US1505566A - Carburetor - Google Patents

Description

Aug. 19 1924.

C. F. JOHNSON CARBURETOR Filed Dec. 21. 1916 HHM fz i

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ATTORNEY vPatented Aug. 19, 1924.

.STATES CHESTER r. JoHNsoN, ornnrao-IT, Mrcmea'n.

Application filed December 21, 1916. Serial No. 138,145.

To all whom t may concern:

Be it known that I, CHESTER F. JOHNSON, a citizen of the United States, and resident of Detroit, Wayne County, State of lWichigan, have invented certain newand useful Improvements in Carburetors, of which the following is a specification.y l

This invention relates to carburetors, or fuel mixin devices.

Une of t e objects of this invention is to provide simple, improved, and efficient quallity regulators for fuel mixing devices.

Another object of my invention is toprovide a carburetor, with improved means for regulating the flow of fuelpto the mixing chamber under pre-determined conditions.

In the form illustrated, the various objects are obtained by varying the pressure of the air on the liquid within the 'fuel chamber.

In general, my invention involves the use of a carburetor comprising a mixing chamber, a fuel chamber, therefor, and a nozzle through which fuel from said fuel chamber is discharged into said mixing chamber; and includes means for admitting pressure to the surface of the fuel within `the chamber in which it is contained to thereby increase the pressure on the fuel as a throttle valve 3@ for controlling the flow of combustible mixture to the engine is opened; thus increasing the richness of the mixture and accelerating the motor with which the carburetor is connected;I said throttle valve and said means for admitting pressure to the fuel in the fuel chamber being connected together s o as t operate in unison. This means is so arranged that after the throttle is opened wider and has come to rest in a new position 40 the pressure upon the fuel is automatically reduced, whereby a satisfactory mixture for each particular position of the throttle will be secured.

The various objects, purposes, constructions and principles involved, will more clearly appear from the following description, taken in connection with the accom- 'panying drawin s, which' form a part of this specification, an in which:

Figure I is a side elevation with portions broken away, of a carburetor embodying a preferred form of my invention;

Figure II is a vertical section, substantially on the line 2--2 of Figure I; and

Figure III is a fragmentary vertical secing chamber on a shaft 18, on the end of which may be secured an `operating arm 19.

Arranged below and suitably secured to the carburetor body 10, is a fuel chamber 20. 'Ihe fuel chamber comprises a float bowl or shell 21, a cover member 22 having an intake ort 23, adapted to be controlled by a need e valve member 24, and a float 25, suitably pivoted to the cover memberv as at 26. It will be noted that the' cover member l22 is formed with a depression 27, in the center of which is formed a fuel nozzle 28, adapted to be fed from the interior of the chamber 20. Suitably mounted between the carburetor body 10 and the cover member 22, is a plate 29 provided with a Venturi tube 3Q. The fuel chamber 20 is provided with a vent or relatively small air port 31 arranged above the normal level of fue therein.

It will also be noted that the carburetor is provided with a primary air port 32, formed in the cover member 22, and that the auxiliary air port 13, if any, is in direct communication with the mixing chamber .11, by means of the laterally .extending portion 12 of the carburetor body.

A conduit, or air'passage 33, is provided, connectin the fuel chamber and the mixing chamber y means of the ports 34 and 35 respectively. It will be noted that the vacuum within the mixing chamber 1,1, will 100 by means of the conduit 33, be communicated to the fuel chamber 20, thus tendmg to normally 'reduce the eect of atmospheric pressure on the fuel within the chamber', v and thereby -retarding the flow of. fuel 105 through the nozzle 28. I

The previously described parts and-passages of the carburetor, are so proportioned and adjusted, that with the throttle 1n any yfixed position, such as .for idling or la- 110 boring `of the motor, or high speed light running conditions, the mixtureproduced 1s ade uate and sufficient for such conditions.

ile the previously described construction and" arrangement of parts may be sufficient for fixed running conditions, it is desired to produce, at times, a richer mixture such as when the throttle valve 17 is opened quickly for accelerating the motor. This means may be in the form of a relatively large air vent or port 36, formed in the cover member 22, of the fuel chamber 20. This port may be controlled by a valve member 37 having a piston or plunger portion 38 arranged in a cylindrical member -39, having a plvotal connection as at 40, with an arm 41, fixed to the throttle shaft 18. The plung ger portion 38 of the valve member 37, is so. dimensioned that lit fits rather closely in the cylinder 39.

