US1922569A - Carburetor - Google Patents

Description

Aug. 15. 1933.

L. DE MARCO CARBURETOR Filed May 20, 1932 3 Sheets-Sheet 1 4 wuw/tw- LOU/5 DKNHRL'O ATTORNEY Aug. 15, 1933. DE MARCQ 1,922,569

CARBURETOR Filed May 20. 1932 3 Sheets-Sheet 2 INVENTOR LOU/5 ZEN/7R ['0 ATTO RN EY L. DE MARCO Aug 15, 1933.

CARBURETOR Filed May 20, 1932 3 Sheets-Sheet 3 (a a A: a 2 3 2.

H I 1 m5 b llllLl Fla. 9

INVENTOR LOU/5 HEM IPZW ATTORNEY :Patented Aug. 15, 1933 1,922,569

UNITED STATES PATENT OFF-ICE 1,922;569 CARBURETOR Louis De Marco, 'Cleveland,'()hio, 'assignor of giiteen per centto Percy A. Sewn-Cleveland,

Application 'May 20,1932. Serial No. 612,534

' "6 Claims. (01. 261-52) This invention relates in general to carburetors tial control is necessary while the engine is runfor automobiles and other internalcombustion ning' under conditiona where comparatively little engines which carburetors effect vaporization of power is required and the suction of the engine-is gasoline or other fuels and themixing of the Substantial.

- '95 vaporized'fuel with a suitable amountof air to With these "and other objects in view'the inso obt in hi h p explosions the cylindersof vention consists in theconstruction andnovcl the engine, and more particularly to suction carcombination of partsfully described hereinafter, buretors such as extensively usedfor automoillustrated, in t e a p y d w bile engines. It is well known that the best re-- pointed out in the claims appended hereto, it

lt are Obtained h th tions' of fuel being understood that various changes in the c;

and-air in the mixture are such'that complete for proportion, size and minor details of combustion of all the gasoline in the mixture struct on-w'it i th D 'OTYCIHJimS, y-

takes'place attheproper time leaving no 1111- sorted to without departing from the spirit of burned parts to be wasted. It is also well known e ve t Ofithat this desirable result is difficult of attain- In the drawing w plified form 70 ment with suction type of carburetors. *Thus, O a Carburetor embodying the inventifln! when theispeed of'fheiengineincreases th Figure lis a side elevation of a-carburetor action produced increases inpropoition- Increased w it g the invention; suctionproportionallyincreases theamount of -F u1' isa longitudinal vertical Section view 26 gasoline sucked from the gas nozzle of the carhr h the carburotorshown in Figurel;

buretor. On the other handg increased' suction v Figure 3 is a Sectional View On 01 does notproportionally 'increase the amountof Figure air passing through the air passage and conse- Figure 4 is a sectional view on line 4 4' ofFig- V quently, at the" higher speeds of thee-rigineythe i 7 25 i t r 111 be t h gasonne e nd Figure 5 is a sectional view on line 55- ofFig- 90 therefore much waste, accumulatibnof'caibon, lire l interference with the proper lubrication of the Figures 6, 7, 9 Shaw diaglammatical Views cylinder walls, and'fouling of spark plugs will. of the positions of the valves the throttle valve occur. I Y a i and the air intake control valveat difierentspeeds When drivingat'm'edium speeds, say coasting h enginevThus $5 range,'or'whileigoing down hill'cor'nparatively Figure 6 ShOWSthe Starting position of Said littlepower is needed. "Under-such conditions valve economy:- and smooth performance of the engine Figure the medium Speed position of Said ca-ll for a'rather'leanmixture, whereas, hard valves;

