US1330796A - Carbureter - Google Patents

Description

P. P. GILLES.

CARBURETER.

APPLICATION FILED SI-1PT.. 1918.

Patented Feb. 17,1920.

I N V E TOR. 62%5 ATTORNEYS.

CARBUBIETER.

Application filed September 17, 1918.

To all whom it may concern:

Be it known that l, PIERRE P. GILLES, born in Switzerland of German parentage, now believing myself to be a citizen of the Swiss Confederation, and having formally declared my intentions of becoming a citizen of the United States of America in conformance with the United States immigration laws, and now residing at Springfield, in the county of Hampden and State of Massachusetts, United States of America, have invented certain new and useful Improvements in Carburetors, of which the following is a specification.

This invention relates to carbureters of the vacuum feed type, and more particularly to improvements in carburetors of the type disclosed in my prior Patent No. 1,269,177, granted June 11, 1918.

Carbureters of the type referred to include a substantially air-tight fuel chamber, into which fuel from a low level fuel supply tank may be drawn by suction, and one or more fuel conducting passages which con nect the chamber to the usual air-intake pipe of the carburetor. Such fuel conducting passages perform their usual function and are also arranged to perform the additional function of vacuuinizing the fuel chamber, the entire construction being characterized in that the fuel conducting passages constitute the only means of vacuumizing the chamber.

Necessarily, in the construction described, fuel is drawn into the supply chamber at substantially the same rate that it is used by beingdelivered into the air-intake pipe of the carbureter. Under normal conditions there is then no difficulty in the regulation of the fuel level in the fuel-supply chamber. However, it is well-known that in certain contingencies, as for example when the automobile with which the carbureter is used is traveling on an upgrade, the degree of suction for a given throttle opening rapidly decreases due to slackened engine speed. This will result in decreased flow of fuel to the air-intake pipe, unless special means are provided to compensate for the decreased suction, and it follows that the delivery of fuel from the low level tank will also be at a decreased rate. The provision. of means to insure an adequate delivery of fuel to the air-intake pipe is more particularly an object of my copending application Serial No. 254,467, filed Sept. 17,

Specification of Letters Patent.

Patented Feb. 1'7, 1920.

Serial No. 254,466.

1918, and the present invention is more particularly concerned with the maintenance of an adequate flow of fuel to the fuel supply chamber under all conditions.

One object of the present invention is to provide, in a vacuum carbureter of the type wherein the fuel conducting passages also constitute the means for vacuuming, the fuel supply chamber and thus for drawing fuel thereto from the low level fuel supply tank, an arrangement such that one passage nermallv has communication with the fuel supply chamber through an opening of constant area and means operable whenever the fuel in the chamber falls below a predetermined level to permit increased area of communication between said passage and the chamber.

Another object of the invention is to provide in a vacuum carbureter of the type described, which includes an air-intake pipe and a substantially air-tight fuel chamber, a fuel conducting passage which functions chiefly at low engine speeds and which, together with other fuel conducting passages, constitutes the sole means of vacuumizing the chamber, the first or slow speed passage having normally restricted communication with the chamber, and means operable when the fuel in the latter falls below a predetermined level to provide increased communication between the slow speed passage and the chamber.

Other objects and advantages will appear in the following description and in the appended claims.

The invention, in an embodiment at present preferred, is shown for illustrative purposes in the accompanying drawings, in which:

Figure 1 is a top plan view, partly in sect on. of a carburetor embodying the inventlon;

2 is a sectional elevational view taken on the line 2-2 of Fig. 1;

F 3 is a cross-sectional view taken on the line 3-3 of Fig. 2; and

Fig. 4 is a fragmentary sectional plan view of the fuel chamber of-the carburetor.

Referring to these drawings: The carbureter casing A is so formed as to provide a main air intake pipe 5, which is suitably flanged at one end for connection to the intake manifold of an engine, and a fuel chamber 6, which is disposed to one side of the pipe 5. The chamber 6 has an opening of-pipe 5, there is provided the usual throttle valve 9 (Fig.1) and such valve, as shown in Fig. 3 is suitably fixed to a spindle 10 which passes entirely through the walls of pipe 5 andis'rotatably mounted therein. A lever 11 is fixed to one projecting end of spindle 10 for connection with the usual throttle operating devices.

