US1579329A - Carburetor - Google Patents

Description

April 6, 1926. 1,5793% A. M. LA GHAPELLE CARBURETOR Original Filed MaIfCh 15, 1920 INVEN To Patented Apr. 6, 1926.

UNITE STATES ALFRED M. LA GHAPELLE, OF CHICAGO, ILLINOIS, ASSIGNOR TO I. H. P. PRODUCTS COMPANY, A CORPORATION OF DELAWARE.

CARBURETOR.

Refiled for abandoned application Serial No. 366,074, filed March 15, 1920. This application filed November 16, 1920. Seria1 No. 424,491.

To (ZZZ whom 2'25 may concern:

Be it known that I, ALFRED M. LA CHAP- ELLE, a citizen of the United States, residing in Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Carburetors, of which the following is a specification.

This invention relates to improvements in carburetors.

The carburetor herein, illustrated as embodying my invention is of the type in which a free body of fuel is maintained at a predetermined level and with the fuel surface exposed to the suction of the engine, said body of fuel being automatically replenished from a source of supply by the suction created by the engine.

An object of the present invention is to provide a carburetor in which the amount of air drawn into the carburetor is controlled by an exterior throttle valve, which throttles the motor and creates a positive vacuum feed within the carburetor. It is also an. object to provide means to automatically control the relative proportions of fuel and air for all motor speeds.

Another object of the invention is to so construct the carburetor that it may be manufactured at a minimum cost and with parts which may be readily assembled.

With these and other objects in view my invention consists in the novel construction, combination and relative position of the parts and members hereinafter described and shown in the accompanying drawings, and particularly pointed out in the appended claims.

Referring to the drawing in which like reference characters indicate like or corresponding parts:

Fig. 1 represents a vertical central sectional view through my improved carburetor.

Fi 2 re resents a horizontal sectional View through the same, the plane of the section indicated by line 22 of Fig. 1.

Fig. 3 represents the bottom view of the carburetor.

Fig. 4 represents a detail sectional view through the carburetor in a plane indicated by the line l t of Fig. 1.

Referring-i l: detail to that embodiment of my invention illustrated in the accompanying drawings: 5 indicates the bowl of the carburetor which is open at the top and has a bottom wall 6 from which depends an annular flange 7. In the flange 7 is of annularly spaced ports or defines a passageway through the bowl 5,

and the space between the tube 9 and the upright wall of the bowl provides an annular reservoir for the fuel.

10 indicates as a whole a cover or top wall for the carburetor bowl v The cover 10 comprises an upright tubular neck 11 which terminates at its lower end in a horizontally disposed flange 12. This flange 12 seats at its peripheral margin on the top of the bowl and forms a closure for the same. The cover 10 may be secured to the top edge of the bowl by extending ears and screws as shown or by any other means. To make a tight joint a gasket 13 is interposed between the top edge of the bowl 5 and the cover flange 12 which secures a gas tight joint. The top end of the tubular neck 11 has the usual connection flange by which the carburetor is attached to the inlet manifold of the motor.

14 indicates an upwardly extending hollow boss formed on the top surface of the cover flange l2 and near its outer edge. This boss 14 has a threaded aperture 14 for connection with a fuel supply line at one end and a communicating aperture 14: at the other end which opens through the flange 12 into the annular fuel chamber. A tubular valve guide 15 has threaded engagement in the aperture 149 and depends into the fuel chamber. l/Vithin the top end of the valve guide 15 is formed a downwardly facing valve seat 15 against which a valve 17 is adapted to close. Within the fuel chamber and surrounding the upright tube 9 is a suitable float 16 pivoted to the bottom end of the valve guide 15 in such manner 7 that the opening and closing of the valve 17' is regulated by the height or quantity of the fuel in the fuel ch.

