US2408104A - Fuel mixture control - Google Patents

Description

Sept. 24, 1946. w. F. STANTON FUEL MIXTURE CONTROL Filed Jan. 2o, 195s throttle valve.

yengine is cold.

atented Sept. 24, 1946 E Reissues 2,408,104 FUEL MTxTURE `coN'rnoI.

Warren F. Stanton, Pawtucket, R. I., assgnor, `by mesne assignments, to American Gar and Foundry Investment Corporation, New York, N. Y., acorporation of Delaware Application January 20, 1933, Serial No. 652,731

(Cl,- lenll) 30 Claims. l 'Iv'his invention relates to thesubject ofmy pending application No. 600,038, filed AMarch 19, 1932, now Patent No. 2,348,033.' In the invention of that application, I provide means for'regulating the richness of the mixture supplied-to an internal combustion engine through control of air admission, or the action of the choke valve, utilizing intake manifold pressure to act upon said choke valve through theY medium of a diaphragm, and being subject to the mixture temperature through a thermostat. I also use this means for providing throttle opening while starting, or when the engine starts to stall.'V My arrangement was such that immediately thev diaphragm starts to move under suction,the choke valveopens and the throttle'starts to close.

I have found it extremely desirable, especially with a choke valve offset/seas to-r tend to open by suction, andwhen starting 'a' cold engine, to allow'a slight flutter of the choke valve While cranking, that is to say, a slight opening of the Valve on the suction strokefollowed by closing of the valve on the compression stroke, thus admitting the slight amount of air necessary to provide a vfiring' mixture, and doing away with the necessity of providing a bleeder or auxiliary air valve. `'This flutter should take place v'without corresponding opening and closing of the I also nd it desirable to make a sharp distinction between the amount Which the choke valve opens under the cranking vacuum, and the .amount which it opens under the firing vacuum. In vmy presentl invention I provide means for procuring the desired flutter without disturbing thev throttle opening, and for sharply dening the amount of choke opening under cranking vacuum.

VI also find desirable a connection between the diaphragm and the choke valve which is yielding for a portion of its action and positive through Vthe remainder. .This allows the thermostat,

when in its coldposition', to,A exert still more resistance to the openii'igv of the'chokevalve and thus provide a richer mixture when the engine is cold. This also permits the `use of a 'lower powered, vand hence cheaper, thermostat to give the desired control. If a high powered thermostat is used, it may be suiiiciently strong to prevent the desired choke valve ilutter when the means between the thermostat and the choke valve which will allow this desired flutter or opening regardless of the strength of the thermostat.

ylido not restrict myself toV anembodiment of my invention which will contaimallforany I- thereforeV -provide yielding ber-of theieatures or the devices before mentioned'V and hereinafter to be described, but my invention is 'Ito be understood as consisting in Vphra'grn/rodand thermostat lever of adierent constructicrfi `from what is shownin Fig. 1.

Fig. 3 isadetail view, in horizontal section, on

vthe une 3'-j3, Fig. 1.

"I ,illustrate my invention yas, applied to a carburetter IIL-,ofthe yso-,called down-draft Jtype, and whichis bolted to the intake manifold II, from which the Imixture flows to the engine. Air enters the carburetter through port I2, the amount of air vsupplied being controlled by the Vchoke valve I3, which is shown of the balanced butterfly type. It may, however, be of any type. The supplyof Vzyniigture from the carburetter to the engine .fis-,controlled by the throttle valve I4, which is manually operated in the usual manner. Fuel is fed to the carburetter from a iioat chamber through jets in the ordinary manner. As the method of feeding fuel Vformsno part of my invention, the float chamber and jets are not illustrated.

'I1-he 'choke valve I3 ,is fastened to a shaft I5 `to the squared end of which is fastened the choke lever IB'. The valve is normally held closed by coil spring I1, one end of which is fastened to "lever |06, and the other end to the carburetter body. Choke valve I3 is .opened by, and according to thedegi'ee of engine suction, by'motion of an engine vacuum'actuated diaphragm I8,`trans -mitted'jbyv diaphragm rod I9, to a pin 20, xed

the .diaphragmV is moved to that position byV Vspring y2 .I,.when there is noV engine vacuum. The

diaphragm is tightly clamped at its `outer rim at a pointbetween wall 25, and the opposite end wall 2l', and the space between the latter and the diaphrzalgm'isconnected by pipe r28, with the carburettsr or intkemani'foldon vthe engine Vside Q f the Lnl icttlg. .that the Vacuum acties Qn ldiaphra 'length that with choke valve fpr'oximately touch arm 42. lstrength of spring 4I, are varied to suit different u that existing in the intake manifold.

