US2156132A

US2156132A - Carburetor

Info

Publication number: US2156132A
Application number: US10721A
Authority: US
Inventors: Thieulin Maurice Clem Philippe
Original assignee: Societe du Carburateur Zenith SA
Current assignee: Societe du Carburateur Zenith SA
Priority date: 1934-03-16
Filing date: 1935-03-12
Publication date: 1939-04-25
Anticipated expiration: 1956-04-25

Description

April 25, 1939. MY c. F. THlEULiN CARBURETOR Original Filed March 12, 1935 3 SheetsSheet 1 April 25, 1939. M. c. P. THIEULIN 2,156,132

GAHBURETOR Original Filed March 12, 1935 3 Sheets-Sheet 2 jmzemo WAM 2?:

April 1939- M. c, P. THIEULIN 2,156,132

CARBURETOR Original Filed March 12, 1935 3 Sheets-Sheet 3 4/ In 85 I Fig.5.

111 I X; l

74 72 7\ 57 75 as osal'osz 9| Patented Apr. 25, 1939 UNITED STATES PATENT OFFICE assignor to Societe Generale dcs carbnratellrs Zenith, wallets-Perle France Application March 12,

1935, Serial No. 10,721.

Renewed August 9, 1937. In Belgium March 11 Claims.

The present invention relates to carburetors for internal combustion engines.

It is known that the fuel mixture delivered to an engine by its carburetor may contain a lower 5 percentage of fuel as the temperature rises, without detriment to the proper operation of the engine. and especially without reducing its power or its capacity of acceleration. This modification of the percentage of fuel in the mixture in accordance with the temperature is even desirable because if the adjustment of a carburetor is such that the power and the acceleration characteristics of the engine are satisfactory at low temperatures. the mixture supplied to the engine by the carburetor thus adjusted is richer than necessary when the temperature is high and the consumption of fuel by the engine is unnecessarily high at high temperatures. Two temperatures influence the working of an engine, to wit: the temperature of the engine itself, and the temperature of the external air. As a matter of fact, many aircraft carburetors are provided with a correction device adapted pilot and which permits of increasing or decreasing the richness of the mixture fed to the engine as desired by the pilot. This kind of correctin device, the principle of which is perfectly sound,

. for practical purposes, some disadvanes. It requires, from the pilot, a correct 39 reckoning of the correction to be made as a function of the temperature, andit occurs often that the pilot, being not thoroughly familiar with the engine, brings the correcting device into a position that does not correspond to good conditions 35 of working of the engine, so that the latter does not work in a satisfactory manner.

The object of the present invention is to provide a device for automatically regulating the richness of the fuel mixture in accordance with 40 the temperature.

A further object of the present invention is to combine an automatic regulating device of this kind with a starting device which is also automatic, and which is intended to feed the engine. in a known manner, with a rich mixture so as to facilitate the starting of the engine from cold when the atmospheric temperature is low.

A carburetor fitted with a regulating device according to the present invention comprises an additional air inlet controlled by a valve which is itself controlled by a thermostatic element, in such manner that the valve opens and thus increases the amount of air admitted through said air inlet when the temperature to which the II thermostatic element is subjected rises. In the to be controlled by the present specification, the term thermostatic element means an element which is deformed when the temperature varies and the deformations of which serve to actuate the regulating organ that it is desired to control. 5

When the carburetor comprises, in combination, a device for automatically regulating the richness of the mixture and an automatic starting device, a single thermostatic element controls both the air inlet valve of the automatic regu- 1 lating device, and a. valve controlling the discharge of mixture from the starting device, that is to say the communication between the mixing chamber of the starting device and the mixture pipe of the carburetor. The connection between the thermostatic element and these two valves is such that, when the temperature rises, the thermostatic element successively operates the valve controlling the discharge of mixture from the starting device and the air inlet valve of the regulating device. As the valve controlling the discharge of mixture from the starting device is initially open, the thermostatic element first causes said valve to close, the air inlet valve of the regulating device remaining stationary as long as this discharge valve is not closed, and it is only after this discharge valve has been closed that the thermostatic element causes the air inlet valve of the regulating device to open.

other features of the present invention will result from the following detailed description of specific embodiments thereof.

