US1606922A - Carburetor - Google Patents

Description

.M. c'HANDLE-R CAR-BRETOR Nw. 16 naar;-

Filed July 1, 1920 z-shevns-sneet 1 j@ iig; 5130-1 Patemed Nov. 16, 1926.

UNITED 'siufrEs' l 1,606,922 PATENT Q.FICE.

MILroHD G. CHANDLER, or CHICAGO, ILLINOIS, AssIGNoR, BY MEsNE AssIGNMIrs,

TO CURTIS IB. CAMP, TRUSTEE, OF OAK PARK, ILLINOIS.

cAItBURnToR.

Application led July 1,

and that of properly proportioning the fuel.

to the amount of air. In a fuel lifting carburetor, however, a third function 'of lifting fuel from a low level supply to the level of the carburetor must be performed bythis suction. .-3.'=` he carburetor of'myinvention is so constructed that although the suctionre-L. quired for lifting fuel may be as high as theY 'equivalent of 40 inches of gasoline in a manometer tube, nevertheless the suction in' the body of thel carburetor may continue 4to be as low as the equivalent'of only 18 to 20 inches of gasoline in a manometer.

The results above named are accomplished tubes, one of whichldelivers fuel into the mixing chamber of the carburetor',another one of which creates the suction for lifting fuel to the float chamber of the carburetor, and a third which isin the form of an eXL panding Venturitube serves to-create suction upon the discharge end of the nozzle Venturi tube to aid in the atomization .of the 'fuel and in the suction produced by the nozzle Venturi tube. l My invention is illustrated in the'accompanying drawings in which like characters represent like parts through. the several ,views Figure 1 is a vertical sect-ion through the main induction passage andnozzle showing the float chamber inoutline. Figure 2 is a section through the ioat. chamber and induction Apassage taken atl right angles to the sections of Figure 1.

Figure 3 is an elevation of the body portion of the carburetor with the iioat chamber removed.

Figure 4 is a `detail showing theV method of controlling the suction and method of adjustment of the suction producing Venturi tube, and K -theshaft 14. 'T he main casting for the body face of the shoe 19 constitutes a wall of the will'constitute a. piston-like wall substantialby means of .an arrangement of .Venturi In accordance with my invention, the body `8 and float chamber 9 areseparable at 1() and so connected by means of -a screw 11 that the float chamber may be turned at any 'angle to thel body for operating the carburetoueither as a vertical or horizontal instrument. The body portion 8 is internally bored to a` gradually tapering shape but has a cylindr1calportion 12 aceiit the engine in which the Vthrottle 13 is mounted on 8 is provided with two parallel spaced wings 16. These wings togetherwith a separable spacing bridgefmember 18 formsa housing 1n which. the pivoted shoe 19 operates. One

in'duction passage 2O yvhilethe side walls 21I of the shoe 19 are machined to fit between the two -wings 16 with only a few thousandths of im inch clearance so that the shoe .80 ly closing one side ofthe box formed between the wingsv 16 and vth'e bridge 18. The externalsurface 22 ofthe shoe 19 is formed cylindrically so that lit* ma operate with slight clearance' of the similarly machined surface 23 of the bridge. A packing strip 24 with suitable spring 25 may be used, for sealingthe space between the shoe and the bridge so that machining a close iit will be unnecessary. The lshoe 19 is preferably rigidly att-achedto a pivot ,pin 27 inserted through openings 29 in the wings 16. A

v small hole 30 afordscommunication between the restricted portieri ofthe induction passage and the space behind the shoe 19. A

spring 31 extends between thebridge 18 and a boss 32,(arried on the shoe 19 which is .preferably 'provided with a cup 38 to prevent 'lateral distortion of the spring due to a change in angle of the shoe. s

A nozzle 36 having Venturi shape, is located at an angle tothe axis of the main in- I duction passage and vhas its discharge end 31 situated in the region of high suction in the induction passage' for all positions of the shoe 19. This nozzle is provided with fuel deliveryzopenings 39 which receive their fuel from an annular passage 40 which comseats.

changed.

e 50 increased flow of air.- This increased sucniunicates lwith the lower part of the ioat and fuel chamber through a hole 40? an in,- ternal bore in the screw l1 and a passage in the casing in which the needle valve' 41 The nozzle Venturi tube 4preferably has its external end openv to atmosphere, though-,the arrangement is such that la ,hot

