US2258003A

US2258003A - Carburetor device

Info

Publication number: US2258003A
Application number: US314243A
Authority: US
Inventors: Robert L Dickson
Original assignee: DICKSON BUTANE EQUIPMENT CO
Current assignee: DICKSON BUTANE EQUIPMENT Co
Priority date: 1940-01-17
Filing date: 1940-01-17
Publication date: 1941-10-07
Anticipated expiration: 1958-10-07

Description

1941- R. L. DICKSON 2258o03 CARBURETOR DEVICE 7 Filed Jan. 1'7, 1940 5 Sheets-Sheet l 1 i7 INVENTOR.

ROBERT L. .DICKSON BY W Mb,

ATTORNEY.

Filed Jan. 17, 1940 5 Sheets-Shet 4 INVENIOR.

ROBERT L. .D/CKSON BY ATTORNEY.

Patented Oct. 7, 1941 UNITED STATES PATENT OFFICE CARBUBETOB DEVICE Robert L. Dickson, Sacramento, Calm, assignor to 31%? as": 5.312353; titsitht Application January 17, 1940, Serial No. 314,243

21' Claims.

This invention relates to carburetors.

An object of this invention is to provide a carburetor wherein the gas is expanded to a predetermined pressure and is fed so as to maintain said predetermined pressure constant, and from which the expanded gas is discharged by a sensitive control responsive to the operation of the engine.

An object of this invention is to provide a carburetor in which the supply of fuel into the carburetor as well as the discharge of the fuel and the discharge from the carburetor is regulated by suction from an engine to which said from the carburetor are positively controlled and regulated so as to maintain a predetermined supply through said carburetor.

Another object of this invention is to provide a carburetor-wherein the fuel is expanded in the presence of heat so that a predetermined constant pressure is maintained for the supply of such expanded fuel to a usual mixing chamber or the like.

Another object of this invention is to provide a carburetor wherein the fuel is expanded in the presence of heatin an expansion chamber and the fuel intake is regulated by a mechanism controlled by the expanded pressure of the fuel, and the discharge from which expansion chamber is controlled by the suction of the engine.

Another object of this invention is to provide a novel and eflicient expansion device for carburetors, and particularly to provide a highly efficient heat exchanger for carburetors in which the fuel is contacted with a large heating surface a carburetor for fuel, such as butane, liquefied petroleum gas, natural gas, or other gases of comparatively low boiling point, wherein the fuel is pre-expanded to a predetermined pressure,

and fed to the engine through devices positively controlled by the engine so as to tightly shut off the feed when the engine is inoperative but to be sensitive to the slightest idling operation of second diaphragm so that said control autowithin a comparatively limited space of an expansion chamber.

Another object of this invention is-to provide a novel mechanism for controlling the feed of the fuel to the carburetor so as to maintain a predetermined gas pressure in the carburetor.

Another object of this invention is to provide a positive fuel discharge mechanism for carburetors which is sensitively controlled by suction from the engine and which provides for idling discharge as well as for positive shutting off of the gas flow from the carburetor when for any reason the engine is stopped or the control is out of order.

Another object of this invention is to provide a method of carburetion for gas wherein the gas is expanded to a predetermined pressure in the presence of heat, the gas beingintroduced to and withdrawn from said heat exchange at the hottest point of the carburetor, and wherematically closes the discharge valve and prevents the discharge of fuel when the suction at the diaphragm is broken for any reason.

Another object of this invention is to provide a carburetor in which highly volatile fuel or fuel of low boiling point and the like is fed to the carburetor under high pressure, is expanded and reduced to a predetermined lower pressure in said carburetor and is completely confined in said carburetor and positively held against escapement by said predetermined pressure and by sensitive balanced discharge mechanisms actuated'by engine suction for controlling the discharge.

Other objects of this invention are to provide a carburetor method and device that will be superior in point of simplicity, safety, inexpensiveness of construction, positiveness of operation, facility and convenience in use and general efiiciency.

