US2762614A - Engine anti-stall device - Google Patents

Description

p 11, 1955 J. scHwElss 2,762,614

ENGINE ANTI-STALL DEVICE Filed March 18, 1952 FIG.6. =0

INVENTOR. JOSEPH SCHWEISS ATTORNEY United States Patent.

ENGINE ANTI-STALL DEVICE Joseph 'Schweiss, St. Louis, Mo., assignor, by mesne assignments, to ACF Industries, Incorporated, New York, N. Y., a corporation of New Jersey I This invention relates to anti-stall devices for use with internal combustion engines, particularly, of the automotive type.

Where the carburetor throttle valve is suddenly returned to its normal idling position, the resultant sharp increase in depression in the engine manifold posterior to the throttle may result in sweeping into the engine whatever excess fuel may have been deposited in or collected on the walls of the manifold. The resulting mixture in the firing chambers may be so rich as to cause a stumble or even to stall the engine. Various dash pot devices have been suggested for delaying the closing of the throttle valve, to avoid this condition, but these devices are rather bulky, complicated, and expensive.

It is the principal object of the present invention to provide considerably simplified and less expensive means for preventing engine stalling under the conditions above noted. According'to the present invention, there is pro- .suctionis established posterior to the throttle and to open the lay-pass when less than idling suction prevails. There is also providedme'ans for delaying closing of the bypass, as the throttle returns to idling position, so that the supplemental air is supplied, momentarily, When there would be, otherwise, the liability of stalling.

In the-accompanying drawing which illustrates the invention:

Fig. 1 is a vertical transverse section through an automotive carburetor embodying the invention.

Fig. 2 is an enlarged section showing the anti-stall valve in its closed position.

Fig. 3 is a view similar to Fig. 2, but showing the antistall valve opened.

Figs. 4, 5 and 6 are detail sectional views showing a modified anti-stall valve mounted in the wall of the carburetor or intake manifold instead of upon the carburetor throttle valve and showing the valve in three different positions.

The carburetor in Fig. 1 has a downdraft mixture conduit 8 with a flange 9 at its lower, outlet extremity for at tachment to the intake manifold (not shown). The discharge of fuel and air mixture is controlled, in the usual manner, by a throttle valve disk 10 which is connected by suitable linkage to the accelerator pedal. Adjacent the mixture conduit is a constant level fuel bowl 11 enclosing a float 12 and, in its lower portion, a main metering orifice element 13 through which fuel is supplied to upwardly inclined, main fuel passage 14. The main fuel passage discharges through a nozzle 15 into the smallest of a series of venturi tubes 16. A choke valve 17 in the inlet horn 18 of the carburetor mixture conduit provides for reducing the supply of air for mixture with fuel issuing from main nozzle 15, in starting.

Idling fuel is supplied through a restriction tube 19, communicating with main fuel passage 14, and passages 20 connecting with ports 21 adjacent the posterior to the edge 2,762,614 Patented Sept. 11, 1956 ice of throttle valve 10, when closed. As is customary, the throttle valve, in closing, is limited to a slightly open position for normal idling in which some air passes the edge of the valve disk for mixing with the extra rich mixture which issues from the idling ports. Main orifice element 13 is controlled by a metering pin 22.

The novel anti-stall device is mounted on the throttle disk and includes a small cylindrical casing 23 with an annularly grooved, upper portion 24 secured within a port 25 in the throttle disk, by means of a suitable riveting or peening operation, as at 26. Annularly spaced, inwar-d lips 27 provide upper stops for the anti-stall valve. The upper end of the casing is open to form a port 28 which exposes the interior of the valve casing to atmospheric conditions on the anterior or upstream side of the throttle valve. The portion of casing 23 on the downstream or posterior side of the throttle is provided with a pair of ports 29, in the side wall thereof, and a port 30 in the lower end wall thereof.

Working in chamber 31 in casing 23 is a slide valve comprising a cup-shaped part 32, and intermediate annularly slotted part 33 and a cylindrical end part 34. Ports 35 connect the intermediate, recessed part 33 with the hollow interior 36 in the upper part of the slide valve. A coil spring 37 is compressed between the ported, bottom wall of the casing and the opposed wall of the cup-shaped portion .32 of the slide valve and constantly urges the slide .valve upwardly. Spring 37 is calibrated, in relation to port 30, so that the slide valve will be drawn fully inwardly, as in Fig. 2, when exposed to at least normal idling suction through port 39. Port 30 is made quite small so that an appreciable time interval will be required to evacuate the interiorof cup-shaped portion 32 of the slide valve and,

complete an air by-pass through the throttle valve, including opening 28 at the top of the valve casing, hollow interior 36 in the upper part of the slide valve, valve ports .35, and valve casing ports 29.

