US2293842A - Carburetor for internal combustion engines - Google Patents

Description

Aug. 25, 1942. M. MALLORY 2,293,842

CARBURETOR FOR INTERNAL COMBUSTION ENGINES Filed Oct. 14, 1940 INVENTOR. MARON MALI-CRY /Wnw. W

ATTORNEYS.

Patented Aug. 25,-1 942 UNITED STATES PATENT OFFICE Marion Manor-y, Detroit, Mich.

Application mm- 14, 1940, Serial No. 361,022

6 Claims. (01. 261-65) This invention relates to a carburetor for an internal combustion engine and in particular to a carburetor for a high speed and high compression en ine.

The invention contemplates a carburetor having an intake passageway or throat of sufflcient size or cross section so that the engine can mented by thepull that diaphragm l3 exerts on arm Il to overcome or counteract the push that spring I] exerts against arm-I I.

The operation of the device is as follows:

Assuming that theengine' is idling, the fixed collar 8 on throttle rod III is held firmly against slidable collar I by spring 5 reacting against collar 6. When air valve 2 is a balanced valve or only very slightly unbalanced then as the throttle rod I0 is moved towards an open position, i. e., toward the left as viewed inFig. 1, collar .6 compresses the spring 5 against the slidable collar 1 which is fastened to the throttle shaft. arm 3. Therefore, it can be seen that spring5 acting through pin l2 and arm ll tends to compress the spring ll in the suction device taken in by the engine at all speeds to maintain an approximately predetermined. high compression without knocking. V

In the drawing the figure is a vertical cross section through a carburetor showing the throttle valve control.

Referring more particularly to the drawing, the carburetor comprises a housing having an air inlet 2| and fuel air mixture outlet 22. The intake passageway or throat of the carburetor is designated M. The carburetor is provided with the usual venturi 23 and fuel nozzle 9.

Y The throttle valve 2 is fixed upon the shaft 4 journalled in the housing 20. Valve 2 may be when the throttle is opened. These two springs,

.are so balanced that spring 5' cannot compress spring I] enough to open .the throttle very wide,

but, as the engine speed increases, the air fiowing through the venturi creates a suction at orifice I, which is imposed on diaphragm l3 and either balanced or unbalanced. Preferably, as

shown, valve 2 is an unbalanced valve.

' A lever 3 is fixed upon the throttle valve shaft 4 and is pivotally connected to collar I which is slidably mounted upon the throttle rod l0.-

Throttle rod I0 i a push and pull rod and has fixed thereon the spaced collars 6 and 8. Slidable collar I is positioned on rod Ill between collars 6 and 8 and backed up by coil spring 5. Lever 3 has a lost motion connection with arm H in the form of a pin l2 fixed on lever 3 which engages arm II in the elongated slot 24. The

other end of arm ll is fixed to the diaphragm l3.

enclosed in the housing It. Chamber I8 in the housing I6 is closed to atmosphere except through conduit l5 which communicates with the venturi passageway 23 through orifice I.

A coil compression spring ll backs up the diaphragm l3 in the chamber l8. Compression spring I! tends to hold the diaphragm and rod II toward the left and thereby hold throttle valve 2 closed. Spring 5 is also a compression spring but weaker than spring II. The force exerted by spring 5 against collar 1 is suppletends to assist spring 5 in compressing spring l1. As the engine speed increases, the suction created by the air flow through the venturi tends to move the diaphragm arm I I back or towards the right away from pin l2 so that spring 5 will cause the throttle valve 2 to move or swing open. Eventually the engin speed will be high enough so that the Venturi suction will be high enough to move the diaphragm arm far enough towards the right so that spring 5 is free to move the throttle valve completely open.

The throttle valve 2 'is shown slightly unbalanced. In this case it is not necessary to use spring 5 to assist the opening of the throttle valve and spring 5 can be omitted. If the valve is unbalanced, the vacuum between it and the engine will tend to open it against spring II as soon as the collar 8 is moved away from the sliding collar I by the movement of the throttle rod Ill. Of course, if a balanced valve is used, it will be necessary to use spring 5 to start its opening. Regardless whether valve 2 is balanced or unbalanced, sufiicient charge will flow by valve 2 when closed to idle the engine.