Other objects of the invention together with the foregoing will be set forth in the following description of the preferred method and the preferred embodiment of means for practicing the same, which is illustrated in the drawings accompanying and forming part of the specificain the introduction of the gas into the carburetor tion. It is to be understood that I do not limit myself to the embodiment disclosed in said description and the drawings as I may adopt variations of my preferred forms within the scope of my invention.

With the foregoing and other objects in view,

which will be made manifest in the following detailed description, reference is had to the accompanying drawings for the illustrative embodiment of the invention, wherein:

Fig. 1 is a front view of the carburetor.

Fig. 2 is a sectional view of the carburetor, the secticrn being taken on the line 2-4 of Fig. 1, also showing diagrammatically the connection to the mixer.

Fig. 3 is a sectional view of the carburetor so as to show the heat exchanger in its expansion chamber. m

Fig. 4 is a front view'of the carburetor partly broken away to show the shut-oil! diaphragm control, and the intake control chamber.

Fig. 5 is a sectional view of the carburetor, showing the intake control and expansion control regulator, the section being taken on the lines 5-5 of Fig. 4.

Fig. 6 is a fragmental sectional view of the discharge regulator infully opened position.

Fig. '7 is a fragmental sectional view of the discharge regulator in fully closed or shut-oi! position;

Fig. ,8 is a sectional view of the discharge regulator in idling position, and

Fig. 9 is a fragmental, sectional detail view, showing the relative arrangement of the spray orifices on the nozzle tube of the heat exchanger device.

In-general the method of carburetion in accordance withmy invention includes the steps of expanding the fuel in the presence of heat, maintaining a predetermined constant pressure of the expanded fuel by controlling the fuel intake by the expanded pressure so as'to keep the fuel intake closed until the expanded pressur falls below a predetermined pressure. and regulating the discharge of the expanded fuelfrom the carburetor by the suction of the engine on which the carburetor is used.

The first step, namely the expanding of the also acts as a safety measure in preventing the building up of dangerous pressure in the expansion chamber of the carburetor.

The third step, namelythe' discharge regulation according to engine suction, is accomplished in two steps. First the discharge of the expanded fuel from the carburetor is entirely and automatically shut o'fi whenever the engine suction deos not operate the discharge regulating mechanism. Upon the starting of the engine and while it is idling the dischargemechanism is unlocked and kept opened to a preset opening by the action of the manifold suction of the engine. Secondly the released discharge mechanism is then regulated by the action of the suction at th mixing chamber of the carburetor leading to said engine. This permits a positive opening for idling of the engine, a flexible control through the usual throttle valve, and the automatic shutting off of the fuel discharge whenever the discharge regulator is not responsive to engine suction.

In the herein illustration is shown an embodiment of my invention in a type of carburetor particularly adapted for use in connection with gases of low boiling point. For instance butane gas is provided in liquid form in pressure tanks and it must be expanded to a suitable lower pressure, such as'to about ten pounds pressure, in order to be used in gas form. The various novel features of my device are capable of different uses in the regulation of fuel feed for combustion.

In the herein embodiment of my device in general I make use of an expanding device A, an intake control mechanism B and a discharge regulating device C.

The expanding device A includes a heat exchanger II and a multiple spray or nozzle tube It above'the heat exchanger ll, both disposed in an expansion chamber I3 and both being covered by a shield ll. The expansion chamber II is comparatively fiat and extends over the surface at many points. In addition the fuel is so circulated that the fuel under pressure is introduced into the carburetor at about the place where the heating medium for the heating element enters and is the hottest. The expanded fuel is also returned through a secondary path to about said hottest portion of the carburetor when the expanded gas is passed toward the discharge orifice of the carburetor.

Thesecond step, namely the maintaining of a constant predetermined expanded pressure, is accomplished by the provision of an intake control mechanism which closes the fuel intake of the carburetor by the direct application of the expanded pressure against a predetermined yieldable opening force so as to keep the intake closed at all times while the expanded pressure is sufiicient to overcome said yieldable opening force.

