US2116596A - Automatic fuel vaporizer and auxiliary fuel supply for internal combustion engines - Google Patents

Description

AUTOMATIC FUEL VAPORIZER AND AUXILIARY FUEL SUPPLY FOB. INTERNAL COMBUSTION ENGIGINEIS Original Filed Jan. 28, 1932 2. Sheets-Sheet 1 May 10, 1938. I, E, COFIEY 2,116,596

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' AUTOMATIC FUEL JAPORIZER AND AUXILIARY FUEL SUPPLY FOR INTERNAL COMBUSTION ENGIGINES Original Filed'Jan. 28, 1932 2 Sheets-Sheet 2 JVZXITUR JE-ZDPFE? JIQLZENEZKE.

Patented May 10, 1938 x AUTOMATIC FUEL VAPOIHZER AND AUXIL- IABY FUEL SUPPLY FOB INTERNAL COM- BUSTION ENGINES Irven E. Coffey, Pine Lawn, Mo.

Application January 28, 1932, Serial No. 589,436

Renewed January 9, 193'! dclalms.

My invention relates to an improvement in the fuel supply for an internal combustion engine for the initial starting of a cold engine, and applies to the type in which a liquid fuel is vapor- 5 ized or gasifled before entering the engine cylinders.

In the present practice of starting cold engines an electric starting motor is used to rotate the crank shaft and reciprocate the pistons for cre- 1 ating a suction to draw fuel into such cylinders from the carburetor. In order to increase the flow of fuel it is usually the practice to use a choke on the air intake which. functions to increase, to a great extent, the amount of liquid 15 fuel in proportion to the air. Usually this fuel is not properly vaporized in the cold intake mani-' fold and a considerable proportion condenses in.

the manifold. Also, the fuel is in the forni of a liquid vapor instead of gas enters the cylinder. 0 When the' gas becomes ignited and drives the engine to the release of the starting motor, the condensed fuel is drawn into the engine, and as it is commonly necessary to maintain the choke more or less closed until the engine becomes 5 warmed, the fuel enters the cylinders in the form of a vapor instead of a dry gas, which-vapors, especially when gasoline fuel is used, wash the lubricating oil from the cylinder walls and pass by the cylinders, diluting the crank case lubri- 30 eating oil. Attempts have been made to remedy this defect by installation of electric heating elements in the intake manifold but it is necessary to heat a large proportion of air compared with the amount of vaporized fuel; therefore, these 35 heaters are inefficient. Attempts have also been made to have an automatically actuated choke but this also has a disadvantage that it always functions even if through inadvertence the ignition switch is not turned to the closed circuit 40 position, in which case the engine usually becomes iiooded with the condensed fuel.

A main object and feature of my invention is at the same time the starting motor is energized to turn over the engine for starting, to inject an auxiliary supply of fuel, preferably from the carburetor into the intake manifold, and toheat this fuel as it is atomized and vaporized, the heating preferably being done by an electrical heating element. In addition, I provide an auxiliary 50 air supply which functions to carry the fuel which is gasifled by heat, and thus provide a, dry gas with heated air for the initial starting of the engine.

After the engine has been initially started and 55 the starting motor no longer functions, and also i the electrical heat is discontinued, I provide an auxiliary fuel supply with additional air to carry such vaporized and gasliied fuel. This forms a secondary object and feature of my invention.

A third. feature of my invention is the provi- 5 sion of a thermostatic control for the secondary auxiliary supply whereby when the engine becomes sufilciently hot to draw the fuel from the carburetor in a normal manner, the auxiliary fuel supply and the auxiliary air is cut off and maintained in a cut of! condition while the engine is running at its normal operating temperatures. However, the thermostatic control is op erativethat should the engine cool to such an extent as to possibly make the starting difficult, the auxiliary fuel supply will come into operation with the auxiliary air to carry such supply, and on use or the starting motor electrical heat will be supplied to the auxiliary fuel and auxiliary air. In one form of my invention the hot gasified fuel is fed without theauxiliary air direct into the intake manifold.

An important feature of my invention is that if the engine is at a sufiicient temperature to operate directly from the fuel drawn through the carburetor on starting, although the electric heating element will be automatically heated, there will be no auxiliary gas or air supply drawn through the heating device.

The operations of my invention may be accomplished in various forms of appliances which may be installed on engines now in use or may be built into new installations.