. air tube leading from a jacket around the exhaust pipe may be connected into the porin tion of the .housing in which this Venturi" tube is located. i

' A vacuum producing Venturi vtube 4 3 `shown in detail lin Figure 4 is mounted in a close fitting cylindrical 'opening in a boss 44' 15 which. extends outwardly from onelo thel ,25 shaped edge of the slot--is eccentric Vto the .pivot of the shoe. It. overlies the edge of the opening of the inner end of the vacuum Venturi vtube 43A and is shaped to suit the f engine,l and' to provide' ai suitably varying obstruction to the iiow of, air through the vacuum Venturi tube 43 for different positions of the shoe 19, depending upon the amount of air being drawn into the carburetor. The slot may be considerably wider than shown in. the'drawings, since the other edge of the slotis not calculated to function in varying the air. passage .through the vacuum Venturi' tube.. As pointed out above,` the rotation of the vacuum Venturi tube 40 443 will' cause its inner opening to be4 obstructed to a greater or less degree by the Y edge of the cam- 45, thereby providing an initial adjustment of the degreeof restric tion, which degree ofV restriction is further controlled by the movement of the shoe`19 and the shape of the cam45. The construc-4 tion of the carburetor inherently'requires that the suction in the mixing chamberof l the carburetor must slightly increase with tion in the induction 'passage ofthe carburetor' creates aninlcreased4 suctionin the passageway ,bounded by the cam A45 andwould create' a. proportionate increased How of air'through the Venturitube 43 `were' it not :tor `the cam 45which,'as illustratedl in Figure. 5,I is shaped so that the dischargey opening from .the Venturi tube 43 is more limited in size under the conditions which provide greater induction passage suction.

The throat of the Venturitube 43 is connected through registering passages 48, 50 and 5l with the upper spaces of the oat chamber for providing an enhanced suction 05 or. depression therein for 'liftingfuel By Lenawee experimentally rcontouriiig the edge of. the .cam 45, the ,suction in the float chamber may be maintained` constant for all positions of the'shoe I9, or maybe caused to either ifi-crease. o r .decrease as the shoev :t9-moves to its wider open position. This arrangementpermits of an accurate control of thev fuel feeding differential between `the float chamber and the nozzleopenings 39 so' that the desired ratio of fuel and air may be ,e l i. -maintalned under all conditions. A lever arm 52 is connected with a dash control not shown) orrotating the Venturi tube 43, andby means of this the suction in the float chamber may be varied to produce a. varied differential between float chamber suction and manifold suctionA so `as to increase cr. decrease the general ,richness of thev mixturel throughout the Vwhole .range of operation., Experienceshows that for "cold starting, the mixture must be richer than for lthe best running conditions aiter vthe engine is heated up.

It is occasionally necessary that the suctionin the float chamber be temporarily increased beyond that necessary for` ordinary driving. This happens when' an auto@ that the lift between the rear tanlr and the carburetor exceeds 40". these conditions the suction will be automatically increased, a ball valve 53 is provided in a iloa-t chamber cover normally sealing the opening between atmosphere and the duct 54 leading through passage 55 to the space back of the 'shoe 19. A pin 56 In order that under mobile, having a tank at the rear ascends `a very exceptional grade such, for example,

iHU

t's closely in an opening through the ioat chamber cover and is adapted to be' engaged by a collar 57 carried by and rising and falling withthe ioat ehamber' valve stem 58 as the fuelraises and lowers in the float los chamber. This', pin 56 is' adapted`when raised by the dropping of the fuel in the float chambre-nite push theball v,53 ott' Aits seatv and thus openv ay communication between atmosphere and the space back of the shoe 19. "'llhe opening v30, through the shoe 19, isrelatively small soethat when `the ball -53 has'raised 'olf vits. Seat by the lowering of' the fu'elin the float chamber, 'the' ysuction back oi" the shoe 19will be somewhat relieved,"causing-the shoe to assume 'a posi- -tion more nearly enclosing the induction passage, thus causing the suction the mix# ing' chamber -to be increased, and conse-v quentlyincreasingthe suction in the carbu retor float chamber." l When this suction 1n the carburetor float chamber has been vinv.