when the expanded pressure becomes lower than the yieldable opening force then the latter acts to open the intake and admit additional fuel to be expanded until the pressure is again built up to close the intake. This step maintains a substantially constant pressure and base I of the casing I! on which latter all the herein devices and mechanisms are supported. The heat exchanger II is formed into a coillike conduit through which a heating medium, such as hot water, is passed. The heat ex changer II is made of a plurality of parallel tubes II the ends of which are mounted in head boxes I Q and II. Each head box is divided by transverse partitions 22 into separate head spaces each of which communicates the adjacent ends of two of the tubes It. The series of partitions 22 of the oppositehead boxes I 9 and 2| are so staggered relatively to each other that the respective opposite heads overlap and connect the tubes ll into one continuous conduit with tubes ll forming turns of the conduit consecutively in opposite directions. An inlet 23 is detachably connected into the end of the first or top turn of the heat exchanger H and an outlet is detachably connected to the lower end turn of said heat exchanger II. It is to be noted that the

connections

23 and 24 are insertable from the outside of the expansion chamber It. The heat exchanger I I is firmly held in the chamber It by set screws 26 extended from the outside of the chamber I3 into engagement with the head box 2| so as to coact with securing nuts 21 of the intake 23 and of the outlet 24 for holding the heat exchanger H in place. The bottom of the expansion chamber II is covered by a removable cover 28 so that the heat exchanger II and parts of the heat exchanger device may be removed from the expansion chamber 3. The heating medium, such as hot water, circulates from the inlet 23 through the turns formed by the tubes l8 and the partitioned head boxes l9 and 2| to and out through the outlet 24, thereby exposing a large heating surface in the comparatively small chamber l3.

The nozzle tube 2 is made of a perforated tube insertable through a hole 29 in the side wall of the chamber l3 and seated in a socket 3| opposite said hole 29. The outer end 32 of the nozzle tube I2 is closed and it is threaded or otherwise adapted to be secured in place. The nozzle tube I2 is extended parallel with and above the first turn or top tube |8 of theheat exchanger II and has a series of nozzles or jets 33 which gradually increase in size toward the closed end 32 so that the fuel is introduced in substantially equalized sprays over the top .ofthe? heat exchanger I I. The fuel is fed'into the open end of the nozzle tube |2 from the socket 3| and from an intake passage 34. It is to be noted that the intakegpassage 34 and the-open end of the nozzle tube 2 are adjacent to the inlet 23 of the heat exchanger II which is the warmest part of the expansion chamber l3. In this manner the fuel is heated in its passage to the nozzles and the subsequent heat exchange is, rendered still more efficient.

The shield 4 is closed at its top and sides and extends over the nozzle tube 2 and over the heat exchanger so as to leave a'space 36 between each of its sides and the adjacent wall of the chamber l3. The shield I4 is open at its bottom end 31. This arrangement of the shield |4 confines the path of the fuel from the nozzles 33 to the surfaces of the heat exchanger I and thereby causes the-fuel spray to impinge upon the many exposed heating surfaces of the heat exchanger and be expanded before it leaves the primary path of the fuel within the shield l4. The fuel thus expanded is forced then to continue on a secondary heat exchanger path name:- ly through the spaces 36 between the sides of the shield I4 and the walls of the. expansion chamber |3 upwardly to the hotter upper part of said chamber 3, and during this secondary path the gas or vapor contacts the warmed walls of the shield |4.

The intake control mechanism 13 is located in a separate valve chamber 38 formed integral with the casing l1 and is offset as shown in Fig. 5 so as to be adjacent and partly in extension of the wall 39 containing the intake passage 34. The wall 39 is the heated wall and it extends to form a part of the wall of the valve chamber 38. In the extension of the wall 39 is securedfrom the outside an intake connection 4| from a usual fuel tank. A protruding intake part 42 on the end of theconnection 4| is located at an angle to the intake passage 34 so as to feed the fuel into said intake passage 34 when the intake port 42 is uncovered. A hole 43 extends through the extension of the wall 39 in continuation of the connection 4| and into the valve chamber 38. Into this hole 43 slidably fits a valve rod 44 which extends across the valve chamber 38 in an inclined position in axial alignment with the intake port 42. The tail end of the valve rod 44 is guided in asocket 46 in the wall 41 of the valve chamber 38. The valve end of the valve rod 44 is recessed and in the recess thereof is secured a compressible valve seat fitting over the protruding orifice of the intake port 42.

