US1856238A - Carburetor - Google Patents

Description

May 3, 1932. R. F. BRACKE 1,856,238

GARBURETOR Filed July 5, 1927 Patented May 3, 1932 UNITED STATES PATENT ori-TCE RBERT F. BRACKE, F CHICAGO, ILLINOIS, ASSIGNOR T0 RTIS B. CAMP, TRIISTEE, OF GLENCOE, ILLINOIS CARBURETOR Application led J'uly 5, 1927. Serial No. 203,294.

My invention relates to improvements in economizers for carburetors.

An object of the invention is to provide an improved economizer for the carburetor of an internal combustion engine, the function thereof being to reduce the amount of fuel delivered to the induction chamber at normal car speeds and load, and to permit maximum operation of the fuel delivery mechanism when the engine is idling or operating under full load.

The invention will be explained as embodied in a carburetor of the type in which the amount of fuel delivered to the induction chamber is dependent upon the amount of air passing through a Venturi tube comprising the fuel delivery means.

A further object is to provide an economizer for a carburetor in Which there are 2g no moving parts, thereby eliminating the possibility of the economizer getting out of adjustment or becoming otherwise impaired through Wear.

A further object is to provide an economizer for carburetors in which the amount of fuel passing through the fuel Venturi tube is rendered proportionate to the actual oper ating requirements of the engine upon \vhich the carburetor is used.

A further object is to provide an economizer for carburetors which is intended for permanent adjustment at the time the carburetor is built, but which may be re-adjusted as for adaptation of the carburetor to an engine of a different type from which the carburetor was initially intended by the substitution of parts of the economizer for similar parts differing only as to size. i

Another object is to provide in a carburetor of the fuel lift type utilizing for its fuel nozzle ay suction multiplying Venturi tube through which primary air to the earburetor is admitted, means for maintaining relatively high depression in the induction passage at the mouth of theiventuri.

A further object is to provide an economizer for carburetors which is extremely simplein construction and in which parts thereof afford a protective housing for that' portion of the fuel Venturi tube subjected to atmospheric pressure.

Other objects and advantages of my invention will appear more fully from the ,following description and from the accompanying drawing, in which similar characters of reference indi-cate similar parts throughout the view. In the drawing: l

The figure is a sectional view of a carburetor embodying the economizer.

The carburetor illustrated herein is that type of carburetor which I have fully illustrated and explained in my co-pending application for patent on vacuum feed carburetor, Serial No. 155,598, filed December 18, 1926, and consists chieiiy in an induction chamber l and air inlet 2, and a delivery passage 3 having its mouth adapted for registration with the intake manifold 4 of an internal combustion-engine. The chamber l and the passage 3 constitute and shall hereinafter be referred to as the induction passage of the carburetor. The carburetor furtherconsists of a spring pressed air valve 5 which opens to permit the passage of air from the air inlet 2 to the induction passage by engine suction, anda fuel chamber 6 which communicates by means of a passage 7 to the throat 8 of a fuel delivery Venturi tube 9. The Venturi tube 9 is projected through the side walls of the induction chamber l and has its intake orifice 10 subjected to atmospheric pressure.

As explained in the co-pending application referred to, the passage of air through the Venturi tube 9 creates relatively high suction at the throat 8 of the Venturi tubeand lfuel is drawn from the chamber 6 into the moving air column in the -Venturi tube whereupon it is delivered in atomized state to the induction chamber 1.

I attain the highest degree of eiieiency in the operation. of the Venturi tube 9 by constructing the `secondary spring pressed air valve 5 at its periphery in such a manner as to deflect air passing between the valve and its seat 5a outwardly toward the walls 30 of fthe inductionvchamber 1 immediately above the valve and in disposing the mouth `or delivery orifice 31 of the Venturi tube 9 immediately above the valve 65. For this purpose the valve 5 has the under surface of its peripheral portion formed with a slight inclined surface 32 which lies nearly in a horizontal plane. The upper surface of the valve seat 5a lies in a horizontal plane. Air passing through the valve is deiiected from surface 32 toward the Walls 30 of the induction chamber and thereafter the separated air stream merges at a point slightly above the Venturi tube 9 where it -may pass through the delivery port 3 of the carburetor. The region above the valve 5 is therefore maintained at slightly higher depression than is any other portion of the induction chamber so that a relatively increased flow of primary air duced. This arrangement results in the highest possible efficiency in the suction multiplying property of the Venturi as the quantity of air passing through the tube in a given time determines the suction multiplying characteristics of the tube.

A butterfly throttle valve 11 is disposed in the passage 3 for the purpose ofcontrolling the passage of fuel from the induction passage to the manifold 4.

The valve 11 is shown in full lines at idle position and at ll-A in dotted lines at part throttle position. At ll-B in dotted lines the throttle is represented at wide open position as when the automobile is traveling at its maximum speed or full load.

The economizer serves to limit the passage of air through the Venturi tube 9 at such times as it is desirable to deliver a reduced supply of fuel to the induction chamber for the purpose of economical operation. It consists in a cap 15 which entirely surrounds the exposed portions of the Venturi 'tube 9 includingthe intake orifice 10. A chamber 16 is thus formed which houses the intake end of the Venturi tube 9. The cap 15 is secured to the body of the carburetorby the provision of an external threaded portion 17.

The chamber 16 communicates by means of a passage 18 with an opening 19 through the wall of the passage 3 at -a point slightly be- Vneath the throttle 11 when the throttle is in idle position, as shown in full lines in the figure. Means for limiting the amount of air which may pass from the chamber 16 through the passage 18 and out through the opening 19 by virtue of depression in the passage 3 conslss in a plug 20 having a restricted bore 21 therethrough which is interposed between the passage 18 and thefopening19 in the man# ner illustrated. This plug 20 is removable and may be replaced with a similar plug having a larger or smaller bore 21 so'as to adapt the economizer to various demands dependent upon the type of engineV upon which the carburetor is used.

