US2661196A - Carburetor - Google Patents

Description

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T. M. BALL CARBURETOR Filed May 13. 1949 Dec. 1, 1953 @-4- f4 JNVENTOR. 'azwds /afz BY Patented Dec. l, 1953 lll-Iil-Il'l'.ElDy STATES).

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CARBURETOR corporation of Delaware Application May 13,' 1949, Serial No. 93,135

(Cl. 2in-41)' 9..Claims. 1.-'.

This'inventionv` relates toA an improved internal combustion` engine carburetor vand more particu-` larly to an improved step up or power jet there-- 1n:

It isl now conventional practice to supply fluid froml the reservoirof# a` carburetor tothe fuel mixture passage thereof through a relativelysmall metering orifice which predetermines` the economy mixture of the carburetor. When en.- richment offthe mixture is-required for power a1-soca1led'stepup valve-is opened: inorder to allow-fv anvadditional supply` of fuelto iiowI from; the' reservoir of Vthe carburetorv to the fuel mixtureV passage. Iny the lpresentinvention opening ofi-thisv step-up. `valvefis` produced byy aVA mechanism which is responsive. to changesiin .manifold vacuum and' which. provides* aplurality. of stepups.` With thismultiple-step-updevice.a change from an economy.` mixtureto aV fullspower mixture is.I made-by. gradual; increments. foundtobe. particularly desirable for use on engines equipped; with .a supercharger.

The; term manifoldfvacuum as used herein is intended to refer to the partial vacuum which is present` inl varying degrees inA theV manifold. downstream; of the throttle valve under engine operating. conditions; andl which is determined bythe. relationship.` of engine` speed to throttleposition. The?. term* drop lin manifold. vacuuml referstoan increase in absolutev pressure -inthe manifold;

In the drawings:

Fig. 1 is;asectionalelevational view, ofa. down draft` carburetorhaving my. multiple step-uprdevice incorporated therein;

Fig. 2 is a. fragmentary view of the multiple step-up, device of Fig., 1 showing thef partsY in their respective positions after one step-up.; has occurred;

Fig. 3 is.k a fragmentary View similar. to Fig. 2s but showing the parts intheir respective positionsv afterA a. secondr increment of vstep-up-.has oc-l curred;

Fig. 4 is a fragmentary view of a modied'stepup device;

Fig. 5- is a partial View of the. device-,of Fig. 4.. showing the relative position of thef parts under high. vacuum. conditions;

Fig. Gis a View similar to Fig. 5-but showing the position of the partsunder mediumvacuum conditions; and

Fig. 7 is a view similar to Fig. 5 but showing the position of the parts under low Vacuum condition..

Referring to. thedrawings, the carburetor comprises an assembly of a body I0, an air horn ll,

rIhis has f been I adapted to be connected by a fuel line (not-- shown) to a source of supply of fuel such as-afuel pump (not shown). The airhorn I I isprovided Iwith atubular part I5 which serves asan airinlet to a fuel mixturepassage- I 6. The egress of the fuel mixture to-theengineintake.mani fold is controlled by athrottlevalve- I'I.

The body portion I0"of-thecarburetor isprovided with a fuel reservoir IB-and the intake-.of

fuel thereto-from the nipple .I 4 `is controlledl by` aneedlevalve IS which is operated by a conventional float mechanism 201which predetermines.

the fuel level in the-reservoir.

The main fuel injection means controls.l the mixture with air of fuel passing through a. metering jet 2l. withm-ixture chamberv I6 through an orifice; 23:

Tubular passage 24.which is connectedvia .ductsA 25 and 26 to atmosphere is concentrically disf..

posed within passage 222 and provided with a plurality. of holes21 in its sidewalls. AirA entering tubular passage24. escapes throughholes l2'I and mixeswith fuelin passage 22* and the atom..

izedI mixtureis discharged from 4orifice .$23.

Liquid for enginefidling is. drawn byY manifold vacuum from passage. 22 through idling tube; 34;.

which is connected through a passage 3l toa passage 38; The latter passage. has an orifice:

39- open to theatmosphere and an orifice 40 operatively connected`r to an idling-j et 4 I A mechanism 28 which includes the multiple step-up device referred to herein is adapted'- to` vary the fuel mixture ratio in response to theY degree of' manifold vacuum. This mechanisml includes a spring loaded piston 29 adaptedV to reciprocate in response to variations in manifold vacuum transmittedthrough anorice 30 anda passagel 3l. A rst valve 35 controls the now of,`

liquid fuel through an orifice 3B which connects the f uelj reservoir I8 and thepassage 22. A second; Valve 4 5 controls the flow of liquid fuel through an orice 46 which connects the fuel reservoir- IB and the passage 22. Piston 28, is forced upward by a spring 41 whichphas a springv rate, such that manifold vacuum in 'passage 3|. can overcome. it to retract piston 129. downwardly. Piston 29 carries an arm 48, which is secured thereto and adaptedu to reciprocate therewith. Valve stems 35. and` 45. each penetrate an open; ing in. arm 48 and each are provided with anup. set head 49 and 50 respectively. A spring 5I. sur-` rounds vali/e stem. 3.5i and... reacts against arm; 48;

