel bowl, so as to enable said bleeder line to conduct fuel flow to a location upstream of the PCV valve;

means associated with the float for actuating said switch so as to enable the switch to be moved from a current-conducting to a current-preventing position, and vice versa;

means electrically connecting said switch to the solenoid of said solenoid valve;

bowl. 2. The improvement of claim 1 wherein the engine is mounted in a vehicle, and the vehicle has an air conditioner apparatus associated therewith, and further including means flow connecting the intake of the carburetor to a cool air source associated with the air conditioner of the vehicle,

3. The combination as set forth in claim 1 further including a hidden switch and an ignition switch connected in circuit with the first switch.

4. The improvement of claim 1 and further including means connecting said switch to the ignition switch of the vehicle so as to permit energization of said solenoid valve only when the ignition switch is in the current-conducting configuration.

Claims (4)

1. In an internal combustion engine having a carburetor connected to an intake manifold, a float chamber associated with the carburetor, a float in the float chamber, a float-actuated valve, a source of fuel, and a PCV valve flow connected between the crankcase and manifold of the engine, the improvement comprising: a solenoid-actuated valve, switch means, a bleeder line; means, including a fuel pump, for causing fuel to flow from the source of fuel to the float chamber; means including a fuel flow line for conducting the flow of fuel from the fuel pump, through the solenoid-actuated valve, to the float-actuated valve, and to the carburetor fuel bowl; means by which said bleeder line is flow connected to the fuel line at a location downstream of the solenoid valve and upstream of the fuel bowl, so as to enable said bleeder line to conduct fuel flow to a location upstream of the PCV valve; means associated with the float for actuating said switch so as to enable the switch to be moved from a current-conducting to a current-preventing position, and vice versa; means electrically connecting said switch to the solenoid of said solenoid valve; the valve of said solenoid valve adapted to be moved from a fuel-flow-permitting to a fuel-flow-preventing position, and vice versa; whereby: said float, when raised to a predetermined position, engages said switch to thereby cause said solenoid valve to assume the fuel-flow-preventing position whereupon the fuel level within the fuel bowl is prevented from overflowing, and, when the engine is deenergized, residual fuel from the fuel pump is prevented from accumulating in the fuel bowl.

2. The improvement of claim 1 wherein the engine is mounted in a vehicle, and the vehicle has an air conditioner apparatus associated therewith, and further including means flow connecting the intake of the carburetor to a cool air source associated with the air conditioner of the vehicle.

3. The combination as set forth in claim 1 further including a hidden switch and an ignition switch connected in circuit with the first switch.

4. The improvement of claim 1 and further including means connecting said switch to the ignition switch of the vehicle so as to permit energization of said solenoid valve only when the ignition switch is in the current-conducting configuration.

Images