US1795319A - Carburetor - Google Patents

Description

March 10, 1931. v C, w, SPOHR 1,795,319

-cARBUREToR Filed oci. 14. 1926 ar/ WS/Do/zr '521W Zz 6 Wmv-M9 Patented Mar. io, 1931 UNITED wSTATES PATENT OFFICE CARL W. SPOHB,

TRUSTEE,

cARBUnn'ron Application iled October 14, 1926. Serial No. 141,448.

My invention relates generally to carburetors. It relates more particularly to the type of carburetors in whichthe vacuum 1nduced in the carburetor itself is employed to draw the fuel from the fuel supply tank, which may be located at a levellower than that of the carburetor.

It is an object of my invention to provide an improved carburetor in which the fuel supply is more accurately and closely regulated, in which mercury is employed as a medium liquid fuel to the float chamber, and to provide means for preventin the mercury from being spilled from the car uretor.

Other objects will appear from the following description, reference being had to the accompanying drawings in which,

Figure 1 is a central vertical section of my improved carburetor. Y

Figure 2 is a diagrammatic iew of an automobile chassis and engine showing how lmy im roved carburetor is installed on an automo ile.

In Figure 2 the fuel supply tank 3 is connected by the usual tube 4 to the carburetor designated generally by the reference character, 5. The carburetor consists of a main body casting 6 which is adapted to be secured to the intake manifold 7 of the engine by bolts passing through its flange, 8. The usual throttle valve 9 is provided to regulate the charge to the intake manifold. Air is supplied to the induction passage 10 thpough the air inlet pipe 11.

An air inlet valve 12, which is resiliently held upon its seat 13 by aspring 14, is arranged to control the admission of air from the inlet pipe 11 to the induction` passage 10.

The degree of pressure exerted by the spring s.

be modified by adjusting the screw.

14 may plug 15 so as to change the initial compression of the spring 16, which is arranged to counteract the pressure of the larger spring 14. The dash pot piston 17, which `may be formed integral withthe stem of the valve 12, prevents fluttering of the valve. During the starting and ordinary operation of the engine,

a considerable vacuum 1s developedin the induction passage 10, so that the atmospheric for governing the admission of the.

pressure upon the lower surfaceof the valve 12, will raise the valve from its seat to admit additional air from the air inlet 11.

The suction in the induction passage 10 is utilized to draw the fuel into the carburetor as will now be described. A Venturi tube 19 is screw-threaded into the wall of the induction passage and is open to the atmosphere, the nozzle of the tube projecting well within the induction passage. An annular fuel passage 20 surrounds the Venturi tube and communicates with its throat, which is slightly enlarged at this point, by ducts 21. The annular passage 20 is supplied with fuel through a canal 22 which terminates in a small chamber 18, surrounding the `stem 23 of the fuel Valve 24. The valve 24 is adapted to rest upon a seat 25 and the stem, 23, of this valve is screw-threaded into a ioat 26, which is preferably made of a phenolic condensation product, such as the product known on the market as Bakelite The float, the valve and its stem are freely reciprocable within a ioat chamber 27, and are guided for Vertical movement by the lowerv end 28 of the float, which is slidable in a suitable guide 29.

The chamber 18 communicates with the float chamber 27 through the small annular passage the walls 0f the float chamber 27 are formed integral with a downwardly projecting tube 31 which extends intothe mercury well 32. The well 32 is formed by a jacket 33, which surrounds the walls of the ioat chamber and the tube 31. A flange 34 on the jacket 33 may be secured with a flange 35 of the float chamber to the body 6 in any suitable manner. The bottom of the well 32, is formed by a cup-shaped member 36, which is screwthreaded over the lower end of the jacket 33, and. isprovided with a vertically ribbed peripheral enlargement 37, which is engaged y a spring detent 38 secured to the jacket by means of screws 39. It will be apparent that by rotating the cup member 37 the level of the mercury within the Well 32 may be readily adjusted so as to govern the degree of vacuum necessary to open the valve 24.

A flaring` compartment 41, the lower portion of which forms the well 32, extends upsurrounding the valve stem 23, and.

wardly, surrounding the Walls of the float chamber 27. The upper end of this compartment communicates with a substantially annular trough 42 through a plurality of vertically drilled holes 43. This trough is open at its upper edge, as shown at 44.

A cap 45 is secured over the top of this circular opening 44 by means of a cap screw 46 which is threaded in the upper portion 47 of the carburetor body. This cap screw has an axial duct 48 which communicates with a diametrical assage 49 extending through the portion 4 It will thus be apparent that the space inside the cap 45 will be maintained at atmospheric pressure because of its communication with the atmosphere through these passages 48 and 49. This cap construction and rather circuitous passage for permitting air from the atmosphere to freely enter into the compartment 41 is thus constructed to eliminate the possibility of mercury leaking from the carburetor, should it accidentally be tilted or be turned up side down. It will be apparent that should the carburetor be inverted the mercury will merely run downwardly through the passages 42, 43, 44 and will be caught within the cap 45. The quantity of mercury in the carburetor is not suiicient to permit it to pass through the ducts 48 and 49 even if all the mercury should drain to the inside of the cap 45. It will also be noted that the top of the ioat chamber 27 i's dome shaped and that the wall surrounding the small chamber 18 extends downwardly a suiiicient distance so that even if the carburetor should be inverted the mercury could not escape through the port which surrounds the valve stem 23 and which connects the oat chamber with the chamber 18. Upon turning the carburetor back to normal position, the mercury w1ll gravitate back into the well, 32. No matter how the carburetor is tilted, it will be imppssible to pour any of the mercury from it, slnce the only passage to the atmosphere 1s through the ducts 48 and 49, and since, due to the peculiar construction, it is impossible for any of the mercury to escape through these passages. This is a very important feature since if, through inadvertence or carelessness in handling, some of the mercury could be spilled from the carburetor this loss would entirely alter' the functioning of the carburetor and make it necessary to completely readjust it. l