It will be noted thatwith the throttle in closed position, the-valve member 37 will rest on, and render the port 36 inactive. If the throttle valve 17 is opened quickly, it will simultaneously lift the'cylinder 39, and anyy tendency for the valve member 37 to remain in its closed position will be momentarily overcome bythe suction between the top of the piston 38 and the cylinder39, thus opening the port 36 and decreasing the tendency of the air passage 33 to retard the flow of fuel through thenozzle 28, and

lriereby accelerating the flow of fuel 4there- A spring 42, may be arranged between the end of the piston lprtion 38 and the cylinder 39, for gradua y relieving the vacuum within the cylinder and returning the valve member 37 to its seat. The return movement of the valve member 37 to its seat will, of course, be governed by the amount of clearance provided between the piston portion and the cylinder 39. If the clearance is great enough, there will, of course, be no necessity for the spring 42, as gravity will return the valvemember 37 to its seat. This clearance may be made variable by having the piston and cylinder formed ofv metals having different coefficients of expansion, thus automatically compensating for variations of climatic or temperature conditions.

It will be understood from the foregoing description, that the port 36 isi-normally closed by itsvalve, regardless of the throttle positlon, thereby prducinga certain quality of mixture, but should it be desired to accelerate'the motor by throwing the throttle 17 open wider, the valve 37 would be lifted by the throttle arm 41, and the cylinder 39, after which the valve is slowly returned to litsseat, and, of course, the vflow of fuel through the nozzle 28 will be accelerated during the period the port 36/is open, with the *result that the mixture is 'enriched for providing 'an accelerating mixture.

While I have described and will specifembodiment of my invention, it will be obvious to those skilled in the art, that various modifications and changes may be made without departing from the spirit and scope thereof. Y

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In a carburetor for internal combuston engines, a fuel chamber, a mixing chamber, a fuel passage'leading from the fuel chamber tothe mixing chamber, a throttle valve, and means independent of the suction of the engine and yieldingly connected with said Vthrottle 'valve foradmitting pressure to the surfacevof the fuel in said chamberwhereby the How of fuel through said passage is controlled.

ling said port, a mixing chamber, a fuel passage leading frorn the fuel chamber to the mixing chamber, a throttle valve, and means comprising an extensible connection for operating said first Vvalve with said throttle valven y 3. In a carburetor,a first passage through which air flows on its way to the en ine, a fuel chamber arranged to supply lel to said passage, a second passage leading from a point in the fuel chamber above the level of fuel therein to said first passage and tending to establish sub-atmos heric pressure in said chamber, a thrott e valve for the first passage, and means for momentarily increasing and afterwards reducing the pressure in the fuel chamber when the throttle valve is moved inv one direction;

4. In a carburetor comprising a fuel chamber` a mixin chamber connected therewith, and a thrott e valve for controlling the How of fluid through the mixing chamber, an `air port leading to said fuel chamber above the level of the fuel therein, a valve for saidvport, and means connecting said two valves so constructed and arranged that the second mentioned valve is opened as the throttle valve is moved quickly in one direction, and is thereafter automatically gradually closed independently of the throttle valve. l

5. In a carburetor, the combination with a fuel chamber having an-air port, a. valve for said port, a mixture passage supplied with fuel from said chamber, a throttle valve for said passage, and interconnected means, independent of the suction of" an engine to which the carburetormay be connected, for

simultaneously opening said valves. said'V L communicating therewith, a port for admitting air to the fuel chamber, a passage connecting the first named passage to the fuel chamber above the level of the fuel therein, and means acting to normally close the port, said means including a cylinder and piston construction arran ed to open the port at will and to therea ter gradually close said 4 port. p

7. In a carburetor, a passage through which air flows to the engine, a fuel chamber communicating therewith, a port for admitting air to said chamber, a passage connecting said lirst named passage to the upper part of said chamber to reducethe pressure therein when the engine is running, a valve for said port, a throttle for the first named passage, and a temperature responsive connection between 'said throttle and said valve.

In testimony whereof I aix my signature.

CHESTER r.y JOHNSON.

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