The intake valve rod 44 is reciprocated by a diaphragm 48 held by a cover 49 across the top of the valve chamber 38. A bell crank 5| is pivoted at one end to-a lug 52 on the underside of the diaphragm 49 and at its comer to a stay 53 fixed in the wall 41. The position of the bell crank 5| is such that its free end 54 fits into a suitable slot in the valve rod 44 and moves the valve rod 44 toward the intake port 42 when the diaphragm 48 is urged outwardly of the valve chamber 38, and is moved away from the valve port 42 whenthe diaphragm 48 is moved inwardly of the valve chamber 38. A spring 56 in the cover 49 normally forces the diaphragm 48 inwardly of the valve chamber 38 so as to urge the valve rod 44 into valve opening position. This spring 56 is ofa predeterminedtension so as to overcome a definite pressure in the valve chamber 38. The spring is such that it will be held compressed, and the diaphragm thus held in the valve closing position, by the constant pressure to which the fuel is to be expanded in the heat exchanger device A. Whenever the ex-. panded gas pressure falls below said desired pressure the spring will move the diaphragm 48 inwardly of the valve chamber 38 and move the valve rod 44 so as to uncover the intake port 42. Thus the fuel under pressure will be introduced into the intake passage 34 and into the heat exchanger device A as heretofore described. When sufficient fuel is expanded to create the desired pressure then the diaphragm is moved outwardly of the valve chamber 38 against the action of the spring 56 and the intake port 42 is again closed. The valve chamber '38 partly overlaps the front wall of'the expansion chamber |3 near the top and a hole 51 through said wall, as shown in Fig. 4, transmits expanded gas from the top of the expansion chamber |3 into the valve chamber 38 so that the diaphragm 48 is actuated by the pressure of the gas expanded by the heat exchanger device A.

The discharge regulating device C includes a diaphragm actuated valve mechanism. On the front part of the top of the expansion chamber 3 is a separate discharge valve chamber 58 which receives the expanded gas through a discharge passage 59 shown in Fig. 2. The discharge valve chamber 53 has vertically aligned threaded openings 6| and 62 into which is threadedly secured a valve cage 63 held in place by an outside locknut 64. The valve cage 63 has apertures 66 around a portion of its side walls through which the expanded gas passes from the discharge valve chamber 58 to the interior of the valvecage 63. On the end of the valve cage 63 in the inner opening 6| is an outwardly extended sharp rim forming a discharge orifice or discharge port 61 which communicates with. the apertures 66 through the inner cavity 68 of the valve .cage 63. The valve cage 63 is hollow throughout its entire length.

A valve 69 is opposite the discharge port 61 and has in itrecessed a compressible seat H for sealing engagement with the mouth of the discharge port 61. From one side of the valve 69 extends a spring cup 12 which also serves as an alignment guide in a spring socket 13 formed in the front of the casing H. A spring 14 in the spring socket urges the valve toward the discharge port 61. Into the other face of the valve 69 is threaded a valve stem 16, a flange of which holds the compressible seat H in place. This valve stem 16 extends axially into the cavity 68 of the valve cage 63. Above the valve cage cavity 68-the passage through the valve cage 88 is narrower and it guides another spring cup 'I'I' from which extends an extension stem 18. In the second spring cup 11 and around the extension stem I8 is another spring I8 which as its other end bears against a bushing 8| adjustably threaded into the outer end of the valve cage 88. The relative forces exerted by the springs I8 and I8 are such that the inner spring I8 is capable to move the valve II into closed position, seat it over the discharge port 81 and hold the valve in closed position in such a manner that in said closed position the closing spring I8 is substantially balanced by the outer spring I8 and by the normal expanded gas pressure issuing'from the heat exchanger device A. To achieve such substantial balance the tension of the outer spring I8 may be adjusted by the bushing 8I.