Fuel is supplied to chamber 6 through an inlet connection 12 secured to cover 8 and the member 12 is adapted for direct connection to a low level fuel supply tank. Fuel is drawn into chamber 6 through the inlet connection 12 by creating a partial vacuum in the chamber. The exhaustion or partial. vacuumizing of the latter is accomplished in a manner closely analogous to that disclosed in my above mentioned prior patent. That is, there are no connections between the chamber 6 and pipe 5 (or any other source of suction) except such as also function to deliver fuel from the chamber into the intake pipe. Thus, the exhaustion of chamber 6 is effected solely by the suction produced in the several fuel nozzles.

One of these connections, which may be considered as a main or high speed nozzle will now be described. This nozzle consists of several passages which are formed in protuberances of the casing A and in the upper wall thereof. The intake end of the nozzle consists of a passage 13 formed axially in a tube 14. The latter is secured at its upper end in casing A and depends into chamber 6 terminating near the bottom of the latter with an open lower end. There is also a restricted lateral opening 15 in tube 1% which permits communication between passage 13 and the upper part of chamber 6. The pas sage 13 terminates adjacent the closed upper end of the tube lt and intersects with a la eral opening 16 in the tube, which opening leads to a circumferential groove 17 formed on the outer periphery of tube 15. A horizontal passage 18 formed in casing A leads from groove 17 to a similarly formed and right angularly disposed passage 19, which leads to the opening in which the throttle valve spindle 10 is journaled.

Such opening, as clearly shown in Fig. 3, is at its upper end made somewhat larger than the spindle 10 to receive a disk 20 which is fixed to and rotatable with the spindle and held in place by an annular nut 21. Disk 20 rotates in the same horizontal plane which includes the passage 19 and, when the throttle 9 is in closed position as illustrated, closes the end of passage 19. There is a radial passage 22, extending through dish 20 and one wall of spindle 10, which passage adapted to connect the passage 19 with an axial passage 23 in the spindle, when the throttle valve 9 is opened. The disk 20 therefore functions as a valve to vary the effective area of communication between the passages 19 and 2-3, as the effective area of the intake pipe 5 is varied by the throttle valve 10, and the opening 22 is so constructed and arranged that variations in the effective area of the int-alto pipe 5 are accompanied by proportionate ariations in the communication between the pass gos 19 and '23. The passage COlllllllllllCul way of a radial opening :21 in spindle 10 with the intake pipe 5 and between the opening 2% and dish 20 there is provided in pa sage 23 a valve seat 25. i needle valve fi l threaded into, and closing the lower end of. passage 23, s arranged to cooperate with seat to regulate the dischz'irge from the passage The second fuel connection, which may be considered as a slow speed nozzle, will now be described. The cover 8 is formed with a hollow upstanding boss 28 and into the lower end of the latter is secured, as by the screw threads illustrated, a plug 99 which has an axial opening 30. The low 1' end of the plug 29 is cupped out with a conical recess to receive the conical upper end of a tube 31 and the upper end of the plug is conical to receive the cupped lower end of a stem The upper portion of the latter is threaded into and closes the upper end of the hollow boss 28 but the lower portion of the stem, except for a flange 33 intermediate its ends, is of such diameter as to leave an annular space between the stem and the interior wall of the boss 18. The flange 33 closely {its such wall and partitions such annular space into upper and lower annular chambers 31 and 35 respectively. The stem 32 has a diametrically disposed hole 86 therein, which lies above flange 33, and from hole 36 an axial passage 87 extends to the lov-wer and conically rcccssed end of the stem in alinemcnt with the passage The tube 31, also has an axial passage 38 therein which forms a continuation of passage 30 and connuuuicatcs with the chamber 6 near the base thereof by means of a restricted opening 39. Since the tube 31 extends below the fuel level in the chamber, it may fill to a considerable height with fuel and thereby form a well from which a rich fuel charge may be delivered for starti g purposes. The upper annular chanil er communicates with one end of a horizontal passage -10 formed in cover 8,

