US1853287A - Carburetor - Google Patents

Description

April 12, 1932 J. scHwElss ET AL 1,853,287'A CARBURETOR Filed Feb. 23, 1929 n' Patented Apr. 12, 1932 I UNITED .STATES PArEuroFFl-ca JOSEPH SCHWEISS AND GEORGE R. ERIOSON, OF ST. LOUIS, MISSOURI, ASSIGNORS TO CARTER CARBURETOR CORPORATION, OF ST. LOUIS, MISSOURI, A CORPORATION oF DEAWABE This invention relates to carburetors and particularly to devices for producing a temporary enrichment Aof the mixture delivered' p when the throttle is opened. The jet throiljgh which this pump discharges is entirely separate and distinct from the main fuel supply means of the carburetor. The arrangement serves not only as a'means of temporarily env riching the mixture upon acceleration of the engine, but as a means of priming the engine before start-ing.

During operation, when the temperature is low, it is desirable to squirt the additional fuel high into the air stream so that a large `part of it will be vaporized by the contact with the air, and to secure the most perfect vaporization,the jet is directed so that the larger drops will impinge on the hotspot or other warm portions of the intake manifold, so that they will be vaporized by the heat thereof. v As the temperature rises, it becomes less desirable to squirt the supplementary jet into the air stream and onto the surface of the intake manifold, and under certain conditions serious interference with the operation of the motor may result fromsuch an arrangement. L A It is an object of this invention to provide means to deflect the `jet'of fuel delivered by the accelerating pump at high temperatures in such a manner that it will not be directed into the most rapidly moving part of the air e stream and- Will not impinge on the hot sur- 40- faces of the manifold.

Another object of the invention .is to provide means automatically operable at high temperatures to prevent the over-enrichment of the fuel mixture by the accelerating pump lwithoutk in any way affecting the operation of the pump itself.

It is another object of the invention to providey means automatically operable at high temperatures to distribute the charge of fuel @o delivered bythe accelerating pump over a i CARBURETOR applicati@ mearebruary 23.11929. serial 1v.k 342,060.

longer period whereby the over-enrichment .of the mixture is prevented and the temporary increase of power is prolonged. Other objects will appearfrom the following description and the accompanying drawings,

referring to which:

Figure 1 is a somewhat diagrammatic cross sectional view of a carburetor embodying our inventionsl Figure 2 is a side elevation of the carburetor shown in Figure 1.

Figure 3 is a side view of one form of thermally operated deflector.

Figure 4 is an end view'of the delector shown in Figure 2.

The reference numeral 1 designates a main body member having a passageway 2 ter'- minating in a flange 3 which is adapted to be secured to the intake manifold of an internal combustion engine, the manifold being indicated at 4:V A butterfly valve 5 of convene tional construction` is mounted on a shaft 6v and serves tol control he flow of mixture through the passageway 2. A suitable lever 7 4is provided for operating the` throttle shaft. Also mounted. on the shaft 6 -is a crank 8 which is pivoted at 9`to the oscillating piston 1() ofthe accelerating pump 11.

The carburetor is supphed with air from the usual air horn 12. The chamber 13 provides a passage for the airto the throat of the venturi 14 and into the`mixing chamber 15A where it is mixed with fuel before passing through the throttle Vvalve and the outlet conduit 2. The fuel is supplied by conventional means through the inlet nipple 16, which is secured to the body member l and communicates with the inlet side of the float valve 17, the movement of this valve being controlled in a well known manner by the oat 19 which is carried inthe float chamber 18. When the fuellevel .in the fuel bowl or lt will be seen that the fuel level A-A is y such as to normally 'maintain a quantity of fuel in the depression 0r accelerating well 40 at the lower part of the chamber 13. This fuel accumulates in the accelerating well during low speed operation and is picked up by an increase in the speed of the air stream, such would occur when the throttle is suddenly opened, thereby giving an additional quantity of fuel for acceleration.

