US1365395A - Casbitbeteb - Google Patents

Description

P. P. GILLES.

CARBURETEE.

APPLICATION-FiLiD SEPT. 17, 1928.

"1,365,395. Patented Jan. 11,1921.

IN V EN TOR.

fimffzz% W Y M A TTORNEYS.

UNITED STATES Parent @FHQE.

PIERRE P. GILLES, OF SPRTNGFIELD, MASSACHUSETTS.

CARBURETER.

T 0 all whom it may concern:

Be it known that I, PIERRE P. GILLns,born in Switzerland of German parentage, now believing myself to be a citizen of the dwiss Confederation, and having formally declared my intention 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 Carbureters, of which the foll0wing is a specification.

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

The carbureter disclosed in my prior patent embodies the usual suction or air-intake pipe and a substantially air-tight fuel chamher, into which fuel from a low level fuel supply tank may be drawn by the suction produced in one or more fuel conducting passages, which connect the suction pipe and fuel chamber. The construction is particularly characterized in that the fuel conducting passages constitute the only means of vacuumizing the fuel chamber. Necessarily, the inflow of fuel into the latter is substantially at the same rate as that at which fuel is delivered from the chamber into the suction pipe and ordinarily therefore there is no particular need of regulating means for maintaining the fuel supply in the chamber at a constant level.

There are times, however,as for example when the automobile, with which the carbureter is used, is traveling on an tip-grade,- when for a given throttle opening the degree of suction tends to decrease due to slackened engine speed and, at such times, it becomes particularly important to insure not only the maintenance of a sufficient supply of fuel in the fuel supply chamber, but also to provide means for maintaining the flow from the chamber to the suction pipe at the desired rate. I The maintenance of the fuel level in the fuel supply chamber is broadly the object of my copending application Serial No. 254,466 filed Sept. 17, 1918, and the present invention is more particularly concerned with the provision of means to insure an adequate supply of fuel to the suction pipe under all conditions of operation.

Specification of Letters Patent. Pat t d J 11 1921 Application filed. Eepteinber 17', 1912.

Serial No. 254,467.

The object of this invention is to provide in a carbureter which involves a suction pipe, a substantially air-tight fuel chamber and fuel conducting passages connecting the pipe and'the chamber and constituting the sole means of vacuumizing the latter, an arrangement of one of the fuel conducting pas sages so that it may communicate with the fuel supply chamber through openings of variable area and means controlled by the fuel level in the chamber to normally maintain such area of communication constant and operablewhen the fuel falls below a predetermined level to increase such area of communication.

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 1n the accompanying drawings, in which:

Figure 1 is a sectional elevational view of a carbureter embodying the invention, this plane of section being indicated by the line 1-1 of Fig. 2;

Fig. 2 is a sectional plan view taken on the line 22 of Fig. 1; and

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

Referring to these drawings, the carbureter casing comprises a main one piece memberA which, as shown in Fig. 2, is formed with an air-intake pipe 5 and a fuel chamber 6, and a cover member 7 which is applied to the top of member A to inclose the chamber 6. The cover member 7 is so applied as to render the chamber 6 air-tight, or substantially so, except for certain passages which communicate with the chamber as will later be described.

The air-intake pipe 5 is adapted for con nection at one end to suction means, and has been shown as suitably flanged at such end to permit its attachment to the intake manifold of an engine. The other end of pipe 5 opens to the atmosphere. Mounted in pipe 5 i the usual throttle valve 8 which may be operated in the usual manner. Between the throttle 8 and the air-intake end of pipe 5 is a Venturi or choke tube '9 and the main fuel nozzle, to be described, delivers into pipe 5 at a point closely adjacent the restricted part of the venturi 9, as

indicated in Fig. 2,

The main fuel nozzle is best shown in Fig.

3 and is contained in a stem 10, which is threaded into the lower part of easing A and extends vertically upward into the pipe 5. The member 10 has near its lower end a hole 11 therethrough with diametrically connects a circumferential groove 12 formed in the external periphery of the stem. To such groove fuel may be supplied as will later appear. From the hole 11, a passage 13 extends axially upward through stem 10 and intersects with an alined passage 14 of considerably larger area, which latter passage communicates with pipe 5. The intersection of the passages 13 and 14 affords a valve seat 15 against which a conical valve 16 may seat, as shown. Valve 16 has a depending stem 17 of approximately square cross-section which rides in passage 13 with its corners in engagement with the wall thereof for guiding purposes. At the same time, the segmental spaces between the squared sides of stem 17 and the interior wall of passage 13 permit the passage of fuel. The head of valve 16 which slides in passage 14 is similarly squared for a like purpose. Valve 16 is adapted to be lifted by suction and when so lifted permits fuel to pass from passage 13 into passage 14 and thus into pipe 5. The valve functions as an outwardly opening check valve to permit delivery of fuel therefrom and to prevent inflow of fluid therein. The valve is limited in its upward movement by an annular ring 18 which is set into and held to the upper end of the stem 10.

