Nov.. 5', 1946. - ç. M. BlcKNEl-_L NONICING CARBURETOR Filed June'24, 1943 2,410,564 Patented Nov.y 5, 1946 2,410,564 UNITED "STATES, PATENT 2,410,564 NONICING CARBURETOR . George M. Biokneu, st. Louis, Mo., assignor to Carter Carburetor Corporation, St. Louis, Mo.. a corporation of Delaware _ Application June 24, 1943, _serial No. 492,146 l claim. (ci. vzel-t1) 2 l . This invention relates to carburetors for `in-> - »fold (not shown) and is controued by a but ternal combustion engines and consists particu terñy throttle valve i0 mounted on a shaft il larly in novel meansfor delivering metered fuel on which is secured the usual throttle lever (not to the mixture conduit substantially posterior to` shown) for connection to the accelerator pedal the throttle valve for idling operation, the idling in the driver’s compartment. Adjacent the mix port being positioned so that the lcoolingseiîect‘ ture conduit there is a fuel bowl l2 within which of the vaporizing idling fuel is not transmitted `fuel is maintained at a substantially constant readily to the throttle plate and icing of the level by a ñoat i3 and needle valve mechanism throttle is thereby retarded or prevented. (not shown). ` In modern carburetors, it is conventional to 10 Located in the lower portion of the fuel bowl is provide an idling:l port which is located imme the main metering orifice element l5 communi diately abreast the edge of the throttle valve eating with main mixture passage IS and nozzle when closed so that as the throttle isopened, Il discharging into the smallest of a series of more of the port is exposed directly to engine venturis I8 located in the middle or mixing cham suction and, accordingly, the fuel supplied 15' ber portion of the conduit. A second metering through the port is increased to insure the forma orifice element I9 is located in the lower portion , tion of a combustible mixture with the increas ing quantity of air which passes the throttle. With this location of the idling port, the vapor ofA bowl I2 and Àcommunicates with passages 2t and 2 I, the latter opening into the mixture con duit through a port 22 located substantially pos izing of the idling fuel, particularly. lust after 20 terior to the throttle plate I2. The idling pas starting under low temperature conditions, cools sage is provided with a restricted air bleed open the throttle plate so that ice may form thereon ing 23 and fuel restrictions 26 and 25. Metering which ’may clog the port and otherwise unde oriñce I5 is controlled‘by a _metering pin 28, hav sirably affect the carburetor operation. ' . ing a lower graduated portion extending through If the idling port is located wholly posterior 25 the orifice, and is pinned at its upper end to a' to the throttle, although .an adequate mixture ' lever 29 pivotally supported on top of the fuel ~ may be supplied for dead idling operation, thisl - bowl. The opposite end of lever 29 is connected mixture would become sharply leaner as the by a link 30 to an arm 3| rigid with throttle shaft v throttle is opened because of the decreasing suc II. Orifice element I9 in the idling passage is tion applied thereto accompanied by increasing 30 controlled by a second metering pin 32, having a air flow. The result would be that for. slightly tapered lower portion extending through the ori open positions of the throttle valve, the mixture ñc'e, and is pinned at its upper end to a second supplied by the carburetor -would be too lean to lever 33 pivoted above the top of the fuel bowl. burn in the engine cylinders. „ ' It-is an object of the present invention to pro vide 'an idling system which discharges sum- - ciently beyond the throttle plate to eliminate . The inner end of this lever isV connected by a link 34 to throttle arm 3|. , In operation, when the throttle plate is in the fully closed position, as in Fig. 1, engine suction is applied to idling port 22 to draw a rich mixture of fuel and air into the engine. At this time little icing of the throttle as the result of vaporization of the idling fuel and provided with means to increase the supply of idling fuel as the throttle 40 or no air passes the throttle plate so that main is opened so as to insure thevformation of a nozzle Il is inoperative and metering pin 32 will combustible mixture. be lowered to a position to bring a relatively large This object and other more detailed objects areA portion thereof into the metering orifice so as attained substantially by the device illustrated ' to provide just sumcient fuel for idling opera in the accompanying drawing in which: 45 tion. As the throttle is opened slightly, the air Fig. 1 is a vertical sectional view of a carburetor _flow past the throttle and also past nozzle il embodying the invention and showing the throttle increases. but is not yet sufilcient to draw fuel in idling position. from- the main nozzle. To provide for this in Fig. 2 is a similar view but showing the throttle creasing air ñow, metering pin 32 is lifted by link and metering valves in different positions. 50 age 34, 33 to bring a smaller portion of the pin ì The carburetor shown has a downdraft mixture end- controlled by a butterfly chokev valve l. The outlet portion 3 of the mixture-conduit is flanged into the orifice, thus increasing the effective size thereof and, consequently, the quantity of fuel drawn through the idling system. When the throttle is opened further, toward the position as as at S for attachment to an engine intake mani in Fig.- 2, fuel will start to discharge from the ' conduit including an air inlet horn 6 at the upper ' 9,410,564, . ’ 4 ' main nozzle and. thereafter, most of the fuel a throttle valve in said conduit, a iioat controlled l come from this source and the idling discharge` ‘ fuel chamber, a main fuel passage extending from said fuel chamber and discharging into said mlx-` ture conduit through an opening anterior to said throttle. a metering oriilce communicating with said main fuel passage. a metering pin controlling said main fuel orifice, an independent idling fuel -becomes negligible. `In the throttle position shown in Fig. 2, main metering rod 28 is lifted to a point to bring the smallest or- power step thereon into orifice element I5. During high speed oper ation, a uniformly shaped portion of pin l2 may -be positioned in orifice I8. The independent idling arrangement, as shown. wherein the idling and main _fuel passages com passage extending from said fuel chamber and discharging into said mixture conduit through a port spaced substantially posterior to said municate with the fuel chamber through sep throttle valve when the latter is> in its closed posi tion. the spacing of said idling fuel port from tageous _in connection with the non-icing ar said throttle being s0 arranged that the vapori rangement of the idling fuel port. However. var zation oi' the idling fuel therefrom will take place fous features of the carburetor as shown are 15 wholly beyond said throttle valve to avoid icing arate metering orinces. is particularly advan-` not essential and these may be modified as will occur to those skilled in the art without depart ing from the spirit of the invention and the exclusive `use of all such modifications as come within the scope of the appended claim is con templated. I claim: sage, a stepped metering pin for said metering orifice, and a connection between said last named metering pin and throttle, whereby the supply of 20 idling iuei will gradually increase with the move~ ment oi the throttle toward open position. e _ the same, a metering oriñce in said idling pas « In a carburetor, a mixture conduit. a choke and GEORGE M. BICKNELL.