US1636793A - Carburetor - Google Patents

Description

July 25, 1927;

. 1,636,793 F. F. STRATTON CARBURETOR Filed Nov. 16. 1921 5 Sheets-Sheetl July 1927? F. F. STRATTON CARBURETOR 3 Sheets-Sheet 2 Filed NOV. 16.1921

. y 1927- F, F. STRATTON bARBUREIOR Filed Nov. 16. 1921 3 Sheets-Sheet 3 the-engine, to better control the correct sup-1 plyof mixture tthe engine under allconditions ofrunning, and to lncreasethe efli- Patented July 26, 1927.

"i-UNITE D TE S PP'A TENT o F F! E.

. CARBURE'I-OR.

I Application filed November 16, 1921, Serial No. 515,518,211111 in Great Britain-November 16;- 1920.

- The objects of this invention are to prorelativeproportions of liquid fueland air to ciency of the apparatus in operation, and

further toenable the carburetor to respond t readilytosudden demands madeupon it by the engine to enable it to accelerate quickly :whencalled upon to do so.

And in orderthat my invention may be -completelyunderstood reference should be made to the accompanying sheets ofdrawings.

Fig. 1 is a sectional-elevationof a-car buretor constructed according to my invention.

Fig. 2 is a section of the carburetor on a line atrlght angles to the section shown in i Fig. 1.

' ning and starting is employed.

Fig. 3 is a plan view. 1

Fig. 4 is a horizontal section on the line X X-of Fig. 2.

Fig. 5 is a sectionalelevation of a modified form of my invention in which a sepa= rate pilot or auxiliary nozzle for slow run- Fig. 6 is a horizontal section on the lin Z Zof Fig. 5. -lVith reference to Figs. 1 to 6, the central a base H= and formed with a circumferential flange-or ring A of largerdiameten- Hounted upon the said flange A? and on either sidethereof, are two outer cylindrical casings B and C, so arranged in respect-to the central casing A, and-the base H, as totorm closed annular chambers B and C above and below the said circumferential- --fla1ige A The upper casing B, forming the oute r walltofthe chamber B is provided dust and dirt into the carburetor;

annular chamber C lViregauze C of suitholes C in order to prevent the ingressof tral cylindrical wall-A is "provided with two sets of ports located above and-below thering flangeA insuch manner that-thefupper ports E, which areofrectangularform,- afford "communication between the central 9 The cens.

mixing chamber A and the upper annular mixture chamber B while the lower ports G, which are of triangular form; are adapted to place-the lower annular air chamber C in communication with-the said chamber A on the lifting of the piston valve.

. The valve D' is slidably mounted within I the said central chamber A and is formed'as a 'sleeve with a closing diaphragml) and a ring of ports F situated in the said sleeve beneath the vsaid diaphragm D which are adapted to register with ports E formed in the wall of the chamber A I The saidsle'eve D is ofsuch length that its lower extremity is adapted tocover the triangular ports G and to uncover same 011 the said sleeve valve -D being lift-ed. The ports E, F'and G are so relatively situated that,- on the sleeve valve D being lifted, the ports F will commence to register with the ports E slightly before the sleeve D commences at to uncover the air ports G.

The base H which is preferably formed integrally with the floatchamber Q, of usual preferablyscrewed into-position, by means of the nut I from beneath the said boss H and formed with aconical surfaceaclaptcylindricalinner casing A is mounted upon edto abut against a similar internalsurface formed within the said boss H in order to afford a' fuel tightjoint.

The liquid fuel is fedto thenozzleI from the fioat-chambenQby means of aduct J drilled in a-projection H formed on: the under side of the base H.

Concentrically surrounding the :nozzle I are two telescopic cylindrical sleeves L and The inner or fixed sleeve L whichproects wlthln aIlCl-lS-'S6Ct1T6Cl to the boss-H? of the base H, has drilled therein at suitable illtBIVtllSfilOIlg its length, rings of small orifices' or'outletports L The rings of ports L are so arranged one abovethe other that the outer telescopic sleeveK; the upper rim of which is-secured to the diaphragm D able mesh, is --adapted to cover'each of the of-the sleeve valve D, on-beinglifted,-un-

- -covers successively-each ring of .ports' L thus varyingthe depression upon the nozzle I in relation to the movement of-the sleevevalve- D.

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so graduated as to vary the area of the orifice of the nozzle through which the liquid fuel is drawn, in relation to the position of the said sleeve D, tothe diaphragm D of which the said needle is attached. The upper end of the said needle is formed as a bolt 0 with a shoulder O and a nut 0 The shoulder O is adapted to engage the underside of the rim of the sleeve K and the bolt 0 passes through a hole R of slightly larger diameter thanthe said bolt in the diaphragm D of the valve D, in such manner that the diaphragm D is securely held between the upper side of the rim of the sleeve K and the nut 0 'Air is admitted to the chamber surrounding the nozzle I and enclosed by the sleeves K and L, by a short length of pipe T (see Fig. 2) screwed or otherwisesecured in the base H and provided with a screw T adapted to cover or uncover holes T in the said tube T for the purpose of accurately adjusting the admission of air. The screw T is provided with a milled head T to facilitate its action. y

In the form of my invention shown in Figs. 1 to 4 the diaphragm D of the sleeve valve D is constructed with a horizontal duct or channel R adapted to communicate with the chamber enclosed by the sleeves K and L through small holes or ports I (Figs. 4 and 5). The said duct R is also adapted to be placed in communication with the annular chamber B through the medium of the ports E, a short horizontal channel R situated above and preferably parallel to the channel R, and a vertical channel R connecting the two said parallel ducts or channels R, R In 'munication with the annular chamber B when the sleeve valve D is at the lower extremity of its stroke. A fine threaded screw S formed with a conical lower end or needle S is mounted above and concentric with the vertical channel R in such manner that the area of the passage through the said channel may be accurately adjusted. The said screw S is provided with a milled head S and a locking nut and sleeve S .in order that the said screw S may be finely adjusted with the fingers.