In operation, the slide valve will assume'the position .of Fig.2 when the engine is operating with the throttle valve in its maximum closed .ornormal idling position so that the slide valve will be exposed, through port 30 to, at least, normal idling suction, while the top of the slide valve is exposed to substantially atmospheric pressure. In this position, spring 37 is collapsed and cup-shaped portion 32 of the slide valve seats against the bottom wall of casing 23 to limit the downward movement of the slide valve. Bleed ports 29 in the side of the casing are cut oil? by cylindrical portion 34 at the upper end of the slide valve. When the throttle valve is opened, reducing the suction applied through port 30 to the undersurface of the slide valve, spring 37 expands, as in Fig. 3, causing registry of ports 29 and 35, as previously explained, and completing the supplemental air by-pass through the throttle valve. This permits air to pass through the throttle valve and dilute the mixture. When the throttle valve is open, such dilution is of no consequence. Because of the restricted suction communication at port 30 into the interior of the suction casing, the motion of the slide valve from the position of Fig. 3 to that of Fig. 2, immediately upon closing of the throttle valve, will be slightly delayed so that, for a short period, more air will be supplied to the engine, than would otherwise be the case, which air dilutes the otherwise excessively rich fuel mixture. This also somewhat increases the engine speed, momentarily, so that thetendency to stumble or stall is avoided.

Since the slide valve will be in its open position, of Fig.

.3, at low suction, the supplemental air duct will be open during starting which may aid in starting the engine with the throttle valve closed.

In Figs. 4, 5, and 6, the anti-stall slide valve 40 reciprocates within a casing 41 which is threadedly mounted, as

cate through clearance space 46 with the engine manifold 44. The open, outer extremity 49 of casing 41 communieates with atmosphere. The slide valve has annularly arranged ports 50 opening into its hollow interior 51.

Fig. shows slide valve 40 in an intermediate position in which its ports 50 are in registry with casing ports 48 and forming with the same, and with clearance space 46,

with the hollow interior portion 51 of the slide valve,

and with the open end portion 49 of casing 41, a supplemental air by-pass into the intake manifold.

In this form, coiled spring 52 is calibrated, with relation to suction port 53 in the end wall of casing 41 to permit the slide valve to be moved to the extreme inward, fully closed position of Fig. 6 when the slide valve is exposed through port 53 to suction at least equal to normal idling suction. When the suction to which the slide valve is exposed drops from normal idling suction, the spring 52 expands, moving the slide valve outwardly, first to the intermediate position of Fig. 5, in which the supplemental air by-pass is opened, then to the closed position of Fig. 4, with the end of the slide valve seated against a valve stop ring 54 lodged in the end of casing 41. This third position of the valve, of Fig. 4, is provided so that the supplemental air duct will be closed during starting and, in fact, at substantially all times except for a short period after the throttle valve is returned to its normal idling position, with the engine in operation.

In this form, as well as in the first form, restricted suc- "tion port 53 provides for a delayed movement of the slide valve from its normal, closed position of Fig. 4, through the open position of Fig. 5, to the again closed position of Fig. 6. The rate of movement of the slide valve, as adjusted by the size of suction port 53 and the strength of spring 52, and the length of suction ports 48 and 50, provide for the by-pass duct being in efiect for the proper length of time to eliminate the stalling condition mentioned above, without, at other times, undesirably increasing the normal idle speed of the engine.

The size of the various suction and air bleed parts and the strength of the slide valve actuating spring will be adjusted, of course, in accordance with the conditions which prevail in the particular engine and carburetor at hand. Details of the valve arrangement and positioning may be modified as Will occur to those skilled in the art and the exclusive use of all modifications as come within the scope of the appended claim is contemplated.

I claim:

An anti-stall device for a carburetor having an induction conduit with a throttle valve, comprising, in combination, a casing forming a chamber mounted on said conduit adjacent said throttle valve, a first port in said casing for exposing said chamber to atmospheric pressure, second and third ports in said casing for exposing said chamber to pressures on the downstream side of said throttle, means in said chamber constantly in communication with said first and second ports and actuable in response to differences in pressures produced by engine speed and throttle position for controlling said third port, including a suctionresponsive valve movable between extreme positions to close said third port in response to variations in pressure differential acting thereon and to open said third in intermediate positions, means for retarding the action of said valve in response to variations in pressure difierential at said first and second ports, a spring biasing said valve in opposition to the eflect of pressure differences, said spring being calibrated to shift said valve to one extreme position to close communication between said first and third ports in response to pressures at said first and second ports when said throttle is open, and to be compressed to close said third port in response to pressures normally present at said first and second ports when said throttle is closed to idle position, whereby throttle movement from open to closed position opens said valve temporarily to supply supplemental air for a short period after said throttle is closed.

References Cited in the file of thi patent UNITED STATES PATENTS 1,718,644 Gilbert June 25, 1929 1,763,362 Linkert June 10, 1930 1,944,397 Berry Jan. 23, 1934 2,102,846 Hunt Dec. 21, 1937 I FOREIGN PATENTS' 405,346 Great Britain Feb. 8, 1934

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