A lever 29 is pivoted on stud 30, fast in body I9, and has an arm 3|, which encircles rod I9, which arm is held against stop pin 32, by spring 33. The other arm 34, of lever 29, has a slip joint connection with throttlearm 35. This is formed by rod 36, which is longitudinally slidable in holes in one end of link 31, and provided with a stop collar 38, and an adjustable connection between rod 31, and throttle arm 35, thaty is a threaded rod 39, screwed into the other end of link 31. With this Slipjont cohnectiomit is apparent that rotation of lever 29 in a 'clockwise direction can move -arm 35, to: openthe throttle I4, but the throttle is free to openv or close beyond this position without affecting lever Rod 36, has slidablymounted upon itfflang'ed y sleeve 40, held by spring 4I, against the end of arm 42, of choke lever I6, spring 4I being of such I3; closed and throttle I4, slightly opened, sleeve 40, will ap- The length and carburetters. Throttle lever 35 is providedl with vthe customary stop 43 and stop screw 44.

'For controlling the ,position of choke valve I3, according to mixture temperature, I provide a thermostat 45, which Vis preferably of the biymetal coil spring type, although I do not limit myself to this type, and which I have shown with ,the outer end 45, in intimate contact with the intake manifold casting so that the position of the thermostat arm 41, reflects vthe temperature of the mixture. However, the thermostat can be located at any desired place@ The other inner end 43, of the thermostat coil is fastened to shaft 49, to which is fastenedarm 41,' and the thermostat coil is so arrangedthat heating itcauses arm 41 to move in a clockwise direction. I preferably shroud thenmostat 45 with a cover 50 which in this case I have designed to provide also a rsupport for the shaft 49and a means for clamp'- ing the thermostat to the intake manifold. Arm 41 is connected by rod 5I, and adjustable connection 52 with lever 53, pivoted on stud 54. A stop pin 55 limits movementof lever 53, in a counter-clockwise direction. Apin`56, on lever 53, coacts with jawface 51, of lever I6, to provide a yielding stop Aagainst opening movement of choke valve I3, when the thermostat is cold, the position of pin 56, and hence the degree of resistance to opening, depending on the temperature of the thermostat. When the thermostat becomes hot, pin 56 coacts with jaw face 58,-0f lever I6, and forms a positive stopl against the closing of choke valve I3.l

To allow moreoriginal opening of choke valve I3, when arm 53 is in its cold position,-I may provide a yielding connection between pin 56 and lever I6. as in Fig. 2, where spring 59 fastened to lever I6, gives a yielding connection with pin 56, for the rst opening movement of lever I6, and by abutting against face 60, then gives a positive connection.

I may use a positive connection between rod I9, and lever I5, as shown in Fig. 2, where jaw 6I, directly abuts pin 26, or a yielding connection aS shown in Fig. 1, where spring 62, fastened to rod I9', co-acts with pin 20, jaw 6I in this case furnishing a positive stop to movement of spring 62.

As hereinbefore described, rod I9 is free to slide in arm 3l of lever 29, but continued movement of the rod to the right under action of intake suction and against the pressure of spring 26, causes ljusted so that when lever arm 3I abuts stop pin 32, the throttle is open considerably more than at normal idling speed. Assume the engine stopped and cold, then lever 53 is held against stop 55 by thermostat 45. As there is no vacuum in the manifold, rod I9 is held by spring 26 in its 'extreme left position with collar 24 abutting against chamber wall 25, choke valve I3 is held shut, and spring 33 holds arm 3| against sto-p 32, and thus, Iby rod 36, collar 38, link 31 and connection 39, holds throttle I4 slightly open, all as illustrated in Fig. 1.

rIhe engine is cranked, thus causing a low vacuum in the intake manifold and communicated lthrough vpipe 28, to the diaphragm chamber to actuate diaphragm I8.` This low vacuum is enough to overcome the resistance of spring 26,