creased suiiicient'ly to cause fuel to be drawn `into the iioat chamber,fthe float again rises permitting the ball 53 to become.either fully or partially seated. The vpassage -v around the ball 53 is outwardly flared such that the larea ot the opening vpraat the ball is greater as the ball is moved toa greater distance off its seat. vWhen under some extreme condition the normal float chamber suction is insufficient to lift fuel from the low level source into the lioat chamber, -then the level of the fuel will drop slightly inl the float chamber. In so doing, the oat will also drop until the ball 53 has been raised oif its seat just enough to create sutiicient suction Ato bring fuel into the float chamber at a rate proper to maintain the new low level therein. If the lift tothe lioat chamber becomes still greater, then the' fuel Will drop still lower andtheball 53 'will be moved still farther off its seat .arid a newt'balance will be found. The variation in fuel level in the fioat chamber will be almostnegligible, however', since the relation of the parts, is such that a -very small change `in level in the hoatcha'inber effects' a considerable change in the size-of the passagegaround the` ball 53. Y, Y

Assuming an engineto be idling, .that is,

operating with throttle 13 substantially closed, the suction in the miXingchamberQO K is insufficient to cause the `shoe 19 to be moved materially ofi its normal position in which it substantially closes the air induction passage. idling must-enter through the fuel feeding Venturi tube 36 and the suction producing Venturi tube43. These twotubes are so pro-V portioned that for the idling-condition their restriction will be'suificient to create a iioat chamber suction of between 30 and 4() inches of gasoline in the `maiiometer tube. The

needle valve 41 provides just the proper re'- striction so that the suction created at thenozzle openings 39 in the Venturitube 36 is just enough greater `than the suction von the fuel in the oat chamber to deliver the .proper proportions of fuel and air.'

As .the throttle 13 is opened and Ithe engine dema-ndis increased, the suction inlthe inixing'chamber 20. increases, thus creating a. greater suction in the space behind the shoe 19 and thus causing the shoe to open proportionately to the engine demand.

The fact that the opening 30 is located at a point of high local suction in the inductionl passage causes the shoeto move in response to .very slight increases iii 'suction in the mixing chamber 20, notwithstanding the increase in resistance offered `by the spring 31 as the shoe is opened.

Therefore allpof the air for" greatest restriction in the intake passage is at the discharge end ,of the nozzle Venturi tube 36, the `suction on that tube increases toa very much great-er degree than the suction in the larger portions of the intake passage.l Infact, it is found that a` suction lof 25.of gasoline in the mixing chamber at a point just anterior to the the Venturi tube 36 is equivalent to 45 to 50 throttle, the suction at the discharge 'end of A Qf gasoline and the suction `at the throat of the -nozzle Venturi at which point the gasoline :is delivered-into it is still higher This ingrease in suction provides the increased amount of'fuel nefessarylto be mixed With the incoming airl to maintain .proper pro` portions'of gasoline and air under the conditionof greater fuel demand'. If the proportions yare not absolutely correct, they may be' varied by shaping the cam 45 to provideeither greater or less suction in the oat chamber as. conditions demand. While my invention is described in connection with the details illustrated-in the accompanying drawing's,'it`gis yto be under- A stood that I do not Wishr to be nndulylimited thereto, certain Vmodifications being pos-I sible Without departing from the spirit and scope of my invention. A

I claim i 1. A` Carburetor comprising in combination a casing forming an induction passage" way, a movable -shoe pivoted in said casing form-ing one wall of the induction passage, and a Venturi tube constituting a fu`el nozzle supported in said casing and situated at an angle to the axis of the induction passage and inclined in the direction of the air flow therethru with its discharge end 'adjacent said shoe when the shoe is in its normal position, the shoe being conformed to tit about theend of the .Venturi tube, and substantiallyparallel with4 the Venturitube at the end thereof when in its normal position for providing an arcuate restriction ofthe induc` `tion passage when the 'shoe is in its normal position.

2. Ina carburetor, thecombination with a casing forming an induction passage, of a movable shoe within said casinfT g, a suction producing Venturi Vtube vextending through said casing 4and `havingits discharge end terminating adjacent the sidel of said shoe, said shoe being provided with a cam to control the area of the dischargeopening of said Venturi tube, and means for deliveringv fuel to said induction passage.

3. In a carburetor, t-he combination with a casing` forming part of an induction pas sage, of a shoe pivotedin said casing and forming a wall of said induction passage, a cam formed in said shoe` a` Venturi tube eX- .tending through said casing and having its inner end terminated adjacent said cam,

' cam, and a duct connecting the tliroatof said Venturi tube with the upper spaces of a fuel reservoir, and means` for delivering fuel from the lower part of the reservoir to the induction passage.

