US2752937A

US2752937A - Carburetor float valve

Info

Publication number: US2752937A
Application number: US172723A
Authority: US
Inventors: Robert H Hieger
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-07-08
Filing date: 1950-07-08
Publication date: 1956-07-03
Anticipated expiration: 1973-07-03

Description

July 3, 1956 R. H. HiEGER CARBURETOR FLOAT VALVE Filed July 8. 1950 11.5 MM 6 O zNVENToR. obef //ecyer BY a 9 M forneq.

United States Patent O CARBURETR FLGAT VALVE Robert H. Hieger, Detroit, Mich.

Application July S, 1950, Serial No. 172,723

2 Claims. (Cl. IS7- 434) This invention relates to carburetors for internal combustion engines, and more particularly to a lloat valve mechanism for such carburetors.

Most carburetors as now constructed include a fuel reservoir in which the fuel is maintained at a substantially constant level by means of a float which controls the inflow of fuel to the reservoir from an engine-driven fuel pump.

The float controlled valve which regulates the inllow of fuel to the reservoir is often subject to misalignment between the movable valve member and the stationary valve member, resulting in leakage of fuel therepast even when the valve is in the closed position, with the result that at idle, when the rate of fuel ilow to the engine is low, the fuel level in the reservoir gradually rises, pro-` ducing an overrich mixture and loading the engine.

Defective operation of the tloat valve mechanism may result from other causes, and is diificult to detect, since commercial carburetors are so constructed that itis impossible, without disassembling the carburetor, to apply a measured amount of fluid pressure or suction to the fuel inlet thereof and note the resulting tlow. Also, if leakage is found or suspected, it is diicult to remedy by means of ordinary shop tools.

The present invention 'aims to overcome these defec by providing a float valve mechanism which is self-align` ing; that is, wherein `the movable valve member is free to move laterally to align itself with its seat. The mecha# nism is `assembled as a unit which may be tested before installation to detect leakage. The invention comprises various other features, all of which .are pointed out in the following description, taken in connection with the appended drawing, in which:

Fig. l is a diagrammatic view of a carburetor and the fuel system thereof showing, on an enlarged scale,` one form of the present invention incorporated therein.

Fig. 2 is an enlarged sectional View of the lloat valve mechanism and its associated parts.

Fig. 3 is a horizontal sectional view taken on `the line 3-3 of Fig. 2.

Fig. 4 is a view similar to Fig. 2, but showing a modited form of valve mechanism.

Fig. 5 is a similar View showing a further modilied form of the invention. f

It is to be understood that the invention is not limited 'in its application to the details of construction and arrangement of parts illustrated in the accompanying drawing, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that .the phraseology or terminology employed herein is for the purpose` of description and not of limitation.

The carburetor shown in the drawing is of the downdraft type commonly used with automobile engines, but may be of any known or suitable construe-tion. It comprises a body 8 forming an induction passage which includes an air inlet lli, a main venturi 12, and a mixture outlet 14 designed to be connected to the intake manicounterclockwise direction.

r. ICC

fol-d of an internal combustion engine, not shown. The induction passage is controlled in the usual manner by a manually operated throttle valve lo. Usually an air cleaner, such as is indicated fragmentarily at i8, is connected to the air inlet. Fuel is supplied to the induction passagefrom a reservoir Ztl, which in the example shown is a float chamber having a float 22 therein, which actuates a valve unit indicated generally at 24 and controlling a fuel inlet 26 leading from a source of pressure, such as the usual fuel pump, not shown. From the reservoir 20 the fuel flows through a passage 28 to the main fuel nozzle 32, which discharges at the throat of the main venturi 12.` In the example shown, a second venturi 34 is provided to form a `discharge member for the main nozzle. A metering oriiice 36 is provided in the passage 2S, as is the usual practice, and an idling fuel passage of any suitable construction, not shown, may lead from the passage 32 to` a point above the fuel level L and discharge adjacent the engine throttle 16 when the same is in closed position.` An economizer 38 of known construction is indicated schematically in the drawing, .and may be of the type disclosed in my copending application Serial No. 158,537 tiled April 27, 1950, now Patent No. 2,617,640 dated Nov. ll, 1952. Suitable acceleration pump mechanism, as well as check valves, vents, and metering ori- `ces may be provided,` as known in the art.