'moving rod I9 to the right*l until lug 63 engages lever arm 3I, when movement of rod I9 stops,

yas the cranking vacuum is not enough to overcome the resistance of spring 33. This movement of rod I9 to the right tends through spring 62 and pin 23, to move lever I6, counter-clockwise,

thus opening the choke, and as there is a slight amount of play between pin 56 and jaw face 51,

a slight opening is obtainedbefore thermostat lever 53 begins to offer resistance. At cranking speed, the movement `of diaphragm I8 will tend to be intermittent, due to the alternate suction and compressionlstrokes of the engine pistons, hence choke valve I3 will have a slight flutter. When the engine is very cold the thermostat holds lever 53 hard against its stop pin 55, and pin 56 offers so much resistance to movement of lever i3, that spring 6,2 compresses, and the choke opens but slightly. If the engine is Warmer, however, lever 53 offers less resistance to movement of arm I6, and spring 6,2 either does not compress at all, or but slightly, thus giving a greater choke opening for cranking when the engine is warm than when it is Very cold. I thus provide for, regulation of the cranking opening of the choke valve by the degree of opposition between thermostat lever 53 and spring 62. I obtain a similar result, but in a different manner by what right, thus opening the choke still more, the

amount of opening depending upon the degree of vacuum and the resistance which the thermostat offers through arm 53 and pin 56 to the movement of lever I6, this resistance being greater the colder' the engine. If the engine is Warm at starting, the thermostat offers but little resistance, and if it is at its normal running temperature, the thermostat has rotated lever 53 suiiiciently in clockwise direction that the choke valve is posi- -tively .held wide open.

The overcoming ofA the resistance ot spring 33 byV movement of rod I9,'farther to the right, by the firing vacuum, causes lug 63, to rotate lever 2S counter-clockwise, thus allowing throttle Ilil .to close toward its normal idling position, the

degree o-f closure depending on the temperature through the resistance offered by thermostat arm 53. Thus the idling speed with a cold engine will be greater than that with a warm or hot engine.

When the throttle is operated manually to vary the engine speed, opening the throttle causes the vacuum to drop. This allows theV choke valve' to close, which actio-n may give too rich a mixture. However, as the throttle'is opened, sleevel 40 is pushed by spring 4I, against arm 42 on lever I6, tending to openV the choke, thus overcoming the effect due to Vthe vacuum drop. This opening being resisted' by thermostat arm 5 3, it will vbefseen 'that a proper running mixture` is attained through the co-operation of intake manifold pres,.- sure, engine temperature and" throttle opening, and none of these elements can be left loutof .consideration and still have a proper mixture.

If the engine while idling either hot or .cold tends to stall, the vacuum irrimediately drops to a degree where diaphragm- I3 is unableto rovercome the resistance ofspring '33, whichiinmediately rotates lever 29 clockwise, lhllS opening 'the' throttle valve and preventing stalling.`

What I claim is:

1. -Fuel control means for engines comprising a f uel conditioning device for delivering the conditioned fuel to the engine, two valves associated With said device in the line of flow of fuel-forming elements to and through said device, automatic valve-,moving means subject to intake vpressure at a point beyond said device for causing fuel conditioning movement Aof said valves, a yielding connectionV between such means and vone, of said valves to permit a lag in its initial movement, and temperature responsive means acting to modify the action of said. valve-moving means.

2. Fuel control means asin claim 1 forA an internal combustion engine in which the conditioning device is a carburetter and the valvesare, respectively, throttle and choke valves.'

3. Fuel control. means as. in Vclaim 1 for an internal combustion enginein whichthe conditioning device is a carburetter and the valves are,

respectively, throttle and choke valves, and having manual throttle-opening means and thedegree of choke being affectedV byf opening the throttle thereby. l Y

4. Fuel control means as in claim 1 for an internal combustion engine in which the conditioning device is a carburetter and the valves are, respec tively, throttle and choke valves, andthe throttle valve is manually operable, and an 'operative connection between throttle and` choke valves.