20 indicates an upright tube concentrically arranged within the upright tube 9 and constituting the primary air inlet tube for the carburetor and extending at its ends above and below the upright tube 9. The top end of the tube 20 which is enlarged in diameter as at 2-, extends into the passageway defined by (110 tubular neclt ll of'the cover 10. The tube 20 is supported at its upper end within the upright tube S) by means of the tube 2- which forms the fuel atomizing or spray tube and which here preferably snown in an inverted U-shape. This atomizing tube comprises a horizontal leg 22, which extends through suitable apertures in the enlarged part of the tube 20, and vertical legs 22", 22", which are brazed or otherwise at.a "led to the tube 9, as shown. The horizontal leg 2-2 has vertically aligned atomizing openings 23, 23, which are coaxial or concentric with the tube 20, and the bottom ends of the vertical legs 22" have openii in communication with the bottom of the fuel chamber through openings 24:, 24;, in the upright tube 9, to thereby afford a supply of fuel from the fuel chamber to both ends of the atomizing tube The depending annular flange 7 is closed at its bottom end by a plate 25, and thus provides a valve casing for a secondary air in let valye 26 which is adapted for vertical movement in said casing. The seconcary air valve comprises a disc 2? which normally bears upon the bottom wall or plate 25 of the valve casing and an upright annular sleeve 28 having ports 28 which are adapted to register with the ports 8 in the flange 7 when the valve 26 in its raised position. An upright inner integral sleeve 29 embraces the lower end of the tube 20 and is operatively slidable over same. light helical expansion spring 29 coiled around the tube 20 is interposed between the disc 2. of the valve and a shoulder 36 formed at the unction of the enlarged part 21 and the main body of the tube 20.

The plate 25- which provides the bottom vall of the secondary air valve casing has av depending tubular extension 31 which is coaxial or concentric with the primary air tube 20. This extension 31 and inner sleeve form in effect a continuation of the primary air tube 20. The sleeve 29 is integrally attached to valve 26. In the extension 31 is located the throttle valve which valve 32 is fixed on a rocl; shaft 33 having support in the extension and in a bearing ear 25 formed integral with the plate A suitable operating arm 3st controls the movement and position of the valve Thus the throttle valve 32 controls the ad mission of air into and through the carburetor, which will be more fully hereinafter.

In the operation of my carlan'etor and assuming that the fuel chamber is empty and that the fuel supply tanli is located in a plane below that of the carburetor, the annular float 16 is therefore in its lowest position in the fuel chamber and the valve 17 in open position allowing of a free passageway from the fuel chamber through the tucl supply line to the fuel supply tank which has an opening admitting atmos 'ihcric pressure therein. The secondary airwalve it; is in its normal position at the bottom or its casing and closing the annular poi-ts 8 in the flange T and the spring 29 serving to further hold said valve in this position Under these conditions, and in order to draw or suck the fuel from the supply tanl; into the fuel chamber, itis desirable to have the throttle valve in the tubular extension 11 of the plate 25 in a closed position.

The crank shaft of the engine is now turned over in the usual manner. The suction stroke of the pistons will lirst displace the air from the interior of the carburetor (it being remembered that the throttle valve is closed) and will produce a partial vacuum therein. This vacuum will actto draw or such into the fuel chamber, a quantity of fuel from the fuel supply tanl: through the supply line and open valve 17. and as the fuel level rises in the fuel chamber the float will raise the stem 18 and valve 1T and the passageway into the fuel chamber from the supply line will be closed and the fuel will have reached a predetermined level. It apparent that as the fuel enters the fuel chamber, it will flow through the openings 2%, 24, and into the vertical legsof the atomizing tube. The throttle valve does not necessarily have to be closed air-tight since the great demand for air created by the impulse of the motor will be sufficient to meet the required vacuum to draw the fuel from the supply tank into the carburetor regardless of any slight leakage around the throttle valve, and closed position which may be adjustably varied for the idle running of the motor. It is obvious that the air thus passing through the throttle opening and through the primary air tube on the way to the en gine cylinders will creat a draught in passing through and around the atomizing tube 22 which will draw the fuel up the vertical legs 22" into both ends of the horizontal section 22". From the drawings it will be seen that the space between the bottom of the air valve 26 and the plate 25 in open com munication with the bottom open end of the primary air tube and thatany suction exerted in the carburetor will be equally exerted upon both top and bottom of the secondary air valve 20, and further that the suction exerted upon the upper surface of explained the valve 26 cannot raise the valve 26 unless the pressure against the outside of the valve is relatively greater than the opposing forces including the weight of the valve and the pressure of the spring 29. Therefore, said secondary air valve will not rise to aposition where the ports 8 and 28 will register .until sutlicient air is admitted through the throttle opening 31 to counteract the reduced pressure immediately above the throttle valve 32, it being remembered that the valve 26 is under reduced pressure while the engine is running. In this manner the throttle valve 32 governs the opening of the second ary air valve 26 and the admission of all the air into the carburetor. The spring 29 opposes the opening of the valve 26 to a pre determined degree of pressure and in this manner sufficient suction is maintained in the carburetor to draw fuel from a supply tank of a level lower than the carburetor and when the motor is running with a wide open throttle valve at a very low speed.