Gasoline, or other liquid fuel, is supplied tothe carburetor by the pipe 4, which terminates in the connection 51 screwed into the carburetor body, and has a passage through the chamber 52, through the strainer 53, and through the ducts 54 into the central chamber 55 which lies immediately above the valve 24. It will be apparent that the upper body portlon 47, may be unscrewed fnom the lower portion to permit the removal of the filter screen or strainer 53, for cleaning.

lows:

Upon starting the engine, air is drawn through the Venturi tube 19 with great velocity. The rush of this air through the tube causes a vacuum at the ports, or ducts 21, at the throat of the tube, which reduced pressure is communicated to the valve chamber 27, whereupon the mercury will rise in the tube 31 until it surrounds the float 26 and raises it sufficiently to remove the valve 24 from its seat 25. Thereafter when the valve 24 is no longer seated, the reduced pressure is communicated directly to the chambers 55, 52 and connecting passages 54, so as to draw the gasoline or other liquid fuel from the suppl tank 3 thereto. Since the quantity of liqui fuel delivered for the proper functioning of the carburetor is dependent upon the dili'erence in pressures between vthe chambers 10 and 27, there will be a fixed quantity of fuel delivered to the carburetor venturi re,

gardless of the fuel lift existing between the main tank 3 andthe chamber 27. This is true so long as the fuel lift does not exceed the depression in chamber 27 and because the differential in pressure between the chambers 10 and 27 is maintained substantially constant by the actuation of the float mechanism before described. Upon cessation of the operation ofthe engine, the valve 24 will seat and cut olf the gasoline supply line.

While the form of carburetor herein shown and described is admirably adapted to fulfill the objects primarily stated, it is to be understood that it was not intended to confine the invention to the one form of embodiment herein disclosed, for it is susceptible of embodiment in various forms, all coming within the scope of the claims which-follow.

I claim:

- 1. The combination of a low level tank with a carburetor having an induction passage, means for utilizing the partial vacuum in said passage to draw liquid fuel from said low level tank, a float chamber, a iioat therein, a valve operatively connected to said float and adapted to regulate the liow of the fuel from said low level supply tank to said induction passage, and a mercury well below said float chamber, the mercury therein being adapted to buoy saidioat upwardly upon the reduction of pressure in said float chamber, that portion of the mercury buoying the float being subjected to the partial vacuum of the induction passage and .the remaining portion being subjected to atmospheric pressure, and means for adjusting the level of the mercury in said well. l.

2. The combination of a low level tank with a carburetor having an induction passage, means forutilizing the partial vacuum in said passage to draw liquid fuel from said low The operation of the carburetor Ais as follevel tank, a float chamber, a float therein,a

valve operatively connected to said oat andI adapted to regulate the flow of the fuel from said low level supply tank to said induction passage, and a mercury well below said float chamber, the mercury therein being adapted to buoy said float upwardly uponthe reduction of pressure in said float chamber, that portion. of the mercury buoying the float being Vsubjected to the partial vacuum of the induction passage and thel remaining portion being subjected to atmospheric pressure.

3. In a carburetor, the combination of a float'chamber, a compartment surrounding said chamber, a oat movable in said chamber, a fuel inlet, a valve for regulating the admission of fuel secured to said oat, a'

vmunicating with the atmosphere 'point within the compartment, but spaced quantity of fluid .of high specific gravity.

adapted to buoy lsaid float upwardly and to open said valve upon a predetermined reduction of pressure in said float chamber, and means for permitting the free admission of air at atmospheric pressure to said compartifnent, but preventing the escape of Huid thererom.

4. In a carburetor, means for supplying fuel to the carburetor including the combination of a float chamber, a compartment surfrom the walls thereof so that the liquid will 70 not escape when the compartment' is inverted.

' In witness whereof, I hereunto subscribe my name this 9 day of October, 1926.

' g CARL W. SPOHR.-

rounding said chamber, a float movable in l l 'said chamber, a quantity of mercury sealing the lowerend of said chamber in said compartment, said mercury being adapted to rise within said float chamber and buoy said float upon a reduction of pressure in said float chamber, and a means permitting the ingress of air to said compartment, butl preventing the escape of mercury from the carburetor.

5. In a carburetor, means for supplying fuel to the carburetor including the combination 'of 'a float chamber, a compartment surrounding said chamber, a well below said said chamber and compartment, walls separating said chamber from said compartment and terminatingv in a tube 'extending into said well, a luid of high specific gravity 1n said well, a passage from the atmosphere to said compartment, said passage permitting air to enter said compartment but preventing l the removal of said fluid therefrom.

6. In a carburetor, means for vsupplying fuel to the carburetor including a' float cham# ber, a compartment surrounding said chamber, passages from` said compartment upwardly through said body, an inverted cupshaped member, closing the top of said compartment, and a assage cummunicating with the atmosphere 7 In a carburetor, means forv supplying om a point Within said cu member but spaced from the walls thereo

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