US1785681A - Carburetor - Google Patents

Description

D 1e, 1930. l 1F. ,sounmp 1,185,681

und aways, 19'

Patented Dec. 16, 1930 FLIX-GOUDABD, OF NEUILLY SUR EINE, FRANCE CARBUBETOR Application filed March 5,1926, Serial N0. 92,596, and in Belgium Hatch 14, 1925.

This invention relates to carburetors of the type whose float chambers have a constant fuel level, which feeds two or more nozzles `successively according to increasing speeds of the motor.

It relates more particularly tol carburetors of the so called submerged nozzle type equipped withk a main feednozzle and an auxiliary slow speed nozzle.

One of the objects of the invention is to rovide `means for regulating the supply rom each of the nozzles at the point where the feed from one nozzle begins to supplev m'ent that of the one already in action. In 1,5 carburetors of the submerged nozzle type `having main and auxiliary feed nozzles, it aims to suppress the excess feed of fuel at the moment when the main nozzle begins to supplement the feed from the auxiliary or slow speed nozzle.

Another object of the invention is to provide means for automatically and simultaneously regulating the pressure on the nozzle in action and the pressure in the float chamber before, during and `after the moment when a second nozzle enters in action.

Other objects will appear in the course of the following detailed description which will be given with reference to the accompanying drawings in which: f

Fig. l represents, diagrammatically, a sectionof the carburetor structure. f

Fig. 2 represents, in a diagrammatic way a section through the same type of apparatus as that shown in Fig. 1 with thermostatic and pressure controls attached to the oat chamber.

Turning'to Fig. 1 of the drawings, acarburetor is shown comprising a constant fuel 40 levelfioat chamber a, a venting well t, an auxiliary or slow speed nozzle b and a main nozzle d. The submer ed well t has theusual function4 of such we ls in carburetors of the so-called submerged nozzle type. Nozzles b and d communicate through properly arranged air intakes with corresponding mixing chamber c ande respectively. The main and auxiliary mixing chambers may be controlled bya vthrottle valve f preferably lo- 5 cated so as to simultaneously open the main mixing chamber passage and uncover the terminal orifice of the auxiliary mixing chamber passage c." During the opening movement of the valve f the suction on 4the auxiliary nozzle c, because of the special position of the valve and also because of the direction ofthe opening movement of the latter, gradually increases until the moment that the main nozzle d enters into action, and as particularly set forth in my coending application, Serial No. 754,622, wliich matured t0 Patent 1,788,051 dated June`24, 1930. The pressure on the lauxiliary nozzle b and the pressure ywithin the float chamber a are made to vary in a parallel manner and in predetermined proportions by providing a tube g connecting the auxiliary chamber c'to the top of the float chamber a andy by further providing an adjustable valve L, open tothe atmosphere, for regulating the effective pressure in the space above the fuel in chamber a. rihe dimensions of the nozzi'es should be such that the nozzle assures a supply sufficient for idling or slow working and theV nozzle d furnishes mixture suilicient in quantity for the full o en positions of the Valve f. The two nozzlbs should be vfurther designed so that, at the point where the motor passes from idling to normal speed i. e. at the moment when main nozzle d enters into action, the total feed of fuel from both noz.-

zles is somewhat more than is actually necessary. If desired, a constriction u may be inserted in the feed i e of the nozzle d to regulate the flow 01p fluel thereto and to the well t.

With the nozzles desi ed as above indicated and with the va ve h properly adjusted, the operation of the carburetor will be as follows:

1. With the throttle inthe closed or idling position, the main assage will be closed and the suction will e limited substantially to the auxiliary mixing chamber c and will be transmitted therefrom via the ktube g to the float chamber a. But this suction, it will be noted, is exerted only through the restricted orifice limited by the lip of valve f and will be relatively small. Since the valve la is adjustedy to be slightly open to the atb will remain, as before, a function of the r difference in the two suction values mentioned.

3.. With a further opening of the valve f and with the terminal orifice of the auxiliary passage completely uncovered, the suction will be transmitted not only to float chamber a by vway of auxiliary passage o and tube g, but will also to the main mixing chamber e. The suction of main passage e and that on the float chamber a will, at this stage of vthe opening movement, be ofthe same order of vagnitude. The suction of nozzle b will be at a maximum and this nozzle willstill be feeding alone.

4. If the throttle is now opened further, lthe suction will be increased on themain chamber e, and will be diminished in the auxiliary feed passage c since the valve will have movedv well past the terminal orifice of thel latter. It is evi-dent, therefore, that the suction on the top of the float chamber will be decreased and the difference in magnitude vof the suction existing in the passage e and that existing in the float chamber a will bring the main nozzle into action. It will be noted moreover, that with the present construction a progressivefeed from nozzle d will have been assured. y

5. With 'still further opening of throttle, a correspondingly greater supply of fuel will befurnished by nozzle d, the suction on the main nozzle increasing in' proportion to lthe throttle opening and that on the float chamjber a decreasing, contrariwise, to ar minimal quantity.

