US2201381A - Carbureting and ignition system for internal combustion engines - Google Patents

Description

May 21,.1940.

MALLORY CARBURETING AND IGNITION SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed March 2, 1940 INVENTOR. MARION MALLORY ATTORNEY .S.

Patented May 21, 1940 UNITED STATES CARBURETING AND IGNITION SYSTEM FOR INTERNAL COMBUSTION ENGINES Marion Mallory, Detroit, Mich.

I Application March 2,

7 Claims.

This invention relates to a carbureting and ugal governor and a vacuum spark advance device is required.

In my invention, I eliminate the centrifugal speed governor. In my system, a spark advance curve is produced equivalent to the one produced by the centrifugal governor by using the vacuum created by the speed and flow of air through the carburetor itself. In other words, as the air flow is increased through the carburetor, the spark is advanced in accordance with the engine speed because the speed of the air through the carburetor is in direct relation to engine speed, and, since the vacuum is increased as the speed of the air increases, I utilize the vacuum to advance the spark which produces a spark curve in relation to engine speed. v

My carburetor is so constructed that, when the engine is operating under light loads or part throttle, to check the air flow, the vacuum is increased in the mixing chamber, and I utilize this vacuum to give additional spark advance for light load and part throttle operation.

In view of the above it will be seen that the object of my invention is to produce a carburetor vacuum operated spark advancing and retarding mechanism which will give proper ignition timing under all operating conditions of the internal combustion engine and which is considerably cheaper to make than the ignition timer with the centrifugal speed governor.

Fig. 1 is a, sectional view partly in elevation showing the vacuum spark advance mechanism and carburetor.

Fig. 2 is a fragmentary section showing a modified form of the invention.

'Referring to Fig. 1, valves l and 2 are connected together by linkage 3 so that they open and close in unison. Suction device 4 is connected into venturi or mixing chamber 5 by conduit 6 and through valve mechanism 1.

It will be understood that the vacuum congb The vacuum between the 1940, Serial No. 321,947

tions in the mixing chamber 5 of my carburetor are different than in the conventional plain tube carburetor. For example, in the plain tube carburetor, the mixing chamber suction is lower when the throttle is partly open than itis when 5 the throttle is wide open. In my carburetor, the vacuum is higher in the mixing chamber when the throttle is partly open than when it is wide open. This produces an ideal condition for ignition timing because it is under light loads and on 10 part throttle that the higher vacuum is used to give more spark advance, and, when the throttle is opened, the vacuum decreases and gives less spark advance.

The carburetor comprises a throat having an air intake opening 2| and a fuel mixture outlet 22 into the engine intake manifold. Fuel is I drawn from the float bowl 23 through passageway 24 into the mixing chamber or venturi 5. For purposes of description rather than by way of limitation, the carburetor throat 20 is also provided with venturi 26.

The suction device 4 comprises a flexible diaphragm 21 mounted in housing 28. The. diaphragm on one side is connected by conduit 6 and passageway IS with the venturi 5. The diaphragm on the other side is subjected to atmospherlc pressure. The timing mechanism is-conventional and as shown consists of the usual rotatable cam 29 which rotates in the direction of the arrow. The electrical circuit breaker 30 is mounted on plate l4 which is rotatable clockwise through a few degrees from the full line posi-- tion shown to advance the spark timing. As shown, the plate I4 is in spark retarding position. .Plate I4 is connected with the diaphragm 21 by connecting rod 3|, one end of which is pivotally connected to plate I as at 32 and the other-end of which is fixed to the diaphragm 21.

Communication between conduit v6 and passageway I5 is controlled by a sliding valve consisting of pistons H and I2 mounted in the cylindrical opening 33 in valve housing I. The upper end of cylinder 33 is open to atmosphere through aperture Ill. The valve H, I2 is provided with a valve stem 9 which is connected to crank arm 8. Crank arm 8 is fixed to pintle 34 upon which throttle valve 2 is mounted. Thus, opening and closingof throttle valve 2 acts upon crank 8 and 'valve stem 9 to open and close valve ll, l2.

The operation of my system is as follows:

Assuming the engine is idling and valves I and 2 are almost closed, there will be an existing vacuum in the mixing chamber between the two valves of approximately of mercury. The

suction device t is powerful and will start to advance the spark at of vacuum in mercury. However, the spark will not be advanced when the engine is idling because the vacuum is shut ofi from suction device t by the valve i2. When the throttle 2 is closed, arm a moves the small pistons ii and i2 upwardly so that piston i2 closes passageway i5 and shuts ofi the suction device from the mixing chamber and air bleeds the suction device through the small hole it. There is just a slight leakage around piston it when it is in its upper position to to permit sufficient air bleed of suction device d. It is necessary to air bleed this device so that compression spring is will retard the timer plate M. As the throttle valves l and 2, which operate simultaneously, are opened, the piston I2 moves downwardly placing passageways i5 and d in communication and connects the suction device to the mixing chamber or venturi 5 through conduits 6 and ii. The vacuum will immediately advance the timer plate It.