Tubularv passage22 connects. jet 2 I4.

accinge and a washer 52 carried on valve stem 35. A similar spring 53 surrounds valve member 45 and reacts against arm 48 and a washer 54 carried by valve stem 45. A guide member 55 is received within an opening in arm 48 and serves to guide the latter as it slides up and down in response to movement of piston 29. v l

1t should be noted that in Fig. 1 the valve stem 85 is shown as constructed of a shorter length than the valve stem 45 so that when both valves are closed as shown in Fig. 1 the offset head of stem is in contact with arm 48 while the offset head 56 of arm 45 projects above the arm 48. It is apparent that when the manifold vacuum decreases in passage 3l sufficiently for the spring 41 to raise piston 29 and arm 48 upwardly that arm 48 will first lift valve stem 35 and thus open orifice 36 so that an additional amount of fuel will be delivered from the fuel reservoir I8 to passage 22 and the parts will assume the position shown in Fig. 2 with the orice 36 open and the orifice 46 closed. Further decrease in manifold vacuum permits spring 41 to further elevate piston 29 and arm 48. The further elevation of arm 48 lifts valve stem 35 further but this has no effect upon the operation of the carburetor for the valve stem 35 was already clear of orifice 35. However, the further upward movement of arm 48 causes upset head 58 to engage arm 48 whereby valve stem is lifted clear of orifice 46 thereby providing a still further passage for fuel from the fuel reservoir I8 to passage 22. There is thus provided a normal supply of fuel to the engine and two additional step-ups which may be brought into action upon decrease in manifold vacuum.

It should be noted that the washers 52 and 54 engage abutments on the valve stems 35 and 45 respectively and that the springs 5I and 53 urge the valve stems downwardly toward their valve closing positions.

Although a pair of valve stems 35 and 45 have been illustrated as controlled by arm 48, it should be understood that a larger number of valve stems could be employed to provide additional increments of power mixture of fuel and air if desired.

In Fig. 4 a modified form of the invention is illustrated. The function accomplished by this form of the invention is similar to that already described in reference to Figs. 1, 2 and 3 although s the mechanical arrangement of parts is somewhat altered and a single orifice two stage valve is substituted for the pair of valves used in the Fig. 1 form of the invention. The arm 48 carried by the manifold vacuum responsive piston 29 is provided with an opening at 6U which a valve stem 62 penetrates. The carburetor body l0 is provided with a valve housing arrangement 64 having an axial passage therethrough. The axial passage in valve housing 64 has a restricted portion 66 and a valve seat 68 formed therein. The valve stem 62 is provided with av needle like extension 18 and an enlarged portion 12 having a tapered portion 14 adapted to cooperate with the valve seat 68. The needle like extension 19 is adapted to penetrate the restricted orifice 66. Thus when the portion 14 of the valve stem rests upon the seat 68 there is no flow of fuel through restricted portion 66. When the valve stem 62 rises enough so the portion 14 uncovers valve seat 68 fuel flows through the restricted orifice 66, but the quantity thereof is limited for the effective size of the orifice is reduced by the presence of the needle like extension 18. Further elevation of the valve stem 62 lifts the needle like' extension 16 out of the restricted orifice 66 s that its effective area is utilized and a larger flow of fuel to the carburetor is provided. There are thus provided valve positions which accommodate either no fiow of fuel through the orifice 66, a first reduced quantity of fuel or a maximum quantity of fuel. 1n order to accomplish this and provide the three operative positions for valve stem 62 in response to movement of arm 48 and piston 29 certain springs are provided on valve stem 62. A pair of lock nuts 16 are threaded on to the upper end of stem 62 above arm 48'. A washer 18 circumscribes stem 62 and a pin 88 limits downward movement thereof. A spring 82 is retained between arm 46 and washer 18. A second pair of lock nuts 84 are threaded to the central portion of stem 62. A second spring 85 surrounds stem 62 and reacts against the lock nuts 84 and a washer 88 which loosely surrounds the lower portion of stem 62 and on occasion abuts against the upper surface of valve housing element 64. The enlarged portion 12 of valve stem 62 is provided with a shoulder 89 below washer 88. The spring 82 is relatively strong while the lower spring 86 is relatively weak.

