US2719707A

US2719707A - Vacuum air lift carburetor

Info

Publication number: US2719707A
Application number: US463397A
Authority: US
Inventors: Rector Enoch
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-10-20
Filing date: 1954-10-20
Publication date: 1955-10-04
Anticipated expiration: 1972-10-04

Description

E. RECTOR VACUUM AIR LIFT CARBURETOR Oct. 4, 1955 5 Sheets-Sheet 2 Original Filed Dec. 18, 1948 6 w W W 7 e aw R h c I m .MWNJMI \\w E R. mwc mm 4 W flflwwfw H 4 km dw w Q J a a WEN a a lllnl MI. flnw IIH- L B M om mm m A \\\N i l 6 :v 1@hmi j m vw um I i I ||M.|| wm ii [I .mm mm a V 7 Wm wb mm 5 Sheets-Sheet 3 INVENTOR. 206]? .Recl'or' BY E. RECTOR VACUUM AIR LIFT CARBURETOR A. h km 8 Oct. 4, 1955 Original Filed Dec.

Oct. 4, 1955 E. RECTOR VACUUM AIR LIFT CARBURETOR 5 Sheets-Sheet 4 Original Filed Dec. 1948 m r w T. O r Md 0 m F mfi. k ..:IL a R. ow m E -m i B M 5 Sheets-Sheet 5 Original Filed Dec. 1948 Fig-JD.

INVENTOR. Enoch Rector United States Patent VACUUM AIR LIFT CARBURETQR Enoch Rector, New York, N. Y.

Substituted for abandoned application Serial No. 66,647, December 18, 1948. This application October, 1954, Serial No. 463,397

6 Claims. (Cl. 261-43) This invention relates to an improved carburetor for internal combustion engines and having a novel design and particular advantage over conventional carburetors.

The main object of the invention is to provide a carburetor with a novel type of means for supplying fuel whereby the usual fuel pump to lift the fuel from the supply tank to the carburetor is eliminated.

A further object is to provide a positive and automatic valve inlet means for controlling the supply of fuel to the bowl of the carburetor.

A still further object is to provide a novel combination of venturi tubes associated with the fuel chamber of the carburetor and so connected thereto as to improve the feed of the fuel from said chamber.

Yet another object is to provide a balanced float valve to maintain a constant fuel level throughout a greater range of vacuum pressures in the float chamber.

Still another object is the provision of a novel and improved form of automatic choke for enriching a mixture automatically whenthe engine is started cold.

Yet another object is to provide an improved form of idling jet in a carburetor.

Still another object is to provide an improved power jet in a carburetor for operation when the throttle valve is wide open.

Further and more specific objects, features and advantages will more clearly appear from a consideration of the detailed specification hereinafter set forth especially when taken in connection with the accompanying drawings which illustrate a present preferred form which the invention may assume and which form part of the specification.

This application is a substitute for my abandoned application, Serial No. 66,047, filed December 1:8. 1.9 and entitled Vacuum Air Lift Carburetor.

In the accompanying drawings:

Fig. 1 is a vertical sectional view of the carburetor taken on the line 11 of Fig. 2;

Fig. 2 is a plan view of the carburetor;

Fig. 3 is a vertical sectional view taken on the line 3-3 of Fig. 4;

Fig. 4 is a vertical sectional view taken on the line 4-4 of Fig. 3;

Fig. 5 is an enlarged vertical sectional view taken on .the line :55 .of Fig. 6, the venturi tubes and the lower part of the carburetor being removed, and showing the idling jet and airadmission valve;

Fig. 6 is :a sectional view :similar to that in Fig. 5 taken on the line 66 of Fig. 5 and showing particularly the power jet arrangement and the :starting .jet passage from theauxiliary fuel chamber;

Fig. 7 is :a horizontal sectional view taken on the :line 77 of Fig. .6;

Fig. 8 .is a plan view of the float and .the .floa't valve;

Fig. -9 is a vertical sectional viewataken on the :line 99 9 :of'Figa8;

Fig. .10 is .a :partialsectionalview showingthemanner in which certain connections are madeabetween the .car-

give an air lift when a lower auxiliary chamber 22, a central through passage 23 in which are disposed

venturi tubes

24, 25 and 26. Near the upper end of the passage 23 is disposed the usual throttle valve 27 mounted on a shaft 28 and adapted to be turned by the usual accelerator pedal (not shown).