In the preferred form of my invention I may employ a piston operating directly as an auxiliary fuel pump, this piston having a diaphragm which is subject to atmospheric air pressure and also to a moderate suction of the engine. With this arrangement the auxiliary fuel and air supply device is placed in the cylinder in which the piston 40 operates in a position to be always in a normal cold position filled with the fuel, the device preferably being arranged at substantially the level of the fuel in the carburetor. A piston or pump plunger operates in this cylinder which is filled with the fuel. A diaphragm is connected to the piston and above the diaphragm there is an auxiliary air connection. The piston carries one element of a needle valve. preferably the seat, the needle being stationary and adjustable. Above 60 the needle valve there is an electrical heating unit, and above this unit a connection to the intake manifold, preferably below the throttle valve. with this arrangement, on energizing the starting motor, the solenoid pulls downwardly on the piston, the action beingto force the liquid fuel below the piston upwardly through the n dle valve and inject this into an auxiliary str 01' air and subject the air and the fuel to the electric heating unit. The dry vaporized gasthus formed passes through the intake manifold to the cylinders of the engine. In this construction, also, I provide a thermostatic control for the auxiliary air, this supply being normally open when the engine is cold, but as the auxiliary air supply becomes heated and the engine heated. the auxiliary supply is shut off. On shutting oil of the air supply the fuel supply through the needle valve is stopped. Therefore, when the engine runs suinciently hot to draw fuel from the carburetor, my device is inoperative to supply auxiliary fuel and auxiliary air, but when the engine is cold and while it is .warming up, first the auxiliary fuel heated to form a dry gas is supplied and then an auxiliary fuel without being heated is supplied, unless the heating circuit is closed. I

In another form of my invention I utilize a piston operating in a cylinder. This piston is normally held in an inoperative position by counterbalanced spring. The piston is under the infiuence of a solenoid which is connected into the starting motor circuit, preferably as a parallel circuit so that on energizing of the starting motor the solenoid is energized to shift the piston. At the same time an electric heating unit also in circuit with the solenoid is energized to provide electrical heat. turning of the engine by the starting motor draws the liquid fuel preferably from the carburetor through a needle valve controlled by and preferably built into the piston. As the fuel passes through this valve, it is atomized and immediately subjected to the hot electrical heating unit. In this case when the engine is cold there is no auxiliary air supply but the hot gasified fuel is injected directly into the intake manifold and mixed with the inflowing air through the carburetor. The secondary fuel supply continues to function after the starting motor circuit is open by the engine operating under its own power unless the suction is sumcient at this stage to close the needle valve.

In the second form of my invention above described in which the liquid fuel is subjected to the electric heating element and thus discharged into the intake manifold as the hot dry gas, the suction for bringing the fuel to the needle valve is created by the suction in the manifold. An auxiliary air supply is provided but when p the engine is cold this is cut ofi by a thermostatic control. However, as the engine becomes heated, the auxiliary air, which is preferably heated by the exhaust manifold, operates the thermostatic control to open the air supply to the needle valve, which breaks the vacuum and stops the suction of the fuel or materially lessens the flow of such fuel. After the engine is running and the thermostatic control heated, the auxiliary air valves are wide open and will function to add a slight additional amount of air to the intake manifold, but as the suction on this manifold tends to close the needle valve, there is an automatic regulation of this additional air supply. Such supply, however, is insuflicient to interfere with the normal operation of the engine.

A main characteristic in my invention in any of its forms is that the closing of the starting' The suction caused by the the additional fuel supply and at the same time this fuel supply is heated and forms a dry gas. Therefore, the closing of the starting motor switch performs two functions of energizing the starter and providing a heated dry gas for the 5 initial starting of the engine. My invention comprehends that instead of using the starting motor switch to energize the solenoid and the electric heating coil I may use an entirely separate switch devoted solely for this, purpose, or 1. utilize the ignition switch of the ignition circuit.

I also contemplate having the solenoid and the heating circuits either in series or parallel with a common switch, or a separate switch may be utilized for either feature, thus having these 1 circuits independent.

My invention is illustrated in connection with the accompanying drawings, in which:

Fig. l is a diagrammatic illustration of the fuel supply and starting system of the engine with my auxiliary fuel device illustrated in elevation;

Fig. 2 is a vertical section through my auxiliary fuel device;

Fig. 3 is a detail horizontal section on the line 25 3-3 of Fig. 2 in the direction of the arrows;

Fig. 4 is a detail horizontal section on the line 4-4 of Fig. 2 in the direction of the arrows:

Fig. 5 is a diagrammatic illustration of another adaptation of my invention;

Fig. 6 is a vertical section through the alternative form of my invention illustrated in Fig. 5;

Fig. 7 is an enlarged vertical section of the piston, needle valve, and air control;

Fig. 8 is a detail horizontal section on the line 8-8 of Fig. 7 in the direction of the arrows;

Fig. 9 is a detail horizontal section on the line 9-9 of Fig. 7 in the direction of the arrows.

