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Publication numberUS1289300 A
Publication typeGrant
Publication dateDec 31, 1918
Filing dateMar 11, 1916
Priority dateMar 11, 1916
Publication numberUS 1289300 A, US 1289300A, US-A-1289300, US1289300 A, US1289300A
InventorsWilliam O Stokes
Original AssigneeWilliam O Stokes
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
US 1289300 A
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Description  (OCR text may contain errors)

w. oi s ToKEs'.



Pmd Dee. 31,1918.


A 1 ou Hi. r

. s'rn Specieation of Letters Patent.


ra l 1' or NEW Yonx, N. Y.

applicati@ mea March 11, 191s. serial no. 83,493.

To all 'whom it may concern:

Be it known that I, WILLIAM O. S'roxns, a citizen of the United States, residing at New York, in the county of Bronx and State of New York, have invented certain new and useful Improvements in Carbureters,'of which the following is a full, clear, and exact specification.

This invention relates to carbureters, and has for its object to combine vwith an ordinary single jet or multiple carbureter an auxiliary carbureter which is especially intended for facilitating the starting of the combustion' engine, and also enabling the engine to run idly at a lower speed than is possible with the ordinary carbureter, and also assisting the ordinary carbureter to plil'olduce a better vaporization of the liquid Ordinary single jet carbureters are expected to vapor1ze the fuel under too wide a range of operating conditions. That is, the air passage has to be of sufficient size to feed the engine at the maximum speed, and

under such conditions the air velocity past the fuel nozzle, which is a function of the vacuum on the fuel nozzle caused by the engine suction, is such as to more or less satisfactorily vaporize the fuel. However, when the engine is throttled down, as by an ordinary butterfly or sliding throttle in the mixing chamber above the fuel nozzle, the air velocity at the fuel nozzle becomes Vso low, and the vacuum so slight, very little vfuel is vaporized. Even if the vacuum bestrong, and the air velocity past the fuel nozzle low, the only result is to draw the fuel from the nozzle in drops instead of inV atomized particles. It, therefore, results that in order to secure any vaporization at low speed, ordinary single jet carbureters are uneconomical at high speed, because they supply too much fuel. Moreover, when it is attempted to thin out the air at highspeed by means of automatic air valves, the low speed conditions .are not bettered, because there is still the defect of not having suliicient air velocity at the fuel nozzle to proper1 atomze the fuel.

' e above defects have induced the pro vision of various arrangements for priming the engine at low speed, such for example as injecting fuel into Athe top of the manifold, but these are not reliable, and are ineffective 5 when the temperature 1s very low.

By this invention, an auxiliary carbureter is provided, which is connected at the fuel end to the float chamber of the ordinary carbureter, and has its mixing chamber connected to the engine manifold above the orl dinary throttle, and above the main `fuel nozzle. The engine is now started solely 0n ythe auxiliary carbureter, with the main 4throttle entirely closed, the result being that the entire vacuum of the engine is directed across the auxiliary fuel nozzle, even atlow hand cranking speed, resulting in a certain vaporization of the fuel and much quicker and better starting of the engine, even at very low temperature. To facilitate the starting, the auxiliary carbureter is provided with a manually controllable needle valveV which can be opened at the moment of starting to permit a freer iow of fuel so 'as to form a relatively rich mixture, the needle valve then closing automatically to the predetermined running position suicient to form a proper mixture to maintain the engine at idling speed. An automatic air valve is also provided which will be come effective at the idling speed of the engine to properly thin out the mixture. As the engine speeds up and the throttle is opened to increase the power, the auxiliary carbureter is always operative, and enables the main carbureter to be set for a'thinner mixture than is otherwise possible. The result isthat by the combination of "1e main and the auxiliary carbureters a m 7 .h more powerful mixture is obtained and tnere is a decided economy of fuel.

In actual practice, it has been found that this invention is advantageous in iat fuel is saved, starting either by crank or :oy power starter is more certain, and more power is obtained from an engine equipped with this invention than one equipped simply with a stock carbureter.