In the -form of the mechanism shown in Fig. l, the fuel inlet conduit 26-connects with the bore 40` of a boss 4l formed on the tloat chamber cover 42. The boss is internally threaded tol receive the threaded reduced end 44 of the valve body. The lower end of the valve body is enlarged to form a sleeve 46 which acts as a guide for a movable valve member 43. The member 48 is of generally triangular crosssection, andis of known construction except as modied for purposes of this invention. As shown, it is machined 'to form notches '50 in its vertical ribs, to thereby reduce the weight of the member and thereby minimize the effect of its impact against its seat, as occurs when the vehicle is subjected to vibration, and which tends to damage both the valve member and its seat.

The upper end of the valve member 48 is formed with three prongs` 2 which extend upwardly from the body of. the member and then` inwardly to form a cage loosely enclosing an obturating member or valve element in the Iform of a ball 54 which is designed to cooperate with the lower end of a` bore 56 in the upper portion 44 of the tubular valve body, which `thus forms a seat for the ball. In order to permit the ball to move laterally within the limits of its cage, and thereby align itself with its seat, it is seated on a washer 58 which is slidable upon the base of the cage. The valve member `4dispreferably drilled longitudinally -to` form a bore 'S7 through which a tool may be inserted to strike ball 54 and vthereby deform the metal of member `4d to cause the seat to conform closely to the shape of the ball.

` Thelloat 22 is` carried by a lever "59 which has oneof its ends secured to the float andis pivoted at 60, so that upward movement of the tical, resulting from rise in the fuel level L, will cause the lever to rotate in the A tang 62 is struck out of the metal of the lever 59 and contacts the lower end of member 48, in known manner, so that as the fuel level rises it moves member 48 upwardly and closes the Valve; As the ball S'd'comes `intol Contact `with its seat, it` adjusts itself by moving with washer .53 laterally to thereby align itself with its seat. When the ball is moved away from its seat, vibration and other factors may move lthe ball and washer out of alignment, but upon each return of the 'ball to its seat the alignment will again be effected. ln the form of the invention shown in Fig. 4, the mov able Valve member 48 is shaped approximately the same as in Figs. 1-3, but the obturating member or valve element is in the form of a pin having an enlarged cylindrical head 64 and having a reduced portion which terminates in a frusto-conical surface 65 designed to cooperate with the lower end of bore 56 to control the flow of fuel. The pin is laterally slidable relative to valve member 48, so that it will adjust itself to alignment with its seat in the same manner `as described in connection with Figs. 143, and the prongs 52 in this case engage the sh-oulder formed by the upper end of portion 64. The pin has a shank 66 which extends into 'bore '57 and. may be struck with la tool to shape the surface 6'5 to its seat.

In the modification shown in Fig. the structure is generally the same as in Fig. 4 except that the reduced portion of member 64 and the cage formed by prongs 52 are omitted; the shank 66 of the valve member 64 being of suiciently smaller diameter than the internal bore 57 to provide a clearance space shown in the drawing, the member 64 is thus made free, unless restrained 'by some external means, to move with respect to member 48, the shank 66 thereof moving within the bore 57. By virtue of such a construction, the bore 57 becomes open at both rof its ends should the member 148 move downwardly away from the member 64 seated at its seat, thus permitting gasoline to flow through said bore 57 in either direction depending upon the relative pressures existing under such condition at the ends of the internal bore 57. In consefquence -thereof any foreign matter that may Itend to accumulate within the bore `57 or 'between the top surface of the member 48 and the bottom surface of the head of the valve member 64 `is washed out, thus preserving the freedom of the movement of the member 64 with respect to the member 48 when the sealing surface '65 of said member 64 tends to accommodate itself to the valve seat. I have found that unless such circulation of fluid is produced, recesses such as 'bore 57, particularly if closed at the bottom, soon become traps for Iforeign matter and, upon getting filled with dirt, disorganize operation of the valve making it less dependable than solid or one-piece valves.