Referring first to the illustration of Fig. l, the engine block with the engine cylinders is indicated by the numeral II, the intake manifold l2, the exhaust manifold by IS, the carburetor by I4 such carburetor being indicated as having a choke valve l5 and a. throttle valve l6, these latter being of conventional type. While the carburetor is illustrated as of the up draft type, my invention applies equally to a down draft type of carburetor.

The starting system indicates a. starting mo tor I1 and a. starting switch l8. This is illustrated as having a bridging piece l9 which connects to the contact points 20 and 2|. The contact 20 is indicated as havinga, lead 22 to the storage battery 23, such being a source of supply, the negative side of this battery being grounded at 24. The contact 2| has a lead 25 to the terminal 26 of the starting motor.

Referring particularly to the device of my invention shown in detail in Figs. 2, 3, and 4, I employ a casing structure 21 which may be attached to the engine block in any suitable manner or, if desired, supported from the carburetor. This has a. cylinder 28 therein which is preferably made of brass. A closure plug 29 is screwed into the lower end of the cylinder and has a packing gasket 30 engaging the case and forming a liquid-tight seal. A fuel supply pipe 3| is connected to a nipple 32 at the lower end of the plug. This plug is provided with a check valve 33, such valve being formed by utilizing a large bore 34. A tube 35 is threaded into this bore and has a valve seat 36 on which a ball check valve 31 is seated. A pin 38 limits the upward movement of this ball. A small bore 75 39 leads through the upper end of the plug into the fuel chamber 40.

The fuel pump comprises a loose fitting, cylinder or plunger 4! preferably having a number of vertical grooves 42. This has a recess 43 at the bottom and is urged upwardly by a compression spring M seated in this recess and bearing on the plug 29. A diaphragm is attached at its periphery to the connecting flanges 46 of the case, the case thus having a lower and an upper section. The center portion of the diaphragm bears on a shoulder ti on a piston or plunger M. A threaded nut 58 threaded on the plug t9 clamps the center portion of the diaphragm and this is held by a lock nut 50. The nut it has a. plurality of outwardly projecting fingers M. The cylinder or plunger M has a fuel duct 52, which duct is carried upwardly by an upwardly extending small iuel tube 53, this arising above the plug 59, and is provided with a valve seat 54 forming a needle valve as hereinunder detailed.

The casing 2'? has a cylindrical upwardly projecting portion 55 with a tube 56 extending there above. This tube has a head 5? in which is threaded the plug 58 to which is connected the stem b3 of the needle til, which forms the needle valve operating in connection with the needle valve seat M. A knurled head ti allows adjustment of the stem and, hence, of the needle in preference to the needle valve seat. A nipple 62 is connected to the tube 5% and to this nipple there is a fuel pipe 63 which leads to the intake manifold M, preferably below the throttle valve indicated it.

The air supply employs an intake air pipe 85 which has a heating coil 6t surrounding the exhaust manifold. This pipe has an open end exposed to atmosphere. A rotary air valve designated by the assembly numeral 67 is constructed in the upwardly projecting portion 555 of the case. This has a cylindrical wall 58, a bottom closure plate 5d, a top plate it, this having a sleeve it through which the stem 59 of the needle extends. The top is provided with a series of ports it which are adapted to register with ports it in the closed top it of the upwardly projecting portion 55 of the case. The side wall 88 is provided with a plurality of circumferential slots is, through which extend stop screws it. These screws limit the rotation of the valve and also support the valve in the upwardly projecting portion 55 of the case.

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The bottom 69 of the valve is provided with an opening ll from which extends upwardly a tube i8,which tube has an inturned flange end l9,there being a small annular opening til between this flange and the tube 53 which carries the seat of the needle valve.