In the accompanying drawings,

Figure 1 is a section of a carbureter embodying the invention;

Fig. 2 shows a simplified modification of the auxiliary carbureter, and y Fig. 3 shows an additional modification applicable to Figs. 1 and 2.

1 represents the intake manifold of the engine, A2 the gasolene supply to float chamber 3 through valve 4 controlled by float. 5,

and 6 is the fuel nozzle controlled by needle valve 7 and located in the air passage 8. 9 is an auxiliary air inlet which is controlled by anair valve as 10 located in the mixing Patented Dee. 31, 1918.-

chamber 11 below the throttle 12. The foregoing parts are all of usual construction,

and may be modified in accordance with high speed t0 practically throttle the fuel outlet 15. 17 is a screw for adjusting the position of float 16. Valve 16, in Fig. 1, is for the'purpose of opening and closing nozzle 15. At a very low engine speed with throttle closed as in `cranking, this valve drops, admitting more fuel, the quantity determined by adjusting screw 17, without decreasing the volume of air and also compensates, according to the opening of throttle 12 in main carbureter. When throttle 12 is closed, valve 16 is vdrawn closed at idling speed of motor. When throttle 12 opens, permitting a How of fuel from nozzle 6, with the proportion of air that'is necessary for the proper mixture, valve 16 remains closed, until throttlev 12 is opened about half Way. After that point of opening, the lvacuum decreases in the `manifold 1 above throttlel 12, also decreasing the vacuum in pipe 30. Therefore, the vacuum at nozzle valve 15, that holds 16 to .its seat, is reduced allowing more fuel to enter through pipe 30, whichpermits more fuel to pass te the weakened, mixture from large carbureter. This is quite necessary to get an economical, homogeneous and powerful mixture. As allicarbureters are'set for the proper mixture, with a small opening of throttle, s ay a quarter to av half opening, the mixture will weaken when throttle passes half opening which decreases power and causes preignitlon unless it is somewhat enriched, as just described. Where such refinement of liquid fuel flow is not desired, the screw 17 may be turned up so asrto cause the Hoat 16 to entirely cut olf the fuel nozzle 15. .The starting fuel nozzle 18 is supplied with .fuel-from-the pipe 14, andis controlled by needle valve 19 having a screw-threaded shank 20 threaded into the casing 21. .Y The screw 20 is provided with a lever arm 22, which is split and can lbe clamped to the screw 20 .by screw23. 24

is a spring having one end attached to the lever 22Yand the other end to the casing 21 tending to turn the screw 20 down into the casing to close the needle valve 19. 25 is a stop on the opposite end of arm 22 which contacts with the casing to limit the closing movement of the needle valve 19. By loosening the screw 23, while the stop 25 is against the casing, the screw 2O can be adjusted in 0r out to give the proper needle valve opening. This is determined by running the engine and adjusting the needle nasascov valve until the properv mixture is obtained, the main throttle 12 at this time being closed. Ordinary throttles 12 usually are cut out so as to leave some slight opening at all times through the mixing chamber, but better results are obtained with this invention if the throttle is caused to completely shut of the main fuel nozzle 6 when closed. This, however, is not essential. The arm 22 is connected by a link 27. either to' the dash, where theengine is equipped with a self starter, or to the. front Where'the engine is to be cranked by hand. Both connections may be used lso that the needle valve can be controlled-whichever mode of starting is used. 28 is the. air inlet for the auxiliary carbureter which is controlled by air valve 29 and the mixture 'passes through the mixing pipe 30 to the inlet manifold above the throttle 12. Valve 29 is for the purpose of controlling vacuum and regulating volume.

