US1822712A - Carburetor - Google Patents

Description

Sept. 8, 1931. 5.` H sKlNNER GARBURETOR Filed April 24, 1926 l a@ 5562 l l @Q j ,I j G 7.2.! u 2 1 www 42].. Q 1%. I fp@ o o 7 l z i j f Patented Sept. 8, 1931 Unirse STATES GEORGE HERBERT SKINNER, OF EALING, LONDON, ENGLAND, ASSIGNOR TO PANY, LIMITED, OF LONDON, ENGLAND PATENT OFFICE S. U. COM- CARBURETOR Application `tiled April 24, '1926, Serial No. 104,254, and in Great Britain April 30, 1925.

This invention relates to carburetors and has particular though not exclusive reference to -carburetors of the type in which a piston valve for controlling the main air passage and carrying' a needlev valve for controlling the liquid fuel supply is under the influence of and is operated by engine suction.

According to one feature of the present invention the said air valve carrying the y needle valve is formed in one with or is directly secured to a piston (hereinafter referred to as the suction disc) which is adapted to work in a suction chamber so that it can be operated to raise the piston valve by the 15 enginesuction. By providing` a combined piston valve and suction disc, the usual spindle or rod'which in carburetors of the kind hereinbefore referred to is located between the suction disc and the piston valve and also the bearing therefor are avoided. A rod may extend upwardly beyond the aforesaid suction disc so as to slidably fit in a sleeve or bearing formed on the upper part j of the said suction chamber, the said sleeve or bearing having a restricted orifice for the escape of air so that a kind of dashpot action is afforded when the said rod is moved upwardly due to the combined suction disc and the piston valve being raised by the engine 30 suction. Communication between the space above the suction disc in the suction chamber and hthe engine side of the main passage leading to the engine induction pipe, may be A, effected through a hole in the aforesaid piston valve so that the combined suction disc and piston valve can be placed under the influence of the engine suction during the running of the engine, and thereby raised to control the said main passage whilst at the same time 4:0 the needle, valve on the piston valve controls the fuel supply. The movement of the combined suction vdisc and piston valve may to some extent be controlled or regulated by the f dashpot action provided by the aforesaid rod which serves as a plunger withinl its sleeve or bearing and the area of the restricted air orifice is chosen or selected to suit the'particular engine for which the carburetor is intended; or in some cases the said restricted f orifice may beadjustable.

According to a further feature of the presi cnt invention improved means are provided to ensure that a fuel tight joint is provided for an adjustable fuel jet tube or nozzle. The

jet tube which is axially adjustable or slidable within a sleeve or the like is surrounded by washers of cork or other material which are adapted to be compressed around the said tube by spring means preferably acting in conjunction with bevelled surfaces, the said jet tube having holestherein through which fuel supplied to thei'nterior of the sleeve from the oat chamber passes to the jet tube orifice throughwhich the aforesaid nozzle valve passes. i

In order that the said invention may be clearly understood and readily carried into effect,l the same will now be described more fully withV reference to the accompanying drawings, in which 7 7o Figure l is a sectional view of a construction of carburetor embodying the improvements according to this invention. Figure 2 is a sectional view taken on the line 2h2 of Figure 1.

Figure 3 is an enlarged sectional view illustrating the adjustable jet tube or nozzle with the associated parts. v

A indicates the main body ofthe carburetor having a mainair passage A leading to the engine induction pipe and fitted with a throttle Azas shown in Figure B indicates a cover orcap which is secured t0 the main body A and constitutes the aforesaid suction chamber. C is the piston valve which is slidable in the body A to control the passage A and which carries the needle valve D that controls thefuel jet tube or nozzle E. The piston valve C is formed integrally with a suctiondisc or piston C which makes a sliding fit in the cover B forming the suction chamber. A guide rod or plunger C2 extends upwardly from the lower part of the piston valve C and'makes va close sliding fit in a sleeve or bearing B provided in the cap or cover B forming the suction chamber. The lower part of the piston valve is provided with a passage C3 through which communication is established between the interior of the suction chamber above the sucmi said Washer as shown in Figure 2.

tion disc C and the engine side of the passage A leading to the engine induction pipe and the space below the suction disc is open to outside air through a passage A3 (see Figure l). rIhe piston valve C is maintained with its passage C3 located in the engine side of the main passage A by means ot a pin A4 engaging with a slot C4 in the said valve C. The combined piston valve and the suction disc'with the needle valve can therefore be raised by engine suction to control the passage A and the fuel jet nozzle E accord.- ing to requirements. The upper end ot" the sleeve B is provided with a screw plug B2 which has a small opening B3 therein that allows air to escapeV from the space above the plunger rod C2 at a more or less restricted rate according to the areaot the orilice. The said plunger rod working in the sleeve with tlie restricted oritice may serve as a dashpot tro-limit or control the movement of the suction` disc'and'piston valve as this movement is to some extent regulated or determined by the'sizel ot the orilicek that' may be chosen to suit the particular engine toy which thecarburetnr is applied. An adjustable orifice may` be providedv it desired.