A plug 22, having a restricted bore 23, is projected through the outer wall of the cap 15 and secured thereto by external threads 24:

which engage with an internally threaded neck portion 25 formed in the cap and performs the function of limiting to a degree the amount of air which may pass from the atmosphere into the chamber 16.

The operation of my improved economizer for carburetors is entirely automatic. At idle position as when the throttle 11 assumes the position shown in the full lines in the drawing, the depression in the induction passage at-the opening 19 and at the delivery end of the Venturi tube 9 is the same and air is free to pass from the atmosphere through the bore 23, the major portion ofl which passes through thevVenturi tube 9 to create a relatively high suction at the throat 8 of the Venturi tube which lifts fuel from the chamber ,6 through the passage 7 into the I Venturi tube for delivery into the induction chamber. A very small amount ofair will pass up through the passage 18 from the chamber 16-and out of the opening 19 but not in sufhcient quantities to in any way reduce the free passage of air through the Venturi tube 9.

At such times as the throttle valve 11 as' passage 18 and bore 21 effects a reduction of the amount of air which is'available in the chamber 16 for passage through-'the Venturi tube 9. Inasmuch as the quantity of fuel delivered through the Venturi tube depends .upon the quantity of air which asses there.

through, the delivery of fuel at t is time will be less than would occur if air was not being exhausted from the chamber 16 to the engine manifold in the manner described. This operation results in a highly economical functioning of the carburetor.

When, however, the throttle 11 assumes the position shown in the dotted lines at ll-B as for full load or maximum speed, then it .becomes necessary to have maximum delivery of fuel.A At this time the opening 19 and the inner end of the Venturi tube 9 are subjected to the same depression, which depression is substantially the same as that in the engine manifold 4. The result is that the Venturi tube 9 is free to operate to maximum capacity for the delivery of fuel much the same as it does when the throttle 11 is in the position,v shown in full lines. n

I claim: I 1. An economizer for carburetors having an induction passage and a fuel delivery Venturi tube, one end of which extends into said induction passage and the other end of which extends exteriorly of the larburetorand dependent in its operation upon pressure at the atmospheric end of said tube, comprising ineans, including an air passage communi eating with said induction passage at one end and with the atmospheric end of said Ven* turi tube, for reducing the pressure at the atmospheric end of the Venturi tube whereby the amount of fuel delivered into the induction passage is reduced.

2. An economizer for carburetors having an induction passage, a throttle valve in said passage and a fuel delivery Venturi tube, one end of which extends into said induction passage and the other end of which extends exteriorly of the carburetor, and dependent in its operation upon pressure 'at the atmospheric end of said tube, comprising means, including an air passage communicating with said induction passage at one end and with the atmospheric end of said Venturi tube for reducing the pressure at the atmospheric end of the Venturi tube, whereby the amount of fuel delivered into the induction passage is reduced, said means being dependent in its operation upon the relative/positions of said throttle valve and that end of said passage communicating with the induction passage.

An economizer for carburetors having an induction passage, a throttle valve in said passage and a fuel delivery Venturi tube, one end of which extends into said induction passage and the other end of Which extends exteriorly of the carburetor, and dependent in its operation upon the passage of air from theV atmosphere through the Venturi tube by atmospheric pressure, comprising a chamber surrounding the air inlet end of the Venturi tube, said chamber having an opening therethrough communicating with the atmosphere and a passage communicating at one end with said chamber and at the other end With said induction passage at a point adjacent to said throttle valve .whereby the amount of fuel delivered into the induction passage is dependent upon the relative position of the throttle valve and the adjacent orifice of said lastnamed passage.

i. In combination, a carburetor hav'A a; an induction chamber, a fuel delivery nozze extending into the chamber dependent in its opeation upon the passage of air at atmospheric pressure therethrough, and an air valve forcontrolling the flow of air into the induction chamber, said valve being constructed so as to deiiect air entering the induction chamber away from the center of the chamber. said nozzle having its delivery oriiice 'substantially at the center of the induc tion chamber.

5. In combination, a carburetor having an induction chamber, a fuel delivery nozzle dependent in its operation upon the passage of primary air therethrough, and an air valve for controlling the admission ofsecondary air into the chamber at atmospheric pressure, said air valve being so constructed as to deiiect air outwardly and away from that region of the induction chamber immediately above the valve, said fuel nozzle having its delivery orifice above-the central portion of the valve and in the area of relative depression caused by deiiectionof the air in the secondary air stream.

6. In combination, a carburetor having an induction chamber, a fuel feed Venturi tube extending into the induction chamber through which fuel is delivered upon the passag-e of primary air through said venturi, asecondary air inlet for the induction cham ber, a valve for controlling the admission of secondary air to the induction chamber, said air valve being so constructed as to create a region of relative depression in the induction chamber imlnediately above its head, said fuel venturi having it-s delivery orifice terminating at a point above the head of the valve Within the region of relative depression,

7. In combination a carburetor having lan induction chamber, a fuel delivery nozzle eX- tending into the chamber dependent in its operation upon the passage of air therethrough, and an air valve for controlling the ioW of air into the induction chamber, said lvalve being constructed so as to deiect air entering the induction chamber away from the center ofthe chamber and the delivery end of said fuel delivery nozzle positioned in the diametrical center of the induction chamber and immediately above said air valve.

In Witness whereof, I hereunto subscribe my name this 29th day of June, 1922.

ROBERT F. BRACKE.

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