For the idling of the engine, when the suction in the usual mixing chamber is not sufficient to open the valve, a positive valve opening device is provided at the outer end of the valve cage 88. A screw plug 81 isadiustably threaded into the bushing 8I. The screw plug is hollow and has therein a slidable plunger 88. A reduced plunger abutment 88 protrudes from the plunger 88 through a small hole 88 in the bottom of the plug 82. A spring 81 in the screw plug .82 urges the plunger "toward the end of the extension stem 18 of the valve 88. The length of the extension stem vI8 is such that in the closed positionof the valve 88 it pushes up the plunger abutment 84.

In this manner the force of the phmger spring 81 is transmitted to the extension valve stem I8 so as to offset the force of the closing spring ll to an adjusted degree and keep the valve slightly open for idling. The extent of valve opening for idling can be adjusted by adlusting the position of the screw plug 82 in the bushing 8| and in the'valve cage 88. The outer end of the valve cage 88 has a cap 88 threaded thereon to protect these valve adjustments.

The discharge valve 88 is regulated and controlled by diaphragms actuated by the suction of the engine on which the carburetors are used. A discharge regulating diaphragm 88 is mounted in a diaphragm control chamber 8|, the bottom 82 of which latter is the front wall of the expansion chamber I8. The discharge regulating diaphragm 88 is held in place on a ledge 88 by a securing and spacing ring 88. An air vent 88 between the wall 82 and the diaphragm 88 releases back pressure and assures free action of the diaphragm 88. A lever 88 is pivoted at one end thereof to 9. lug 81 of said diaphragm 88. The lever 88 is extended through a large opening 88. in the ring and in the side of the chamber adjacent the discharge valve 88 and has its outer end bent and forked so as to form a yoke 88 fitting over a neck groove III at the base of the valve 68. The lever 88 is fulcrumed at I82 on ears I88 near its bend or corner so that when the discharge regulating diaphragm 88 is moved toward the lever 88 then the latter moves the valve 88 away from the discharge port 81 and when said diaphragm 88 is not subjected to suction then the outer or closing spring I8, is permitted to move the valve 88 back toward the discharge port 81.

The suction for the operation of the discharge regulating diaphragm 88 is created at the usual 7 mixing chamber I88 of a usual carburetor, the fuel line I88 of which is connected through a replaceable Venturi outlet ill to an outlet space I88 into which the fuel is discharged'from the into said outlet space I88 so that the mixing suctionisalsoexertedonthedlaphragm". This auction depends on the degree of opening of the throttle valve I88 but it is lower than the manifold suction between the throttle valve I88 and the engine. Thus the discharge of the expanded gastoandthroughthemixingchamber iillis regulated and controlled in amanner quickly responsive to the throttle valve adjustments.

When the engine stops entirely then the aforesaid idling opening must be closed by an automatic shut-oi! mechanism. For thlspurpose a so-calledlockingdiaphragmlflisdisposedinthe diaphragm control chamber 8I and is held in parallel spaced relationto the regulating diaphragm 88 between a front cover III and the top of the spacing ring 88. The locking diaphragm I I I separates the chamber under the dished cover III. A locking abutment II8 on'the locking diaphragm III abuts against the h1g8! on the regulating diaphragm. A spring Ill in the center of the cover II! bears against the center of the locking diaphragm III so as to urge the locking abutment II8 against the lug 8.1 and against the end of the lever 88 so as to positively force the discharge valve 88 into closed position and firmly lock it against opening. The space in the dished cover II! is connected by a conduit II8.to the engineat a pointpast the throttle valve.l88 wasto subjectthe outside face of the locking diaphragm I I I substantially to the manifold suction. The manifold suction is much higher and exerts more suction force than the suction in the mixing chamber I88. Therefore as soon as the engine is started; the manifold suction quickly pulls the locking diaphragm III out of locking position, and holds this locking diaphragm I I I in inoperative positionvas long as the engine is in operation. This permits the opening of the discharge valve 88 for idling and its regulation thereafter through the lever 88 and the regulating diaphragm 88 and by the suction in the mixing chamber I88 of the carburetor. If the engine stops, or the locking diaphragm I I I for some reason is out of order and does not react to suetion, the spring Ill automatically shuts off the gas supply and podtively prevents the flooding of the carburetor.

When the gas is shut-off at the discharge port 81, the pressur .in the expanding mechanism shuts-off the intake also and prevents excessive pressure in thedevice.

