US2547873A - Combined carburetor choke and nozzle - Google Patents

Description

April 3, 1951 M. J. KITTLER COMBINED CARBURETOR CHOKE AND NOZZLE Filed March 31, 1950 Mdhiitlar INVENTOR.

Patented Apr. 3, 19 51 UNITED STATES COMBINED CARBURETOR CHOKE AND NOZZLE I Milton J. Kittler, Detroit, Mich, assignor to George M. Holley and Earl Holley Application March 31, 1950, Serial No. 153,165

The Object of this invention is to improve a type of carburetor in which the fuel discharges at a point locatedon the centerline of the choke plate. If the discharge nozzle intersects the centerline of the choke'plate it cuts through the choke shaft which means that the choke shaft must be made in several pieces, resulting in a difficult assembly problem and also a weak construction that is difiicult to keep in proper alignment so that it will work freely. The purpose of this invention is to permit the use of a one piece choke shaft and stillhave the point of fuel discharge located on the centerline of the choke plate. This is accomplished by the use of a hollow spool which fits over the choke shaft and to which the discharge nozzle is connected at a point not on the centerline. The'fuel is then carried around the choke'shaft and discharged at a point on the centerline of the choke plate, thus accomplishing the desired purpose. An additional advantage also is obtained since the arrangement of the fuel discharge holes in this spool is subject to a great number of variations which are very useful in controlling the distribution of fuel to the engine.

Fig. 1 shows in cross-sectional elevation the preferred form of my invention.

Fig. 2 shows a cross-sectional elevation on plane 2-2 of Fig. 1.

Fig. 3 shows an alternative nozzle construction in partial cross-sectional plan view.

Fig. 4 shows another alternative nozzle con-- struction.

Fig. 5 shows still another alternative nozzle construction.

In the figures, I0 is the air entrance. I2 is the right hand venturi of Fig. 1. hand venturi of Fig. 1. I6 is the right hand throttle below venturi I2. I3 is the left hand throttle below the venturi l4. 2%] is the throttle shaft for both throttles l6 and I8. 22 and 24 are the two low speed orifices cooperating with the throttle I6. 26 and 23 are the two low speed orifices cooperating with the throttle I3, 39 is the low speed passage connecting the orifices 22 and 24 with the chamber 32. 34 is a restricted air passage which derives its air from the chamber 36. Restriction 38 is a fuel restriction from a well '58. The well it derives its fuel from a restricted orifice 52 which is located in the constant level float chamber i=3. Dipping into the well 40 is a perforated tube as which is in restricted communication through a restricted passage 48 which derives its air from the air chamber 50, The air chamber 50, in its turn,

H3 is the left 6 Claims. (01. 261-423) I2 through the opening 64.

derives its air from the annular air chamber 7 36 which is at atmospheric j pressure. The fuel is drawn out of the upper end of the well if] and the downstream edge of the restricted air orifice 52 through a fuel and air passage 5 t in the inclined passage 56. This inclined passage 56 terminates in the bent pipe 58. This bent pipe 58 engages with a drum 60. This drum 59 is located within the centralportion of the butterfiy choke 62. In the position in which the choke 62 is shown, that is the wide open position, the lower lip' of the butterfly choke G2 splits theopening 64 of the drum '63. The elements to the left of Fig. 1 have the same characteristics and function exactly the same as those to the right.

The choke shaft 556 and the choke lever 68 drive the intermediate shaft (0 which shaft drives the left hand choke l2 and the left choke shaft M. Actually, however, the shaft 65, iii and M are made out of one shaft. The left hand choke 12 is an exact counterpart of the right hand choke 62.

Fig. 3 shows an alternative construction in which a drum 16 with narrow lateral slots in it replaces the drum with the large circular opening lit shown in Figs. 1 and 2.

In Fig. 4 a perforated drum l8 replaces the drum M! which has but one opening fi l.

Fig. 5 shows a drum 8!) replacing drum 66 and having two openings 82 and 84 to replace the single opening 6 of Fig. 2.

The choke 62 in each case is identical with the choke 62 shown in Figs. 1 and 2.

The shaft E56 is identical in thesethree figures with the choke shaft 66 of Figs. 1 and 2.

The intermediate shaft TB is identical with the intermediate shaft if! of Fig. 1.

The shafts 66 and '10 might be made integral as shown in Figs. 1 and 2.

Operation In the operation, as the choke 62 is rotated clockwise in Fig. 2 the opening 64 is subjected to the full suction of the engine and the rich starting mixture is drawn down the twisted tube 58 and the inclined passage 56. When the choke valve 62 is placed in the wide open position, in which it is shown, the rich mixture that is discharged from the twisted tube 58, to the insid of the drum G0, escapes into the venturi The result of this is that this fuel is divided equally intothe air stream and a uniform mixture results. The operation of the low speed connections 22, 2 3,

26, 28 and the low speed passage 30 are those in general use and form no part of this invention.

In the case of Figs. 3, 4 and 5 a still greater atomization of the fuel descending the twisted tube 58 is made. The object of these alternative constructions is to increase the atomization and thereby improve the distribution of the fuel in the air stream.

What I claim is:

1. In a carburetor for an internal combustion engine having an air entrance passage, a fuel mixture outlet and a throttle valve therein, the improvement comprising a combined choke valve and fuel nozzle, said fuel nozzle comprising a hollow cylindrical drum symmetrically located in said air entrance passage with its axis extending transversely thereof, a shaft extendingaxially and rotatably through said drum, a butterfly choke valve mounted radially on said shaft and having a rectangular opening closely embracing said drum, means for conducting fuel to the hollow interior of said drum, fuel discharge means on the downstream side of said drum, said fuel discharge means being arranged to discharge fuel on both sides of the downstream lip of said choke valve when said choke valve is in open position and on the engine side thereof when said choke valve is closed.

2. A device as set forth in claim 1 in which said fuel discharge means comprises an opening through the wall of said drum, said opening having a portion lying on each side of the plane of said choke valve when said choke valve is in open position. 7

3. A device as set forth in claim 1 in which said fuel discharge means comprises a plurality of circumferentially spaced axial slots through the peripheral wall of said drum.

4. A device as set forth in claim 1 in which said fuel discharge means comprises a plurality of openings through the peripheral wall of said drum, said openings being symmetrically arranged on the downstream side of said drum.

5. A device as set forth in claim 1 wherein there are two identical air entrance passages and fuel mixture outlets adjacent each other and wherein said shaft extends through both said passages, there being one of said choke valves and one of said nozzles in each of said passages.

6. A device as set forth in claim 1 wherein said air entrance passage comprises a Venturi restriction and wherein the axis of said drum lies substantially in the plane of the minimum diameter of said restriction.

MILTON J. KITTLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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