In the main fuel chamber 21 ordinarily known as the float chamber, there is disposed a ring-like float 29 provided at diametrically opposite portions with pins 30 to which outer ends of a forked yoke member 31 are pivoted. This yoke member is connected to a plate 32 pivoted on bearings 33 fixed within the chamber 21 The opposite ends of the plate 32 have inwardly extending portions 34 connected to a slide valve 35 which has a central passage 36 extending through from one end to the other. This slide valve moves up and down in a sleeve 41 which projects upwardly from a valve plug 39 which is suitably pinned at 40 to the casing of the carburetor. As the valve 35 moves up and down, it opens and closes ports 42 disposed at the lower end of the sleeve 41. The sleeve has a slot 41' in which ride the portions 34. The valve plug 39 also has a circular Wall 43 surrounding and extending above the bottom of the slide valve 35 and the ports 42 to admit the fuel into the chamber 21 without causing too much turbulence therein. As shown in Fig. l the sleeve 41 extends through and above a wall of the carburetor casing and is threaded to receive a closure cap 44 which facilitates its proper securement. It will thus be seen that if the slidevalve 35 is subjected to any pressure and any variation of pressure, this will be balanced against the bottom and top thereof which are of equal .area, and are connected by the passage 36, and the valve 35 will be in a state of equilibrium even though the pressures may vary in the system. Consequently, the valve 35 is moved up and down with extreme ease in response to the buoyant action of the fuel on the float .29. This construction permits of a very accurate and exact fuel level being maintained throughout any range of fuel pressures.

As shown in Figures 1 and 10 the fuel is lifted by means later to be described from a tank 45 into which extends a pipe 46 connected at its upper end by a suitable coupling member 47 t0 the valve plug 39. The lower end of the pipe 46 has a hole .48. Within the tank 45 and for a considerable distance above the tank, the pipe 46 is surrounded by a cylinder 48' in any manner tightly disposed therealong to provide a passage around the pipe 46 for air. The pipe 46 throughout its length within the cylinder 48' is provided with apertures .49 for the admission of air from the surrounding cylinder into the pipe 46. The upper end of the cylinder .48 is connected at its upper end to a pipe 50 shown in Figures 2, 4 and 10, and .the function of the pipe 50 will be hereinafter more fully explained.

The lower auxiliary chamber 22, as shown in Fig. l, is provided with a ball check'valve 51 shown in Fig. 4, which controls the gravitationalflow of the fuel through the passage 52 from the main float chamber 21 into the auxiliary chamber 22 when the engine is not running. When the engine is operating the suction in the fuel chamber will tend to seat the ball valve 51 and prevent reverse flow of fuel or air from the chamber 22 back into the chamber 21. As shown in :Fig. 1 the auxiliary chamber 22 is provided with an air inlet 53 leading to a vertical vent passage 54 connected at its upper end to a vent hole 55 well above the level of the fuel in the main chamber 21. This construction therefore permits the fuel in the auxiliary chamber 22 to be subject to atmospheric air pressure which is utilized in a manner later to be described.

The lower venturi tube 26 as shown in Fig. 1 projects upwardly from the bottom of the auxiliary fuel chamber 22 and into the lower end of a cylindrical liner sleeve 56 snug fitted within the passage 23 and within which the two

upper venturi tubes

24 and 25 are disposed as shown. A larger cylindrical sleeve 57 is disposed in the float chamber 21 around the lower end of the sleeve 56 and forms what I choose to call an auxiliary or acceleration well 58. The lower end of the sleeve 57 is provided with ports 59 leading to the float chamber 21, and the ports 59 may be closed by check valves 60 as shown. The lower venturi tube 26 is provided with jet elements 61 which are disposed at its narrow throat portion and their outer faces somewhat spaced from the adjacent lower end of the sleeve 56.

The intermediate venturi tube 25 is at its throat provided with a series of jets 62, certain of which, as shown in Fig. 3, are connected to a horizontal passage 63 in which there is disposed an orifice member 64 and connected to a vertical passage 65 leading to the bottom of the casing and opening into the auxiliary fuel chamber 22.

One of the venturi jets 62, as shown in Fig. l, is connected by a passage 64' to the upper portion of the float chamber 21 above the normal level of the fuel therein.