5. Fuel control means asin claim 1 for aninfternal combustion engine in `which the conditioning device is a carburetter and the valvesare, respectively, throttle and choke valves, and; the throttle valve is manually operable, andr an loperative 'connection 'between throttle 'and choke valves, saidv connection being yieldable inthe direction to transmit motion from the throttle vvalve to the choke valve.`

6. Fuel control meansy for internal combustion engines comprising a carburetter, a choke valve, a throttleV valve, valve-moving meansk vfor both valves subject to intake manifold pressure and ,mwableinqne direeiioutherebr.; and a plurality eff assessing acties 'rieldable resistance i@ Increment ef.- ad valve-moving means- 7. Fuel control means for internal combustion engines comprising a carburetter, achoke valve, athrottle valve, valve-moving means subject to intake manifold pressure and movable in one direction thereby, said movement first opening the choke valve and then closing the throttle valve While the opening of the choke valve continues.

` 8. Fuel control means as in claim 7 in which comparatively'low resistance is opposed to primary opening of the choke valve and a substantially higher resistance is opposed to the closing of the throttle valve and further movement Yof the choke valve. f v

" 9. Fuelcontrol means asin claim V6 having tem.-

u perature responsivemeans acting to kmodiiyaction of the valve-moving means."

10. Fuel control means asin claim 6 having temperature responsive means acting to modify action o f the valve-moving means andhaving manual throttle opening means, the vdegree of choke being affected whenthe throttle is opened.

1 1. Fuel control means for an internal combustionv engine comprising a carburetter having a choke valve, means loperatively connected with the choke valve and. situated to be actuated by the engine vacuum when cranking and when ring that varies the amount of opening of the choke valve according to the vacuum inthe respective cases, the,l opening being slight under cranking vacuum, the valve being free to utter during cranking. a throttle valve, an operative connection between choke valve and the throttle valve that permits'uttering lmovement o-f the choke valve independentlyof the throttle valve, and an operative connection between said vacuum actuated meansand the throttle valve.

12,. In an internal combustion engine, a carburetor, a suctionoperable choke valve. for said carburetor, means ac ting in addition to the suction applied directly to said choke and operated by saidf engine for. controlling said choke valve, said operating means tending 'to closev saidchoke valvejwhen said engine is operating at R. P. M. or less vand said means 4tending to open said choke valve when said engine is operating at `speeds substantially above 100 RL. P. lVLQand temperature controlled means forlimiting the'movement of said control means.

1,3.k Fuel control means for an internal combustion engine comprising a, carburetor for delivering conditioned fuel to thel engine, throttle and chokeA valves associated with said carburetor in the line of iiow of fuel-forming elementsl to and` through said carburetor, automatic valvemoving means subject to intake pressure at a point beyond said carburetor for causing fuel conditioning movement of said valves, a yielding, connection between such means and one of said valves to permit a lag in the initial movein the line of flowA of fuel-forming elements to and through said carburetor, manual throttleopening means associated With said carburetor, the degree of choke being affected by opening the throttle thereby, automatic valve-moving means subject .tointakepre'ssure at a point. beyond said carburetor for causing fuel conditioning-movement of said valves, a yielding connection between such means and one of said valves to permit a lag in the initial movement ofisaid'valve, and temperature responsive means acting to'modify the action cf said valve-moving means.

15. Fuel control means for an internal combustion engine comprising a carburetor for delivering conditioned fuel to the engine, a choke valve and a manually operable throttle valve associated with said carburetor in the line of flow of fuel-forming elements to and through said carburetor, an operative connection between the throttle and choke valves, automatic valve-moving means subject to intake pressure at a point beyond said carburetor for causing fuel conditioning movement of said valves, a yielding connection between such means and yone of said valves, and temperature responsive means acting to modify the action of said valve-moving means.

16. Fuel control means for an internal combustion engine comprisinga carburetor for delivering conditioned fuel to the engine, a choke valve and a manually operable throttle valve associated with said carburetor in the line of flow of yfuelforming elements to and through said carburetor, an operative connection between the throttle and choke valves, said connection :being yieldable in the direction to transmit motion from the throttle valve to the choke valve, automatic valvemoving means subject to intake pressure at a point beyond said carburetor for causing fuel conditioning movement of said valves, a yielding connection between such means and one of said valves, and temperature responsive means acting to modify the action of said valve-moving means.