The device is simple and unitary in character. The expansion chamber l8 functions as a base which is covered at its front by the diaphragm control chamber 8I, and carries at its top, or at its heated end both the intake control chamber 88, and the separate discharge chamber 58, with an outlet I 81 in front of the discharge chamber 88. The mixing chamber may be directly mounted on the outlet I81 or the device may be connected by the flexible line I88 to a usual carburetor mixing chamber I88.

It is to be understood that while the features in the herein illustrative embodiment are described as parts of a carburetor, certain of the novel features herein may be used on fuel vaporizerg or fuel expander devices for different purposes so as to render the combustion of gases discharge port 81. The opening 88 also opens chamber through which the fuel is passed in said carburetor; of aheat exchanger in said chamber comprising, a conduit extended through said chamber and carrying a heating medium, means to introduce said fuel into the chamber and over said conduit, and a shield spaced from the chamber walls and extended over the said fuel introducing means and over said conduit so as to confine a primary fuel path around the surface of said conduit, and a secondary path for the ex-.

panded fuel in the space between the shield and the chamber walls.

2. In a carburetor the combination with a chamber through which the fuel is passed in said carburetor; of a heat exchanger in said chamber comprising, a conduit formed substantially in the shape of a coil and containing a heating medium, a spray conduit extended along said conduit for introducing a fuel, a shield fitting over said spray conduit and said coifto direct the primarypassage of the fuel over the turns of said coil, said shield being 'open' adjacent the last turn of the coil, and being spaced from. the wall of said chamber so as to provide a secondary passage for the fuel, an outlet from said expansion chamher outside of the closed end of the shield, and means adjacent said outlet to control the intake of the fuel into said spray conduit.

3. A heat exchanger for fuel gas, comprising an expansion chamber, an intake nozzle to conduct the fuel gas into said chamber, means extended over said nozzle in spaced relation to the walls of the chamber so as to divide the chem.- ber into a primary path and a secondary path wherein the gases pass successively in opposite directions the primary path leading away from said nozzles, and a heating element with a tortuous heating surface positioned in the primary path of the fuel.

4. In a carburetor, the combination with a heat exchanger for expanding the fuel andmeans to introduce the fuel to the heat exchanger; of an adjustable intak mechanism. between the fuel introducing means and the fuel supply, means acted upon by a predetermined expanded fuel pressure from said heat exchanger to keep said intake mechanism closed, and means operating only at expanded pressures lower than said predetermined pressur so as to open said intake mechanism.

5. A control mechanism for fuel intake comprising, an intake port, a valve to cover the intake port, a pressure chamber adapted to receive fuel under pressure, means in said pressure chamber to normally urge the valve into intake opening position, means actuated by the pressure in said chamber to hold said urging means in valve closing position whenever the pressure in said chamber is at or above a predetermined pressure and to release said opening at other times, and means to introduce expanded fuel under pressure into said pressure chamber independently of the intake valve for controlling the intake valve position.

6. An intake control for a carburetor having an expanding means for the fuel, of a separate control chamber, an intake port outside said chamber leading to said expanding means, a valve slidably extended through a wall of the chamber to cover said port, a diaphragm in said chamber being actuated by the pressure in said chamber, means of connection between the diaphragm and the valve to close said valve when the diaphragm is held under predetermined pressure in the chamber and to open said valve when said predetermined pressure, and means to conduct expanded fuel from said expanding means into said chamber.

7.'In a carburetor, an expansion chamber, a heat exchanger mechanism in said chamber, means to.introduce the fuel to said heat exchanger means, a pressure regulator chamber communicating with the expansion chamber so as to have equalized pressure in both chambers, a pressure actuated mechanism in said pressure regulator chamber, a closure element connected to said pressure actuated mechanism and extended through the wall of said pressure regulator chamber to the intakeof said fuel intro ducing means so as to close and open said intake in accordance with the positions of said pressure actuated mechanism, said pressure actuated mechanism being adiustable to be held in intake closing position by a predetermined pressure in said chamber, andmeans to move said pressure actuated mechanism to intake closing position when the pressure in said regulator chamber is below said predetermined pressure. v