Referring particularly to Figures 1 and 5, it will be noted that above the intermediate venturi tube 25 and just below the shaft 28 of the throttle valve 27, there is disposed a valve plug 65 in which a valve disk is slidably disposed against its seat on a stem 67. A spring 68 hearing against a washer 69 on the stem 67 tends to hold the valve 66 against its seat. An adjustable nut 70 on the stem 67 determines the degree of compression of the spring 68. The front end of the valve 66 is provided, as shown in Fig. 5, with an axially disposed rod 71 which is adapted to he engaged by the throttle valve 27 when it is in wide open position as shown in Fig. 5, in which position the throttle valve 27 presses against the rod 71 and holds the valve 66 definitely against its seat. The casing of the carburetor is provided with a passage 72 open to the atmosphere and leading to a chamber 73 back of the valve 66. The sleeve 56 is cut away at 74 to permit projection of the rod 71 and the passage of air into the venturi passage when the valve 66 is unseated.

At the opposite side of the carburetor casing, as shown in Fig. 5, is another passage 75 open to the atmosphere and to a jet element 76 disposed in alignment with a passage 77 leading through the sleeve 56 to the venturi passage below the throttle valve 27. The passage 77 is formed in a plug 78 supporting the jet 76, and the plug 78 is provided with lateral passages 79 opening into a chamber 80 around the reduced end of the plug 78. The

chamber 80 is connected by a passage 81 to the upper end of the acceleration well.

Referring now to Figures 3, 4 and 6, it will be noted that the shaft 28 of the throttle valve 27 has mounted on one end a cylindrical valve 82, which is turned as the shaft 28 is turned in response to the operation of the accelerator pedal (not shown). When the throttle valve 27 is in its vertical position, as shown in the above mentioned figures, the cylindrical valve 82 is provided with passages 83 and 84 and the shaft 23 is provided with a through passage 85, so that when the valve 27 is in the vertical position, a passage 86 connected to the atmosphere (see Fig. 6), permits air to pass into the valve by way of the passage 83 and into the pipe 50 which is connected thereto in Fig. 4, and down through the valve into the passage 84 to connect with a passage 87 opening into a dependent tube 88 extending down into a well 89 below the fuel level in the fuel chamber 21, which by means of a lower port 90 connects with the main fuel float chamber 21. Therefore, when the valve 27 is in the wide open position air can pass into the well 89 and into the pipe 50. As the air passes into the well 89 below the fuel level, it moves up through the fuel therein and carries some fuel up around the tube 88 into a horizontal passage 91 which opens to one of the jets 62 of the intermediate venturi tube 25 as seen in Fig. 3.

In Fig. 11 there is shown a modification of the float valve the operation of which is entirely automatic, and control over the flow of fuel into the chamber 21 will depend upon the difference in pressure existing on either side of the plunger 95. The construction of this modification includes a cylindrical sleeve 92 tight fitted to an opening in the carburetor casing and to the outer end of which the coupling member 47 of the pipe 46 is connected. The arrangement is held in place by means of a washer 93 and a lock nut 94.

Within the cylinder 92 is a slidable plunger 95 having a through bore 96 and an inner reduced end 97. Between the reduced end 97 and the inner wall of the cylinder 92 is disposed a compression spring 98. The inner end of the cylinder 92 has holes 99 connecting its interior with the float chamber 21.

The float 29 is connected through pivot pins 30 to the yoke members 31 as before stated, and these yoke members 31 are pivoted at 100 in any suitable manner to the interior wall of the carburetor. The plunger 95 has a valve seat 101 against which a ball valve 102 may seat. The ball valve 102 is on a stem.104 fixed to a plate 103 which is mounted on and moves with the yoke members 31. In operation as the vacuum in the float chamber 21 increases, the fuel coming through the pipe 46 will push the plunger 95 inwardly toward the chamber 21. As the degree of pressure or vacuum in the chamber 21 varies, the degree of compression of the spring 98 will vary, and the plunger 95 will move back and forth causing the float 29 to be more or less submerged in order to resist the greater or less fuel pressure against the ball valve 102 induced by the vacuum in the chamber 21. The ball valve 102 never stays seated for any great length of time but is held in a partly open position most of the time by means of the float 29 to allow only sufficient fuel to pass to maintain a proper fuel level in the chamber 21.

OPERATION Automatic choke In describing the operation of my carburetor I will assume that the engine is cold and not operating. In such case the throttle valve 27 and the idling valve 66 are closed so that when the ignition is turned on and the starter turns the engine over a considerable amount of vacuum is created beneath the closed valves which will tend to pull up fuel from the auxiliary chamber 22 through passage 65, jet member 64, passage 63 and out of one of the jets 62 in the Venturi tube 25. This will produce a very rich mixture because the engine suction will readily pull up the fuel from the chamber 22, since the surface of the fuel in this chamber is open to the atmospheric air through the

ports

53 and 55 and the passage 54. When turning the engine over with the starter there will be enough vacuum created to open the idling valve 66 against the resistance of the spring 68. After the engine has started and then later stops the auxiliary chamber 22 which may have been partly or entirely emptied will fill by gravitational flow ready to supply the starting jet for subsequent starting of the engine. In the event that the auxiliary chamber 22 is emptied during the operation of the engine, it is clear from Fig. 3 that cool air from the atmosphere will be sucked into the chamber 22 through the ports shown in Fig. 1 and up through the ports shown in Fig. 3 thereby tending to cool the carburetor. i

