US1792495A - Carburetor - Google Patents

Description

2 Sheets-Sheet l CARBURETOR mar F. A. HEATH Filed Aug. 17, 1923 Feb. 17 1931.

Feb. 17, 1931.

E. A HEATH gwuemtoz a cuff;

glazes! Patented Feb. 17, 1931 Foe-REST A. H

mezeee FATE, e3 Jan-remit, Mi'CEEGAN 1 hp ineihn3125512115; 17, 'isz 5651411 N5. 557,551.

5 "e 1 1t hot1y of fuel is gasoline in proximity to.

the eii rhnhetor, My eerhuretol' also belongs in thet elfss having hykpaths for admitting anxiliery snioplies' ofgzioline and ahto the intake man ifold of an intefnal combustion m my cu buretor may be characteri zed the following p'efticniei's.

fii' rst thefe e novel air inetel in'g valve p1 oy ide'cl with a tnel metering {3111 which is "movable in eyllchiljOhifil With'the' air lneterah efand .oont roleth e ztdniixtnre of air eld gesoline inthe mmmixing chamber of the ertmetr with the gasoline Supply e nterinhl; in auxi'liery' or modulating ply oi eir in 7 edema of oomn'lingling With the inziih supply ofjeir. V

$eeond, a novelpriming vie-We is 'eJrtiew ted with an hi1 Choke valve, with the 'priI nvhl e adapted to be opened only during l e'st 'fet zd egi'ees of movement of the choke 'vgiltg in eeing. This ermits, pertia'l w gl'mpst complete elosjhg not the choke velve Within, the employed in V'erious dejre eof the egzplosiife i iXtnre for inotor operetion during Warnh 'g-up? or tintter 'snh nerml motoiteinpefattire conditione ithout opehing theprtiing' valve. Q Third, there ere 1'1 v'el ineens for breaking ii) 51- gomerwi e disintegrating globulee or other email bo{d ies w ot gasoline Whieh may i thi'oufgh the mixing chamber Without eing thofronghlyetojrnized and these lnterfeieili fi eleme ts are 106 d so as tohe eonftgihtly etiye for the p imingaeemin su plig of; e1 to the lnoto-i. In breaking er titles 01- fu el whi'oh lney h'e in suepension I weenie genie inhetterbondition for com- I e? .t, we! heect at mg upon the fuel the passages in the carburetor, the manifold eerhfu ewr, 'hecatie the fuel-breaking ehd thefue'i and air mixing teeters of this ca 'lnt rete'r produce constant hemegeneity in the mixture created. It has been found that in a hoznogeneens 'nn tm'e the fuel c'onteht "new he widely varied, especially in the di reetioz i of diminiehment from the percentage en'- proxinmted in the COHTVSDtiQYll type of em r5. buret r, wvith'out afieoting; the functioning; of the motor. The-ponventionel type "of eai'huz'etor s ming no means of insm-in homoity in themixturefihe higheet degree 21ft ed being duets; a synchnonizetio of the Inigiing efi eots due-to the and snepe of and the intakes of the motor eyhntlei's. Wi thth'e co-nventio-nel carburetor, the Veriz: tionof the feel heed%eve1 1"to the degree in volved throilgh the shaking hf'tho contents of a float chamber in motor Vehicle operation over road suffice other then absolute smoothfcauses varizition in the fuel content of the mixture. which changes the effects pieduo'ed by the mixing faetors entering into the synehronizet'ion referred to, and changes in turn the degree of homogeneity in the mixtore agri ing in the eomhustionehemher of the motor cylinder. This var'i'etion not;only ohange s the average power output of the cylinder explosio-nsthrough the 'ehei'lging of 6 the average degree of richnees of the mixture at the point in the co'ln 'are seed mess W the Ignition occurs, but, in the case of a multiple cylindef motor, changes the were e fuel content of the charge delivered. the nhrious cylinders-through the similarzieriation of the degree of homogeneityet the point in the manifold Where distribution to the various:

L My oelfhuretol possesses other eh ist-ice that. will a opeer e fully de Qh'y p mung dran'lngs, Where Fignre l is e yextieeh longitudinal feo detecheel 7133 a portion of the carburetor, and

Fig. 7 is a side elevation of the carburetor showing the adjusting mechanism between the air choke and priming valves.