As in cases of other embodiments of the invention, the bore 57 of the construction of Fig. 5 may be used for the passage of a tool to strike the shank 66 in order to peen or burnish the seat for the cone-shaped valve portion 65.

In any of the forms of the invention disclosed, the

valve body

44, 46 may be formed of brass or other material which is resistant -to the action of gasoline and the acids or other impurities contained therein, land the obturating member may be of stainless steel `or other noncorrodible material which is also resistant -to wear. In order to further minimize the inertia effect whereby the obturating member is pounded against the seat by vibration, the obturating member may be formed of a light gasoline-resistant plastic such as cast nylon, which may be machined to -fit accurately to its seat.

The valve mechanism 'herein disclosed is particularly resistant to factors tending to cause leakage, but if there is a question 'whether fuel is escaping past the obturating

member

54 or 65 when the valve is closed, or if it is desired to test the functioning of the valve under various degrees of pressure, it `is only necessary to remove the float chamber cover from the carburetor and unscrew the valve unit therefrom. A measured force, corresponding to that exerted by the iloat When the level L is at its designed maximum, may 'then 'be applied upwardly on valve member 48, while a measured fluid pressure is applied to the bore 56, to determine whether the valve unit passes any fluid when closed. Where leakage is i found, a punch or other tool may be inserted in bore 57 to tap the obturating

member

54 or 65 and cause the seat to conform to the shape of the obturating member.

Although the invention has been described with reference to the illustrated embodiments thereof, it may be embodied in other forms within the skill of artisans in this art, and is not limited except by the terms of the following claims.

I claim:

1. In a carburetor having a fuel reservoir, a fuel inlet to said reservoir, a valve mechanism controlling said inlet, and a float Aoperatively connected to said valve mechanism for `actuating the same in response to level of fuel in said reservoir; said valve mechanism comprising a removable valve body, .a passage in said body to provide a controlled fuel passage therethrough, a valve seat formed `in said passage, a movable valve-carrying member having -a through inner passage and at least one through outer passage for passage of fuel through either of said inner and said outer passages, a valve element carried by said movable member and having `a sealing surface cooperating with said valve seat to close and to open the same and a pressure surface cooperating with la surface on said movable member, said surfaces forming when separated, a fuel passage communicating with said inner recess to permit ow of fue1 between said pressure surfaces.

2. In a carburetor having a fuel reservoir, 'a fuel inlet to said reservoir, a valve mechanism controlling said inlet, `and a float operatively connected to said valve mechanism for actuating the same in response to level of fuel in said reservoir; said valve mechanism comprising a tubular body having a fuel passage therethrough with a valve seat formed therein in one of its portions and being enlarged in its lremaining portion to have a cylindrical recess, e. cylindrical body slidably lfitted into said cylindrical recess and having outer recesses to provide fuel passage therethrough and an inner bore open at both ends, a valve element carried by said cylindrical body and comprising a cone shaped head adapted to cooperate with said valve .seat to close and to open the same, and a shank loosely fitted into said bore to provide for relative longitudinal and limited transverse movement of said Valve element with respect to said cylindrical body, said cone head thus having provided thereon a shoulder bearing on said member for transmission of valve closing forces but providing` fuel passage when the shoulder is separated from said member.

References Cited in the file of this patent UNITED STATES PATENTS 571,168 Mott, Jr Nov. 10, 1896 1,032,521 Wangelin July 16, 1912 1,041,237 Budlong Oct. 15,1912 1,044,311 Wall Nov. 12, 1912 1,100,679 McGuire June 16,1914 1,270,213 Roesch June 18, 1918 1,340,123 Smith May 11,1920 1,567,807 Mock Dec. 29, 1925 1,763,486 Strong .Tune 10, 1930 1,779,893 Schmitz Oct. 28, 1930 1,841,663 Miller Ian. 19,1932 1,926,505 Turner Sept. 12, 1933' 2,130,847 Kersgieter Sept. 20,1938 2,261,234 De Lancey Nov. 4,1941 2,414,577 Adair et al Ian. 21, 1947 2,446,274 Gladden Aug. 3, 1948 2,599,073' Sloane June 3,1952