Preferred embodiments of the present invention will be hereinafter described with reference to the accompanying drawings, given merely by way of example, and in which:

Fig. 1 and Fig. 2 ditically show, in longitudinal section, a carburetor provided with a regulating device and with a starting device, both controlled by the same thermostatic element. In Fig.1 the partsare shown in the position they occupy when the engine is cold and in Fig. 2 they are shown inthe position they occupy when the engine is warm;

Fig. 3 atically shows, in elevation 45 and partly in section. a preferred embodiment of a carburetor including in combination a starting device and a regulating device both controlled by thermostatic means:

Figs. 4 and 5 atically show, in longi- W tudinal section. the combined arrangement of regulating means and starting means on the carburetor or Fig. 3.

The carburetor shown in ms. 1 and 2 is provided with a starting-device including a mixing 56 chamber 21. This mixing chamber 21 communicates with the mixture pipe I of the carburetor, behind throttle valve 2, through a mixture outlet 28 controlled by a valve 29. The mixing chamber 21 of the starting device is fed with fuel from float chamber 5 through a calibrated jet 39 and a conduit 3!. This conduit 3i is provided with an emulsifying air inlet hole 32 located slightly above the level X-X of fuel. The mixing chamber 21 is fed with air through air inlet orifices 33 of sufficient section.

The iegulating or correcting device includes an additional air inlet 34 controlled by a valve 35 and communicating through a conduit 39 with the mixing chamber I2 of the carburetor.

Valves

29 and 35 are both controlled by a floating thermostat 31 filled with a liquid, a gas, or a vapour. This thermostat 31 is disposed in a casing 38. Valve 29 is connected to thermostat 31 through a rod 39 passing through guiding means 40 carried by the end of casing 39. Valve 35 is connected to thermostat 31 through a rod 4|. The guiding means 49 and the additional air inlet 34 are disposed at opposite ends of casing 39, respectively. A spring 42, compressed between the end 43 of thermostat 31 and the end 44 of casing 39. tends to keep valve 35 applied against its seat.

This device works in the following manner:

When the engine is cold and the external temperature is low, thermostat 31 is contracted and the various parts occupy the position shown in Fig. l. The valve 35 of the regulating or correcting device is opened, while the valve 29 of the starting device is open. When the pilot starts the engine, the starting device supplies the engine with a rich mixture consisting of air delivered through air inlets 33 and of fuel delivered through jet 39. This mixture, which is formed in mixing chamber 21, is delivered to the mixture pipe I of the carburetor through fuel mixture outlet 29 and is added to the main mixture supplied by the main carburetor. The additional air conduit 39 is inoperative since valve 35 is closed.

When the temperature rises, thermostat 31 dilates and gradually closes valve 29. Therefore the starting device delivers to the mixture pipe I of the carburetor a smaller and smaller amount of supplementary rich mixture. When the temperature is suificient for causing thermostat 31 to and conduit 36 feeds to the mixing chamber of the carburetor additional air which reduces the percentage of fuel in the final mixture fed by the carburetor to the engine. The various parts now occupy the position shown in Fig. 2. It should be noted that the opening of the valve of the regulating or correcting device takes place only after the closing of the valve controlling the mixture outlet of the starting device.

In the embodiment of Fig. 3, an intermediate collar 45 is interposed between a flange on the intake pipe 49 of the engine and the flange 41 of the carburetor. The combined regulating and starting device 49 is fixed on the intermediate collar 45 by means of the threaded end 49 through which extends the outlet conduit 59 of the starting device. The device is fixed in posiiion by means of lock-nut 69. Conduit 59 opens into the central bore 5| of intermediate collar 45 which establishes a communication between the mixture outlet of the main carburetor and the engine intake pipe 46. In the main carburetor, a float chamber 52 feeds fuel through known means, not shown in the drawings, to fuel outlet 53, which opens into choke tube 54. An idling system, not shown in the drawings, feeds a fuel mixture to the idling mixture outlet 55, which opens into pipe I close to the edge of throttle 56, when the latter is in the closed position.

The starting device is fed with fuel through conduit 51, the end of which is provided with a calibrated hole 59 immersed in a vertical tube 59 carried by the float chamber. This tube 59 is fed with fuel through an immersed jet 99 connected with the' float chamber through a conduit 5|. Tube 59 is fed with air at its upper part through orifice 62.

