US2134667A - Carburetor - Google Patents

Description

ocr. 25,. 193s. W, EIBING 2,134,667

GARBURETOR Filed Nov. 6, 1936 3 Sheets-Sheet 2 .Fi-g. .5

52T! Fry.;

CARB URETOR Filed Nov. 6,1936 3 Sheets-Sheet 3 um .o

Eg. l! 4f sa /j .96 "IIIIIIIII gig .97 9.9 I y r. E1n/umm l /VM//m "1 .5e/ff?? A d a- Fig.. J4

@Moc/ms Patentedv Oct.. 25,` 1938 PATENT voF-Flc-r.

cannmm'ron William E. Leibing, Detroit, Mich., assignor to Leibing Automotive Devices, Incorporated, Detroit,l Mich., a corporatonof Nevada Application November 6, 1936,l Serial No. 109,607

21 Claims. (Cl. 261-41) This invention relates to improvements in methods and apparatus for operating internal combustion engines, and more particularly to.

novel methods and means'of carbureting such engines.

Inrpresent day carburetors at `idling speed and at light loads, the fuel fed through the idling jets is not intermingled to any great extent with the'air passing through the'intake conduit, but instead is fed only at `one side in the form of a more or less solid fuel stream while the air is supplied around the entire periphery 'ofv the carburetor.thrott1e. Obviously this results in a poor mixture. Further, it has been found that the butterfly valve normally employed as a throty tie which is always at an acute angie to the axis of the conduit in which it is mounted, will at speeds where the main jets supply the fuel, divert a major portion of the-fuel tov one wall of the conduit. All these factors contribute to an unsatisfactory mixture, such factors being the major causes of ",gassing, wet manifold", unequal distribution Aand power rumble.v

In overcoming the aforesaid disadyantages,it

is a major object of thepres'ent invention to provide a novel carburetor whereinthe fuel mixturefis delivered. concentrically voi' the intake conduit, and'a thorough and complete mixture is obtained at all stages of operation including the idling and light load stages.

It is also a major object of this invention to provide a novel method of setting up the entering air and fuel streams so that the air as orig-- inally introduced is substantially in contact with the manifold walls until a complete mixture has ybeen obtained, this method being found to be of tremendous value in eliminating gassing and insuring uniform distribution with a consequent smooth quiet performance of the engine.

Another object of this invention resides in the provision of a novel method and means for insuring degassing in combination with carbureting means which are of relatively simple character.

'appended claims taken in connection with the accompanying drawings, wherein:

Figure 1 is a cross section of a down draft carburetor embodying my invention' and illustrating in particular the j et for delivering fuel under 5 light loads.

Figure 2 is an elevation of the throttle section fof Figure 1 illustrating the axes for supporting the throttle blades and the connection to the carburetor pump. l

Figure 3 is a section taken on the center line of the throttle section of Figure 1 illustrating the arrangement of the fuel jets andtheir r`e1ation to the throttle blades.

Figure 4l is an elevation of the connecting 15 means for the throttle blades viewed from the right side of Figure 3 with the casing cover shown at the right side of Fig. 3 removed. l

Figure 5 is a section taken on a vertical line passing through the idling jet of Figure 3 and 20 looking toward the right of Figure 3. -Figure 6 is a perspective of one of the throttle blades of a .carburetor enbodying my invention.

\ Figure 'I is a bottom view of the throttle section of Figure 2. 25 Figure 8 is a section of the intake conduit similar tothat shown in Figure 3 illustrating a further preferred embodiment of my invention.

'Figure 9 is a section taken at right angles to the section shown in Figure 8. 30

Figure 10 is a section of a further embodiment of my invention wherein a novel degasser is provided in combination with the carburetor of Figure 1 and means is provided `-`lfor adaptation of the presentv invention to carburetors now inuse.

Figure 11 is an elevationof a part of the device oi Figure 10 taken at right angles to Figure 10 and illustrating a novel manner of assembly of the units embodying my invention.

Figures 12 and' `A 13 illustrate additional modi- .40 iicgtions of the degasserand throttle combina# tion shown in Figure 10.

Figure 14 is a-section of an updraft carburetor illustrating a" method of combination of the degasser of my 'invention with a carburetor em'- 45 ploying a throttle of the butterfly type.