The electrical system employs a solenoid iii, the winding of which is indicated 'as being on the outside of the cylinder 28 in the lower portion of the case 21. An electrical heating coil 82 is mounted in the air valve 61. There is illustrated a terminal 33 which extends through the cylindrical wall 68. The lower end of the heating coil is connected to this terminal at tit and the upper end is connected to the sleeve ii at'85. Thus, the heating coil may rotate with the air valve housing. The thermostatic control is by means of a bi-metallic thermostatic strip 86, which is arranged in the form of a spiral, one end being connected at 81 to the insulated terminal 83 on the outside of the valve 61. The opposite end has an outwardly bent finger 38 which operates between the contact 89 of electric terminal 90, which terminal extends through the wall of the case 21. A stop 81 on this wall limits the movement of the free outer end of the thermostatic strip. Iemploy an electric lead 92 which is illustrated as connected to a selector switch 92' connecting to a source of power and ground.

The solenoid has a first terminal 93 to which the the chamber 40 as the fuel chamber because the device is installed at substantially the level of the fuel in the carburetor so that the fuel seeking its own level will rise'past the check valve 33 and into the fuel duct 52. The arrangement, however, must be such that the needle valve seat 54 is never below the level at which the fuel would rise in the auxiliary fuel device when the liquid seeks its own level. The upper part of the chamher 9'! above the diaphragm-may be considered as the air chamber.

The manner of operation and functioning of my device is substantially as follows:

When the selector switch M is closed, the current flow is by lead 92 to terminal 93, solenoid winding iii, terminal 95, lead 915, terminal 93 to 89 through closed contact 88 to thermostat coil 86 when this is cold, through terminal 84 to heating element 82 and ground at 85. The cur-. rent through thermostat 86 heats and expands this, which, together with the heated air drawn from around the exhaust manifold at 66 through pipe 55 causes the thermostat to actuate the air valve iii and also to open contact at tit.

Presuming the engine is cold, the compression spring it maintains the combination piston and bottom plate til of the rotatable air valve 6?.

When in this position the stem of the needle valve is adjusted so that the needle valve is closed or substantially closed and in this position the ports with liquid fuel.

When the starting switches are actuated to the closed circuit position, a circuitis closed to the starting, motor which rotates the crank shaft and reciprocates the pistons and to the ignition circuit is also closed. At the same instant the solenoid Si is energized and a current is conducted through the bi-metallic thermostatic strips to the heating coil 82, which is designed to substantiallyinstantly become hot. The solenoid exerts an attraction on the cylinder or plunger M which functions as the armature of the solenoid and draws this downwardly, this action also pulling down on the diaphragm, causing this portion of the device to operate as a pump and force the liquid fuel in the chambers til and Q6 upwardly through the liquid duct 52 and through the needle valve at the top of the tube 53 where the fine atomized fuel immediately comes into contact with'the heating coil 82. As the pistons are reciprocating they create a suction in the intake manifold but as the auxiliary fuel pipe 63 is con: nected below the throttle valve, that is, on the carburetor side of such valve, there is but a slight suction. This, however, is suificient to draw atmospheric air through the air pipe 65 into the chamber 91 above the diaphragm. This air engine is started and the starting switch I3 is opened, in which case the solenoid is deenergized, as is also the heating coil. The spring 44 then forces the piston or plunger upwardly but, as above mentioned, when this is in its upper position the needle valve is partly opened. The auxiliary air with a reduced amount of liquid fuel is then drawn by suction through the ports 12 and I3, which are open, and the fuel pipe 63 into the intake manifold. This gas is not automa'ticaliy heated, however. At the same time the engine draws fuel directly from the carburetor and the exhaust manifold becomes heated, and by means of the heating coil 66 heats the air through the pipe 65. As the air becomes heated in the chamber 81 the thermostatic strip 86 is heated and expands so that the free end 88 moves from the contact end 88 of the terminal 80 and abuts against the stop 9i. The further expansion of the thermostatic strip then causes the the engine is still hot and the thermostatic strip 86 still hot, the circuit is broken at 88 and SI,

hence, neither the solenoid nor the heating coil is I energized and no auxiliary fuel fed to the engine.

In the construction illustrated in Figs. 5 through 9, the air valve control device designated generally by the numeral I employs a cylinder IOI at the upper end of which there is a solenoid I02, thewindings being indicated, and outside of this solenoid there is a cover or case I03. A closure head I04 is secured to the top of the case, and

in a large recess I there is threaded a tubularplug I06. This plug has a nipple I01 to which is connected a gasoline feed tube I08, this tube being indicated as connected to the carburetor at the base thereof at I08. A bottom closure H0 is connected to the lower end of the case I03 and connects to the cylinder IOI. A sleeve III is fitted on the lower portion of the cylinder and is retained in position by a ring II2 secured to the lower end of the cylinder IN. A piston II3 (note Fig. '7) slides in the cylinder I 0|. This piston has a downwardly projecting portion II4. A relatively small bore 5 extends upwardly through theportion II 4 of the piston and there is a relatively large bore H6 at the top or at the piston proper. A fixed fuel and air tube III extends through the bores H5 and H6 rising to a considerable height above the piston, and this is retained in place by a screw threaded connection 'I I8 with the lower part of the bore. The tube has a head I I9 with wrench kerfs I and a downwardly extending sleeve I2I.