pulling of the engine at low speedsfor {instance F gu e ii' high speediposition of said a v 90 while climbing a hill, must be met with a-slightly and richer mixture. Figure 9 the high power position of said valves The primary object of the present invention'is 'at relat v l low p to provide means for controllingthe amount of W q p of Carburetor A illustrated 40 :airdrawn into the mixture chambersothatthe herein embodies three main parts, the gasoline proper mount 0fair:wi11.be automatically "fed orfloat chamber B; the barrel or mixing chamber into'the carburetor and mixe'dwith-the gas 'to C and the air intake D. The carburetor A is form the gas and air mixture-most efficientunder spli h i y as t thus p v in n pp r the'existing conditions of speedetc. part 3 which forms a cover member for float 7 Aiurther object of the:inventionisto provide chamber B arranged in a lower part 4. A-float a valve: arranged inthe air intake of the carbu- 5 within chamber Bhingedly attached to upper rotor and controlled by the suction of the engine, part3, as at controls the movements of needle for'reeding a correspondingly increased volume valve 6 in inlet passage 7 of a valve body 8 for of'air into the mixing chamberwhen the suction maintaining the gasoline in chamber B at a preof the engine increases. determinedlevel. An inlet passage 9 adjacent a A: still further object of the invention is to conremovable strainer 10 and in communication with plc the automatically actuated control' of the a fuel container not shown feeds gasoline into valve in the air intakelwiththe throttle valve of passage 7, from whence it'flows into chamber B thecarburetortoeffect partial control of the whenever the float 5 drops suificiently to open valveinthe air intake by the throttle. .Such parvalve 6. 10

Float chamber B communicates with the barrel or mixing chamber C, through a spray nozzle 11 threadedly secured within and extending through a passage 12 formed in the lower part 4 of the carburetor. Nozzle 11 is formed with a lateral passage 15 adjacent its lower end in alinement with and forming a continuation of a short passage 1'? formed in the bottom wall of chamber B.

The desired charge of gas will thus be sucked from chamber B through passages 17 and 15 and thence out through the central opening 16 in nozzle 11 into mixing chamber C. The customary idling jet 2o also draws fuel from chamber B upwardly and discharges into barrel chamber C through port 21 arranged with its outlet end adjacent the edge of the common butterfly throttle 22, so that it operates only when said throttle is slightly opened.

An air intake D communicating with barrel chamber C furnishes the necessary air, when the suction of the engine creates a vacuum in barrel chamber C, and a vacuum controlled air valve 23 of common butterfly type controls the amount of air flow. Valve 23 is actuated by a piston 24 arranged within a cylinder 25, on upper part 3 of carburetor A. This cylinder communicates through passage 26 with barrel chamber-C just above butterfly throttle 22 for continuous exposure to the suction of the engine. A downwardly extending piston rod 27 on piston 24 and preferably integrally formed therewith is guided in a longitudinally slotted sleeve on-extension 28 of cylinder 25 and this piston rod is coupled with valve 23. Thus piston rod 27 is slotted at 29 for engagement with a lever 30 pivotally mounted on shaft 31 of air valve 23 and yieldingly secured thereto by means of a spring 33 attached at one 7 end to an extending arm 34 of said lever and at its otherend to a clamp 51 rigidly secured to the shaft '31, to permit of slight relative movement of lever 30 with respect to shaft 31 for a purpose later to be described. The free end 35 of lever 30 is formed with a flat circular enlargement 36 which extends through slots 3'7 in extension 28 of cylinder 25 and thence into slot 29 for actuation during shifting of piston 24 and its piston rod 27 Piston 24 is yieldingly forced in a downward direction by means of a compression spring 38 arranged within cylinder 25 and seated between piston 24 and the top wall 39 of said cylinder, a

sleeve likemember 40 serving as a guide for the spring to prevent buckling when under compression.