Fuel is supplied to the described groove 12 and thus to the main nozzle through a series of connecting passages now to be described with reference to Fig. 3. A passage 19 extends horizontally in casing A from the groove 12 to the lower end of a passage 20, which extends vertically upward in casino; A. into an alined passage 21 in cover '7. The passage 21 leads to a horizontal passage 22 which extends horizontally in cover 7 and opens into a vertical hole 23 therein. A tube 24, the upper end of which slidably fits in the lower portion of hole 23, has an axial passage 25 therethrough by means of which communication between the lower part of chamber 6 is constantly afforded.

The tube 24 is supported by levers from afloat 26 in chamber 6. Thus, two spaced levers 27 (Fig. 2), one on each side of tube 24 are pivoted at one end to a post 28 de pending from cover 7 and their other ends are forked (Fig. 1) to engage a pivot rod 29 carried by float 26. The tube 24 has a circumferential groove 30 in its outer periphery in which groove projections 31 on levers 27 are adapted to ride. Thus, when the fuel in chamber 6 is at or above a predetermined level, the tube 24 is held by the float in the illustrated position, the upward movement of the tube being limited by the engagement of a shoulder 32 thereon with the cover 7. Should the fuel in chamber 6 fall below a predetermined level, tube 24 will be moved downwardly. This downward movement of tube 24 is made to vary the area available for suction to act on the upper end of the tube. Thus, a needle valve 33, adjustably mounted in cover 7, depends into cotiperative relation with the upper end of the passage in tube 24 and restricts the delivery end of the passage. When the fuel in chamber 6 fall below a predetermined level, however, the tube 24 is carried away from the needle valve 33 to permit full and unrestricted communication between the passage 25 and hole 23.

There is provided on the cover 7 a fuel inlet connection 34 which is adapted for direct connection with a low level fuel supply tank. Fuel from such tank is drawn to chamber 6 by the creation of a partial. vacuum in the latter and the main nozzle, and the passages connecting it to the cham ber, together with a second fuel conducting passage to be described, constitute the sole means for vacuumizing the chamber 6. The vacuum is thus created in the latter through the fuel conducting connections themselves in a manner substantially like that disclosed in my above mentioned prior patent.

The second fuel conducting connection be tween the chamber 6 and intake pipe 5 will now be described with particular reference to Fig. 1. This connection, which functions as a slow speed nozzle, involves a passage 35 (Fig. 2) which extends horizontally in casing A and radially outwardly from pipe 5 to the lower end of a passage 36 (Fig. 1) which extends vertically upwardly in casing A and 1 leads into an alined vertical passage 37 in cover 7. Passage 37 opens into a horizonta passage 38 in cover 7 and the latter passage opens into an annular chamber 39. The latter is formed between a stem 40 and the interior wall of the hole in cover 7 in which the enlarged upper end of the stem is threaded. A flange 41 on stem 40 intermediate its ends closely fits the wall of said hole and prevents communication between the chamber 39 and a like annular chamber 42 below the flange. Stem 40 is provided with an axial passage 43 which extends, from its lower and conically recessed end, upwardly to a diametrically arranged hole 44 in stem 40 which hole opens into the described upper annular chamber 39. The lower annular chamber 42 closed at its lower end by a plug 45 which is provided with a conical upper end to cooperate, with the recessed lower end of stem 40, as a valve to control the communication between the passage 43 and chamber 42- The latter communicates with the atmosphere by way of an opening 46. Thus, air may be admitted to passage 43 in quantities which are regulable by turning the threaded stem 40. The plug 45 has an axial passage 47 therethrough which alines with passage 43 and also with a passage 48 which is formed in a tube 49. The latter extends from plug 42 downwardly into the chamber 6 and has a conical upper end to mate with a like recessed lower end of plug 42. Passage 48 communicates with the chamber 6 by means of a restricted opening 50 in the lower end of tube 49. Thus, suction from the air-intake 5 may be applied to chamber 6 to a degree controlled by the size of the opening 50 ans may be further restricted by the admission of air between the mating ends of the plug 45 and stem 40. It is to be noted that the slow speed. fuel connection delivers into pipe 5 at such a point that communication between the pipe and chamber 6 is prevented by the throttle valve 8 (in Fig. 2) when the latter is in closed position as illustrated.

The described tube 49 is suitably guided, as indicated in Fig. l, for vertical sliding movements and is supported in the illustrated position by. means of the described float 26' in the following manner. Two spaced levers 51, one on each side of tube 49, are pivoted at one end to a post 52, which depends from cover 7. The other ends of levers 51 connect with the'pivot rod 29 of float 26 and intermediate the ends of levers 51 are projections 53 which engage in a circumferential groove formed in the external periphery of tube 49. Thus, as long as the fuel in chamber 6 is at or above a predetermined level, the tube 49 remains in its illustrated position and only restricted communication, (by way of hole 50) is afforded between passage 47 and chamber 6. However, should the fuel in chamber 6 fall below such predetermined level, the tube 49 will be carried away from plug 45 and increased area of communication between the passage 47 and chamber 6 will be afforded by way of the space between the cooperating conical ends of tube 49 and plug 45.