Figure 15 is an elevation of the edge of the throttle of Figure .14 immediately adjacent the conduit leading tothe degasser.` i

Referring to Figures 1 and 3, I have there 50 show n a preferred embodiment of my invention which may be readily, embodied in carburetors now being manufactured and is capable of readyv installation on carburetors now in use.V A portion of a downdrait carburetor is shown at il duit I3, and a float chamber of the usual type generally indicated at F. A throttle housing or section I4 is provided in well known manner and connected to conduit I3 and manifold I5 in the usual manner, a heat insulating gasket. preferably being provided between the manifold end section I4.

In the present invention, the conventional throttle of the buttery type is replaced by a pair of throttle blades I1 mounted to rotate on axes I8 and I9. When the intake is round, the blades are formed with a rounded outer edge. When the intake is rectangular in section or square, the outer edges of the blades are formed accordingly to effect a closure when in closed position. Preferably the throttle section is formed with a conduit having flattened sides as shown in Figure 'I and the throttle blades are shaped to fit. It will be noted that the blades I1 are secured to their axes by screws 2f or similar fastening means, the axes I8 and I9 being formed half round in section and the blades `I1 secured to the upper side thereof whereby the axes do not interferewith the fluid flow over the upper surfaces of the blades I1. Axes I8 and I9 are so disposed in conduit I3 that they are each equidistant from thecenter of the conduit.

It will be noted that the blade construction described closes and opens the conduit simultaneously at each side wall and in the center, thereby giving a three point' control of the conduit as a closure along three lines.

Each blade I1 is formed with a half round notch 22 and a half cup 23 on its inner edge as shown in Figure 6, the notches 22 cooperating to form an aperture 2l open when the blades are in closed position as shown in Figure 5, and the half cups 23 cooperating to form a closed cup '25' when the blades I1 are in closed position as shown in Figure 1.

Housing I4 is formed with a rib 26 extending thereacross and preferably of stream-line shape as shown in Figures 1 and 5. Rib 26 is formed with a conduit 21 connecting with a fuel conduit I6 preferably connected to the float chamber of the carburetor and opening into jets 28 and 29 that may be termed auxiliary jets. 'Ihe opening into jet 29 is unmetered, whllethe opening into jet 28 is preferably metered by a needle valve 3l capable of adjustment by screw 32 in a-manner well known in the art.

It will be noted that tube 28 is of less diameter than aperture 24 through which it projects when blades I1 are in closed position as shown in Figure 5, and tube 29 is of a'size and length to be entirely enclosed within cup 25 formed when blades I1 are in closed position as shown in Figure 1.

Assuming the device to be assembled with an engine and the engine to be running with the blades I1 in closed position as shown in Figures 1 and 5, a very low pressure equal to the pressure in the intake, manifold of the engine will be present on the engine side of the blades I1. Remembering that the aperture 24 is somewhat larger than jet 28, a small amount of air at extremely high velocity will be drawn around the end of jet 28. Since jet 28 is directly in the low pressure area, it is subject to both the kinetic energy developed by the injector action of the incoming air around the jet and to the low pressure existing on the engine side as downstream side of the blade I1. Thus a suction of great magnitude is effective on the engine end of jet 28.

` with the usual venturi I2,` main fuel jet I2', con- As previously pointed out, fuel is delivered from conduit I8 to conduit 21 and thence to jet 28. Were a solid column of fuel brought to jet 28, it would be impossible to adjust valve 3| satisfactorily due to the extremely low pressure effective at the lower end of jet 28. Therefore other means must be employed.

As previously pointed out, as long as blades I1 are closed or nearly closed, cup 25 is formed (Figure 1) the mouth or open side of cup 25 being toward the atmospheric side of blades I1. Jet 29, having its free end Within cup 25 on the upstream side of the throttle is therefore exposed to air at atmospheric pressure whenever blades I1 are closed and is free to conduct air into conj duit 21. By properly sizing jet 29 and conduit 21, any desired amount of air can be drawn into conduit 21 through jet 29 to obtain a desired air-fuel ratio. Adjusting screw 32 therefore permits both air and fuel to be drawn from conduit 21 through jet 28 and the extreme sensitiveness of the above mentioned solid column of fuel is eliminated.

A further difficult problem in carburetion has always been the progressive movement of the throttle away from the fully closed position. Any movement in this direction immediately requires additional fuel. Since the pressures within the manifold are rapidly rising, a material problem arises in the provision of such additional fuel. During this time the main jets in the carburetor are useless as they have not yet started to function.