The carburetor comprises a body 1 having a mixing chamber 2 and an air chamber 3 separated by a partition 4 provided with a valve seat opening 5 adapted to establish communication between the chambers 2 and 3.

One side of the carburetor body'l has a warm air intake connection 6 communicating with the air chamber 3 and in this connection is a conventional form of butterfly choke valve 7 carried by a transversely disposed rock shaft 8 having its outer end provided with a crank 9. The air intake connection 6 is also adapted to communicate with the mixing chamber 2 through an upwardly directed auxiliary air by-path 10 in an enlargement 11 of the partition 4 at its juncture with the carburetor body 1. The by-path 10 may be restricted or completely closed by a conventional form of screw vale 12.

The bottom of the carburetorbody 1 has an opening 13 and mounted in said opening and suitably secured to the carburetor body 1 is a base piece 14 having a depending stem 15 provided with an axial bore 16. The lower end of the bore 16 is enlarged and its walls interiorly screwthreaded to receive the port ed nipple 17 of a fuel inlet connection 18 which is provided with an adjustable needle valve 19 that may be set to regulate the inflow of liquid fuel, as gasoline or kerosene, into the bore 16 of the stem 15. On one side of the stem 15 is an enlargment 20 having an angularly disposed priming by-path 21 communicating with the bore 16 through a part 22 and the passage of fuel from the bore 16 into the by-path 21 is controlled by a screw valve 23 movable to and from the port 22. On the outer end of the screw valve 23 is a crank 24 having a screw and slot connection 25 with a link 26 pivotally connected, as at 27, to the crank 9 of the choke valve 7. The manner of articulating the choke valve 7 and the screw valve 23 is such that the screw valve is only open during the final closing movement of the choke valve, thus leaving said valve free for adjustment within the limits employed for controlling the main intake of air to the carburetor.

The inner wall of the air chamber 3 has an enlargement provided with a by-path 28 establishing communication between the bypath 21 and the mixing chamber 2, at a point above the opening 5, so that when this opening is closed priming fuel may enter the mixing chamber 2 for priming purposes as will hereinafter appear.

Alining with the stem 15 of the base piece 14 and extending upwardly through the air chamber 3 into the opening 5 is a fuel inlet member or stud 29 having its walls longitudinally fluted, as at 30 and the lower ends of the flutes terminating at a shoulder 31. Axially of the fuel outlet member 29 is a bore 32 communicating with the bore 16 through a tapered or restricted portion 33 afiording a valve seat 34. Above the seat 34 are radially disposed and outwardly flared fuel outlet orifices 35 opening into the flutes 30 of the fuel outlet member 29.

Slidable on the fuel outlet member 29 is an air metering valve 36 adapted to close the opening 5 of the partition 4 and said air metering valve has an apertured top wall 37 with its apertures 38 disposed to com1nuni cats with a plurality of air passages formed by the flutes 30 of the fuel outlet member cooperating with the inner annular wall 39 of the air metering valve 36. This air metering valve is adapted to be automatically raised or unseated by reduction of atmospheric pressure in the mixing chamber 2 produced by the reciprocable pistons in a multi-cylinder internal combustion engine. The valve is adapted to close by gravity and to limit the sliding movement of said valve on the fuel outlet member 29 the base piece 14 is provided with horizontally disposed yoke shaped abutments 40 and 41 adapted to be engaged by a peripheral flange 42 on the lower end of the air metering valve 36.

Extending into the bore 32 of the fuel outlet member 29 is a metering pin or fuel controlling valve that may be integral with the air metering valve 36 or loosely suspended axially of said valve from the perforated top wall 37 thereof. The metering pin or valve 43 extends into the tapered portion 33 of the bore 32 and is adapted to engage the seat 34- and close the bore 16 relative to the bore 32 or the fuel outlet orifices 35.

The top of the carburetor body 1 has a manifold connection 45 communicating with the mixing chamber 2 and provided with the usual flanges 46 by which the carburetor can be readily connected to the intake manifold of an internal combustion engine. In the manifold connection 45 is a conventional form of butterfly throttle 47 adapted to be usted in the usual manner to control the supply of an explosive mixture to the cylinders of an engine, and in the manifold connection, above the throttle 47, is an interference member comprising a sleeve 48, a swirling fin 49 and superposed screens or bafiies 50. The sleeve 48 is suitably fixed in the manifold connection 45 and the swirling fin 49 is in the form of a spiral convolute to impart asWirhng action to the mixture which impinges against said. tin, and the screens 50 are of a foraminous construction, made of woven wire or the like, and are adapted to cooperate with the fin 4:9 in breaking up any 1 large particles of gasoline or kerosene which escape atomization in the lower part of the carburetor. Large particles of fuel will impinge against the screens and spread thereon as films to be attacked by air and thoroughly atomized.