Referring to Fig. 5, it will be seen that under high vacuum conditions the valve is completely closed with the tapered portion 'I4 of the valve stem in engagement with the valve seat 68 and springs 41, 82 and 86 cooperate to oppose the vacuum which maintains piston 29 in its downward position. On a rst reduction in manifold vacuum the combined effect of the springs 41, 82 and 86 tends to elevate piston 29 and the parts assume the intermediate position illustrated in Fig. 6 in which spring 86 is compressed while spring 82 is extended and relaxed with the arm 48' in contact with lock nuts 16. Under these conditions the tapered portion 14 of the valve stem 62 is lifted above the valve seat 68 although the needle like extension 18 still penetrates the restricted orifice 66. On further reduction in manifold vacuum the combined effects of spring 41 and spring 86 further elevate the piston 29. ment of piston 29 elevates arm 48', which through lock nuts 18, elevates valve stem 62 until washer 88 is lifted off valve housing element 64 and the spring 86 is allowed to extend until washer 86 engages shoulder 89. like extension 19 is lifted entirely out of the restricted orifice 66 to provide a maximum fiow of fuel through the orifice 66. The spring 82 serves an additional useful purposein that it permits piston 29 and arm 48 to overtravel relative to valve stem 62. the necessity of having piston 29 reach the bottom of its stroke simultaneously with the seating of the tapered portion 14 of valve stem 62 on valve seat 68.- Thus, even though the valve seat 68 is engaged the vacuum may move piston 29 downward an additional increment.

I I claim:

l. In a carburetor adapted to supply fuel to an vinternal combustion engine having vacuum producing means, means defining a fuel reservoir, means defining a fuel and air mixing chamber, means defining an open fluid passage connecting the reservoir and the mixing chamber, means defining first and second supplemental fiuid passages connecting said reservoir and said chamber, a valve in each of said supplemental passages and a common operator for said valves operable to open one of said valves under a first vacuum condition in said vacuum producing This upward move- At this time the needle This is desirable for it obviates" 7^` :.f' .u mennen@ Qperable, .Q 09?... underasecohd vacuum condi on in said vacuum producing meansu, i ;'.I.;:;:f,'. y

s2.: .In a. earburetenada .ted te nnniyiuel i en internal combilstie. engine-lining meeuw-PIO; dueine means. nie .defining meansdenins. affnelzanelair.- ...s means denmngan Open-.Quid neeSaseenneCiIis thelreservoir and the ,mXinefeheinleertmeenS ,def nains nrst;andseeondsnnplemenial :fluid 10a-S.-VV sages .connecting .said reservoir .andrsaidfehe ber-,1.a valve ,in each of; V.Said-.S.u..1e.p1.e.n1entail De sages;Y amovable element assoeiated with.. Sa el valves@ and.-,operab1e te ,sequentially enen; Seid, valvesfwhen Innyedin. a first. dir eti 11,; a spring... urging said element Ato, movein said .first vdirection and-means denninaa passage exposing l said ele; ment -tey vacuum: from seid; yeeuumf ,producing means to oppese-.eadrenrine whereby underfa flrstzvacuum condition f saidl spring moves said element .sufficiently te enen @neef ',Saidsyalieerelldf under a second vacuum condition said 'springs moves said element sufficiently to open both of said valvesz. y.1

3. In a carburetor adapted to supply fuel to an internal ,combustion engine having vacuumi producing means, means defining a fuel reservoir, means defining a fueland-air mixing chamber, meansfdefining an open fluid passage connecting the reservoinand the mixing chamber, means `defilling firstand second supplemental fluidl passages connecting said reservoir and said chamber, a-valvei-n eachvof said supplementall passages and a vacuum responsive device operably connected to one ofsaid valves to open said one valve when aA predetermined vacuum condition exists in said vacuum "producing means, said device having a lost motion,I connection with .the other valveso that said last mentioned valve is opened when a second predetermined f-vacuu-m. condition is obtained insaid vacuum producing means.

4. In, a carburetor adaptedto supply `filetto an internal combustion engine having vacuum producing means, means defining a fuel reservoir, means defining a fuel and air mixing chamber, means dening an open fluid passage connecting the reservoir and the mixing chamber, means dening rst and second supplemental huid passages connecting said reservoir and said chamber, a valve seat associated with each of said supplemental passages, a valve stem associated with each of said seats, a vacuum responsive device having a piston element adapted to move in a rst direction in response to a decrease in vacuum in said vacuum producing means and to move in a second direction in response to an increase in said vacuum, means carried by said piston element and adapted to move one of said valve stems off of its associated seat in response to a predetermined movement of said piston element in said rst direction and to move the other of said valve stems oil of its associated seat in response to continued movement of said piston element in said first direction.