In describing the action of blades I1 when they begin to open, let it be assumed that the engine is idling with blades I1 fully closed and the screw 32 to be correctly adjusted to provide the correct air-fuel ratio. The action of blades I1 in correcting the mixture as the flows fall off due to higher pressure on the engine side of blades I1 will now be described.

As discussed above, jet 29 has its open end in an area of atmospheric pressure defined by cup 25 when blades I1 are closed, but as the blades are opened, this cup is no longer at atmospheric pressure, but gradually decreases from atmospheric pressure to the pressures equivalent to that in the engine manifold and even below `due to the kinetic energy developed at the end of jet 29 betweenthe opposing ends of blades I1. Therefore by p'oper proportioning thel size of jet 29 to the diameter of `cup 25, it is obviousthat any degree of progression desired may be readily obtained.

It is apparent to any one skilled in the art that with the present device, the point of least delivery of fuel is when jet 29 has its free end subject to atmosphericv pressure where it is free to bleed a maximum amount of air into conduit 21 and to reduce the suction on fuel line I6 thereby, and it is equally apparent that any change from atmospheric pressure to a lower pressure on the jet 29 diminishes the amount of air so bled and therefore increases the actual effective pull on the fuel in fuel line 21. 'I'hus even with a higher pressure in the intake manifold, the fuel fed therein is increased.

This function of jets 28 and 29 is better appreciated when it is considered that modern carburetors have their main jets so designed thatthey supply only approximately 30% to 40% of the fuel at speeds equal to 2000 to 3000 R. P. M. It is therefore apparent that any improvement in atomization and therefore distribution in the manifold, orI any improvement in the method of obtaining the throttle progression is of extreme importance. Further, any improvement in atomization in closed throttle position is of extreme importance to eliminate gassing for it has been repeatedly proved that gassing is'caused primarily by a wet mixture and therefore a wet manifold, the manifold in fact often containing pools of raw fuel which boil out with extreme rapidity under the low pressures caused by de` celeration. This boiling off causes the mixture to become rich to an extent that it cannot be consumed by the engine .and as a consequence, the engine exhausts this obnoxious gas.

As previously explained, blades I1 are allowed to come tightly together at closed throttle when aperture 24 will supply about 90% of the air rel quired by the engine. l'Ihe balance of air neces- -At the same .time an annular ring of air defined by the outer edgesy of the blades is formed in a manner whereby the wet mixture is insulated from the conduit walls until the air and fuel have lbecome a substanially homogeneous colloidal gaseous mixture of fuel particles suspended in air.

The ends of both shafts I8 and I9 as viewed inFigure 4 extend through bearings in housing I4 and are squared, keyed, or otherwise shaped on their outer ends to receive geared segments 36 and 31, so that the blades I1 operate in unison and in opposite directions of rotation. Either shaft I8 or I9 is extended as at 36 for connectionv to the throttle of the engine. The opposite end of either shaft I8 and I9 has a crank 39 keyed thereto, a rod 4I being connected to the crank' and to the conventional carburetor pump.

Tapped hole 42 as shown in Figure 7 is provided for receiving the spark control line. the

'smaller hole 43 connecting hole 42 with the intake conduit at a point immediately above one of blades I1 as shown. in Figures 1 and 5. 'I'his position of hole 42 is in' accordance with the usual spark control connectionto the carburetor throttle whereby under small movement of the blades I1 away from the closed position, the hole 42 is transferred from an atmospheric location to one subject to full engine vacuum so that the operation ofthe sparkcontrol will be correct.

Referring to Figures 8 and 9; a further preferred modified form `of 'throttle valve is there illustrated wherein 'two blades 44 pivoted as shown in Figures 1 and' 5v are formed to provide intheir closed position a truncated conical section 45 open at its lower end as shown .in Figures 8 and 9. Disposed in this section and at a predetermined distance from thev open bottom thereof is a jet 46 which connects with a fuel conduit 41 formed in a stream-lined rib 48 extending across the conduit and controlled by a needle valve 49.

When the throttle blades 44 are in closed position, as shown in Figure 9, by reason of the engine. vacuum being effective on the lower end thereof, a *considerable ow of air is induced through the open cone 45 which, when the needle valve 49 is properly adjusted, draws the correct amount of fuel from jet 46 to provide a correct air fuel ratio for the engine at idling speed. An

adjustable by-pass for additional air is provided at I, a needle valve 52 being provided in connection therewith.

