US1526317A - Carburetor - Google Patents

Description

web, .17, 1925l M. G. CHANDLER CARBURETOR Filed June 28, 1920 2 Sheets5heet l web., l?, w25.

Filed June 28, 1920 M. G. Cl-{ANDLER .CARBURETOH A 0mm/5 ,iiiaieaieci Feb. i'i", i925.

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iygghgfiiii F i C if PATENT MZLFRD G. CHANDLER, 0F CHCAGO, IiIiINDIS, ASSIGNR, BY MESNE ASSIGMENG'S, '110 URTIS B. GAME?, TRUSTEE, OF OAK PARK, ILLINGS.

CARBURETOR.

application med June as,

To all whom t may conce/m.'

Ble it known-that if, Mirroirs G, CHANo- Lisa', a citizen of i'he United States, and resident oi' Chicago, in' the county of Cook and c State of illinois, have invented a certain new 'and useiui improvement in Carburetors, of which the following is a foil, clear, concise, and exact descriptiori, reference ben ing had to the accompanying drawings, forming a part-,oi 'this speciiicaiion.

My invention reiates iio vcarbureiors for 1 iiiteraai combustion engines. The carbureior to which my invention is applied is arranged ioriiiiioo' fue-1 from a ioW ieve-i suppiy taiiir izo izhe. i oat cbaioiiber oi the carbureior by suction derived from the sucf tion of the engine,

is is the objeci of this invention io pro- -vide ay fusi biting carburetor iii which the air entrance io the mixing chamber is in a iform simuiating `au expanding Venturi tube, izhe. uei mosaic being,l ioeaied `so as to discharge in position near the i'iroat of his Venturi tube Where the suciion is ai a Ways i'iigher than thai of ihe mixing cham ber, i f

iii is characteristic of rhe carburetor iii which ibs fuei is ied to the induction as sage by suction produced ai; poiri; oi resa siriciion in said passage rather than by Sorce anterior ihroiziing device such as an aurerior air waive, that a greater proportion oi? fusi per, roiume oit air Wiii be delivered to the carburesor ai, high engine demands haa ai; ieri engine demands unless some means 'is provided io overcome his characn ier s i. The characierisiic above referred io is .markediy present "Where the air is drawn iriro thc carburetor through a Fixed orifice. liu carbureiors in which. the orifice euiarges, as ibdoes in the present carbure# ser, and is which the fuel is fed at subsizaa 4iiaiiy ihe throat ci this orifice, the` characterissic' above rcerredto, of the tendency to enrich at high demands, yis ordinarily more than. compensate-d for by the lack of increased velocity through the oricc. due to its eniarged size ai: high engine demands. Y .in rire present carburetor, "this overrompeusai'iou is again compensated for by so shaping ihc oriiice thai) it more nearly simuiaiies ,a Venturi. tube Wheu `iride operi than 'when it is iii a more neariy vclosed positioiareauitirigr iii a higher proportioriaie sancties ai' the -iiseharge and oiv the nozzle sic Sii

. sponso to' slight, changes in size of the main `rotatably mounted .upon iihe pivots 2O and 19%0. Serial No. 392,152.

for high engine demands `than for ioW eugine demands. v

A further object or" the invention is the provision of mechanism operable in re air inlet, which mechanism coiiirois the suction on the surface of the uei m the car-L `iouretor float chamber to regulate the fuei feeding differential between the iioabv cham; ber suction and that which draws the fusi into the induction passage.

Other objects of the invention Wiii be poinedioui 'in the following detaiicd de scri 'tion of the appara-tas AiviOyinvention is illustrated iii ihe accompa'i'iyinfgvdrawing iii which i Figure l is vertical seciioii iirough the intake passage of the carbureiorn Figure Qiis an elevation, with Abhe iioai; chamber removed Figure. 3 is a section on che iiue 3-f3 or urs l.

`iirgure 4 is a section oaths iise'indicaied by iff-4 in Figure 3. e v

Figure- 5 is s perspeciiive of one of ihe expanding shoes. i

Figure 6 is a section through the vaciu'im Venturi tube and its housing, and

Figure i .is a diagram showing the con tours i, iB and 7C of the opening *through the induction' passage ai the' respective piaoes indicated ai. 7, "if and ic oi Figure 3 when Ithe shoes are in the position shown inv Figure 4i.

flanged annulus 10 foi-uis a portion or" 'the induction passage enciosure and carries Ahe rhrottie ll consroiicd by au arm i2.' Side Wa-iis 13 and 14 pariiaiiy eiiciose lche mixing chamber l5 and are joined at li by screws 1S.` The inner faces of ihese waiis 13 and 1i are Ashaped to conform to the intersection of two surfaces oi rotation cololstructed around the centers 20 and 2; the

shape being; such thaiJ the'shoes' 22 and 23 2l, when moved io-various :ingu/hir posiim tions about theirr pivot points, consiitu'se" substantial. seais against `i`eairage between the. carburetor mixing chamber T5 and the spaces 25A and Qbehind the shoes. The air gieof divergence between i-heside. plaies 13 i and 1li is about 7 1X3?, and the shoe-is 22 and 23ste formed so that their surfaces coming adjacent `these side piatespconiorm Ato such divergence as weil as' tothe curvature M of the side plates, as clearly shown in Figures 3 and 5. The openingsback of the shoes 22-and 23 are closed by means of plates and 31.

