US1813206A - Carburetor - Google Patents

Description

July 7, 1931. R, sHlPMAN Y 1,813,206

' GARBURETOR F'iled July 1.192'7 2 Sheets-Sheet l CARBURETORv Filed July 1, 1927 2 sheets-sheet 2 gwoon-to@ Ithiman RALPHJYSHIPVMAN; F11 SUNBURY," PENNSYLVANIA cmuamoa,

. Application mea Julyi, 1921.. Barnim. 1102.941.y

This.inyenti on. ,has v:for its, ob]`ect f to pro.- vide.a;con structi on;in, carburetors by .which is accomplished a ifto.; or: apart afrom- .the abovei v`yailichjokefadjficent to the znozz stru theseveral 2 fallar..descri` nyention,7 g further consists-.in the. conf.y

Referring-tothe accompanying drawings intwhichcorrespondin 4parts.are... designated g by,corresponding mar s of Jreference':

Figurelisa verticalsectionpartly in,eleva.

1re- 2fis'afvertical sectionof parts shown ind?.y re.-;1;withithe casingremovedre.3 isaview similar lto Figure 2, but

-.pnff-.angjenlarged vscaleandfwlth vcertain parts .4A isaplan view. of the .fuel nozzle 511....:l

bro

vne 5 fis. `afside relevation thereof. 30,@ Laiska. side view ofthe air choke sleeae ndi itsfassociated weight.

'is a-.plan view lof the parts shown in-,Flg'lll Figure 8 is a detailv representing the man- 35 ,ner of. mounting ofthe metering pin. v

Referring-,to the drawin 1 lrepresents a suitable carburetor casing, orming a mixin chamber, having mounte n which', is to be connected to the manifold of tothe/en ne, the throttle 2 in the form of a butteri7 and having about midway of its height arestriction forming a Vsto for the member to be hereinafter described, and

preferably forming the seat 3 ofv an air valve,

15 to be, hereafter described. The mixing chamber casing below the seat 3 is connected to an. air intake 4, having the.usual choke 5 therein, the bottom of the casing being provided-with a fuel intake 6 which leads from 50 the .usual float chamber 7 to a gasoline nozzle desired vcontrol. of the. fuel.: mixture. Fior thisgpurpose. I provide f means ,whelgebydhei Qsifion of iai-'fuely throttlingele.-l "ment rin); he.. ucl .nozzle.is'controlled ;by the:`

` f^?pressure.:existing.on` opposite.`

sual air throttlesand in, which, t th by, Sissa. aboye.; agspecified: gdeman'dffor. 1 'ainby the. en,-

y controlled- :by such .pressure diierences.

cti0n;,= ,arrangement andfscombination 4of Eartsaswl hereinaftermore V lcarbure,tor. .embodyingmyinvention.2

'1ower.one,`20b,. and the two being unitedby ear its upper en 8. Thisnozzle enters and extends uprthrough Thenozzlepasses.through a suitable; packing f box l y9 tformedQ .Lonv :the bottom: of fth'effcasing, an'd throughl ani. iupwardr' extension. 10- -fa's. l5 tened.to. suchf bottom, it lbeingI threaded. finto the latterfo'r adjustment;v Wlthin thenozzley is threaded the stem ofmetering pin =13,`fvl1"av4 ingla conical head 14 normally terminating i, below ythetopA of thenozzle.- In onder ftofpre-x.v serve @alignment fof the head. kon. adjustment, the threaded stem "is" connected. byi a .ball-fand-il socket joint showngat- ;15.in Figure-3 w-ith.l the. conical head of zthepin;

annular', terminates `slightly'below-the nozzle 8,and forms -theseat Ifor `an air choke sleeve, it having notches 16 in its upper Aouter-edges toI assfa limited. 'quantityxofv air at all times-.-4

ithinthe u per part of the mixinglzch'am-z ber;is contained `a memberf20I shown: as cone 1 sisting 4.oftwo cylindrical parts, the upper one, 20a, beingk of greater diameter than the a tapering portion 20c which cooperates with.y andseats upon ythe seat 3 in the mixing'J chamber.l Theupper portion of this member-20 is hollow .and forms a cylinder whosefunction will be describedflater. The member 20 is guided. for movement byhaving its-lower 80 l portion20b enterin the .upper endv of afper` forated shield 24 -w 'chzrises from the base of the carburetor andsurrounds the fuel nozzle and the extension10,.being,spaced some-- what therefrom.L Also for the purpose 'of guiding the member 2O its upper endreceives a piston head 21 fast on a tubular `guide v22, whoseupper end is ysleeved. on the throttle shaft 23, therguidecxtendingw'throu hsthe upper vhead 25 of themember20.- eair passage 26 within the tube hasv its u per end communicatingy with .the space vva ove` the throttle, such communication being control# led by a ballcheck valve 27 The Vhead 25 of the member 20` is threaded onto thecircumferential walls vthereof to-permit the assem. blage within the member of jdesired parts, a spring 30 beinginterposed betweensuch head and the piston head. This spring serves to carry the weight of the member 520;.and-

The upperend of.theiextensionalfwhichis 05 fold and the metering-tube moves u parts mounted thereon, and when the engine is not running, maintains the member slightly o' the seat 3. The space between the head 25 and the piston head is in communication with the bore 26 of the tubular guide through a port 31 of restricted dialneter'in the wall of the guide.

