US1739818A - Carburetor - Google Patents

Description

Dec. 17, 1929. E. v. BEALS 739,818

CARBURETOR Filed Aug. 29, 1927 gwuento'u Patented Dec. 17, 1929 EBL V. BEALS, OF BOSTON, MASSACHUSETTS cannuanroa Application filed August 29, 1927. Serial No. 216,264.

This invention relates to charge or mixture forming devices for internal combustion engines and more particularly to devices for forming a combustible mixture from non- 6 readily vaporizable liquid fuel, such as naphtha, kerosene, distillate, and air.

While it is comparatively easy to form suitable mixtures of the non-readily vaporizable liquid fuels and air for use in internal combustion engines operating under constant load conditions, a serious difficulty arises when mixtures of such fuel and air are supplied to engines operating under varying load conditions.

The load conditions of engines employed in automobiles, trucks, tractors and the like vary greatly, and an object of this invention is to produce a device by means of whlch combustible mixtures of such fuels may be. obtained for use in engines operating under varying as well as constant load conditions; a device by means of which efiicient and smokeless operation may be obtained under all load conditions encountered.

A further object of this invention is to produce a device by means of which liquid fuel such as kerosene, naptha, distillate or the like is so prepared that when mixed with the proper amount of air, areadily combustible mixture is formed for use in internal combustion engines operating under widely varying load conditions.

These, as well as other objects which Wlll be readily apparent to those skilled in this par ticular art, I attain by means of the device prises a casing 1, having an air-inlet-port 2 and a mixture-outlet-port 3. Valves 4 and 5 of'the butterfly type are shown for respectively controlling said inlet and outlet.- A Venturi choke tube 6 is shown located within the air and mixture passages and a floatchamber 7 having a constant-level float 8 is also shown.

A tubular member 9 depends from the central portion of the top of the carburetor, through the float-chamber and out through a hole in the bottom thereof, being clamped to the bottom of the float-chamber by a nut 10. Down through this tube 9 extends a heatertube 11 whose upper end is provided centrally with a fuel-exit, which exit is controlled by a needle valve 12 threaded through the top leg 13 of the carburetor, the urpose of this valve being, as usual, to regu ate the outflow of the fuel into the venturi 6. The

upper end of the gasifier-tube 11 is provided with a flange which is seated in a groove in the top member of the carburetor, and this gasifier-tube 11- is anchored in place by means of a nut 14 screwed on its lower end and hav-- ing abutting relation with the lower end of tube 9. The tube 11 is of less diameter than the tube 9, so as to thereby provide an annular air-space between the two tubes. Fuel flows into the interior of the gasifier-tube 11 by means of one or more short tubes 15 fitted into coincident holes in the two tubes.

The lower end of the gasifier-tube 11 is closed by means of a metal plug 16 which is threaded up into an extension 17 of the tube 11, this extension being made of insulating composition and being threaded on the lower end of said tube 11 and being strengthened by a tight exterior band of metal 18. Theplug carries the heater element, which consists of a coiled nichrome wire 19 supported by the plug and within the gasifier-tube 11. This nichrome wire has its upper end connected electrically to the upper end of the central rod 20 which extends up through the plug and is electrically insulated therethrough. A pair of nuts 21 threaded on the lower end of this rod 20 afford a means of clamping the pin 20 to the plug and also one terminal of the circuit to this pin 20. One

end of the resistant element 19 is connected to the upper end of the rod 20 and the other end is electrically connected to the metal plug 16, and this lug 16is provided with a binding-post or c amp-screw 21' connecting the other terminal of the circuit. With this construction, it will be observed that the heater element may be readily removed from the carburetor by merely unscrewing the plug 16; this contributes to ease of assembly and also to cleaning and repairing the heater.

A suificient volume of current is continuously maintained in the circuit to heat the body of fuel in the tube 11 to a pointabove vaporization, so thatpressure will at alltimes, during the running of the engine, be maintained in this tube, with the result that the fuel will be jetted up into the stream of air going to the engine. In this way, the suction pf the engine is not altogether depended upon for delivering fuel into the ingoing stream of air. To get this result, it is necessary that the fueldellvery opening be reduced in area to a considerable degree below that usually employed for spraying cold or slightly-heated liquid fuel into the venturi. The maintaining of a small body of fuel in the gasifiertube (which virtually constitutes a small boiler in my process) at this high temperature causes the fuel as it jets *up'into the venturi to flash immediately into virtually a dry gas, so as to thereby be in an ideal state for thoroughly mixing with thelin'coming stream of air. 0 permit this instant flashing into gas, it is desirable that the inconiing stream of air be heated so as to avoid'condensing the fuel before it goes into a gaseous state device, therefore, operates better with that type of carburetor in which means areiprovitled-for heating the air before carburization. A feature of importance lies in the fact that the gasifier-tube. is built into the body of the carburetor, so that it will be entirely surrounded by the liquid fuel in the float-chainher and thus utilize the tube 9 and the body of the liquid to conserve the heat. The heat is further conserved materially by the interposition of the air-chamber between thetwo tubes 9 and 11. What heat does escape to thetube 9 is transmitted to a considerable degree to the fuel body, thus being utilized to preheat the fuel, rendering it more readily vaporizable.