The sleeve valve D is adapted to be reciprocated by the movement of a bell-crank lever N connected to the said valve D by a link M, one end of which is rotatably mounted upon a pin D" arranged in hollow bosses D diametrically formed on opposite sides of the upper end of the said sleeve valve D. The said bell crank lever N is pivotally mounted upon a bracket N secured to the upper casing of the carburetor. The bracket N is formed with a bridge piece N through which an adjustable screw sto P is adapted to pass. The said screw P is provided with a locking nut P and is adapted to limit the maximum movement of the said lever N. Four bolts WV pass through the annular chambers of the carburetor and serve to hold the said outer casings B and C and the central casing A firmly in position upon the base H.

When the sleeve valve D of the carburetor is at its lowestor closed position as shown in the drawings, the ports E and G are not in communication with the inner or mixing chamber A, the chamber surrounding the nozzle however is in communication with the annular chamber B and is therefore open to the suction of the engine, causing a rich mixture of fuel and air necessary for slow running to be drawn from the carburetor. The relative proportion of fuel to air is adjusted by means of the screws S and T On the sleeve valve D being lifted the ports F commence to register with the ports E, thereby placing the chamber A in communication with the annular chamber B and the engine. At the same time the outer telescop1c sleeve K uncovers the lower row of ports L in the inner sleeve L placing the chamber A in communication with the chamber surrounding the nozzle I, while the area of the nozzle orifice is increased due to the air ports G are uncovered and air is admitted to the mixing chamber, at the same time further rings of ports L in the sleeve L are uncovered by the sleeve K, causing a less restricted passage for rich mixture from the nozzle chamber to the mixing chamber, in proportion to the increased volume of air admitted. The outlet of the duct or channel R is now raised above the port E and consequently ceases to function.

As the sleeve'valve D is further raised,

tained in the most efiicient proportion at any speed, while a very rapid acceleration is given to theengine when required.

With reference to Figs. 5 and 6 this form of my invention is constructed and functionsin a similar manner to that described with reference to Figs. 1 to 4 with the exception that in lieu of the channels R, R R and R and the adjusting screw S in the sleeve valve D, a separate pilot or auxiliary nozzle is employed. This auxiliary nozzle consists of a tube V of two internal diameters V V forming at their junction a conical shoulder V The tube V is screwed at V into the base H in such position that the internal bore V communicates with the fuel passage J from the float chamber Q. The tube V passes through the annular air chamber C the flange A and the annular mixture chamber B and projects through the upper casing B, where it is held in posi= tion by the nut V which also provides a gas tight closure. The internal diameter V is provided with a flne internal thread at its upper end into which is fitted the screw S of an adjusting needle S, in such manner that the conical end S of the needle S may be screwed down towards the tapered shoulder V to adjust the area of the orifice for the passage of liquid fuel. The needle S is provided with a milled nut S and a locking nut S. Above the shoulder V are diametrically arranged holes or ports V approximately in line with the ports E and which afford communication between the internal bore V and the annular chamber B The area of the said holes or ports V is governed by the position of the needle S which covers or uncovers these said outlet-s. Air is supplied to the auxiliary nozzle through the passages T* and T (Fig. 6) and is adapted to be drawn across the jet through the outlets V The area of the air inlet -channel T is adjusted by means of the conical ended screw T provided with a milled head T and a locking nut T On the sleeve valve D being at its lowest or closed position the ports E will be covered and the holes or outlets V* will be subjected to the full negative pressure thereby causing the liquid fuel in the bore V to rise above its normal working level and impinge upon the needle S where it meets and mixes with the air flowing through the ports or outlets V. This rich mixture of fuel and air is drawn into the engine and provides mixture for slow running. The proportion of fuel to air is adjusted by means of the screws S and T lVhen the sleeve valve D is lifted and the ports E opened the negative pressure in the annular chamber B will fall, causing the liquid fuel in the bore V to drop to its normal working level and the auxiliary nozzle will cease to function.

What I do claim as my invention and desire to secure by Letters Patent is 1. A carburetor for internal combustion engines comprising a mixing and control chamber, concentrically arranged with a central nozzle chamber, and surrounded by superimposed annular chambers, the lower for the admission of air and the upper for the passage of the mixture, a nozzle within said nozzle chamber, a sliding Valve for placing the annular chambers in commimication with the mixing chamber, and means for operating the sliding valve, said nozzle chamber comprising telescopic sleeves the inner of which is perforated and the outer of which is operatively connected to the sliding valve and moves therewith to uncover the perforations of the inner sleeve for controlling the passage of the mixture from said nozzle chamber to the mixing chamber.

2. A carburetor for internal combustion engines comprising a mixing and control chamber surrounded by superimposed annular chambers, the lower for the admission of air and the upper for the passage of the mixture, the mixing and control chamber having vertically spaced openings therein affording communication with the superimposed annular chambers, a sliding valve operable within the mixing and control chamber for placing the annular chambers into communication with the mixing and control chamber, said valve having a horizontal partition intermediate its ends and openings therebeneath adapted to be placed in registration with the upper openings in the mixing and control chamber when the valve is raised, a perforated sleeve secured within the mixing and control chamber, a sleeve carried by the valve and telescoping the first mentioned sleeve, the two sleeves forming a nozzle chamber, a nozzle extending into said nozzle chamber, a needle depending from the valve partition for controlling discharge from the nozzle, and means mounted above the valve partition for raising and lowering the valve.

FENTON FREDERICK STRATTON.

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