The additional air supplied by the correcting or regulating device is delivered to the carburetor through conduit 53. This conduit 53 opens into an annular space 94 provided between the outer wall of choke tube 54 and the inner wall 55 of the mixing chamber of the carburetor. Owing to this arrangement, the additional air is regularly distributed around the main mixture of air and fuel issuing from choke tube 54, which ensures the homogeneity of the final mixture.

The details of the combined regulating and starting device 49 are shown in Figs. 4 and 5. The body 91 of this device includes the threaded end part 49 which serves to fix it in the intermediate collar 45, and through which is provided the mixture outlet conduit 59 of the starting device. This body 91 is further adapted to receive the end of the fuel feed conduit 51. A seat 69 is tightly held between a shoulder 99 of body 91 and the threaded end of a shell 19. This seat 99 is provided with holes 1|, which constitute the air inlet orifices of the starting device. It is further provided, in its central part, with a cylindrical guiding sleeve 12, in which is slidably mounted a rod 13 carrying a valve 14. This seat 99 is further provided, in its peripheral part, with a cylindrical extension 15 provided with calibrated holes 19. A spring 11, interposed between seat 59 and a pin 19 extending through rod 13, tends to keep valve 14 applied against the end of cylindrical part 15 (Fig. 4). when valve 14 is moved against the action of spring 11, it may be seated against a shoulder 19 of body, which constitutes the seat of said valve, so as to stop mixture outlet 59 (Fig. 5). The annular space 99, existing between valve 14 and body 91, constitutes the mixing chamber of the starting device.

Shell 19 is provided with a cylindrical guiding surface 9|, in which is slidably mounted a sleeve 92. This sleeve 92 is provided at one end with a. flange 93. A spring 94, stronger than spring 11, interposed between said flange 99 and a shoulder 95 on shell 19, tends to push flange 93 toward seat 99. At the opposite end, sleeve 92 is provided with orifices 9|. A thermostat 99, which is filled with a liquid, :3. gas, or a vapour. is flxed to the end 91 of sleeve 92, and when it expands, due to a rise 01' the temperature, its end 99 comes into contact with the end of the rod 19 that carries valve 14 and pushes said valve against its seat 19, against the action of spring 11.

At its and opposed to seat 99, shell 19 is open and forms a circular seat 99 adapted to cooperate with a valve 99 rigidly carried by sleeve 92.

armies The additional air conduit I is ilxed to shell II. Valve OI tends to be applied. its seat a bythe action the flange 81 ot said-sleeve, I v

This device worksin the following when the engine iscold and the'external temperature islow. the various parts-oi the device occupy the position mamas 4. Thermostat 8B is contracted. Spring ll keeps valve OI in the closed position, so that noadditonal air can be led through conduit. Spring .11 keeps valve ll applied against the end part Ii. There is a certain clearance'between the end of valve rod 13 and the end of thermo stat 86. When the engine is started, thethrottle valve 56 of the carburetor being closed. the-mixing chamber "of the startin device is fed with air only through orifices 16 of small section,

which themselves communicate with the atmospiece ll and valve '0.

phere through holes 1| provided in seat 68 and through ports 9| provided in sleeve 82. Valve 14 permits free communication between mixture outlet conduit 50 and the 'Iuel inlet conduit 51. A considerable suction is then transmitted through conduit 51 and calibrated orifice it to tube 59. Conduit 51 feeds the mixing chamber of the starting device, I0,,with a considerable amount of iuel'emulsifled by air admitted into tube 59 through calibrated orifice 62. On the contrary, this mixing chamber ll receives but a small amount of air through orifices It. which are of small section. Therefore the starting device supplies the engine with a very rich mixture which is particularly well adapted to permit the starting of the engine lrom cold. It the pilot opens throttle valve iiso as to use the engine, the very rich mixture fed by the starting device is added tothe normal mixture delivered by the main carubertor, and facilitates the running of the engine which is still cold.-

As the engine grows warmer, expands gradually more and more. Its end It comes into contact with the end of rod II, and gradually pushes valve ll, which is rigid with thermostat l8 said rod, toward the left hand side, against the action of spring'lfl. Valve II is thus moved away from the end of cylindrical part 15 and thus the amo mt of air admitted into the mixing chamber I. of the starting device. At the same time, valve I! is moved nearer and nearer to its seat ll, thus reducing the section of flow for the mixture issuing from chamber Ill and fed to the engine through mixture outlet ,50. This produces a reduction of the suction created in chamber and a reduction of the richness of the mixture supplied by the starting device. At the same time, the amount of mixture that is fed by the starting device decreases and it becomes zero when valve 1 is brought into contact with its seat 18. The starting device is thus gradually brought out of action when the engine grows warmer and warmer.