32 is an auxiliary air inlet for the auxiliary carbureter which is controlled by a spring pressed angular valve 33, the tension of the springbeing adjusted by nut 34. Air valve 33, is for the purpose of controlling the vacuum and ladmitting more air into manifold. Valve 33 is made of regular polygons of stock which preventsv valves from sticking or becoming clogged. This auxiliary air inlet valve 33 is adjusted so that it does not open when the engine is being cranked, eitherby hand or by thev starter, but when theengine isV running idly, its speed is su'liciently increased to produce suiiicient vacuum so as toslightly open valve 33. This thins out the mixture t0 the proper degree so as-to produce even and powerful explosions in the engine cylinders. The lever 22 is only actuated momentarily as the engine pistons begin to move, so vas to let the liquid fuel iow freely through nozzle 18 while nozzle 15 is closed. Owing tothe relatively small size of pipe 28 and the high air velocity across the fuel nozzle' 18, the action is similar to that of an atomizer, and the fuel is strongly atomized and thoroughly mixed with the air before it reaches the engine cylinder. 36 is a set screw for clampu .ing the nut 34 in adjusted position.

cutting down the initial air and producing a somewhat richer mixture and easier starting. From the foregoing descriptlon, 1t 1s thought vthat the operation of the device can be clearly understood. It will be seen that in operation, there will always be some vacuum through the auxiliary carbureter even with the main throttle wide open, and this will produce a powerful mixture upon a minimum quantity of fuel. As the main throttle 12 is closed, the vacuum becomes stronger through the auxiliary carbureter and thereby produces a better mixture than can be produced by the main carbureter at low speed.

' The small carbureter produces ample mixture to both start the engine, and to allow it to idle, and in practice where this invention has been applied to a stock carbureter it has been found that the engine will start easier, and idle at a much lower speed than was possible by the stock carbureter alone. This is a feature of decided advantage owing to the present trend toward high speed engines, because it has been found that many of these engines do not idle well with the ordinary stock carbureter unless at a rather high speed. When equipped with this invention a much lower idling speed can be secured without galloping or jumping, or flooding of the carbureter. the engine is developing power, a greater drive at low speed is produced because of the better and more homogeneous mixture.

Various modifications and changes may be made in the detailed construction herein shown without departing from the scope of the appended claims.

Having thus described my invention, I declare that what I claim as new and desire to secure by Letters Patent, is

1. An auxiliary carbureter for attachment to a main carbureter, said auxiliary carbureter being of low capacity for starting and idling and being inversely effective according to the opening of the main engine throttle, comprising a casing having a fuel inlet contalnlng` a fuel nozzle, an a1r inlet, a mix- At runnlng speeds, where ing passage extending from said nozzle to the main carbureter mixing passage, a needle valve in said fuel nozzle having a closing spring, adjustable means for limiting the closed position, and means controllable from a distance for opening said needle against the spring, said needle valve returning to its adjusted open position when released.

2. An auxiliary carbureter for attachment to a main carbureter, said auxiliary carbureter being of low capacity for starting and idling and being inversely effective according to the opening of the main engine throttle, comprising a casing having a fuel inlet containing a fuel nozzle, an air inlet, a mixing passage extending from said nozzle to the main carbureter mixing passage, an auxiliary air inlet having an automatic air valve, a needle valve in said fuel nozzle having a closing spring, adjustable means for limiting the closed position, and means controllable from a distance for opening said needle against the spring, said needle valve returning to its adjusted open position when released.

3. In combination with a main carbureter comprising a float chamber, fuel nozzle, mixing passage, auxiliary air inlet, and throttle, a flow controlled fuel throttling valve in the fuel nozzle, and an auxiliary low capacity carbureter connected between said float chamber and said mixing passage beyond said throttle, said auxiliary carbureter having an air inlet to its fuel nozzle, a spring closed needle valve therein, and an adjustable stop for limiting the closing of said valve so that it closes from wide open position to a predetermined open runnlngv position.,

In testimony whereof I aix my signature, in presence of two witnesses.

WILLIAM o. sroKEs.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3669420 *Nov 17, 1971Jun 13, 1972Automotive Exhaust Control CorAuxiliary air fuel mixture control system for reducing automotive exhaust emissions
US3963670 *Mar 7, 1975Jun 15, 1976Acf Industries, IncorporatedIntegrated idle and by-pass system
U.S. Classification261/41.5, 261/50.1, 261/54, 261/121.3, 261/DIG.800
Cooperative ClassificationY10S261/08, F02M3/12