In controlling the speed of the motor, the manipulation of the carburetor is similar to those having the throttle valve at the carburetor outlet and between the fuel device and the engine intake manifold. The difference, however, lies in the fact that when the throttle valve in the carburetor herein shown is closed, the suction or vacuum in the carburetor increases while in the aforesaid conventional type now in use, the suction or vacuum decreases. The arrangement herein provided affords the utilization of the suction or vacuum, to produce a positive feed apparatus for supplying fuel to the carburetor, and to cause the fuel to vaporize more readily than is possible at atmospheric pressure. This is of great importance since most of the driving of motor vehicles is under conditions with the throttle valve partially closed.

As has been explained, the opening of the secondary air passage is controlled by the throttle valve 32 and that when the motor speed is low and the throttle valve 32 is wide open, the spring 29* will maintain a given amount of suction in the carburetor in the space above the valve 26 by retaining the secondary air valve in a closed or partly closed position against a suction which is sufiicient to draw fuel to the carburetor from a given level below the carburetor. The amount of suction exerted by the motor is equally exerted in all parts of the carburetor and because of this the amount of fuel is proportioned to the incoming air by the draught created by the air in passing through and around the atomizing tube 22 that is, as the velocity of the air increases, the fuel raised from the fuel chamber into said tube 22 will increase in proportion. The jet of air passing through the openings 23 and 23 affords an automatic fuel metering means. A smaller volume of fuel will pass through the opening 23 into the jet of air at low velocity than will at a higher velocity. In this manner the proportions of the mixture are maintained when secondary air is admitted.

I claim:

l. A carburetor for combustion engines comprising a bowl having an upright wall, an inwardly extending flange forming a bottom therefor, an upright tube adapted to be fixed to the inner edge of said flange, and extending to a point adjacent the upper periphery of said upright wall, said upright tube, flange and upright wall defining a fuel chamber, an inverted U-shape spray tube within said upright tube, the upright leg portions of said tube being connected with said fuel chamber and in open communica tion therewith, an air inlet tube supported on the upper portion of said spray tube, said U-shaped spray tube being provided with apertures aligned with said air inlet I tube, said air inlet tube extending downwardly below the bottom of said bowl, anc communicating with the atmosphere, it throttle valve controlling the admission of air into said air inlet tube, an auxiliary air valve between said fuel chamber and said throttle valve and resilient means normally 90 maintaining said auxiliary air valve in closed position, said auxiliary air valve being arranged to admit air into said upright tube and around said air inlet tube for admixture with the air passing through the upper end of said air inlet tube, and the relative opening of said auxiliary air valve being controlled by the opening of said throttle valve and the speed of the engine.

2. A carburetor for combustion engines comprising a bowl having an upright wall, an inwardly extending integral flange forming a bottom therefor, an upright tube adapted to be fixed to the inner edge of said flange and extending to a point adjacent the upper periphery of said upright wall defining a fuel chamber, a combined cover and neck positioned above said fuel chamber, the space between the upper periphery of the upright tube and said cover being restricted, an inverted U-shaped spray tube within said upright tube, the upright leg portions of said tube being connected with said fuel chamber and in open communication therewith, an air inlet tube sup- 1 ported on the upper portion of said spray tube, said U-shaped tube being provided with apertures aligned with said air inlet tube, said air inlet tube extending downwardly below thebottom of said bowl and communicating with the atmosphere, a throttle valve controlling the admission of air into the said air inlet tube, an auxiliary air valve between said fuel chamber and said throttle valve, and resilient means nor- 130 inally maintaining said au.\:iliar air valve in closed position, said auxiliary air valve being arranged to admit air into said upright tube and around said air inlet tube for admixture With the air passing through the upper end of said air inlet tube, and the relative o iening of said auxiliary air valve being controlled by the opening of said throttle valve and the speed of the engine.

In witness whereof, I h ve hereunto sub- 10 scribed my name this 12th day of November 1920.

ALFRED M. Li CHAPELLE.

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