As the temperature further rises (Fig. 5). the end 88 of the expansible thermostat 8' coma to bear against the end of the rod 13 of valve II. which is itself applied against its seat ID. The opposite end of thermostat IO pushes the end ll of sleeve '2 to the s ring as under the effect of a further expansion thermostat 86, valve II, which is rigid with said sleeve 02, opens, and additional air is fed to conduit I through the space between the end I! of This additional air is led intothe annularspace surrounding thechoke tube of the main carburetor and reduces the perof spring-(ll. wbith applied against" a i a fore the amount of vary with the conditions of whatI deem tObe P ri ht, against the action or" ce tage oi fuel in the fuel mixture fed to the engine by the carburetor. Valve OI is the more widely open as the temperature is higher. Thereadditionalair delivered by the correcting or regulating device increases simultaneously with the temperature, so that the mixture fed to the engineby the carburetor becomes poorer in fuel as the temperature rises.

When the engine is started, if the external temperature is not very low, valve Il may be already in an intermediate position between the end of cylindrical part I5 and shoulder 19. Therefore the richness and the amount of the mixture led to the engine by the starting device temperature in which placed and with the requirements of While 1 have, in the above description, disclosed tical and efiiclent embodiments of the present invention, it should be well understood that I do not wish to be limited thereto as there mightbe changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended within the scope of the appended claims.

What I claim is:

l. A carburetor for an internal combustion engine which comprises, in combination, a carbu retor body lowing a mixing chamber, means for feeding fuel into said chamber, a main air inlet for said chamber, an additionalv air inlet, a valve for controlling said additional air inlet, a starting device including a mixing chamber for forming a rich mixture or fuel with air. and a passage for leading said rich mixture from said last mentioned chamber to the engine, a valve for controlling said passage, and thermostatic means for controlling both of said valves so as to leave the last mentioned valve open when the temperature of said thermostatic means is low and gradually close it when said temperature rises and to move said first mentioned valve in the opening direction thereof when the temperature of said thermostatic means exceeds a predetermined value and is rising. and in the closing direction when said temperature drops toward said predetermined value.

a 2. A carburetor for an internal combustion engine which comprises, in combination, a carburetor body forming a mixing chamber, means for feeding iuel into said chamber, a main air inlet for said chamber. an additional air inlet adapted to reduce the percentage of fuel in the mixture ted by said carburetor to said engin a valve for controlling said additional air inlet, a starting device for forming a rich mixture of fuel with air, a passage for leading the rich mixture from said starting device to the engine, a valve for controlling-said c, said last mentioned valve being normally open at low temperature, a thermostat filled with a fluid, means for connecting one end oi said thermostat with the second mentioned valve so as to cause said last mentioned valve to close gradually when said thermostat expands under the thermostat to the first mentioned valve, so as to cause said first mentioned valve to open when said thermostat expands to a suflicient degree, and elastic means for yieldlngly Opposing the opening of said first mentioned valve.

3. A carburetor according to claim 2 in which said valves are positioned parallelly with each otherandareadaptedtoopenbothlnthesame direction, the means for connecting one end or the thermostat with the second mentioned valve including a. rod rigid with-said valve and against which said end of the thermostat comes into contact after a given expansion of the thermostat, and the means for connecting the other end of the thermostat with the first mentioned valve being rigid connecting means.

4. A carburetor according to claim 1 including a throttle in said mixing chamber in which said additional air inlet opens into said mixing chamber ahead of said throttle.

5. In a carburetor for an internal combustion engine comprising an induction passage and fuel and air inlets for supplying mixture to the engine for normal operation; auxiliary fuel supply means arranged to discharge into the induction passage, an auxiliary air inlet arranged to discharge into the induction passage, independently operative valves controlling said auxiliary fuel supply means and said auxiliary air inlet, and a floating thermostat connected to the valves and arranged to successively close one of said valves and open the other as the temperature rises.