The air control is by means of a rotatable 75 sleeve I22 which is fitted over the upper end of this strip is secured to-the piston, preferably tov the top. The tube III has a series of ports I30, and the sleeve I22 has ports I3I, these ports being adapted to align for flow of air. The air intake is by means of an air duct I32 through the top I04, there being an air tube I33 connected to this duct, and this air tube has a heating coil I34 wound around the exhaust manifold.

There is an air chamber I35 between the piston and the cover I04.

The piston is provided with counteracting or counterbalaneing springs, there being a lower spring I36 which rests on a washer I31. This washer is connected to a ring I38 on the inside, and on the outside rests on a split ring I39 which fits in an annular groove I40 in the lower end of the cylinder IN. The upper end of the spring bears on the shoulder ill of the piston. Above the piston there is a second spring I42 which at its lower and bears on the cup I24, and its upper end is seated in a recess I43 in the cap or cover I04. It is to be noted that the sleeve I I I is freely rotatable on the lower end of the cylinder IOI and it is provided with a wrench grip head I44 to effect this rotation for a purpose hereinunder detailed. A packing washer I45 fits between the head I44 and the bottom plate H0.

The automatic heating arrangement utilizes a tubular housing designated generally by the numeral I46. This has an uppersection I41 providing a relatively large chamber I48, and this has a screw threaded connection I49 with the sleeve III. A set screw I50 allows clamping together of these parts.

A depending tube I5I is screw threaded and threads into the intake manifold. An end plate I 52 is secured to the depending portion I Si by pins I53, there being spacers I54. This provides a plurality of radial slots I55 for discharging in the intake manifold. A packing gasket I56 is provided outside of the intake manifold. An electric heating coil I5'I has its lower .end I58 connected to the closure member I52, this forming a ground connection. To the upper end there is a lead I56 which is connected to an insulated connector I60 which extends through the wall of the upper section I41. An electric lead I6I extends from this connector I60 and to one end I62 of the solenoid coil. The opposite end of this coil has a lead I63 which is illustrated as'being connected to a lead I64 from the starting motor switch I8 and the connection 26 of the startingmotor I'I. Therefore, when the starting motor switch is closed to energize the starting motor, the solenoid is energized and also the heating coil.

The needle valve construction employs a valve seat I65 which is formed in the' fixed tube II5 adjacent the lower portion of such tube and through this seat extends the needle point I66 on the stem I6'I. This stem is connected to a raised center portion I68 of the end plate I52. The needle may be adjusted as to its seat by loosening the set screw I50 and rotating the sleeve III. As the lower structure I46 is held in a fixed position in the intake manifold and the upper part of the casing having the solenoid is held from rotation by its connection to the fuel supply and auxiliary air supply, the rotation of the sleeve Hi threads the upper part of the housing with the solenoid and the valve seat up and down with reference to the fixed housing I45. An initial adjustmentmay thus be obtained of the needle valve suitable for different engines.

The manner of operation and functioning of the device of Figs. through 9 is as follows:

Normally the ports I30 and E3! in the fixed tube H5 and the rotatable sleeve I22, respectively, are in the closed position when the engine is cold, that is, when the thermostatic strip is in the cold condition. This represents the position on starting the cold engine. The piston is supported on the lower spring. This piston has a relatively loose fit in its cylinder so that the needle valve is but partly open. The sleeve HZ has a fairly close sliding fit in the tubular plug 165.