which passage leads to the upper end of a vertical passage 41 formed in the cover. The casing A has a vertical passage 42 -which forms a continuation of the passage ll and delivers into one end of a horizontal passage 43, which, as indicated in Fig. 1, delivers into the intake pipe 5 at such a position as to be closed when the throttle 9 is closed. Thus, the passages 39, 38, 30, 37, 36, 34, d0, 41, i2, and 43 provide a connection between the pipe 5 and chamber 6 through which connection fuel from the chamber may be drawn into pipe 5 by the suction produced in the latter.

For the purpose of regulating or adjusting the degree of suction for any given throttle opening or engine speed, any suitable means may be provided. One advan tageous means of effecting this result is by the admission of air in restricted and regulable quantities into the slow speed fuel connection. Thus, the mating ends of plug 25 and stem 32 constitute a valve whereby communication may be established between the passage 37 and the annular chamber The latter communicates with the atmoshere by way of an opening 44 formed in boss 28 (Fig. 2). Thus, the suction produced in the slow speed connection is effective partly upon the chamber 6 and partly upon the atmosphere and, since stem 32 is adjustable, it will be obvious that, for any given degree of vacuum obtaining in the passage 37, the vacuum produced in passages 30 and 38 may be reduced as desired. In practice the stem 32 is originally adjusted to secure the desired ratio of fuel distribution between the high speed and slow speed nozzles, and once so adjusted is generally not disturbed.

The described tube 31 is slidably mounted in suitable guides as indicated and is arranged to rise and fall accordingly as the fuel level in chamber 6 rises and falls. Thus, two spaced levers 45, each pivoted at one end to a lug on cover 8, have their free ends pivotally connected to a float 46 in chamber 6. The levers 4E5 lie on opposite sides of tube 31 and have parts 4L7 which eX- tend toward the tube and engage in a circumferential groove 48 formed in tube 31. It will thus be apparent that, as long as the fuel in chamber 6 is at or above apredetermined level, the tube 31 will be held in the illustrated position, but when for any reason the fuel falls below a predetermined level the tube will drop away from the plug 29 and provide increased area of communication between the slow speed connection and the chamber 6.

In normal operation, the passages 39, 38, 30, 37, 36, 40, ll, 42, and 43 function as a slow speed passage or nozzle. That is that slow speed passage has but restricted communication with chamber 6 by way of the opening 39 and, since the degree of vacuum operable on the chamber by way of such opening may be made less than that obtaining in other parts of the slow speed passage, as by adjustment of stem 32, only relatively small quantities of fuel are delivered therethrough. The slow speed passage functions chiefly on low engine speeds when the throttle 9 is nearly closed. Obviously, then a much higher degree of vacuum is then exerted on passage 43 than when the throttle is wide open, so that sufficient fuel may be delivered through the slow speed passage for slow speed operation although at higher speeds, the delivery of fuel may be less.

The passages 13, 16, 18, 19, 22, 23, and 2a function as the main or high speed passage or nozzle. Through such passages the main supply of fuel is delivered and the regulation of flow therethrough is effected by valve disk 20, which varies the effective area of the high speed fuel passage proportionately with the variations of the air-intake pipe 5 by the throttle valve 9, whereby the ratio of fuel to air is maintained substantially constant as more particularly pointed out in. my above mentioned prior patent.

It will be noted that the two fuel passages described constitute the only means of vacuumizing the chamber. These passages act chiefly by the removal of fuel from the chamber 6 to induce the flow of more fuel therein from the low level tank and communicate with the chamber near the base thereof where fuel will always be present. At certain times, however, when the fuel in chamber 6 drops below a predetermined level, the slow speed passage is permitted, by reason of the falling of the float supported tube 31, to communicate unrestrictedly with the upper part of the chamber. This arrangement associated with the slow speed passage, thus comes into play when needed to increase the exhaustion of chamber 6 and aid in increasing the flow of fuel thereto.