In View of the deterioratingeifect of gasoline on die cast metal, the float chamber 32 and nozzle support 33 are preferably made of brass and suitably attached to the halves 13'and 14 by screws 34 and 35. To facilitate drilling of passageways for fuel and suction as hereinafter Inore fully described, the float chamber casting is preferably made separate from the nozzle support and attached by meansof the screws 3G. The nozzle 38 is of venturi form and is so positioned that its discharge end is nozzle support 33 in a manner-which pro-l vides a fuel passage 42 entirely surrounding the nozzle Venturi tube so that fuel delivered substantially equally, through all of the openings 41. rlhe annular space 42 is connected by'means of registering passageways -li and 44 with the lovver portion of the float chamber 32, the opening 41 being controlled by a needle valve 45. The nozzle support 33 is enlarged at 47 as shown in dottedv lines, l `igure 7, to conform to the curvature of the upper and lower shoes so that when the shoes are in their most contracted positions, they'l contact with the member 47 and substantially cos.- the entrance into the mixing chamber, excepting through the nozzle Venturi .tube 38 and through the vacuum Ventui-i tube 50. The vacuum Venturi tube 50 is supported in a projecting part 5l formed n the outside of the side plate 14. This Yent'uri tube connects with the mixing chamter through the passage 52 and has its throat t-onnccted by the passage 53 and registering bas-sage 54 with the upper part of the float.

chamber. The rod interposed across the passage 52 constitutes `a restriction in said pass ge and is so shaped as to provide the rarying restrictions as demande-d to provide tlwproper diterential between the float chamber vacuum and the iiixing' chamber `at-num to supply the right proportions of 'vcl at all engine speeds. t 'lhe rod 55 is rwiprocated by means of the rack 5G and Minions 5T. These pinions are carried upon the extended ends of the pivot rods 2() and and serve not only to reciprocate the rod from the mixing chamber to the closed spaces behind the shoes. Springs 59 are supported between the inner parts of the shoes and the cover plates 30 and 31 and are arranged for suitable adjustment by means of screws 60.

vFloat chamber 32 is provided With the usual float anda tloat control valve for maintaining a constant level of fuel. The float chamber cover effectively seals the upper part of the iioat chamber so th ata depression may be maintained therein for lifting fuel from a low level supply tank, this fuel being brought into the tloat chamber through the connection 61 in a manner Well understood.

l In the operation of this device, starting, for example, at low engine speed, the nozzle Venturi tube 38 together with the vacuum Venturi tube 5t) are so sized v,as to supply the necessary air for idling, While at the same timeconstituting such airestriction as to provide a depression or suction in the carburetor mixing chamber equivalent to about 19 inches of gasoline in a manometer tube. With this degree of Suction in the mixing chan'rber` the vacuum Venturi tube 50, by its multiplying action. provides a depression or suction of about 36 inches of gasoline in the upper spaces of the fioat chamber, this amount being suiiicient to maintain a supply of fuel in the float chamber und'erthe assumed conditions of operation. lf agreatcr float chamber suction is desired, a smaller opening for the nozzle Venturi tube must. be providedA so that that tube Willbconstitute a greater restriction to the incoming air. `When the throttle 11" is opened toi something greater than the engine idling position. the suction in the mixing chamber will tend to increase.

This suction is communicated tothe spaces behind the shoes, and tends to open the shoes against. the tension of the springs 59 because portions'of the shoes extend outwardly from the Apoint of contact of the shoes with the member 47 and those portions are exposed to atmospheric pressure. The springs 59, therefore, are soadjusted that ivith a very slight increase in mixing chamber suction, the shoes start to open and thus admit air through the secondary air passage around the vprimary nozzle 38, and thus prevent the mixing Vchambei` suction from increasing more than ust that amount necessary lor creating a balance. i

lVhen the. air@ enters the mixing chamberl between the shoes and 23 and the enlargement '47 surrounding the end of the nozzle Venturi tube 53S, a local increase in suction vis created at a point indicated on the drawing by the numeral 65. From this point toward the throttle, the local suction gradu-I ally disappears until the mixing chamber backfire. The present structure inherently provides an excess of fuel at the time of sudden inrushes of air due to the quick opening of the throttle because the suction, which is communicated to the mixing chamber by the. quick opening of the throttle, first acts upon the inner faces of the shoes 22 and 23 drawing them toward onel another and thus momentarily enhancing the suction in the mixing chamber-and increasing the flow of fuel to the mixing chamber. This action of the shoes is due to the restriction interposed by the holes 5S Which prevent the lo calized suction of the mixing chamber from being immediately communicated to the spaces behind the shoes. In other words, since it requires a little time for air to circulate through the openings 58 to bring up the suction behind the shoes 22 and 23, the suddenly increasing suction in the mixing chamber partially closes the shoes and consequently provides a momentarily increased flow of fuel through the jets. is also aided by the fact that the suction on top of the fuel in the tioat chamber is derived through a somewhat long and quite small passage from the throat of the vacuum `Venturi tube 50 to the upper spaces of the float chamber which acts to preventthe suc tion on the top of the fuel in the float chamber from increasing materially at the time of the sudden increase in suction at the jets.