5. In a carburetor adapted to supply fuel to an internal combustion engine having vacuum producing means, means defining a fuel reservoir, means defining a fuel and air mixing chamber, means defining an open fluid passage connecting the reservoir and the mixing chamber, means dening a supplemental fuel passage connecting said reservoir and said chamber, a valve adapted to control the ow of fuel through said supplemental passage, said valve including a movable stem having a rst open position adapted to acn Yci adaptedwto accommodate. a reduced4 flovv# o'f'ful meanstoftherebyiducemoyement offsald c pgsitioniwhich. prevents". the. iloiv' of' any/fuelr through said ,supplemental A ment, A'passafge'ffrnirig mea'msv Ytiex'pose said con;A trol element tovacurn in said valcuunilprodiici i en @enseignent .dejenme n' respete, toi' ineneaeed nieuwe eenditenefin 'Se-id ,Veeue-efe ducing means, al first spring means opposing all" mo of ,saidV element saidy first direction'gaid' liningV ai supplemental fuel passage .connecting said reservoir and saidf chamber, af single,l o'rf'it'ie'r two.Y stageKA valve` controlling', the .flovvl 0f l.fuel through said.. supplemental' passage, said Vvalve having a .valve stemv mountedfor linear. move,- ment, a vacuum .responsive .device mouteclii linear movement in y.response vto variations inl vacuum in said va'ciuin'lproducingv means, an4 arm tioned adjacent stem, a flrstspringintrposedV Abetweensaid`| arm and said stem'` and' adau `tedjso oppose. movement ,offsai'd larm in ,one direction relativetol said stem', said" stem having an abutment engageable by said arm to accommodate movement of said stem with said arm when said arm moves in a second direction, a second spring having one end abutting a portion of said stem and the other end positioned to engage said fixed abutment whereby under a first vacuum condition movement of said arm in said first direction by said device is opposed by both of said springs and movement of said stem with said arm in said second direction is facilitated by cooperation of said arm with the abutment on said stern and the movement in this second direction is assisted by said second spring.

7. A carburetor adapted to supply fuel to an internal combustion engine having a manifold and means for producing a vacuum in said manifold, said carburetor including a body part defning a fuel reservoir, an air and fuel mixing chamber and a main fuel passage connecting said reservoir and said mixing chamber, said body part being provided with auxiliary fuel passage means operably interposed between said fuel reservoir and said mixing chamber and adapted to provide an additional supply of fuel for said mixing chamber, valve means movable to a closed position, an open position and a restricted flow position relative to said auxiliary uid flow passage means, a piston slidably mounted in said body part for movement in response to variations in manifold vacuum, an arm carried by said piston and first and second springs positioned to sequentially oppose movement of said arm and provide a lost motion connection between said arm and said valve means to accommodate abrupt movement of said valve means to said positions in response to movement of said piston.

8. A carburetor adapted to supply fuel to an internal combustion engine having a manifold and means for producing a vacuum in said manifold, said carburetor including a body part defining a fuel reservoir, an air and fuel mixing chamber and a main fuel passage connecting said reservoir and said mixing chamber, said body part being provided with auxiliary fuel passage means operably interposed between said fuel reservoir and said mixing chamber and adapted to provide an additional supply of fuel for said mixing chamber, valve means movable to a closed position, an open position and a restricted flow position relative to said auxiliary fluid flow passage means, a spring opposed pressure differential operated element mounted for movement in response to variations in manifold vacuum, a member carried by said element and having a lost motion connection with said valve means and first and second springs acting upon said valve means and operable to move said valve means rapidly from said closed position to its restricted flow position and to its open position at predetermined conditions of manifold vacuum.

k9. A carburetor adapted to supply fuel to an internal combustion engine having a manifold and means for producing a vacuum in said manifold, said carburetor including a body part defining a fuel reservoir, an air and fuel mixing chamber and a main fuel passage connecting said reservoir and said mixing chamber, said body part being provided with auxiliary fuel passage means operably interposed between said fuel reservoir and said mixing chamber and adapted to provide an additional supply of fuel for said mixing chamber, valve means movable to a closed position, an open position and a restricted ow position relative to said auxiliary fluid flow passage means, a pressure differential operated element mounted for movement in response to variations in man1- fold vacuum, a first spring operable to move said element in response to decrease in manifold vacuum, a member carried by said element and having a lost motion connection with said valve means so that a first increment of movement of said element by said first spring occurs when manifold vacuum decreases Without opening said valve means, a second spring acting upon said member and said valve means and cooperating with said first spring during the aforementioned first increment of movement, said second spring being operable only during relative movement between said member and said valve means, a third spring acting upon said valve means and reacting upon said body part during a portion of the movement of said valve means from its closed position to its open position and means carried by said valve means and operable to carry said third spring out of operative relation with said body part when said valve means has moved a predetermined amount in a direction tending to open said valve.

THOMAS M. BALL.

References Cited in the ille of this patent UNITED STATES PATENTS

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