Due to the conical shape of aperture 45, there` .44 but only to a portion thereof as determined by the distance of the end of jet 46 from the upper end of hollow cone '45. As the throttle valve gradually opens, the conical effect of cone 45 is gradually eliminated, and jet 46 becomes exposed to the full vacuum of theuintake manifold, which increases the amount of fuel being drawn through the jet. This increase in the amount of fuel is accompanied by an increase in the quantity oi' air not only through the central opening of the throttle, but also around the outer edges thereof so that the correct air fuel ratio is maintained at all times. Subsequent opening of the throttle 44 'permits the vacuum in the intake manifold to become effective upon the main jet of the carburetor, positioned back in the venturi or adjacent thereto and not shown in Figures 8 and 9 to carry the heavier loads. This 'modification is particularly desirable where it is desired to use only one auxiliary fuel jet.

In this modification, I have shown means whereby the throttle and degasser and all of the modifications thereof illustrated herein may be readily installed in existing 4carburetor in stallatlons. .InFigures 8 and 9, conduit 56 may be a portion of a carburetor from which the original throttle has been removed and containing a fuel supply line to the idling jets of the carburetor. To prevent interference by thel openings 51 for the operating shaft of .the original throttle and to use the original fuel supply jets with my improved device, I provide a sleeve 58 of a diameter to fit snugly within the original carburetor conduit 56 to seal the throttle shaft openings 51. Sleeve 58 has a groove 59 in the wall thereof forming a passage with 4the inner wall of conduit 56 to conduct fuel from the original idling jets of the carburetor to the new jets "of my no vel throttling device. This arrangement eliminates the necessity of providing new fuel supply lines when applying my invention to a standard carburetor since the original lines are utilized.

Itis to be understood that the sleeve arrange- Vment shown in Figures 8 and 9 may be used both with the combined throttle and degasser of this invention and with'the throttling device of the present invention when no degasser is employed.

.Referring to Figures 10 and 11, I have there shown a novel form of degasser for use with the governor and throttle of the present invention. As shown in Figure 10, a cross rib 26 is employed with'a fuel conduit 21', jets 28' and 29', and needle valve 3| similar to parts 26 to 3l of Figure 3. The fuel conduit 21 is connected to a cross conduit 53 leading into a fuel supply conduit 54 controlled by needle valve 55.

The throttle blades 6I, when in closed position, form an aperture 24 and a closed cup 25 as in the governor of Figure 1, and in addition form an aperture 62 which fits closely about a conduit 63. Conduit 63 is connected by a con- 68 is provided in casing 66 to urge diaphragmv'l 61 to the right as shown in Figure 10 with more power than can be developed in the chamber 65 by engine intake pressures. A counter-opposed spring 68, adjustable by means of a screw 1| and a locknut 12, opposes the 'action of spring 68 in a manner whereby at idling, the valve 55 which is connected to diaphragm 61 through a connecting rod 13, is held by the balance of the engine manifold pressure and springs 68 and 69 in a position sufficiently far off its seat to permit satisfactory idling of the engine.

Aperturas 1l are provided in a casing 15, the latter being in threaded engagement with casing 66 to hold diaphragm 61 in the proper position. Casing 15 also serves to support adjustment member 1l.

To appreciate the value of the degasser shown, it must be remembered that a degasser should be rendered effective or ineffective by a very small movement of the throttle 6l as in the order of .010 inch. Prior degassers have always employed mechanical means to multiply this movement, but such mechanical means have not been found satisfactory since it is practically impossible to mechanically multiply, with., accuracy, such small movement of the throttle blade as .010 inch in a commercial carburetor.

In the operation of the degasser shown, assuming the engine to be idling or operating at closed throttle and the device to be correctly adjusted, the throttle substantially seals the upper end of conduit 63 when the throttle blades are in closed position and subjects the entire lower end of the jet to the influence of the engine manifold pressures. The adjustment of springs 68 and 69 will be such that needle valve 55 will be sufficiently far off its seat to permit the passage of fuel necessary to idle the engine. Thus there is no interference with the engine at its idling speed.