The automatic actuation of air valve 23 by the suction of the engine is partially limited by throttle valve 22 to prevent unrestricted opening of air valve 23, except when valve 22 is fully open. Thus a lever 43 rigidly attached to shaft 41 of throttle valve 22 is pivotally connected to a lever 45 by means of a connecting rod 33, the free end of lever 45 being in turn pivotally connected to the part A of the carburetor. Lever 45 is formed with a bifurcated outer end 49 which slidably embraces the piston rod 27, the latter being provided with a flange 48 at its lower end for limiting the upward movement of piston 24, when the forked shaped end 49 of the lever 45' engages with flange 43. It will of course be understood that a manually operated choke valve is unnecessary because of the automatic choking action of the carburetor.

When a very rich mixture is desirable, as in starting a cold engine, the throttle valve is slidably opened manually, whereas the air valve will of the engine so that spring 38 can force piston sequently the mixture decreases in richness, due

to the admission of an ample supply of air, see the diagram shown in Figure 7, which shows driving at medium speeds or on a smooth road where comparatively little power is needed, and the engine suction is relatively high.

When full power is desired, the throttle valve 22 is fully opened. This will raise lever 45 to the position shown in the diagram of Figures 8 and 9 thus permitting the full opening of air valve 23 and also the closing of air valve 23 when the suction of the engine materially decreases. Assuming the engine is going at high speed with fully opened throttle, then the suction of the engine is so high that piston 24 will be fully raised and air valve 23 fully opened (see Figure 8). Decrease of engine speed for instance while climbing a hill with fully opened throttle valve materially decreases the suction 24 downward and thus partly close the air valve 23. This action automatically increases the richness of the mixture at a time when most needed, a diagram showing the relative position of throttle valve 22 and air valve 23 under conditions just recited is shown in Figure 9.

The yielding connection of air valve 23 with lever 30 permits relative rotation between shaft 31 of valve 23 and lever 30 and thus prevents damage or breakage of lever 30 by backfiring.

Throttle valve 22 is actuated as customary by a push and pull element (not shown) ordinarily mounted on the steering gear or instrument board of the automobile. A wire connection also not shown interconnects said ,push and pull element with the operating lever 42 on shaft 41 of throttle valve 22,

Having thus described my invention:

What I claim is:

1. A carburetor comprising a body, mixing and fuel chambers in said body, a nozzle in the mixing chamber, a throttle valve in said mixing chamber, an air intake chamber, a valve in said air intake chamber, means to yieldingly hold said .latter valve in closedposition, means adapted to open said latter valve according to the speed of the engine and means for limiting opening of said latter valve according to the position of said throttle valve.

2. In a carburetor a throttle valve and a valve controlling the air intake, means to open said latter valve according to the speed of the engine, and coupling means between said throttle valve and said other valve for limiting the opening of said other valve to definite positions in accordance with the opening of said throttle valve.

3. In a carburetor a throttle valve and a valve controlling the air intake, means to open said latter valve according to the suction of the engine, and coupling means between said throttle valve and said other valve and preventing full opening of said other valve unless said throttle valve is sufliciently opened.

4. In a carburetor a throttle valve and a valve controlling the air intake, a cylinder communieating with the intake side of the engine, a piston within said cylinder coupled with said air controlling valve, means to yieldingly close said latter valve, and means coupling said throttle valve with said air controlling valve and preventing Iull opening of said air controlling valve unless said throttle valve is sufiiciently opened.

5. In a carburetor a throttle valve and a valve controlling the air intake, a cylinder communieating with the intake side of the engine, a piston within said cylinder having an extension coupled with said air controlling valve, a lever pivotally mounted on said carburetor connected with said piston and .means on said extension of said piston cooperating with said lever to limit the upward movement of said piston and therewith the opening of said air controlling valve unless said throttle valve is sufficiently opened.

6. In a carburetor, a throttle valve, a valve controlling the air intake, a cylinder communicating with the intake side of the engine, a piston within said cylinder having a slotted extension, ,a lever coupled with said air controlling valve and slidably interengaged with said slotted extension of said piston and means coupled with said throttle valve and slidably interengaged with said extension of said piston for limiting the operation of said air valve by said piston in accordance with the position of said throttle valve.

LOUIS DE MARCO.

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