Iclaim:

1. In combination with a carburetor for an internal combustion engine having an intake passageway provided with a venturi, a throttle valve in said passageway on the engine side of said venturi, resilient means tending to close said throttle valve, manually operated primary means tending to, open the throttle valve and weaker than the above said resilient means for closing the valve, said manually operated primary means having a positive connection with the throttle valve for completely closing the same to idle the engine, and a suction device communicating with the venturi and applying a force against the said resilient means which force increases in magnitude as the speed of the air flowing through said venturi increases, said suction device supplementing said primary means to overcome said resilient means and opening the throttle valve as the speed of the air flowing through the venturi increases.

2. In combination with a carburetor for an internal combustion engine having an intake passageway provided with a venturi, an unbalanced throttle valve in said intake passageway on the engine side of the venturi and tending to open due to the vacuum on the engine side thereof, resilient means tending to close said throttle valve and for holding the same closed when the engine is idling, and a suction device communicating with the venturi and applying a force against the said resilient means which force increases in magnitude as the speed of the air flowing through said venturi increases, said suction device supplementing the unbalanced pressures on the unbalanced throttle valve tending to open the same and for overcoming said resilient means and opening the throttle valve as the speed of the air flowing through the venturi increases.

3. In combination with a carburetor for an internal combustion engine having an intake passageway provided with a venturi, a throttle valve on the engine side of the venturi, manually operated means having a lost motion connection with the throttle valve for opening the same and a positive connection with the throttle valve for completely closing the same to idle the engine, resilient means tending to close said throttle valve, a primary means controlledby said manually operated means and weaker than said resilient means tending to open the throttle valve when the manually operated means are moved in a throttle opening direction, and a suction device communicating with said venturi and responding to the vacuum created by the flow of air through the venturi for supplementing the said primary means with a force which increases in magnitude as the speed of the air flowing through the venturi increases to overcome said resilient means and open the throttle valve as the speed of the air flowing through the venturi increases. v

4. In combination with a carburetor for an internal combustion engine having an intake passageway provided with a venturi on the atmosphere side of the throttle, a throttle valve, manually operated means having a st motion connection with the throttle -valve'for opening the same, and a positive connection with the throttle valve for completely closing the same to idle the engine, a spring tending to close said throttle valve, 9. spring weaker than said flrst mentioned spring tending to openthe throttle valve when the manually operated means are moved in a throttle opening direction, and a suction device communicating with said venturi and responding to the vacuum created by the flow 01' air through the venturi for supplementing th weaker spring to overcome said stronger spring and open the throttle valve as the speed of the air flowing through the venturi increases.

5. In combination with a carburetor for an internal combustion engine having an intake passageway provided with a venturi on the atmosphere side of the throttle, a throttle valve in the intake passageway, a manually operated push and pull member, a pair of spaced stops on said member, a connection between the throttle valve and said push and pull member movable between said stops, a spring positioned between one of said stops and said movable connection tending to open the valve when the push and pull member is moved in a throttle valve opening direction, a spring relatively stronger than the aforementioned spring tending to close said throttle valve, and a suction device communicating with the said venturi and responding to the flow of gas through the venturi to supplement the action 01' the weaker spring to overcome the stronger spring and open the throttle valve commensurately with the increase in the speed of the air flowing through said venturi.

6. In combination with a carburetor foran internal combustion engine having an intake passageway provided with a venturi on the atmosphere side of the throttle, a throttle valve, manually operated means having a lost motion connection with the throttle valve for opening the same and a positive connection with the throttle valve for completely closing the sameto idle the engine. a spring tending to close said'throttle valve, pressure means acting on said throttle valve when the manually operated means are moved in throttle opening direction and acting against said spring to partially open said throttle valve, and a suction device communicating with said venturi and responding to the vacuum created by the flow of air through the venturi for supplementing the said pressure means to overcome said stronger spring and open the throttle valve further as the speed of the air flowing through the venturi increases.

MARION MALLORY.

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