If, however, the load conditions tend to drive the engine as for instance when a car is pushing an engine during deceleration or when de-v scending a hill, the engine manifold pressure will fall substantially lower than that at idling. Under such conditions, an undesired amount of fuelfis drawn into the engine intake and results in so-called gassing. With the present device in proper adjustment, as the pressure in the engine manifold falls substantially lower than that at idling, this pressure is communicated through conduits 63 and 6l to the interior of chamber 65 to move diaphragm 61 to the left and closeV needle valve 55, thusvshutting off all fuel flow. No further fuel ow can occur at closed throttle until the manifold pressures again equal those for which the adjustment was made, that is, the manifold pressure at which the engine will idle, which will only be when the speed of the engine again equals idling speed, at which point an even, reliable stream of idling fuel will be passed. y

A further advantage of the present degasser is evident when it is considered that an engine may idle 'at a vacuum of 18 inches, and still may have an open throttle or cracked throttle position that equals 20v inches of mercury. Obviously any balancing feature cannot function correctly when these conditions are present, for when at idling pressures of 18 inches, the device must be on the point of functioning, it is apparent that it will be operated at 20 inches. 'Ihus 20 inches on deceleration must work the device and 20 inches in running condition must not work the device. 1

This situation is cared for by the present device. Assume that the enginev is idling satisfactorily at 18 inches in the manifold and the space between conduit 63 and opening 62 in throttle 6| is closed enough to permit of a 17 inch vacuum in the chamber 65. The springs 68 and 66 are balanced to permit valve 55 to be olf its seat sufciently far to pass the necessary amount of fuel for the engine. Any decrease below 18 inches in the engine manifold will shut the fuel off completely. At the same time if throttle 6| is opened 0.010 of an inch the vacuum within chamber 65 will fall olf from 17 inches to approximately 13 inches, even though the manifold vacuum has increased from 18 to 21 or 22 inches. This is due to the 0.010 inch movement enlarging hole 62 around conduit 63, thereby allowing more air to pass therearound and reducing the effect of the. engine manifold vacuumv on the conduit 63 and the pressure in the chamber 65. Accordingly at cracked and all running throttle positions a proper supply of fuel is permitted to flow by valve 55, while during deceleration when the engine vacuum exceeds the normal idling vacuum and when the throttle valve is closed, the fuel supply is cut off.

Briefly reviewing the operation of the degasser, it will be noted that when the throttle is in closed position, the size of conduit 63 and the size of aperture 62 formed by the closed throttle valve are such that there is no leakage of air past conduit 63 and through aperture 62, the full manifold vacuum being effective upon diaphragm 61 in chamber 65. At this vacuum, springs 68 and 69are adjusted so that they maintain needle valve 55 in open position and permit of flow of fuel to the idling jet 28. Assuming that the car be driving the engine or the engine be decelerated, a manifold vacuum above idling vacuum is created at aperture 62 which vacuum iscommunicated to the interior of chamber 65 to draw diaphragrns 61 to the left and close needle valve 55 to shut off the fuel 110W. 'I'his operation of course occurs when the throttle valve remains in closed position.

Assuming that the throttle valve is moved toward open position and the vacuum in the intake manifold is higher than idling vacuum, aperture 62 will then not be closely fitted about conduit 63 and will permit atmospheric air to flow from the upper side of the throttle through the now enlarged aperture 62. This reduces the effect of the engine intake vacuum upon jet 63 and increases the pressure in chamber 65 to move needlevalve 55 to open position.

It will be noted that-the degasser is exceedingly sensitive to a very slight movement of the throttle during a critical range, this movement of the throttle resulting in a very quick action of the degasser valve so that there is no interruption in fuel supply except when intended. It is therefore apparent that the present invention provides a degasser which operates satisfactorily under all conditions of operation without need of mechanical aid, the degasser being extremely sensitive and responsive to the range of conditions within which it is designed to operate.

In Figure 11, I have shown a preferred method of assembly of the present invention, the method being shown by way of example in connection with the degasser combination. The housing 82 is formed with opposing slots 83 having tapered side walls as shown. The rib 26 of Figure 3 or rim 26' of Figure 10 is formed to carry the jets i finished before they are assembled with the governor. Obviously this effects economies in manufacture-since the ribs wouldbe diicult to maof the throttle immediately below a conduit 16 corresponding to the conduit 83 of Figure 10.

The under edges of the conduit are beveled as shown at 11 to engage the adjacent surface of the throttle. A

Figure 13 discloses a somewhat analogous modification wherein a throttle blade 18 isf shown, one' wing of which is provided with an aperture 19. Disposed immediately above aperture 19 is a conduit 8| the lower portion of which is curved so as to provide a substantially abutting engagement with the upper surface of the throttle. Instead ofV curving conduit 8|, the lower surface thereof maybe cut transversely at an acute angle to the' conduit axis to provide a'surface parallel to and ttlng against the adjacent surface of the throttle when closed.