An annular shoulder32 is formed within the upper cavity of the member 20 and is threaded to receive the plug 33 which forms the lower head for the cylinder in which the piston head 21 is contained. The plug has an annular flange 34 on its upper face, within which is received a second piston head 35 on the upper tubular end of a piston 36, the lower end of which terminates in a tube 36a which enters the upper end of the nozzle, and at about the level of the end of the nozzle is tapered. The upper tubular end of the piston 36 receives t-he lower end of the tubular guide 22 through a suitable self-centering packing box. This self-centering packing box may consist of a washer 37 snugly surrounding the tubular guide 22 and held within a cavity 38 in the top of the piston 36. The interior cavity at the top of the piston 35 communicates with the central bore 26 of the guide and through ports with the s ace below the piston head 35, so that in sucii last named space also exists the same pressure as exists in the manifold. The annular shoulder 32 has ports 40 therein communicating with the space within the base of the enlarged portion 21 of the member-2O and such space communicates with the space exterior of the member through peripheral ports 41, so that while manifold ressure exists in the space above the piston ead 21 and below the piston head 34, the space between thepiston heads has mixing chamber pressure within it. Hence the member 20 moves up and down as a whole in response to the variation of differences of pressure in the mixing chamber and the maniand down in respect to the member 20 in response to the same variation of ressure, a spring normally lifting the p1ston head to its upper limit of movement.

A shoulder 42 is formed on the interior of the member 20 at about the upper end of the -lower portion thereof, and serves as a su port for the annular weight 43 for the air choke sleeve and which has a corresponding engaging shoulder 44, by which such Weight member is carried in the member 20.

The lower end of the weight surrounds the upper reduced end of the annular air choke sleeve 45, the bottom of which is interiorly tapered and surrounds and cooperates with the upper end of the primary air valve seat formed on the top of the extension 10. The sleeve 45 thus surrounds the` tube 36a which enters the fuel nozzle and which has perforasleeve, where it is mixed with aid which has passed the air choke, and which passes through the central bore of the weight 43 to the peripheral ports 41,

AIn order to prevent this passage being closed at such times as the weight member 43 is lifted from its seat by the sleeve, the for Vmer has its upper end notched as at 47.

The general operation is as follows:

When the engine is not running, the parts are in the position shown in Fi res 1 and 2, that is to say, the member 20c 1s slightly off the seat, 3 and has lifted the weight 43 off the air choke'sleeve which is resting on the fuel nozzle 10. The' secondary iston 35 is held raised within'the member 20 y its spring 60.

If the engine is running idle with the throttle more or less closed, the differences in pressure existing in the manifold and in the mixing chamber below the throttle willby the excess of the latter pressure over the former, depress the secondary piston and lower the tube 36a with a consequent reduction in the fuel fiovv areabetween it and the nozzle 8, fuel beingasperated through such area by the air passing through the notches 16 in the edge .of the fuel nozzle. The pressure dierence als'o causes the member 2O to descend and seat on the seat 3 but the weight 43 will not be at this time in contact -with or rest on the air choke sleeve. As the engine increases its demand for air, the air drawn up throu h lthe notches 16, will drag ,with it the air cho e sleeve, increasing the iow area for the air.

At sometime in its movement, this sleeve will contact with its weight 43 and its movement will then be dependent not only on its own wei ht but on the mass of the weight.

lpon a further opening of the throttle to increase the engine speed the pressures on the two sides of the butterfly tend to equalize so that thespring 30 vis enabled to lift the member 20, thereb unseating the member from the seat 3 an at the same time lifting the weight 43, this enabling the choke sleeve to resume`its free movement until again-retarded by the weight.

The differences of pressure may still vbe suiiicient to compress the spring 60 and to hold the secondarypiston 36 down. As the throttle is still further opened with the consequent greater equalization of pressure on both sides of it, the spring 60 comes into action to lift the secondary piston 36 and in consequence to increase the fuel iiow area around the tapered end 36a of that piston. On a reverse actuation of the throttle the reverse movements occur.

In order to retard the movements of the member 20 and the secondary piston 36, and to prevent an abrupt change in fuel condition before the engine has had an opportunity to respond to the change in position of the throttle, the check valve 27 is employed.