The extent to which valve h is opened may be fixed `once forl all, for any given motor operatin under given conditions of temperature an pressure. The valve, may therefore be replaced by a simple calibratedorifice. It is preferable, however, to employ al valve, as shown in the device illustrated, in Fig. 1, and to regulate the opening in accordance with changes in operating conditions. When the valve h is to be adjusted, lit is only necessary to open the valve to a maximum, to placethe throttle in theA osition where the main and auxiliar nozz es give, together, an excess of fluid, t en to gradually close the valve until the nozzles deliver the proper amount of fuel. The valve L, it is obvious, may be regulated once for all, or may responsive to the slightest changes in the conditions of operationvof the motor.

To this end, the form of construction shown in Fig. 2 has been devised. As will be `seen from the drawing, this structure contains all the elementsdescribed in connection with the device shown in Fig. 1. It contains, in addition, a ball-valve z' inserted between the top of the-float chamber a and the tube g. The ball i is held by gravity in the seat lc and cuts off communication between the float chamber y and the auxiliary feedpassage c, exce t under conditions when the suction in c is su cient to lift the ball. -When the motor is very ra idly accelerated, the sudden opening of the t rottle almost completely suppresses the suction y v o'n the-carburetor. Under-such conditions,

the ball z' will fall into the seat k, thesudden change in the suction will not be transmitted to the float chamber and the feed of the two nozzles will not be affected. The ball-valve will vtherefore function automatically to cut out the regulating effect of tube g and an excess feed of fuel will be maintained until the suction willhavebecome again sufficient, with increasing speeds of motor, to elevate'the ball z'. In order to regulate the lifting of ball i, an orifice Z, adjustably controlled by valve m, is provided open to the atmosphere in a position somewhat downstream of the valve i along the tube g. The section of orifice Z is preferably made very small as compared to orifice h, so as to not interfere with the functioning of the latter. The apparatus shown in Fi .2 is further provided with a thermostatic evice, responsive to changes yin temperature within the motor, and comprising a bimetallic strip g having a pointed extremity p extending into `an orifice n open to the atmosphere and independent of the orifice h. The orifice n is made sufficiently large so that, when unobstructed, it is able to compensate completely and to `annul, the effect of the suction transmitted through tube g to float chamber a. yThe element p is of the usual type of strip deformable with change of temperature and 1s arranged so as to open orifice n at low temperatures and to obstruct it at high temperatures. i

perature of Amotor rises, gradually reestablishes the regulating 'effect of this tube.

It is to be understood that eithery the ball valve control fortube g or the temperature iao be used alone in connection with the carburet or shown in Fig. 1 or both devices may be attached thereto. The complete structure shown in Fig. 2 constitutes a unit capable of automatically adjusting itself to all ordinary changes in operating conditions.

W at I claim is :k

1. A carburetor comprising in combination a main nozzle, an auxiliary nozzle, a main mixing chamber, an auxiliar mixing chamber communicating with sai mixing ,chamber and with the auxiliary nozzle, a throttle valve operable to simultaneousl control the outlets of the main and auxi iary mixing chambers, a chamber provided with means for 4maintainin a liquid at a substantially onstant level t erein, and a conduit connecting said auxiliary mixing chamber to the upper part of the last-named chamber.

2. A carburetor comprising in combination a main nozzle, an auxiliary nozzle, a main mixingA chamber, an auxiliary mixing chamber communicating with the main mixing chamber and with the auxiliary nozzle, a throttle valve operable to simultaneously control the outlets of the main and auxiliary mixing chambers, a fuel supply chamber provided with meansv for maintaining a liquid at a constant level and having an orifice opening to the atmospherev and al conduit connecting the upper part of said fuel su ply chamber to said auxiliary mixing cham er.

3. A carburetor comprising in combination i a throttle valve, a main nozzle, an auxiliary nozzle, a main mixing chamber, an auxiliary mixing chamber, a float chamber, a conduit connecting the dome of said float chamber to said auxiliary mixing chamber, avball valve adapted to obstruct or open communication between said conduit and the float chamber in accordance with change of pressure differential between the conduit and the float chamber, and an air inlet in said conduit located between the b all valve and the auxiliary mixingchamber.

4. A carburetor comprising a main nozzle, an auxiliary nozzle,said main and auxiliary nozzles coacting with independent air intakes, a main mixing chamber, an auxiliary mixing chamber communicating with said main mixing chamber and with the auxiliary nozzle, a throttle valve operable to simultaneously control the outlets from the main and auxiliary mixing chambers, a fuel chamber provided with means for maintaining a liquid at a substantially constant level therein, and

. a conduit connecting said auxiliary mixing chamber to the upper part of the fuel chamber.

In testimony whereof I have hereunto set my hand.

FLIX GOUDARD.

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