Idling amen In this operation illustrated in Figures l and 5, the engine has been started and is now operating idly without any pressure on the throttle. Therefore, the valve 27 is still closed and-the valve 66 is open. However, the chamber 22 has been exhausted of fuel and only air is coming from said chamber through the upper jets '62. Now, however, a small amount of air is let in laterally justbelow the throttle valve through the passages 75 and '77 and the jet element 76 as appears in Fig. 1. This innish of air passes the openings 79 connected to the upper end of the accelerating well 58 connected by-the check valves 60 to the float chamber 21. The suction created by this fast moving air tends to suck up a small amount of fuel from the well 58 to mix with the air to provide sufficient fuel for the engine when idling. The fuel thuspulled up into the well 58 past the check valves 60 between these two

chambers

21 and 22 will fill the well 58, andthere will occur in it a liquid level higher than that in the chamber 21. Additional air as required is drawn in by'the suction of the idling engine by way of the spring controlled air valve 66. This additional air is produced by the increased vacuum induced by the increased speedof the engine pulling open the valve 66 until the washer 69 serving as a stop abuts the shoulder of the plug 65'. The position of the washer 69 on the stem 67 may be adjusted by means of the nut 70. The adjustment mentioned is calculated so that just enough air will be admitted together with the air passing through the idling jet element 76 for idling purposes. After the engine is started the idling valve 66 opens and remains open until the throtle valve 27 is wide open or nearly so, in which case the vacuum in the venturi decreases sufliciently to allow the spring 68 to close the valve 66. This action will keep on indefinitely as long as the engine is idling and thus the well 58 is kept full. When the throttle valve 27 is opened larger quantities of air are thereby admitted to the venturi passage and this flow of air will cause fuel to be drawn out of the main lower jets 61 by reason of a pressure differential created on the fuel in the main chamber between the upper and lower jets, wherein certain of the jets are connected to the main chamber above the normal fuel level by way of the passage 64'. When the engine is idling and the well 58 is filled, if the throttle is suddenly opened and there is a sudden demand for more fuel, the extra supply needed is temporarily supplied to the main lower jets by reason of the differential head or liquid level in the well 58. If the chamber 22 has not been exhausted of fuel before the engine starts to idle the fuel from the chamber 22 will continue to be sucked up and join the fuel sucked in through the jet 76 to produce a rich mixture of air and fuel in the engine, but as soon as the chamber 22 becomes emptied the mixture changes to a less rich kind in nature. The volume of fuel in the chamber 22 is calculated to be sufficient to warm up the engine so that the normal fuel setting can thereafter well meet the required demand.

Power jet action When the throttle valve 27 is wide open, Figures 3 through 6 the cylinder valve 82 will into the position indicated in Fig. 3, so that air is drawn through the passage 86 and may pass not only into the pipe 50 but also pass down through the tube 88. The suction of the engine efiects this drawing of air and as it passes down through the pipe 50 it will enter the cylinder 48' and pass into the pipe 46 through any of the holes 49 above the level of the fuel in the tank 45, mixing with the fuel and vapor in the pipe 46, thus lightening the weight of the column and causing a lift of fuel to he float chamber 21. Similarly, the suction of air down through the tube 88 into the body of liquid fuel in the float chamber will cause it to facilitate the lifting of fuel from said chamber into the passage 91 to pass through one of the upper jets 62. Thus under a wide open throttle the air lift effect is applied not only to the main as shown in have moved 6 fuel tank but also to the float chamber. This readily augments the fuel being supplied through the main jets and meets all power demands. It is to be noted that when the air is pulled into the pipe 50 and passes up through the float valve into the chamber 21, it is allowed to escape into the venturi passage by reasonof the passage 64-connecting the tube at the top of the floatchamberwith one of the jets 62. It is necessary to use the air lift from the tank only when the throttle valve is wide open, or nearly so, as the vacuum pressure, when the throttle valve is in a partly opened position, is suflicient to lift the fuel to the carburetor. The power jet into the float chamber by way of the air tube 88 is only needed at this time for wide open operation and therefore, it is convenient to connect the two operations by the movement of the single valve 82 shown in Figures 2 and 4.