17. In an internal combustion engine having an intake manifold, a carburetor, a choke valve, means for opening said choke Valve when the temp-erature is high, means for closing the choke valve when the temperature is low, a suction actuating element responsive to pulsations of the. motor being cranked when the choke valve is in position, resilient means connecting said suction responsive element to said choke `valve for setting up a fluttering action during cranking, a throttle valve, means for holding said throttle valve in partial open position at low vacuum, and means for varying the low vacuum position of said throttle in accordance with temperature.

18. The substance of claim 17 characterized in that the low vacuum position of the throttle is independent of the iiuttering movement,

19. In a carburetor for attachment toan intake manifold of an internal combustion engine, a throttle valve, a choke valve, said choke valve having its position determined by the position of the throttle as the throttle valve is moved from its closed position, means for holding said throttle valve in partially opened position at low vacuurn, and means for varying and maintaining said choke position dependent upon said throttle position as controlled by temperature and vacuum.

20. In an internal combustion engine having an intake manifold, a carburetor, a choke Valve, means for opening said choke valve when the temperature is high, means for closing said choke valve when the temperature is low, a suction actuated element responsive to pulsations of the' motor being cranked with the choke valve in closed position, and resilient means connecting said suction responsiveelement to said choke valve for setting up a fluttering action during cranking.

21. In an internal combustion engine having an'intake manifold, a carburetor, a choke valve, means for opening said choke valve when the temperature is high, means for holding said choke valve in closed position when the temperature is low, a suction actuated element responsive to suction variations in said manifold, spring means for retaining said suction responsive element in its inoperative position, resilient means opposing said spring means, a resilient connection between said suction actuated element and said choke valve, said choke valve being fully responsive to said suction actuated member upon normal vacuum conditions when the temperature is high in the manifold and independent of said resilient connection, and means for opening said throttle beyond fast idle position for cold starting.

22. The substance of claim 21 characterized in that means are provided for positively opening said choke valve upon a drop in manifold vacnum due to movement of said throttle to open position.

23. The substance of claim 21 characterized in that means are provided for opening the choke upon a drop in vacuum due to movement in said throttle to an open position, said choke position being determined by temperature.

24. In a carburetor, a choke valve, a heat responsive device for controlling the choke valve, a suction responsive element operatively connected with said choke valve for setting up a fluttering action when the motor is cranked with the choke valve in closed position, said fluttering action being independent of the action of the heat `responsive device.

25. In a carburetor, a choke valve, a heat responsive device for controlling the choke valve, a suction responsive element resiliently connected with said choke valve for setting up a fluttering action when the motor is cranked with the choke valve in closed position, said fluttering action being independent of the action of the heat responsive device.

26. In a carburetor, a choke valve, a throttle valve, a heat'responsive device for controlling the choke valve, an operative connection between the choke valve and the throttle valve, a heat responsive device for controlling the choke valve, a suction responsive element operatively connected with said choke valve for setting up a nuttering movement of the choke valve when the motor is cranked with the choke valve in closed position and independent of said heat responsive device and an operative connection between said vacuum actuated means and the throttle valve.

27. In a carburetor for attachment to an in- -take manifold of an internal combustion engine, a throttle valve, a choke valve, the position of which is determined by the position of the throttle, means for holding said throttle valve in partially open position at low vacuum, and means controlled by temperature and vacuum for varying said choke position, said vacuum controlled means being initially ineffective to operate said choke.

28. In a carburetor for attachment to an intake manifold of an internal combustion engine, a throttle valve, the position of which is controlled by temperature, a choke valve, the position of which is determined by the position of the throttle, means for holding said throttle valve in partially open position at low vacuum, and means controlled by temperature and vacuum for varying said choke position.

29. In an internal combustion engine,a choke 9 10 valve movable towards open position by suction, f duction conduit, a choke valve movable towards a choke shaft for mounting said choke valve, and open position by suction means, and operating spring means for preventing initial opening movemeans between said choke valve and suction ment of said choke valve by suction during cold means including a clutch, said clutch being inopstarting, said spring means engaging a member 5 erative during the initial movement of said sucxed to said shaft. tion means.

30. In an interna] combustion engine, an in- WARREN F. STANTON

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