Considering the operation of the carburetor, the air involume determined by position I a of butterliy throttle 47 enters through warm air connections 6, raises the air metering valve 36 until the opening 5 is of sufficient area to accommodate said volume, less the amount of air entering modulating passages at the shoulder 31 and entering by-path 1O governed by idle adjustment valve 12 and reaches nr 'n mixing chamber 2. 1

Fuel, in volume determined by position of fuel metering valve 43 (which in turn is determined by the extent of rise of air meter-- ing valve 36), in the tapered fuel bore or passage 33, enters atfuel supply member 13 which is carried by the stem 15, passes through radial fuel orifices where it is car ried by air through passages 30 to a primary fin L2, and then passes through the interference member 48 at theangle of spiral rotation a ainst which the fuel articles are more h thoroughly broken and homogeneously diffused through the air medium.

For starting a cold motor, especially in very low temperatures, the ordinary procedure of closing the choke valve 7 opens the primer screw valve 23 through the primer actuating mechanism 24 and 26 which is connected with the choke shaft 8. This primer actuating mechanism is of such a nature that the primer valve 23 is opened only during the last few degrees of movement of the choke shaft 8 in closing the choke. This permits partial to almost complete closing of the choke valve 7, in other words, free use of the choke valve within the limits employed in the various degrees of enriching of the mixture for motor operation during the warmin up period or under sub-normal motor temperature conditions-without opening the primer valve 23. Then the primer valve is opened fuel flows through the prnner by-paths 21 and 28; andthe throttle 47 beopen to a greater degree than the choke valve 7, the vacuum of the motor cylinder is 1 c, "n des stut er: n and compa it vely rapidl'fiamepropag gq. j

f the uel star n l b w y I he item-erasin pin-4a fe fih ass 6 wouldbe eerie-meat metering pin seat 34:, because "when t fe an yel s- 36 is" at must be seated to shiitbff the flow of fuel that would otherwise continue under head pressure. The abutment 41 has the double function of limiting the rise of the air me- .tering valve 36 to themaximum air-requirements of the motor and of silencing its action when thus limited. In the case of fuel drawn from a point below the level of the carburetor the air valve 36 and metering pin 43 may be integral and may'rest on the abutment ll because the necessity no longer exists of shutting off a fuel flow.

Inthe case of fuel supplied from a point below the carburetor, the carburetor is changed in no way except that the air valve 36 is given sufficient weight to set up the required amount of sub-atmospheric pressure in the main mixing chamber 2 necessary to lift the fuel the required distance.

Considering the motor idling adjustment, the areas of the annular passage between the air valve 36 and its seat, and of the annular passage between the fuel metering pin and the walls of the tapered seat 34, are known quantities. Adequate tolerance in the production of parts involves slight variations in these annular passages. The function of the idle adjustment is to compensate for these variations, and further to make such variations of the known quantities as may be required by variations in the compression of the motor, whether created by design or deterioration, or variations in the volatility of the fuel or the density of the air. This basic abutment,

ill

nular passages to be increased along straight lines maintaining the relationship established in the calibration of the metering mechanism, from minimum air and fuel at idling motor speed up to maximum air accommodated by the motor cylinders or determined by the abutment 4:1 and maximum fuel determined by the limiting action of the maximum fuel valve 19.

What I claim is In a carburetor, a fuel outlet member hav ing lateral outlet orifices, an adjustable air metering valve having an apertured top piece, said air valve spacedly surrounding said fuel outlet member and orifices and affording an annular air passage open at its lower end to permit of air in said passage sweeping past and removing fuel from the lateral outlet orifices of said member and carrying the fuel to a primary mixing chamber formed by the upper end of said fuel outlet member and said top piece of said air metering valve, a metering pin extending into said fuel outlet member and controlling the outlet of fuel from the lateral orifices of said member and means for limiting the opening and closing movement of said air metering valve.

In testimony whereof I aflix my signature.

FORREST A. HEATH.

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