The tube 20 is connected to the fioat chamber at a point below the fuel level to provide a main fuel supply. The accelerating pump 11 communicates with the conduit 21, the inlet valve 22, and the outlet passage 23; an inwardly opening check valve 24 is seated against-the inlet`22, as shown, thus forming an inlet check valve for the pump. The passage 23 is provided with a shoulder 25 upon which is seated a ball check 26 forming an outlet check valve for the pump. A suitable jet nozzle 27 is secured to the upper end of the bore 23 and serves to retain the ball check 26 in position as well as to form the discharge nozzle for the accelerating pump.

The body of the carburetor is provided with a bore 28 to receive a substantially cylindrical plug 29, and a set screw 30 is provided to releasably hold the plug 29 in4 position. The upper end of the plug is provided with a screw driver slot 31 which serves to adjust the plug and to indicate its position. The inner and opposite end of the plug is slotted to receive a strip of bimetallic thermally responsive metal 32 which extends downwardly and toward the line of discharge D of thel jet 27. Upturned lugs or baliles 33 are attached to the strip 32 and are preferably formed in the manner shown to a diameter not greater thanv that vof the bore 28 so that they can be readily withdrawn or inserted with the strip through the bore 28.. The lugs are attached to the thermostatic strlpxlpy a rivet at the lower end only, so that the nding of the strip under the infiuence of temperature changes will not be interfered with by the stiffness of the flanges.

The strip 32 com rises a strip of metal 34 having a.- low coe cient of expansion attached to another strip of metal 35 having a high coefficientof expansion.

The operation of the device is as follows:

' When the carburetor is in operation, suction in the manifold 4 draws air through the turi 14. The reduction of pressure at the throat of the venturi draws fuel from the` tube 20 and causes it t-o be sprayed into the mixing chamber 15. The throttle 5 controls the passage of mixture from the mixing chamber into the manifold. When the throttle valve is moved toward closed position, the piston 10 is moved upwardly in the P iliary fuel through said nozzle upon a movepump 11, drawing fuel through the inlet 22 past the ball check 24 and` into the pump.

When it is desired to accelerate the engine,

the throttle is opened causin the crank 8 tovpicked up by the air passin the walls of the conduit is vaporized morev slowly-and is eventually picked up bythe air stream and carried into the engine. A

As the temperature rises, the drops of fuel which impinge on the walls of the passageway are vaporized more quickly, resulting in a sudden over-enrichment of the mixture .i

upon operation of the' pum and insufficient duration of time during which the additional fuel is supplied. Under these conditions, the increased temperature bends the strip 32 to the left, as shown in Figure 1, and intercepts a portion or all of the jet, causin the fuel to be deflected against the wall o the chamber 13 below the venturi.

The rate of flow of air in this part of the carburetor is lower than the rate of flow through the venturi, the outlet passage 5, and the intake manifold 4; and for this reason the deflected fuel is vaporized more slowly than if it had been squirted ydirectly through the throat of the venturi and the most rapidly moving partof the air stream onto the warmv surfaces over which air is passing at a relatively high speed.

The fuel will, however, eventually be through the chamber 13 and carried into t e engine. `It is also quite likely that the walls of the chamber 13 will be cooler than the walls of the conduit 2 and the intake manifold 4, and for this reason also the slower vaporization will occur. B this arangement, the interval durin plied 1s lengthened while the temporary supply of over-rich mixture is avoided.

It will be seen that we have provided a simple, reliable, and easily manufactured device for. the purpose described, and that the w ich the enriched mixture is supinvention may be embodied in various ways.

Accordingly, we do not wish to be limited, exce t as set forth in the following claims.

e., claim:

-1. In a carburetor, a mixin conduit, a main fuel supplly tube connecte lto said conduit to norma `y supply fuel thereto, a valve for controlling the passage of mixture through said conduit, an auxiliary fuel supl'y nozzle, means for discharging a jet of auxment of said throttle, a baille, and thermally operable means to move said bale into the path of said jet when temperature rises.