As the valves i and 2 are further opened, the vacuum will continue to increase as long as valves i and 2 restrict the engine breathing or suction, but as soon as the valves are opened wide enough so that they no longer restrict the engine breathing or suction, the vacuum in the mixing chamber 5 will decrease and the spark timing will retard. Advancing of the spark now depends entirely on the vacuum created in the mixing chamber or venturi 5 by the speed of the air flowing through the venturi. It will be observed by the drawing and explanation that my system produces two spark advance curves-one for light load or part throttle, which gives more advance, and one for wide open throttle or full load, which gives less advance. Thus the venturi suction in the carburetor is used for wide open throttlespark advance and the mixing chamber vacuum for part throttle advance.

Although the suction device 4 is never subjected to the full intake manifold vacuum due to the action of valve l2, however, the system will work without this valve 12. In the absence of valve 12 the spark would be considerably advanced at idle but not enough to cause trouble.

The modified form of the invention shown in Fig. 2 is identical with that shown in Fig. 1 except that valve i2 is omitted and conduit ii communicates with the large venturi 26 by means of passageway 40. The carburetor is identical with that shown in Fig. 1. Due to the absence of valve 12, the spark is considerably advanced at idle but not enough to cause trouble.

I claim: v

1. In an internal combustion engine the com-- bination of an ignition timer, a fuel mixture intake" passageway including a venturi, two throttle valves spaced apart in series in said passageway one on each side of the venturi arranged to open and close in unison, suction controlled means for varying the position of thetimer, and a passageway connecting the suction means with the venturi whereby the said means is controlled to vary the position of the timer by the suction produced by the flow of air through the venturi at .wide open; throttle and by the suction of the mixing chamber for part open throttle.

v 2. In an internal combustion engine the combination of an ignition timer, a fuel mixture intake passageway including a venturi, a second venturi positioned in the first venturi, two throttle valves spaced apart in seriesin said passageway one on each side of the venturi arranged to open and close in unison, suction controlled means for varying the position of the timer, and a passageway connecting the suction means witn the second venturi whereby the said means is controlled to vary the position of the timer by the suction produced by the flow of air through the second venturi at wide open throttle and by the suctionof the mixing chamber for part open throttle.

3. In an internal combustion engine the combination of an ignition timer, a fuel mixture intake passagewayincluding a venturi, two throttle valves spaced apart in series in said passageway one on each side of the venturi arranged to open and close in unison, a suction chamber for varying the position of the timer, and a passageway connecting the suction chamber with the venturi, and means responsive to a predetermined one on each side of the venturi arranged to open and close in unison, suction controlled means for varying the position of the timer, and a passageway connecting the suction means with the venturi, valve means in said passageway operatabie when the valve is in closed or idling position to close the passageway between the venturi and the suction means and to vent the suction means to atmosphere, whereby the said suction means is controlled to vary the position of the timer by the suction produced by the flow of air through the venturi at wide open throttle and by the suction of the mixing chamber for part open throttle.

5. In an internal combustion engine the combination of an ignition timer, a fuel mixture intake passageway including a venturi, two throttle valves spaced apart in series in said passageway one on each side of the venturi arranged to open and close in unison, suction controlled means for varying the position of the timer, and a passageway connecting the suction means'with the venturi, a valve in said passageway, a connection between the valve and the throttle whereby when the throttle is in closed or idling position the valve closes the passageway between the suction means and the venturi and as the throttle is moved from idling toward open position the valve is opened to permit free communication through said passageway between the suction means and the venturi whereby when the throt tle valves are partly open the suction means is subjected to manifold vacuum and when the valves are fully opened the suction means is subjected to the suction produced by the flow of air through the venturi.

6. In an internal combustion engine the combination of an ignition timer, a carburetor having a fuel and air mixing chamber with a fuel inlet into said chamber, two throttle valves spaced apart in series on opposite sides of the fuel inlet and arranged to open and close in unison, suction controlled means for varying the position of the timer, a passageway connecting the suction means with the mixing chamber between the said valves whereby the said suction means is controlled to vary the position of the timer by the suction produced by the flow of air through the mixing chamber at wide open throttle and by the suction of the mixing chamber for part open throttle. 1 I

"I. In an internal combustion engine the combination of an ignition timer, a carburetor having a fuel and air mixing chamber including a venturi with a fuel inlet into said venturi, two throttle valves spaced apart in series on opposite sides 10 of the fuel inlet and arranged to open and close in unison, suction controlled means for varying the position or the timer, a passageway connecting the suction means with the venturi adjacent the fuel nozzle inlet whereby the said suction means is controlled to vary the position 01' the timer by the suction produced by the flow of air through the venturi at wide open throttle and by the suction of the mixing chamber for part open throttle.

MARION MALDORY.

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