It is to be understood that the float valve construction shown inFig. 1, or that shown in Fig. 11, may be employed depending upon the conditions existing and the action required.

While the invention has been described in detail and with respect to the preferred form shown in the drawin'gs, it is not to be limited in such details and form since many changes and modifications may be made in the invention without departing from the spirit and scope of the invention in its broadest aspects. Hence, it is intended to cover any and all forms and modifications of the invention which may come within the language or scope of any one or more of the appended claims.

1 claim:

1. In combination, a carburetor having a main fuel chamber and a venturi passage in which are disposed an upper and a lower venturi tube in tandem, a tank for fuel, connections between the fuel tank and the chamber, said chamber having a well connected to it, a tube in said well extending below the fluid level therein, a single valve means operated by the operator to introduce air from the atmosphere into said connections and into said tube, said carburetor having a passage in the main chamber connecting its upper portionwith the upper venturi tube and also a passage connecting the upper portion of the well with the upper venturi tube, said carburetor having a passage connecting the lower portion of the chamber with said lower venturi tube.

2. In combination, a carburetor having a main fuel chamber and a venturi passage in which are disposed an upper and a lower ventun' tube in tandem, a tank for fuel, connections between the fuel tank and the chamber, said chamber having a well connected to it, a tube in said well extending below the fluid level therein, a single valve means operated by the operator to introduce air from the atmosphere into said connections and into said tube, said carburetor having a passage in the main chamber connecting its upper portion with the upper venturi tube and also a passage connecting the upper portion of the well with the upper venturi tube, said carburetor having a passage connecting the lower portion of the chamber with said lower venturi tube, a throttle valve in the venturi passage above the tubes, said single valve means connected to said throttle valve and operated to admit air when the throttle valve is moved to full throttle position.

3. In combination with an engine carburetor having a main fuel chamber and a venturi passage, a fuel feeding system comprising a tank for fuel, connections between the fuel tank and the chamber, means operated by the operator to introduce air into the fuel in said connection, said carburetor having a passage connecting the main fuel chamber and the venturi passage for delivering fuel to said venturi passage, said carburetor having a second passage above the normal fuel level in the chamber whereby the entrained air is separated from the fuel and permitted to escape into the venturi passage.

4. In combination with an engine carburetor having a main fuel chamber and a venturi passage, a fuel feeding system comprising a tank for fuel, connections between the fuel tank and the chamber, an auxiliary fuel chamber located below said main chamber and connected to the venturi passage by means of an open passageway, means operable whenthe engine stops to transfer fuel from the main chamber to the auxiliary chamber, means operated by the operator to introduce air into the fuel in said connections, said carburetor having a passage connecting the main fuel chamber and the venturi passage for delivering fuel to said venturi passage, said carburetor having a second passage above the normal fuel level in the chamber whereby the entrained air is separated from the fuel and permitted to escape into the venturi passage.

5. in combination with an engine carburetor having a main fuel chamber and a venturi passage, a fuel feeding system comprising a tank for fuel, connections between the fuel tank and the chamber, said chamber having a well connected to it below the normal fuel level in the chamber, a tube in said well extendeding below the fuel level therein, said carburetor having a passage therein connecting the upper portion of the well to the venturi passage, a single valve means operated by the operator to introduce air from the atmosphere into said connections and into said tube, said carburetor having a passage therein above the normal fuel level in the chamber and connecting said chamber with the venturi passage whereby the entrained air in the chamber is separated from the fuel and permitted to escape into the venturi passage.

6. In combination with an engine carburetor having a main fuel chamber and a venturi passage, a fuel feeding system comprising a tank for fuel, connections between the fuel tank and the chamber, said chamber having a well connected to it below the normal fuel level in the chamber, a tube in said well extending below the fuel level therein, said carburetor having a passage therein connecting the upper portion of the well to the venturi passage, a single valve means operated by the operator to introduce air from the atmosphere into said connections and into said tube, said carburetor having a passage therein above the normal fuel level in the chamber and connecting said chamber with the venturi passage whereby the entrained air in the chamber is separated from the fuel and permitted to escape into the venturi passage, a throttle valve in the venturi passage, said single valve means being connected to said throttle valve and operated to admit air when the throttle valve is moved to full throttle position.

References Cited in the file of this patent UNITED STATES PATENTS 1,274,965 Weiland Aug. 6, 1918 1,383,044 Weiland June 28, 1921 1,889,922 Justheim Dec. 6, 1932 2,087,116 Prentiss July 13, 1937