2, In a carburetor, a mixing conduit, an

accelerating pump adapted to discharge a jet of fuel into said conduit, a baille normally out of the path of said jet, and thermally operated means for moving said baille into the discharge jet of said pump when the temperature is high. 1

3. In a carburetor, a mixing conduit, an accelerating pump having a discharge jet directed toward the most restricted part of said conduit, and automatic means operable upon an increase in temperature for deflecting said jet into a less restricted part of said conduit.

' by temperature changes to deflect said dis- 4. In a carburetor, a mixing conduit adapted toV convey an air stream, an accelerating pump having a discharge jet arranged to discharge fuel into a rapidly moving part of said air stream, and means operable at high tempera-ture to deflect said jet into a slower moving part of said air stream.

5. In a carburetor, a mixing conduit adapted to convey an air stream, a pump having a discharge jet/arranged to'discharge fuel into a certain part of said conduit, and automatic means operated by temperature changes to cause said fuel to be discharged into a diiferent part of said conduit.

6. In a carburetor, means forming a main conduit, an accelerating well in the lower portion of said conduit, an accelerating pump adapted to discharge into said conduit above said accelerating Well, and means operated charge into said accelerating well.

7 In a carburetor, a mixture conduit, a fuel chamber, a main fuel supply means normally supplying fuel from said chamber to said conduit, a pump for supplying additional quantities of fuel to a certain part of said conduit, and thermally-operated means for deflecting the additional. quantities of fuel to another part of said conduit when the temperature is high.

'8. In a carburetor, a fuel chamber, a mixture conduit, means normally supplying fuel from said fuel chamber to said mixture con- I trolling said valve, means operated by said controlling means for supplying add1tional quantities of fuel to a part of said conduit, and a delectoroperable at 1.high temperatures 'to deflect the additional fuel to another part of said conduit.

9. In a carburetor, a body member having a-chamber therein, a passageway' forming an outlet for said chamber, a manually operable valve controlling said passageway, a pump, a discharge nozzle for said pump mounted in the wall of said chamber, means for simultaneously operating said pump and said valve, and a thermally operated baffle in said chamber.

from in a substantially axial directiorf, a baffle member carried by said strip and attached thereto only at a point near theend of the strip opposite the plug, vwhereby flexing of said strip will not be interfered-with by the stiffness of ysaid baille member. n

v11.'In a device of theclass described, a substantially cylindrical plug, a birnetallic strip attached to an end of said plug and extending in an axial direction therefrom, a flanged baflle carried by said strip, said plug, flange, and strip being insertable through a circular opening of the same diameter as said plug.

12. In a device of the class described, a substantially cylindrical plug, a bimetallic. strip attached to an end of said plug and ex- -tending in an axial direction therefrom, a

flanged baille carried by said strip, said plug, flange, and strip being insertable ina circular opening of the same diameter as said plug and an eccentric screwdriver slot in the end of said plug opposite said strip for receiving an adjusting tool and for indicating the position kof said baille.

13. In a device of the class described, a conduit, means forming a conduit, a manually operable priming pump for dischargving a jet of fuel into said conduit, a baffle adapted to be moved into or out of the-path of said jet, and thermostatic means for moving said baille. '1

' 14. In a carburetor, means forming a mixing conduit and a constant level fuel supply chamber, a main fuel nozzle discharging fuel 100 from said constant level supply chamber into said mixing conduit, a pump having a fuel inlet from said constant level supply chamber, a check valve for controlling-said inlet said.. pump having a discharge nozzle for discharging fuel into said mixing conduit and heat controlled means for returning a portion of the fuel dischargedby saidpump towards said constant level supply chamber.

In testimony whereof we aix our signatures this 14th day of February, 1929.

. JOSEPH SCHWEISS.

GEORGE R. ERICSON.

10. In a device of the class described, a cylindrical plug, a bimetallic strip secured at p one end of said plug and extending there-

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