In the example illustrated the jet tube E isslid'abl-y tted in a two part sleeve'F and F iitted within the lower part otthe main body or casing A. The lower sleeve portion F which is flangedv aft its upper end is held withinan externally threaded. nut 'G whichisscnewed. into thebody; Arend bears againstl a cork washer Gr through' a` metal2 ring G2 having; bevelled surtace that engages the lower sleeve portion vF retains the upper sleeve portion; F7 1n position around. the

upper end of the jettube which portion F is provided with openings F2 that establish Comunication between an. opening Af in themam body leading fromf the float chamber' A6 to the interior of the 'lower :sleeve portion F vso that the fuel is supplied to' the ,said interiorof the sleeve portion F and can: passI through holes E in the jet tube E whence-it passes through the orifice controlled by thel needle valve D. Thej et tube mall-esl awfairly closey sliding' lit' inthe lower `end of the sleevel portion Fand the upper en'd of the sleeve portion F, and its slidingY movement can be limited by a liange E thereon engaging with an adjustable nut or abut-mentV F3 screwed on the lower end of the sleeve FA against ay spring F4` that bears against the nut G. In order to provide a petrol tight` closure torthe adjustable jet tubel FJ, cork washers Hk surround the jet tube and inthe example shownY are maintained betweenY bevelled surfaces on the saidv sleeve portions 'srpringjllzl2 which bears-against the said` rings F and F and on rings H by an interposed 'H so that by reason 'of these said'bevelled surfaces -the cork washers. :are compressed rvIlhe saidv tightly around the said tube E without however preventing it from being slidably moved to vary the position of its orifice in relation to the tapered needle valve D. By this construction a liquid tight closure is provided Jfor the slidabletube E and it is not necessary to provide light tight closures between the metal surface of the jet tube E and the surrounding portions ot the sleeve parts F and F. Any suitable meansl may 'be provided for adjusting the jet tube E and in the example shown a lever I is pivoted to the end of the tube and to a link I pivotally mounted on the body A the leverbeing actuated through any appropriate connection. By adjusting'th'e nut F3f on the sleeve F` the limit oli` inward movement ot the jet tube can be varied owing to the flangey E2 on the jet tube E vengaging this nut; andIby this arrangement the` jet tube may beV conveniently set from the exterior'ofv the carlniretory and it. may be adj usted: to provide a suitable-supply offuel for slow running of the engine. Instead of employing ra two par-t sleeve F and F" a single sleeve may be used-and the body A may bezsuitably` formed: at the upper endv ot the jet tube to receive the cork washer H..

What I claim and desirev to secure by Letters Patent of the4 United .States is l. A carburetor comprising a body having a' straight through airand mixture passage, a; piston valve vertically movable acrosssaid passage, a needle valve onf the lower surface of said: piston-valve, a. tuel' jet. nozzle arranged infthe lower part'of said4 passage andV conrtrolled' by saidY needle valve, a suctionpchamber in theupper'part -ofsaidlbod a flangelikeI portion on the .top of said? pistonvalve forming asuction: disc working iii-,said chamber, an upwardly extending; plunger on1 said pistonA valve, a sleeve disposed mainly within .said suction chamber and adapted toreceive said.. plunger, 'and 'means providing a restrictedfegressof aint-rom the upper part of said sleeve' when said pistonvalve is moved upwardly, said pistonY valve being provided with a duct establishing communica-tion between said suction chamber above said suction disc Iand the'engine side of said passa-ge, and said body` being provided with a duct communicating with the atmosphere below :said suction disc'. a

2. A carburetorcomprising a body having a straight through lair andmixture passage, a piston valve vertically movable across saidv passage, said piston valve. having a recess therein, a: needle valve on the lower surface of said-piston-val-ve, a fuel jet nozzle arranged in the lower part of' said passage and ycontrolledvr byl said needle valve, a suction cham- 'ber' in the upper part of said body, :aflangelike portion on the top of said piston valve forming :a suction disc working'in Isaid chamber, a plunger extending'upvvardly'from the base of said piston 'valve vinto: said recess, an

internal elongated bearing sleeve Within said suction chamber projecting into said recess, and means providing a restricted egress of air :from the upper part of said sleeve.

3. A carburetor comprising a body having a straight through air and mixture passage, a separate cover member thereon forming a suction chamber, a piston valve vertically movable across said passage, said piston valve having a duct therein, a needle va'lve on said piston valve, a fuel jet nozzle arranged in the lower part of said passage and controlled by said needle valve, an integral enlarged portion on the upper part of said piston valve working in said suction chamber, a plunger extending upwardly from said piston valve, an internal sleeve integral with said cover member adapted to receive said plunger, and means providing a restricted escape of air from said sleeve When said piston valve is caused to move upwardly under the inuence of engine suction acting on said enlarged part through said duct.

4. A carburetor comprising a body having a straight through air and mixture passage, a separate cover member thereon forming a suction chamber, a piston valve vertically movable across said passage, said piston valve having a recess therein, a needle valve on said piston valve, a fuel jet nozzle arranged in the lower part of said passage and controlled by said needle valve, an integral enlarged portion on the upper part of said piston valve working in said suction chamber, said enlarged part surrounding said recess, a plunger extending upwardly out of said recess, an integral sleeve internally disposed in said cover member and projecting into said recess, and means at the upper end of said sleeve, providing a restricted escape of air therefrom, said piston valve being provided with a duct establishing communication between said suction chamber above said enlarged part and the engine side of the said passage, and said body being provided With a duct establishing communication between the space belogv said enlarged portion and the atmosp ere.

GEORGE HERBERT SKINNER.

GERTECA'EE 0F CQRREGTEON,

Patent No. 1,822,712. Granted September 8, 1931, to

Genese HERBERT SMNNER.'

It is hereby certified that the aheve numbered` patent was erreneeusly issued te "S. `U. Company, Limited, ef Landen, England", whereas said patent should have been issued to Morris lndnstries, Limited, el Landen, England, as assignee of the entire interest in sai invention, as shown hy the reeerds of assignments in this office; and that the said Letters Patent shenid be read with this correctien therein that the same may eenlerm te the reeerri ei the case in the Patent Office.

Signed and sealed this l'th clay of November, A.. l). 1931.

M. J. Moore, (Seal) Acting temmissioner of Patents.

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