US1872537A - Carburetor - Google Patents

Description

Aug. 16, 1932.

H, H. c. WEED CARBURETOR Filed June 14. 1930 2 Sheets-Sheet 2 ENVENTCR um. W5 5 a m ATTORNEY nuen'n. 'c.

OF GLA'QTON, MISSOURI, ASSIGNOK TO CARTER CABBUBETOBCOB- Patented Aug. 16, 1932 ESfPATE r OFFICE.

v rom'rIoR, or s'r aoum, ,mssouannconroaanon or DELAWARE cannumiron Application am June 14,

internal vcombustion engines, and particubut also, generally,

, a carburetor in which the boiling of gine. I

Other objects will appearfrom the follow-Q larly to carburetors of the downdraft type,

are exposed to heat from the engine.

It is an object of this invention to provide the fuel will be prevented.

- his a further object of this invention to provide a carburetor in which the fuel is sub jected to a cooling action. a p

It is a further object of this invention to provide a carburetor in which the fuel is pro- J from the heat of the em tected or insulated mg description and the accompanying claims.

The invention will-be upon consideration of .the accompanying drawings, referring to which: I

Figure lrepresents a sectional elevation of a downdraft carburetor constructed ac cording to my invention.

Figure 2 represents a plan view of the car-. buretor shown in Figure 1.

Figure 3 is'a sectional plan view of the carburetor taken along the line 3-3 of Figurel.

The carburetor comprises a main body member 1, having a vertically extending air chamber 2 at the upper end thereof. This )assa ewa is contracted into a venturi, the

throat of which is indicated at 3, and the a venturi tapers gradually downwardly and outwardly, the cylindrical outlet passageway 5. This outlet is surrounded by a flange 6 which is provided with bolt holes 7 or any suitable means by which it may be attached to the manifold of an internal combustion engine.

A butterfly throttle 8 mounted in a conventional manner upon a shaft 9 is provided. The up is expa ded to a size sufficient to receive the fuel bowl 11 which is attached to a support;

member '12. The upper rim of the bowl is held in fluid tight relation to the support' member at 13, a suitable gasket being pro to any carburetors which better understood as indicated at 4, terminating in er part of the body of the carburetor 1930. Serial No. 461,089.

buretor and retained in position by bolts 14,

as shown in Figure 2, or other suitable means. The support member is provided with an extension 15 extending downwardly into the bowl 11 and'this extension isthreaded at 16 "to receive the end of a flanged nozzle memher or inverted standpipe 17which, when screwed into the threads 16,'retains' the fuel bowl tightly in place. The standpipe is provided with a 'restrictedportion or primary venturi 18 which tapers gradually "out to the cylindrical bore 19 of the standpi'pe.

The extension 15 of the support member is provided with a well or downwardly extending opening 20 which is in communication with the atmosphere at its upper end. In the lower portion'of this well a 'concentric member 21 is fitted, and this member carries an accelerating well 22 and an inverted thimble 23 having one ormore accelerating holes 24 formed therein. The member 21 isprovided witha bore 25 to loosely receive a "nozzle member 26. This nozzle member -extends upwardly to a point just above the float level in the bowl and below the top of the thimble, as shown, and it extends downwardly to a point near the throat of the venturi 18. It will be understood that the nozzle member is attached to the support member 12 bythreads 27 or other suitable means. g

A spider or cross member 28 is formed in the member 12 to extend across the lower part ofthe well 20 to receive the threads 25'and 27. A bore29 is formedextendin'g transversely into the extension 15 and longitudinally through thespider 28. This bore is threaded as shown to receive a jet nozzle 30 which controls the main fuel entrance to the carburetor. It will be understood that the bore 29 communicates with the bore 25 and through the accelerating holes 24 with the well22.

Fuel is supplied to the fuel bowl 11 from a conventional fuel pump (not shown), or other suitable means. A pipeconnection 31 receives the fuel which is supplied to the carburetor in a conventional mannerf The carburetor is-provided with a fuel pump 32 opon the shaft 35 is provided. An idle tube connects with the passage 29 and also with the port 37 through the passages 38,- 39, 40,

' and 41. Air bleeds 50 and 51 are provided to prevent siphoning when the device is not in operation.

The carburetor is shown as being mounted on a manifold 10 of an internal combustion engine. This manifold is provided, in a conventional manner, with heating means, such as an exhaust conduit 42 through which passes at least a portion of the exhaust from the engine for the purpose of more completely vaporizing the mixture as it passes to theen ine.

t will be understood that this manifold gets extremely hot, particularly after a period of high speed operation. \Vhen the motor is slowed down, after being operated at a high speed, the rate of air and fuel flow through the carburetor and manifold decreases, and the heat of the engine readily communicates to the carburetor.. important object of this invention to restrict the communication of heat to the fuel in the bowl, and the substantial annular space 43 between the fuel bowl and the outer wall of the carburetor is provided for that purpose. During the operation of the engine, air is drawn downwardly through this annular portion and thereby traversesthe walls of the fuel bowl 11. The high speed of this air substantially prevents transference of heat from the body portion 1 in the carburetor to the bowl, and even when the engine slows down or stops, a thick layer of air between the carburetor body and the bowl forms a substantial resistance to the transference of heat.

The operation of the device is as follows:

Fuel is supplied from a conventional fuel pump vacuum tank or other supply device to the inlet 31 and passes through the conventional float valve (not shown) which is controlled by the float 44 which maintains a fuel level slightly below the u per end of the tube 26. Suction occurring, ue to the operation of the engine, draws air down through the primary air inlet 45-past the spider 28 and through the venturi 18, thereby creating a suction in the interior of the thimble 23 and drawing fuel through the jet 30 and up over the ,top of the, tube 26. Air also enters the accelerating holes 24 and mingles with the fuel inside the thimble, the air and fuel then passing in the form of an emulsion down through the conduit 26.

The major portion of the air entering the carburetor flows through the annular space 43 around the bowl. and begins to mix with the primary air and fuel at the throat of the venturi 3.

It will be understood that the particular It is an construction of the interior of the carburetor bowl and the fuel mixing passages may be varied without affecting the utility of my invention. In the present case, the carburetor and the fuel bowl are cooled by air passing through the bowl and also by a larger quantity of air assing around the bowl, but it should be un erstood that my invention is not limited to a carburetor in which air passes through the bowl, and that it is sus: ceptible of application to .carburetors in which none of the air enters the fuel bowl.

I claim:

1. In a carburetor, means forming a mixing chamber, a throttle valve controlling the flow through said mixin chamber, a venturi discharging into sai mixing chamber, a frusto conical air inlet'chamber having its small end dischargin into said venturi, a fuel bowl substantial y within said air chamber and slightly spaced therefrom, thereby forming an air passage between said fuel bowl and said frusto conical chamber.

2. In a downdraft carburetor, a fuel bowl,

co-axially mounted a passage through said fuel bowl, an air inair horn surrounding said fuel bowl and .o

spaced therefrom to rm a substantial annular downwardly conducting air passage around said fuel bowl, said air horn being constricted below said fuel bowl to form a venturi, and a throttle valve mounted below said venturi for controlling the flow of carbureted fluid through the carburetor.

In testimony whereof, I aflix my signature. HUGH H. C. WEED.

IllO

Images