US1904022A - Carburetor - Google Patents

Description

April 18, 1933. J. L. wHlTEMAN CARBURETOR Filed Oct. 14, 1951 Patented Apr. 18, 1933n UNITED. STATES PPSATENT oid-#FICE f i JAMES LEIGHTON WHITEMAN, or PUTNEY, LoNnoinnNeLANn j onnisunnmonV Application led October 14, 1931, S'eral No. 568,8e0,and.in Great Britain December V5&4, 1930.

This invention relates to carburetors and atomizers for internal combustion engines of the kind in which the fuel passes through a jet tube having its delivery endv controlled by a needle or other valve movable axiallyk to increasev andreduce the fuel passage, said needle or other valve being moved away from'the end vof the jet tube by'means of an air valve which is'y opened bythe suction of the engine, and the jet tube being independ# ently adjustable axially within a nxed tube orother support, so that its position relative to the needle valve may be controiled independently of the automatic movement of vsaid needle valve. 1

The object of the present invention is to provide an improved form of construction and-improved fuel control and heating means adapted for use with both'petrol and heavy oil engines.

JAccording to the invention, in a carburetor or atomizer of this kind the jet tube and needle valve are so arranged that by movement of the jet tube beyond its normal work- 5 ing range', said tube is adapted to cut off the fuelsupply and open the airl valve so as to Y deliver uncarbureted air tothe engine. for cooling or braking. Y

Preferably, the jet tube is formed at its lower end Vwith rack teeth adapted to engage a pinion operatively connected with external control means for causing axial movement of the jet tube. Y Y

If'desired, the air valve may comprise'a spiral spring of conical formation, the adjacent turns of which are adapted to move apart and so open the valve upon movement of the needle valve. Alternatively, the airl valve may comprise. one or more flaps pivot- 40 ally mounted adjacent to the needle valve and adapted to open upon movement of the latter. f Further, the needle' valve may itself constitute a slow-running jet and V1may be carried by V,an iouter tube disposedroutside the fixed tubesaid outer tube being springinfluenced tocause'the needle valve to enter 4 the jet tube. The outer tube may be a sliding fitupon the upper end oftheixed tube and may be formed with one or more holes or oriiices so arranged that upon upward move# oil.

mentof the outer tube, said holes or orifices are progressively uncovered orregulatedr by. Y the fixed tuberil i Y f Preferably, the needle valve and air valveare disposed within an induction pipe or chamber which is progressively increased in cross-sectional areafrom'a position adjacent to the needle valveV and is then progressively diminished in cross-'sectional'a'rea to a position at which a throttle is provided. In this case lthe inductionv pipe may be provided at one side'withV a bulged portion, the opposite sideV being straight, and the angle of divergence of the bulge being Vless than the angle of convergence taken ingthe direction of the mixture flow through the'inducf i tion pipe. l j The invention-is illustrated inthe acc0mpanying drawing, in which v Figure l is a sectional` elevation of Vone 70 form ofinductionpipe and atomizer .arrangement, the usualV float chamber being omitted;v Ava J l -Figure 2 is a fragmentary sectional ele- Us i Vationof a modified form of air valve; and

- in Figure y1 is suitable more especially for use'l l with afloat chamber (not shownyof'known type Vand for operation with heavy or` crude {il} The induction system comprises a body 10 formed with an airinlet 11 and an induc-v Y v .Y

tion chamber 12, ay throttle or otherycontroll v valve 13 being provided at its upper end wfor 85 control of the delivery of fuel .mixture to thereY engine.Y `The lower portion ofthe-.body v1(7) is secured toV a b-lock or fitting' 14, which usuallyl constitutes va portion of the Yfloat chamL ber, the Vliquid Vfuel being `deliveredfrom 90` the latter through a passagevvl. Aviixed tube. ljisscrewed to the upper portion of the block 14 so fas to extend vertically within kthe induction chamber 12,V ajet tubegl being slidably mountedwithin thexed tube 16, and being formed-'withan oriiice'lav 'Y through :which `fuel is delivered from the passage 15. The lower end. 0f the jet tube is'inftheform of a cylindrical block 18 provided at one side with rack teethV 19,',adapt- 100 ed to engage the teeth of a pinion 20. VThe latter is fixed upon a spindle 21 and passes outwardly through a packing gland (not shown), so as to be operated manually by means of the lever 22, for raising and lowering the jet tube 17 within the fixed tube 16.

An outer tube 23 is slidably mounted upon the fixed tube 16 and is iniuenced by means of a helical spring 24 to move downwardly, the reaction being taken by a Collar 25 se! cured to the fixed tube 16. The upper end of the outer tube 23 is formed with a number of apertures 26 which. are adapted t@ be @Cevered progressively as the outer tube 23 is raised, a tapered needle valve 27 being secured tothe upper portion ofthe outer tube, and being adapted normally to extend within the jet tube 17. 'A f y The air valve comprises a spiral spring 28 of conical formation secured at its outer edgey to the body 10, and at its centre portion to the outer tube 23 ybelow the holes 26. Thus, the spring 28 tends to move the outer tube 23 downwardly,fand the spring 28 is arranged so that when fully contracted its adjacent turns are touching, so effectivelypreventing the passage of air into. the induction chamber 12.