Originally the chamber 6 may be filled with fuel in any desired manner. For eX- ample, the engine may be turned over to produce the suction and if throttle 9 is nearly closed a strong suction is obtained to act on the slow speed fuel passage. The stem 32 may be turned down if desired. to entirely close oh the entrance of air to the slow speed passage and thus aid in rapidly vacuumizing the chamber 6, which, by reason of the separation of tube 31 from plug 29, has full and unrestricted communication with the slow speed fuel passage. The

chamber 6, once filled to the desired level, I

may be maintained at such level by the suction produced in the high speed and slow speed fuel passages, the former having a constant, but restricted communication and the latter a variable communication with i the upper part of chamber 6 to insure the maintenance of a sufficient supply of fuel in the latter.

The invention has been disclosed, in a form at present preferred, for the purposes of illustration, but the scope of the invention is defined by the appended claims rather than by the foregoing description.

lVhat I claim is 1. In a carbureter, an airintake pipe adapted for connection to suction means, a substantially air-tight fuel chamber adapted for connection to a low level fuel supply tank, -means normally connecting said pipe to said chamber below the fuel level in the latter, and means operable when the fuel in said chamber falls below a predetermined level to permit communication between said connecting means and the chamber above the fuel level in the latter.

2. In a carbureter, an ainintake pipe adapted for connection to suction means, a substantially air-tight fuel chamber adapted for connection to a low level fuel supply tank, means connecting said pipe and cham her and normally affording communication with the latter below the fuel level through an opening of constant area, and means operable when the fuel in said chamber falls below, a predetermined level to permit increased area of communication between the chamber and said connecting means.

3. In a carbureter, an air intake pipe adapted for connection to suction means, a substantially air-tight fuel chamber adapted for connection to a low level fuel supply tank, and fuel conducting devices connecting said pipe and chamber and constituting the sole means of creating a vacuum in said chamber, said fuel conducting devices including a conduit from the pipe to said chamber, a tube in the chamber normally forming an extension of the conduit and affording communication with the chamber below the level of fuel therein, and means operable when the fuel in the chamber falls below a predetermined level to separate said tube and conduit, whereby additional area of communication between the latter and said chamber is afforded.

4. In a carbureter, an air-intake pipe adapted for connection to suction means, a substantially air-tight fuel chamber adapted for connection to alow level fuel supply tank, fuel conducting means connectin id pipe andvchamber and constituting the sole means of creating a vacuum therein, said fuel conducting means including two conduits each extending from said pipe to said chamber and terminating in the latter with a tube which opens into the chamber below the fuel level therein, one of said tubes having a restricted opening affording communication with said chamber near the top thereof, the other tube normally having restricted communication with the chamber, and means operable when the fuel in said chamber falls below a predetermined level to permit additional communication between said chamber and second conduit.

5. A carburetor, comprising, an air-intake pipe adapted for connection to suction means, a throttle valve in said pipe, a substantially air-tight fuel chamber adapted for connection to suction means, a fuel conducting passage connecting said pipe and chamber and communicating with the latter near the base thereof, a valve associated with said passage and operable to vary the ellectivc opening thereof proportionntely with the variations of the intake pipe by said throttle. valve, a second fuel conducting passage be tween said pipe and chamber and having restricted communication with the latter near the base thereof, and means operable when the fuel in said chamber falls below a predetermined level to permit communication between the second fuel passage and chumber near the upper part of the latter, said fuel conducting passages constituting the sole means of creating a vacuum in said chamber.

6. In a carbureter, an air-intake pipe adapted for connection to suction means. a. substantially air-tight chamber adapted for connection to a low level fuel supply tank, a fuel conducting passage connecting said pip and chamber and terminating near the upper part of the latter, a tube normally forming an extension of said passage and slidable in the chamber, said tube communicating at one end with the latter near the base thereof and normally communicating at the other end with said passage, and a float in said chamber operable to hold said tube in normal position and operable when the fuel in said chamber falls below a predetermined level to lower the tube and permit direct communication between said passage and oh amber.

PIERRE ll (rliililltt

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