The operation'of the carbureter will now be described. The chamber 6 may be originally filled with fuel in any desired manner. One manner in which this result may be accomplished is by exhaustion through the slow speed fuel passage. Thus, the throttle 8 may be opened just sutliciently to uncover the passage 35 and then, when the engine is turned over, a strong suction will be applied to the slow speed fuel passage. Since the chamber 6 is empty, tube 49 will be in its lower position, whereby the slow speed fuel passage will have full and unrestricted communication with the chamber for the pur pose of rapidly vacuumizing it. The stem 40 may also be turned down, if desired, to close off the admission of air into the slow speed fuel passage and thus aid in increasing the suction effective upon the chamber for the purpose of filling it.

In normal operation, the fuel is drawn into chamber 6 by the suction produ ed in the fuel passages themselves. That is, the removal of fuel through the two fuel passages causes an inflow of substantially a like amount of fuel into the chamber 6. Both high speed and slow speed passages communicate with the latter through constant 7 openings and the flow through each, for a given degree of suction, is regulable by the adjustable members 33 and 40 respectively. The slow speed fuel passage has no 'maliy restricted communication with the chamber and its adjustable member 40 is set so tilt this passage functions to deliver fuel chiefly on slow speed operation, that is, when the throttle 8 is moved nearly to closed position. The high speed fuel passage normally l' communication with the chamber 6 three an opening of constant area, namely the nular space between the needle valve 33 and the upper end of tube 24.

When the carburetor is used in automobile service t frequently happeir 1. suction decrease for a iven throttle op ing, due to slaclrened e gine speed. if the automobile, having been mm high speed with a full opening of tl encounters an upgrade, the engine speed will gradually decrease and thereby t 1 suction effective to draw fuel into the i pipe 5 as well as into chamber 6, dccrci. at a time when more l is required. prevent the depletion the fuel supply in chamber 6, the tube is supported by the float 26 and arranged to seaaratc, or fall away from, plug 45 whenever the fuel in chamber 6 falls below a predetermined level. This action permits increased, and even ful and unrestricted, communication be; I the slow speed passage and whereby the decrease in degree effective to draw fuel t 131Oll1 is compensated by the increased available for the decreased suction to act on. the chamber. Simultaneously, the falling of Heat causes the lowering of the tube and thus the removal of the restriction in the area of the high speed fuel passage. Thus, as before, increased area of communication is pro vided to compensate for the decrease in the degree of suction, whereby the fuel supplied to the intake pipe 5 through the high speed fuel passage may ,be maintained at the desired rate even though the degree of suction falls off due to slackened engine speed.

The invention has been disclosed, in an embodiment 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.

What I claim is- 1. 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, fuel conducting devices connecting said pipe and chamber and constituting the sole means of producing a vacuum in the latter, said fuel conducting devices including a passage connecting said pipe and chamber and constantly communicating with the latter, means normally restricting the effective area of said passage and means operable when the fuel in said chamber falls below a predetermined level to increase the effective area of said passage.

2. in a carburc er, 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, a passage connecting said pipe and chamber, a tube siidably mounted in the chamber and constantly communicating one end with the chamber and at the other end with said passage, a float in said chamber, means connecting the float and tube to support the latter, and means normally restricting the last-named end of said tube, all constructed and arranged so that when the fuel in the chamber falls below a predetermined level the tube is movco relatively to said restricting means to provide increased effective area of communication between said passage and chamber.

3. In a arbureter, 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, means normally connecting said pipe and chamber and communicating with the latter below the fuel level therein through a constantly restricted opening, a passage connecting said pipe and chamber and constantly communicating with the latter below the fuel level therein, means normally restricting the effective opening of said passage, means operable when the fuel in said chamber falls below a predetermined level to increase the effective areaof said passage, and means operable when the fuel in said chamber falls below a predetermined level to permit said connecting means to communicate with said chamber above the level of fuel therein.

4:. 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, two fuel conducting passages connecting said pipe and chamber and opening into the upper part of the latter, a tube telescoped at one end into one of said passages and depending into the chamber to provide constant communication between the passage and chamber below the level of fuel in the latter, a needle valve normally cooperating with said end of the tube to restrict its effective area of communication with itspassage, a float in said chamber connected to said tube to support the latter, and a second tube supported from said float and normally connecting the other passage to the chamber below the level of fuel therein and movable when the fuel falls below a predetermined level to permit the second passage to communicate directly with said chamber.

5. 'In a carburetor, 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 a low level fuel supply tank, a fuel conducting passage connecting the intake pipe at a point adjacent the throttle to the upper part of said chamber, a tube normally connecting the chamber end of said passage to the lower part of the chamber and means operable when the fuel falls below a predetermined level to move said tube so as to cause said passage to communicate directly with the upper part of said chamber, a second fuel conducting passage connecting said chamber and pipe and opening into the pipe at a point between the air-intake end thereof and said throttle, and a valve associated with the last-named passage to prevent flow of fluid from the pipe to the chamber.

PIERRE P. GILLES.

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