On closing the starter motor switch the engine is turned over by such starting motor creating a suction in the intake manifold through the carburetor, at the same time the solenoid is energized and elevates the piston i it. This carries the valve seat away from the needle and. opens the needle valve. At the same time the heating coil i5? is energized and becomes hot. The suction of the engine quickly draws the liquid fuel upwardly through the pipe tilt. This liquid fuel flows downwardly through the tube i 95 and past the needle valve where it becomes atomized, and as the liquid fuel is subject to the hot wire coil lfil" the drops of liquid fuel are immediately converted into a gas, which gas in expansion forces its way outwardly through the slots i255 into the intake manifold and is carried with the intake air and any generated gas from the carburetor into the engine. The gas is too rich to be combustible by itself but on mixing with the intake air in the intake manifold develops an explosive mixture in the engine. As soon as the engine is started operating under its fuel, the starting switch is opened, which deenergizes the solenoid and the electric heating coil. In this stage, however, the device will function to meter fuel to the engine. For instance, when the solenoid is deenergized, the piston returns to its normal riding position; this is with the needle valve partly open. With the throttle nearly closed the suc tion on the piston is greater and pulls this down, closing the needle valve to a greater extent, al lowing but little fuel to pass such valve; but when the throttle is opened wide the piston is forced upwardly by the lower spring, thus opening the needle valve to a greater extent and allowing an increased injection of atomized liquid fuel into the intake manifold where it is mixed with the air and fuel vapor from the carburetor.

There is always a certain amount of air suction around the piston, which has a relatively loose fit, so that in all stages of operation there is an air flow through the air intake pipe I33 which has the heating coil I34, and as the air becomes heated, passing around the piston, which heats the thermostatic strip, which functions to obtain a relative rotation of the piston and the sleeve E22 fitting over the tube H5, which action is to open the ports E36 and HI, that is, bringing such ports into registry. In addition, the intake manifold itself becomes heated and the conduction of heat heats the thermostatic strip. Thus, when the engine becomes hot there is an air circulation through the tube I33, the ports IN and W0, and the slightly opened needle valve. This connection to atmosphere operates to break the vacuum in the fuel pipe I08 and, hence, no

fuel is drawn upwardly into the auxiliary fuel supply device when the engine is running normally hot. There is, however, a slight additional metered air supply to that in the intake manifold, for when the throttle is nearly closed the suc-- tion on the piston maintains the needle valve nearly closed due to the increased vacuum in the intake manifold; but when the throttle is opened the vacuum in the manifold is decreased and the piston elevates, opening the needle valve wider, thus allowing a greater inflow of air which has been preheated by the coil I35. Thus the device operates to function as an air metering device for operating the engine under normal conditions. When it is desired to start the engine while hot, the ports I30 and 138 are open so that on closing the starting motor switch, although the solenoid is energized and the heating coil i5? is also energized, there is no liquid fuel drawn through the auxiliary fuel device but only an additional flow of air.

It is believed obvious that my device may be made as an integral part of a carburetor in both forms. The form of Fig. 2 is illustrated as supported by the carburetor but the form of Fig. 6

' could also be mounted on the carburetor for direct connection to the intake manifold. It may of times until the engine is running properly. I

find that a suitable diaphragm may be made from fabric which is impregnated with varnish; this withstands the action of the gasoline.

A characteristic of my invention is that the fuel which is initially supplied in the liquid form becomes immediately converted into a gas which is a dry gas, and expands many times the volume of its form in a liquid, and this gas immediately is taken into the intake manifold where it mixes with the air being taken into the engine. Also,

the additional hot air supplied with the additional fuel forms a dry gas mixture. Therefore, if the engine does not immediately start but this dry gas is pumped through the engine, it will not condense on account of the fuel being in the dry gas state.

Various changes may be made in the details of construction without departing from the spirit or scope of the invention as defined by the appended claims.

I claim:

1. In the methods of supplying fuel to an engine having an electrically operated auxiliary liquid fuel valve, comprising on starting the engine and by the suction of the engine drawing auxiliary liquid fuel, at the same time sucking an auxiliary air supply into intimate contact with the auxiliary liquid fuel, heating both the auxiliary liquid fuel and air to form a dry gas, introducing such dry\gas into the main fuel supply, heating the auxiliary air by the engine heat and after discontinuing the heating of the auxiliary liquid and air, causing the heat of this auxiliary air to stop the flow of the auxiliary air and auxiliary liquid.

2. The methods of supplying auxiliary fuel to J an internal combustion engine during the warmutilizing engine suction to supply an auxiliary fuel and air mixture of substantially uniform proportions to the engine intake during the warm-up period, heating the auxiliary mixture,

and controlling the quantity of auxiliary mixture 5 A supplied and the heat applied thereto in accordance with temperature.

4; The method described in claim 3 in which the priming charge initially supplied upon starting the engine is heated for vaporizing the 10' charge.

IRVEN E. COFFEY.

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