4. In a carburetor, the combination with 10 a casing, of a pivoted shoe mounted in said .casing, a housing enclosing the side of said shoe away from the induction' passage of the carburetor, an opening between the space behind said shoe and the induction passage of said carburetor to create a suction behind the shoe for moving the same, a'fioat chambei', a float in said chamber, and a valve in said float chamber operated by the float therein, and'adapted to be unseat'ed when the float descends, said valve, when-opened, affording communication between the atmosphere and the vspace behind said shoe, and means for delivering fuel from the ioat chamber into the induction passage.

5. In a carburetor, `the `combination with an induction passage, of a fuel chamber,

means connecting the upper part of the fuel chamber with the induction passage for creating a-suction in the fuel chamber for lifting fuel' thereto which under lsome conditions is greater than the suction in the in- 'ductionpassa e, a Venturi tube constituting a fuelnozzle iscliarginff into said induction passage andv lying adacent a stationary side thereof, anda movable membeixconstituting a sideof said induction passage and so shaped as tosubstantially seal the communication between external atmosphere and the induction passage around the inner end-of the said Venturi tubewhen the movable member ,is in normal position, said member being adapted to be moved by the suction-in the induction passage to ,open and enlarge the communication between atmosphere andthe induction passage around the inner endof said Venturi tube, but being so shaped for all of its positions the region 'of' highest [suction is close to the inner end bf the Venturi tube.

l/. In alca'rbui'etor, the combination with alcasing 'forming an induction passage'of a stationary side wall, and an opposite movable side Wallfor said induction passage, a

` wallienclosingff'the space behind said movablel sidewall, the movable side-Y wall being Lacasse for delivering fuel into the induction Vpassage. f

7, In acarburetor, the combination with an induction passage of a secondary air inlet therefor, a chamber in suction communication with the induction passage, a movable wall for said chamber ,controlling in its` movement the size. of the` opening through the secondary air inlet, an atmospheric inlet for said chambera"valve controlling said inlet, said valvewhen'opened serving to relieve the suction in said chambergto `an extent sufiicientto partially close theopening through the secondary air inlet, and means float in thev reservoir falls below a predeter- 'l mined level, and means to deliver fuel' from the fuel reservoir to the induction passage.

9. In acarburetor, the combination with an induction passage' of a fuel reservoir receiving suction from the induction passage for lifting fuel to the 'fuel reservoir, means for delivering fuel from the fuel reservoir to the induction passage, a secondary air inlet for the induction passage, a chamber in suction communication with the induction passage, a movable wall for said chambercontrolling in its movement the size of the opening through the secondary air inlet, an atmospheiic inlet for said chamber, a valve controlling said inlet, a float in the fuel reservoir, connecting means between said float and said valve for opening the atmospheric communication to said chamber when the float iii the reservoir falls below a predetermined level, whereby the wall of said chamber` is moved and the entrance to the induction passage is restricted and the suc- V47tion in the` induction passage is increased,

the suction connection between the induction 'passage and the fuel reservoir serving, under ,so shaped as to constitute withithe stationaryth/ereto through a greater height, the open'- side wall a graduallyeXpa/nd /ininatingin the induction Vpassage-iieaij theV region of greates'tffsuctioiiY therein, animeans' ing inductimf'ing past the valve in said atmospheric inlet passage, l thg/aaestfricted portion of which/,'ilgingproportioned sothhat the degree of in- 44cresed suction in the induction passage will ide -b'e only sufficient for lifting fuel to the fuel Yreservoir in such quant-ities as is necessary lll() tending into said passage, a fuel chamber, a duct connecting the restricted part of said Venturi tube With the upper space of said fuel chamber, a member autmati'callymovable in response to engine demand, a cam movable with said member, said cam being arranfred t0 pass opposite the inner end' of said tfenturi tube, and `to variably obstruct the discharge opening from said Venturi tube into the induction passage by overlapping the discharge opening from said Venturi tube dierentamounts for different ention passage.

In Witness whereof, I hereunto subscribe mytname this'23rd day of June, 1920.

MILFORD G; CHANDLER.

.gine demands, and a nozzle for'deli'very-of j fuel from the fuel chamber into the induc-

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