Although my invention is shown and' described in reference to a specific embodiment, it is to be understood that certain modifications may be made from this embodiment Without departingfrom the spirit Ior scope of my invention.

What I claim is:

1. In a carburetor the combination with an induction passage of apair of movable `shoes constituting opposite walls of said passa e, a pair of closed chambers in which said sioes operate, and means affording va passageway between .the induction passage and the spacesbehind said shoes for creating a suction in said spaces for causing the movement of said shoes and means ccn-4 trally located ,between the shoes to deliver fuel to the induction passage.

2. In a carburetor the combinaticn with i a body portion constituting a part of an in-4 tion in the induction vpassage .for movingsaid shoes about their Vsupporting pivots to enlarge the restricted opening into said induction passage.

3. In a carburetor for raising fuel from a low-level supply tank to a chamber aprIhis action purtenant to the carburetor, the combination with a fuel-feeding Venturi tube of a suction-producing Venturi tube having'its discharge end opening into the induction passage of the carburetor and having a connection between its throat and the chamber pertinent to the carburetor for creating suction therein for lifting fuel thereto, a pair of movable Walls adapted to assume various positions dependent upon the quantity of air passing through said induction passage, and means movable under the influence of said movable walls for controlling the sizeof the assageway between said vacuum-producing enturi tube and the induction passage of the carburetor.

4. In a carburetor for raising fuel from a low-level supply tank to a chamber appurtenant to the carb'uretor, the combination with a Venturi tube for crea-ting suction in the chamber appui-tenant to the carburetor for lifting fuel thereto, means for varying the opening into the induction pas sage -of the carburetor and means' for vary` ing the opening between the suction-producing Venturi tube and the induction passage of the carburetor, said means being operatively connected together and a nozzle Venturi tube for delivering fuel from the chamber pertinent to the carburetor to the induction passage. l

An expanding ipduction passage for carburetor-s comprising a pair of opposed shoes pivotally mounted so as to present faces forming diverging Yalls for said induction passage, said shoes when open forming with other Walls of the induction chamber a passage having substantially a. venturi shape when the shoes are swung to their wide open positions, and openings through said shoes for the creation of suction behind the shoes for causing the operation thereofI and a nozzle Venturi tube located centrally between said shoes and discharging at a point of high suction in the induction passage.

6. Anv expanding induction passage for carburetors comprising a pair of opposed shoes pivot'ally mounted so as to present. faces forming diverging walls for said iu-` duction passage, said shoes when open forming with Vother ywalls of the induction chamber a passage having substantially a venturi shape When-the yshoes are swung to their wide open positions, an opening through one of said shoes for creating suction behind said shoe for causing the operation thereof. a mechanical connection between said shoes causing them to operate in unison and a Venturi tube constituting a fuel nozand discharging into the same at a point of high suction therein.

7. In a carburetor the combination with a body portion constituting anl induction4 4:5 zle located centrally in the induction passage .said shoes toward said nozzle, means communicating between enclosed spaces behind said shoes and the induction passage at a point near the discharge end of said nozzle, and a fuelsupply chamber connected with said nozzle.

8. In a carburetor the combination with an induction passage and a fuel chamber, a

tube forming a small inlet into, the induc- `tion passage, a connectioufrom an intermediate point in said tube to the upper space of the fuel chamber, means responsive to suction in the induction passage for controlling the size of the inlet to said induction passage which admits the bulk of the air thereto, means o eratively connected .with the passage contro ling means for varying the discharge orice of said tube vtor varying-the degree of suction in the fuel chamber, and a nozzle for delivering fuel Jfrom said chamber to .the induction passage.

9. In a carburetor the combination With an induction passage, of a float chamber, a vacuum producing Venturi tube extending from atmosphere into the induction assage and having its throat connected with the upper space of said float chamber for roducing la suction therein to lift fuel thereto, a nozzle'enturi tube also extending into said induction passage and having its throat connected with the lower part of said fuel chamber for extracting. fuel therefrom and delii; ering the same tothe induction pass-age,

an automatic device for controlling the How of secondary airinto the induction passage, and means connected With said automatic device :tor controlling the flow of air throu h the vacuum Venturi tube for delicate y regulating the suction inthe float chamber. In Witness whereof, I hereunto subscribe my name this 23rd day of June, 1920.

MILFORD G. CHANDLER. .Witnesses:

Enna V. G'UsTAFsoN, ANDREW WINTERCORN.

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