8. In a carburetor, the combination with the expansion chamber of the carburetor and the means to convey the fuel to the expansion chamber, of a separate chamber containing the same the pressure in said chamber is reduced below pressure as that of the expanded gases in the expansion chamber, an intake in a wall and outside of the separate chamber leading to said fuel conveying means, a slidable valve member in the separate chamber extended into the wall of the separate chamber to cover said intake, a

diaphragm in the separate chamber, means to' urge the diaphragm into the space of the separate chamber by a predetermined force, said diaphragm being so located in said separate chamber that the gas pressure in said separate chamber counteracts said urging means at said predetermined pressure, and means of connection between said valve member and said diaphragm to hold said valve member in intake closing position when the pressure in said separat chamber is suiiicient to resist said urging means.

9. In a pressure regulator for carburetors, a fuel expansion means for the carburetor, a separate fuel intake regulator chamber, a fuel passage leading in a wall and outside of said regulator chamber into said expansion means, a valve member slidably guided within said chamber and into said wall so as to obstruct said fuel passage in closed position, a diaphragm in said regulator chamber, resilient means to hold said diaphragm at a predetermined tension against the pressure in said chamber, a connection between said diaphragm and said valve member to hold the valve member in passage obstructing position until the pressure in said regulator chamber is insufl'icient -to counteract the predetermined tension of said resilient means.

10. A discharge mechanism for a gas carburetor, comprising a discharge orifice, a valve for covering said orifice, resilient means to hold said valve seated on the-orifice in a substantially balanced closing position, resilient means to unbalance said first resilient means so as to keep the valve open to a predetermined discharge opening, and means to automatically seat said valve against the action of said second resilient means when the engine is not running.

11. A discharge mechanism fora carburetor, comprising a discharge orifice, a valve adapted to be seated on said orifice, a diaphragm actuated lever to regulate the moving of said valve away from the orifice, means to connect said diaphragm to the suction action of the carburetor mixing chamber, means to force the lever into valve closing position, and a second diaphragm actuated by the manifold suction of the engine to relieve the valve closing action of said forcing means from said lever when the engine is runmug.

12. A discharge mechanism for carburetors, comprising a discharge orifice, avalve for the discharge orifice, a diaphragm actuated by the suction of the carburetor mixing chamber, means of connection between the valve and the diaphragm for opening said valve in accordance with the suction in said mixing chamber, means to hold the diaphragm and said means of connection in valve closing position, and suction actuated means to release said holding means when the engine is in operation. 13. In a carburetor, a fuel -a valve to cover said orifice, and means to control said valve. comprising, a pair of spaced diaphragms," the space between the diaphragms communicating with the suction of the mixing chamber of the carburetor, the first diaphragm,

being adapted to be actuated by the suction in the mixing chamber, means of connection between said first diaphragm and the valve for opening the valve by said suction, the second diaphragm being connected to the manifold suction of the engine so as to be actuated thereby, means to normally force the first diaphragm into valve closing position, and means of connection between said forcing means and the second diaphragm to release said forcing means from the first diaphragm when the second diaphragm reacts to a manifold suction.

14. In a carburetor, means to discharge fuel to the mixing chamber of the carburetor, a valve to control the fuel discharge, and a valve control mechanism comprising, a pair of spaced diaphragms, the space between the diaphragms communicating with the suction in the mixing chamber, means connecting one of said diaphragms to said valve so as to open the valve when the diaphragm is subjected to said mixing chamber suction, yieldable means exerting on the first diaphragm a locking force greater than and opposite to the force of the suction on said first diaphragm soas to hold the first diaphragm in valve closing position, the second diaphragm being so related to said yieldable means as to overcome its locking force when subjected to suction, and means to subject said second diaphragm to manifold suction of the engine so as to release the force of said yieldable means from said first diaphragm.

15. A valve control for anism of carburetor, comprising, a pair of spaced diaphragms in the same chamber, the space be-' tween the diaphragms communicating with the discharge suction of the carburetor mixing chamber, a lever extended from said space to connect one of the diaphragms to the discharge mechanism so as to control the discharge from said discharge mechanism, means exerting a yieldable force on said diaphragms so as to hold said first diaphragm and said lever in a dis: charge closing position, and means to conduct the force of the manifold suction to the outside of the second diaphragm so as to release said yieldable force from the first diaphragm and allow opening of the discharge mechanism.