ForV the purpose of starting, an electrical resistance coil or heating element 29 is provided at the base of the fixed tube 16 and this serves, when connected with a supply of electricity, to 'heat the tubes 16 and. 17 and so cause the oil or fuel contained therein and also the induced air, to be warmed. VVihen the engineV is running the fuel and/ or thejairy may be preheated by any known means.

lnthe operation of the device, the upper end 30 Qf-the body `1Oris connected with the induction system' of the engine so that as the throttle 13'is opened, a partial vacuum. is created'in the chamber 12. Owing to the P nature of the air valve comprising the spring `28, the atmospheric pressure causes the latter to open by extending upwardly, thus piermitting airto enter the chamber 12, and at thesame timeraising the needle valve 27, which allows fuel to be drawn through the holes 26 and so atomized andmixed with the air.

' The strength or richness of the fuel mixture may be'regulated by movement of the jet tube 17' through the medium of the lever 22. Thus', as the Jet tuber17 is lowered, the effective Varea'of the tube 17 Vis increased, and the mixture is made correspondingly richer.

Vhen the vengine is being revolved by means'of power other than its own, such for instance, as when a motor vehicle is descending anincline, the jetrtube 17 is raised manually by means of the lever 22, so that the orifice 17a is closed by the fixed tube 16, the needle valve 27 closing the upper end ofvsaid tube-17 Vand then raising the outer tube 23, thus openingtheair valve comprisedby the spring 28, so that air only is supplied to the' engine. This feature is especially y useful since the deposit of liquid fuel in the induction Vsystem is effectively prevented.

kThe body 10 is formedat one side with a bulge 31 preferably so arranged that the divergence is rather more gradual than the convergence, asy shown in Figure 1. It is found by this arrangement that on minimum speeds, the fuel mixture passes directly from the air valve 28 to the throttle 30; on greater speeds, however, a portion of the mixture flows around the bulge 31 and re-enters the main direct stream of mixture at an angle therewith and also ata lower velocity. This has the effect 0f. causing @onside-ral@.lev @flflyne and. consequently vitrerie/ation and theroueh mixing readily take Place In' the form of device shown in Figures 2 and 3, which show a modified form of air valre, e block? havne'a rectangular bore or aperture` 33 is supported within the. body lOvadj acent totheupper portion` of the outer tube 23, and carries two pivoted flaps34l and 36 provided with crank arms'36, 37, respectively, which at their innermost ends are adapted to engage in an annular groove formed-in the outer tube 23.,"Thus, when`r the latter isinits lowered position, the flaps34: and 35 meet one another along a plane containingtlie vertical axis of thel fixed tube 16,

while upward' movement of the outer tube Qlases the flaps Se. and 35 about their niv* AtalaXeSand alloue air t0. enterthe induction chamber 12.- y

As shown, the needle valve 27 is formed with passa-ees 38, andrrovded with ari adjuste-b1@ regulating. Screw 39, S0 .that Whetever theposition of the `air valve 28r andneedle Valve 27, a small amount of fuel maybe Sppldthrcieh.the passages. 'for' theme- .Qee Ot Slew tunning- 1-V A carburetor including. a fuel passage having an. atnlet, a iet tube .Controlling the ,fuel admission beth@ Passage, an ail', valve, controlling tube ,Surreundng the jet tube, a needle valve carried by the air valve controlling Vtube and cooperating with the upper yendort-the jettube, means for operating the jet. tube to initially cooperate with the needle valve and` thereafter lift the aii` valvecOntrollingtube, and an air valve lQontrollingthe admission of air Vfrom the air inlety tothe fuel-passage and operatedin the movement4 of the air valve controlling tube. 2. Ai carburetor including a fuel passage having an air inlet, a j et tube controlling the fuel admissionvtoV the passage,an air valve controlling tube surroundingthe jet tube, a needle valve carried` by theair valvecontrolling tube and cooperating with*y the upperend ofV the jettube, means for operating the jet tube to initially cooperatefwith the needle valvev and thereafter lift the air valve controlling tube, an air valvecontrolling the admission of air from the air inlet i to the fuel passage and Operated in the movement of the air valve controlling tube, and

means for normally influencing the air valve controlling tube to a position to maintain the air valve substantially closed.

Vsigned my name.

3. A carburetor or atomizer as claimed in claim l, wherein the air valvecomprises a spiral spring of conical formation, the adjacent turns of which are adapted to move apart so as to open the air valve upon movement of the needle valve.

4. A carburetor or atomizer as claimed in claim l, wherein the air valve comprises one or more flaps pvotally mounted adjacent to the needle valve and adapted to open upon movement of the latter.

5. A carburetor as claimed in claim wherein a xed tube is arranged intermediate the jet tube and air valve controllingtube and forms a sliding support for both said tubes. v

6. A carburetor or atomizer as claimed in claim l, wherein the needle valve is formed as a slow-running et.

7. A carburetor or atomizer as claimed in claim l, wherein the outer tube is formed with one or more holes ororilices arranged so that upon upward movement of the outer tube said holes or orifices are progressively uncovered or regulated.

8. A carburetor or atomizer as claimed in claim l, wherein the needle valve and air valve are disposed within an induction pipe or chamber which is progressively increased in cross-sectional area from a position adjacent the needle valve and 1s then progressively diminished in cross-sectional area to a position at which the throttle is provided.

9. A carburetor or atomizer as claimed in claim 1, wherein an induction pipe is provided formed at one side With'a bulged portion, the opposite side'being straight, and the angle of divergence of the bulge being less than the angle of convergence taken in the direction of the mixture iiow through the induction pipe.

In testimony whereof I have hereunto JAMES LEIGHTON WHITEMAN,

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