Upon the opening of the throttle there immediately results an`abrupt decrease in the vacuum (increase of pressure) in the 4manifold with an increase of vacuum (decrease of pressure) in the mixing chamber. Upon the increase of pressure in the manifold over that existing between the two piston heads 21 and 35, the ball 27 will seat, trapping above the piston head 21, and below the piston head gases under the pressure which had existed in the manifold prior to the opening of the throttle andhence more or less nearly equal to the new conditionof pressure existing in the mixing chamber. Hence the elements above described, which depend for t-heir action upon the pressure differences, are for the time being rendered inert and this inert condition will continue until leakage restores them to their previous Arelative condition of pressure. In order to prolon this period, without making such close ts as` would induce friction, I may, as shown in Figure 1, provide a vacuum chamber 66 exterior of the carburetor but connected to the central bore 26 of the guide 22 through the pentral bore 67 in the shaft 23 of the butteryAs a convenient and eilicient device for manually varying the fuel supply, the metering pin 14; is employed. By lowering this pin so-that its tapered head becomes oppositethe lower end of the tubular base of the piston 36a the supply of fuel to the interior of such piston may be controlled and hence the flow offu'el from the ports 36?) in such pistonI `under the pull of the air iowing through `the air choke sleeve may also be controlled.

. Having thus described my invention what I claim is 1. In a carburetor the combination of a mixingl chamber, a fuel nozzle therein, a

throttle near the exit end of the mixing chamber, an air choke sleeve adjacent to the nozzle and an air valve whose position is determined by the differences of pressure on opposite sides of the throttle and which controls the area of the air choke and also the area of an air passage in the mixing chamber but remote from the nozzle.

2. In a carburetor the combination of a mixing chamber, a, fuel nozzle therein, a throttle near the exit end of the chamber, an air choke sleeve surrounding the nozzle and restricted fin itsmovement by a yielding abutment and means actuated by difference of pressure on opposite'sides of the throttle for controlling the position of the abutment.

3. In a carburetor `the combination of a mixinof chamber, a fuel nozzle therein, 'a throttle near the exit end of the chamber, an air choke sleeve surrounding the-nozzle and Y movable under the flow of air through the same, a yielding member restricting the movement-of the choke' sleeve and means aotuted by difference of pressure on opposite double headed cylinder in the mixing sides of the throttle for controlling the position of the yielding member.

4. In a. carburetor, the combination of a mixing chamber, a fuel nozzle therein, a throttle near the exit end yof the chamber, an element throttling the nozzle, a cylinder, a piston head shiftable there-in by the pressure vdifferences above and below the throttle and differences above and below the throttle and controlling the movement of the fuel throttling element, means controlled by the pressures above and below the throttle for shifting the cylinder and piston head therein, an air choke sleeve surrounding the nozzle and means actuated by the cylinder for controlling the movement of the air choke sleeve.

6. In a carburetor the combination of a p mixing chamber a fuel nozzle therein, a

throttle near the exit end of the chamber, a

double headed cylinder in the mixin chamber, a fixed piston head near one end of the cylinder, a movable iston head near the op posite end of the cy11nder,the space between ythe pistons communicating with the mixing chamber below the throttle and the spaces between each piston. and the adjacent end of the cylinder communicating with the space above t e throttle and a throttling element for the fuel controlled by the movable iston head.

7. In a carburetor the com ination o-f a mixin chamber, a fuel nozzle therein, a

loc

,thrott e near the exit end of the chamber, a

charnber, a fixed piston head near one en of the cylinder, a movable iston head near the opposite end of the cylmder, the space between the pistons communicatin with the mixing chamber below the throttle and the spaces between each piston and the adjacent end of the cylinder communicating with the space above the throttle, a throttling element for the fuel controlled by the movable piston head, and an air cho e sleeve surrounding the nozzle and controlled by the movement of the cylinder.

.8. n a carburetor, the combination of a mixing chamber, a fuel nozzle therein, a throttle near the exit end of the cylinder, a double headed cylinder and a piston contained in the mixing chamber, one of the said elements being fixed and the other movable, a second pist-on head in the movable element, the s ace between the second piston head and the xed element communicating with the mixino chamber below the throttle and the space between the first piston head and the cylinder and between the second piston head and the moving element communicating with the space above the throttle and aA metering element controlled by the second piston hea-d.

9. In a carburetor, the combination of a mixing chamber, a fuel nozzle therein', a throttle near the exit end of the cylinder, a double headed cylinder and a piston head contained in the mixing chamber, one of the said elements being fixed and the other movable, a second piston head in the movable element, the space between -the second piston head and the fixed element conununicating with the mixing chamber below the throttle and the space between the first piston head and the cylinder and between the second piston head and the moving element communicating with the space above the throttle, a metering element controlled by the seco-nd piston head, and an air choke controlled by the movement of the cylinder. y

l0. In a carburetor the combination with a mixing chamber, a fuel nozzle therein, a throttle near the exit end of the chamber, a, cylinder Within the-chamber, a piston head within the cylinder, one of the last two elements being movable, the space vwithin the cylinder being in communication with the space above the throttle, a check yalve controlling such communication, means for controlling fuel mixture controlled by the movement of the movable element, and a vacuum reservoir exterior of the carburetor and connected with the space within the cylinder.

In testimony whereof I hereunto aix my signature.

RALPH SI-IIPMAN.

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