Throttle-valve 5 (valve 4 being a chokevalve), by means of suitable levers 30 and 31 and link 32, is connected to the stem of needle-valve 12 in such manner that as the throttle is opened and closed the needle-valve will be turned in or out more or less, whereby the effective area of the top opening of heatertube 11 is controlled in accordance with the position of the throttle-valve. A knob 34 is provided in order that normal setting of the needle-valve may be made. 35 is a clamping-bolt for clamping the lever 31 in position on the valve-stem after the normal valvesetting has been obtained.

It has been found in practice that starting of the motor is facilitated if some type of primer for injecting one or two charges of gasoline into the intake manifold opposite the inlet-ports is used. This lightens t e burden on the starter with which the engine is equipped and allows the engine to get under way quickly.

. It has been found that the gasifier is so effective thatit is not necessary to warm up the engine before using the heavy non-readily-va'porizable liquid fuel, such as distillate, The asi-fier provides a mixture which is complete y consumed and which has been found to leave no carbon deposits even when the en gine is operating under widely varying loads.

It will be understod that the essence of the invention hinges on the close cooperation of the flow of electric current with the flow of fuel. If too much current flows, the small heating-chamber becomes filled with gas, which is drawn up in one or two gulps by the engine and then follows a series of coughs. On the other hand, if too little current flows, the fuel is merely atomized, is not all burned, and smoky exhaust follows, with its attending carbon-deposit and inefficiency of the engine; all of which, of course, tends to mitigate against the operation of the engine under varying load conditions. I have illustrated in Fig. 2 a diagram of a wiring system WhichI have found to be eflicient. In this diagram, 36 is an electric generator one of whose terminals is connected by a conductor 37 to one of the terminals of the heater and whose other terminal is connected to ground through a manually-adjustable rheostat 38. The other terminal 21 of the heater is connected to one side of a stora e-battery 39, and the other side of this battery is grounded. At a convenient point in the length of the conductor 37 I provide a grounding-button 40 which is adapted to be momentarily operated to ground the conductor 37 In operation, with the groundingswitch 40 open, current from the generator passes through the heater and thence to ground through the battery, and from this ground back to the rheostat 38, and thence to the generator. The generator, therefore, supplies the current needed for heating the ele- *ment 19 and also recharges the battery 39.

The manually-controlled rheostat 38 enables the current supplied to the heater to be nicely controlled, so as to maintain the engine in efiic'ient operation. In starting, when of course the generator is not in operation, the battery is employed for initially heatin the element 10, this being accomplished y simply grounding the battery current through the grounding-button 40. By observation of the running of the car, the driver can readily set the rheostat to give the best results.

What I claim as new is: h 1. In a carburetor, a float-chamber having a tube depending therethrough, a heater-tube supported at its upper end anddepending through the aforesald tube and provi ed with a fuel-exit at its upper end, means associated directly with the heater-tube for controlling the exit of fuel, and a removable plu closing the lower end of the heater-tube an carrying a heating element extendingup into the tube. 4

2. In a carburetor, a float-chamber having a tube depending therethrough, a heater-tube supported at its upper end and de ending through the aforesaid tube and provi ed with a fuel-exit at its upper end, means associated directly with the heater-tube for controlling the exit of fuel, a metal plug removably attached to the lower end of said heater-tube by insulating means and serving to close the same, an electrical heating-element mounted upon said plug and extending up into said heater-tube, and means whereby said heatingelement issupplied with current.

3. In combination with a float-chamber having a tube extending down into the fuel and through the bottom of the float-chamber a heater-tube extending down through said tube and having its lower end open and carrying a clamping-nut abutting the lower end of the aforesaid tube, and a removable plu closing the lower end of the heater-tube an carrying electrical heating devices extending up into the heater-tube.

4. In a carburetor embodyin a float-chamber having a tube de endin own through the liquid fuel cham 'er'an extending out through the bottom thereof. a heater-tube mounted within said tube and being smaller in diameter than the'same to thereby provide an annular air-chamber between the two tubes,

a fuel-conveying tube extending from the float-chamber through both tubes into the interior of the heater-tubeto continuously convey fuel intotheheater-tube,.and a plug for closing the lower end of the heater-tube, this plug carrying electrical heatin devices, the

eating element of which exten heater-tube.

5. The combination with an ap aratus for making a charge for internal-com ustion engines, said apparatus embodying an electrical heating-element haviiig two terminals, of an upwardly-facing shoulder at the up 0 making a charge for internal-combu'stion engines, said apparatus embodying an electrical eating-element having two terminals of an electrical system for said heating-element embodying a batter grounded at one side and having its other si e' connected to one of the terminals of said heating-element, a generator having one of its terminals grounded through a manually-controlled rheostat and its other terminal connected to a terminal of the heating-element, and a manually-controlled device for temporarily grounding the battery through the heating-element, for the purpose set forth.

7. In a carburetor, a float-chamber having acasing-tube depending therethrough, a heater-tube dependin tube, the upper end 0 this heater-tube being provided with a lateral shoulder engaging'ag r en the casing-tube, this heater-tube being also provided'with a closure-member at its top provided. with a fuel-opening, an adjustable through said casingtube down in position within the casing-tube,

and an electrical heating device in said heater-tube, said heater-tube and casing-tube being provided with openings for putting the interior of the heater-tube in communication withthe fuel in the float-chamber.

In testimony whereof I hereunto aflix my signature.

ERL V. BEALS.

up into said

Images