6. In a carburetor, a mixture control device comprising a floating thermostat having one end movable in a predetermined direction upon rise in temperature and the other end movable and biased in the same direction, a valve member connected to said one end and arranged to close upon movement of said one end in said direction, a second valve member connected to the other end and arranged to close upon movement of said other end in the same direction, and fuel and air inlets controlled by said valve members for influencing the richness of the mixture generated by the carburetor.

'7. A carburetor as defined in claim 6, wherein one of said valve members is associated with a fixed valve seat which acts as an abutment against which the thermostat reacts in actuating the other valve member.

8. A carburetor as defined in claim 6, wherein one of said valve members is associated with a valve seat which, when in contact with its valve member, acts as an abutment against which the thermostat reacts in operating the other valve member, and the other valve member is associdirection.

ated with a valve seat which, when in contact with its valve member, acts as a stop to limit movement of the thermostat due to said bias.

9. A carburetor havinga main induction passage, a mixture control device comprising a floating thermostat having one portion movable in a predetermined direction upon rise in temperature, means biasing another portion of the thermostat in the same direction, auxiliary fuel and air passages connected to the induction passage and designed to influence the fuel-air ratio of the mixture generated by the carburetor, and valve members connected to said portions of the thermostat for controlling said auxiliary passages.

10. A carburetor for an internal combustion engine having an induction passage, comprising in combination a main air inlet, an additional air inlet, and an auxiliary starting device including a mixing chamber, a. mixture passage connecting said mixing chamber and said induction passage, a floating expansible thermostat, a valve member connected to said thermostat and arranged to 'close said mixture passage upon expansion of the thermostat, and a second valve member connected to said thermostat and arranged to open said air inlet upon expansion of the thermostat, said thermostat being biased in a direction to tend to close said mixture passage.

11. In a carburetor for an internal combustion engine comprising an induction passage and fuel and air inlets for supplying mixture to the engine for normal operation; auxiliaryfuel supply means arranged to discharge into the induction passage, an auxiliary air inlet arranged to discharge into the induction passage, a valve operative when moved in one direction to close said auxiliary fuel supply means, a second valve operative when moved in the same direction to close said auxiliary air inlet, means limiting the movement of each of said valves in said same direction, a temperature responsive connection between said valves operative to move the valves away from each other upon a rise in temperature, and means biasing said connection in said same MAURICE cut'mn'r PHILIPPE rumours.

:CERTIFIOATE or ooasscrrou.

Patent No. 2,156,132.

April 25, 1959.

mimics CLEMENT PHILIPPE THIEULIN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column, line 35, for the word "opened" road closed; page 5, first column,

line 39, -10:- "carub erton" read carburetor; line I0, before "thermostat" insert of; and that the said Letters Patent should be read with this correction' therein that the same may conform to the record of: the case in the Patent Office Signed andsealed this 12th day of March, A. D. 191 0.

Henry van Arsdalo Acting Coamilssioner of Patents.

direction, the means for connecting one end or the thermostat with the second mentioned valve including a. rod rigid with-said valve and against which said end of the thermostat comes into contact after a given expansion of the thermostat, and the means for connecting the other end of the thermostat with the first mentioned valve being rigid connecting means.

11. In a carburetor for an internal combustion engine comprising an induction passage and fuel and air inlets for supplying mixture to the engine for normal operation; auxiliaryfuel supply means arranged to discharge into the induction passage, an auxiliary air inlet arranged to discharge into the induction passage, a valve operative when moved in one direction to close said auxiliary fuel supply means, a second valve operative when moved in the same direction to close said auxiliary air inlet, means limiting the movement of each of said valves in said same direction, a temperature responsive connection between said valves operative to move the valves away from each other upon a rise in temperature, and means biasing said connection in said same MAURICE cut'mn'r PHnuPPE'rHnnnJN.

CERTIFIOATE or ooaascrrou.

Patent No. 2,156,132.

April 25, 1959.

MAURICE CLEMENT PHILIPPE THIEULIN.

line 39, -10:- "carub erton" read carburetor; line I0, before "thermostat" insert of; and that the said Letters Patent should be read with this correction' therein that the same may conform to the record of: the case in the Patent Office Signed and sealed this 12th day of March, A. n. 19h0.

Henry van Arsdalo Acting Coamilssioner of Patents.