16. A discharge mechanism for carburetors comprising a casing secured in the discharge chamber, a discharge orifice on said casing, a

fuel discharge mechvalve for engagement with said orifice, means to support the valve in a substantially balanced closed position, a valve stem extended from said valve axially into said casin an abutment holder adjustably secured into said casing, an abutmeans and hold the valve open to an opening determined by the position of said abutment.

17. A discharge mechanism for carburetors comprising a casing secured in the discharge chamber, a discharge orifice on said casing, a valve for engagement with saidorifice, means to support the valve in a substantially balanced closed position, a valve stgin extended from said valve axially into said casing, an abutment hold- ""er adjustably secured into said casing, an abut-- ment slidably' held in said holder so as to abut said valve stem, and resiliently yieldable means to urge said abutment against the stem so as to offset thebalance of said valve supporting means and hold the valve open to an opening determined by the position of said abutment, and means automatically to close said valve against the aciralilcgi of said abutment when the engine is not rung. 18. A discharge mechanism for carburetors comprising a casing secured in the discharge chamber, a discharge orifice on said casing, a valve for engagement with said orifice, means to support the valve stem extended from said valve axially into said casing, an abutment holder adjustably secured into said casing, an abutment slidably held in said holder so as to abut said valve stem, resiliently yieldable means to urge said abutment against the stem so as tooffset the balance of said valve supporting means and hold chamber, an intake regulating chamber, a discharge regulating chamber, said expansion chamber and said intake regulating chambers communicating with each other so as to contain xsubstantially equalized pressure, the pressure in said discharge regulating chamber being controlled by the suction at the fuel discharge orifice of the carburetor; a' diaphragm actuated fuel intake control mechanism in said intake regulating chamber including a diaphragm responsive to the pressure in said intake regulating chamber, and an element extending to the outside of said intake regulating chamber to control the fuel intake'of said expansion chamber; and a discharge control mechanism including a diaphragm in said discharge control chamber to operate said discharge control mechanism in accordance with the suction at the discharge orifice.

20. A carburetor comprising an expansion chamber, an intake regulating chamber, a discharge regulating chamber, said expansion chamber and'said intake regulating chamber communicating with each other so as to contain substantially equalized pressure, the pressure in said discharge regulating chamber being controlled by the suction at the fuel discharge orifice of the carburetor; a diaphragm actuated fuel intake control mechanism in said intake regulating chamber including a diaphragm responsive to the pressure in said intake regulating chamher, and an element extending to the outside of said intake regulating chamber to control the fuel intake of said expansion chamber, a discharge control mechanism including a diaphragm in said discharge control chamber to operate said discharge control mechanism in accordance with the suction at the discharge orifice, releasable means to lock said discharge control mechanism in a position to close the discharge orifice, and a second diaphragm in the discharge control chamber acted upon by the manifold suction of the engine so as to release said locking means.

21. A carburetor comprising, an expansion chamber, an intake regulating chamber, a discharge regulating chamber, said expansion chamber and said intake regulating chamber communicating with each other so as to contain substantially equalized pressure, the pressure in said discharge regulating chamber being controlled by the suction at the fuel discharge oriilce of the carburetor; a diaphragm actuated fuel intake control mechanism in said intake re ulating chamber including a diaphragm responsive to the pressure in said intake r ating chamber, and an element extending to the outside of said intake regulating chamber to control the fuel intake of said expansion chamber; a discharge control mechanism including a diaphragm in said discharge control chamber to operate said discharge control mechanism in accordance with the suction at the discharge orifice, releasable means to lock said discharge control mechanism in a position to close the discharge orifice, a second diaphragm in the discharge control chamber acted upon by the manifold suction of the engine so as to release said locking means, a heat exchange member in said expansion chamber, an inlet for the heating medium for said heat exchange member being adjacent to the intake regulating chamber and to the fuel intake of the expansion chamber.

ROBERT L. DICKSON.