In Figures 14 and 15, the degasser of my invention is shown as applied to a carburetor ofthe updraft type with the usual throttle valve of the butterfly type. With such types of throttles, it has been difficult to obtain satisfactory operation of the degasser since means hitherto employed has not been suiciently sensitive to the different conditions created `by the throttle during its course of movement, particularly from a fully closed toward open position. While prior devices have attempted to increase the sensitivity of the degasser by mechanical means primarily as by involved systems of levers and linkages, none has proven as satisfactory in actual operation as the present degasser wherein mechanical means are almost entirely eliminated and a very fast action of the degasser is obtained through a predetermined and relatively slight movement of the throttle.

Referring to Figure 14, a carburetor conduit is shown at '84- with a venturi 85, and a buttery valve 86. A fuel supply line 81, preferably leading from the float chamber of the carburetor, has a valve seat 88 therein and'connects with jets 89 and 9| for feeding fuel at idling and light loads. A diaphragm housing is provided at 92, the housing being either cast integral with the carburetor or secured thereto by suitable means. Housing 92 is provided withva cover 93 having apertures 94 leading to the atmosphere, a diaphragm 95 of rubber, .Duprene or similar material being secured therebetween. Springs 96 and 91 are provided on opposite sides of diavalve 99 is mounted on the right side of diaphragm 95, spring 98 being adjustableby a'plug 98 threadedly mounted 'in cover 93. A needle an edge of throttle 88 when closed. The point of connection of conduit |0| is such that when throttle 88 is closed the vacuum above throttle 86 or' the vacuum in the engine manifold is effective upon the right side of diaphragm 95. It will be noted that the connection |02 is at the point where the throttle blade has 'a' maximum movement for apredetermined angle of oscillation. This location contributes to the sensitivity and responsiveness of the degasser.

'I'he springs 96 and 91 areso adjusted that when 4the throttle is closed and the engine is idling, the vacuum in the engine manifold is insumcient to move the diaphragm to the right to close valve 99. When theengine is decelerating vor theA car is driving the. engine as when going down hill, the vacuum in the engine manifold` will be greater than that at idling and diaphragm 95 will move to the right to shut off the fuel supply to jets 89 and 9|. When throttle 88 is opened even to a veryslight degree, connection |02 will be subject to the pressure effective on the lower side of throttle 86 and diaphragm 95 will quickly move to the left to open valve 99 and permit the freeflow of fuel to jets 89 and 9|. The quick response of diaphragm 95 is desirable to prevent an interruption in fuel ow when not desired. l l

To increase the sensitivity of the degasser, the edge of throttle 88 immediately adjacent connection |02 preferably is cut away to form a knife edge |03:` Thus only a very slight movement of `or essential characteristicsithereof.'i The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, vthe scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come Within the meaning and range of equivalency of the claims `are therefore intended to` be embraced therein.

, What is claimed and desired tov be securedby ,Y

United States Letters Patent is: y

l. In a carburetor, va conduit; a venturi in said conduit; a main fuel jet in said venturi; a

"the center of said conduit whereby closing of sai`d conduit along three lines is accomplished, said blades being inclined toward one another and toward the axis of said conduit in a direction with the fluid ow; and an idling jet to introduce fuel at a point along said central line of closure, the inner edges of said blades-being recessed to form, an opening for said idling jet.

2. In a carburetor forran internal combustion engine, a conduit: a venturi in said conduit; a main fuel jet in 'said venturi; a throttle in said conduit downstream of said main jet comprising a plurality of individual blades arranged to meet and effect a closure therebetween substantially along a diameter of said conduit, said blades being pivoted on axes spaced from the conduit walls to effect closing of said conduit along three lines; and a jetto discharge fuel for idling purposes into said conduit at a point substantially midway of said diameter, said blades in closed position deningan aperture surrounding said jet whereby said jet is subject to the intake manifold vacuum of said engine when said throttle is closed.

3. The combination set forth in claim 2 wherein said aperture is of a size to permit a restricted iiowof air around said jet to further increase the flow of fuel therefrom and atomize said fuel.

4. The combination set forth in claim 2 wherein means effective in closed position of said throttle to mix air with said fuel prior to its delivery from said fuel discharge means to aidin the atomization thereof is provided, said means including a second fuel jet positioned upstream of said blades when in closed position and subject to the pressure on the downstream side of said blades when said blades are in open positiOn. f

5. In a carburetor for an internal combustion engine, a conduit; a throttle in said conduit comprising a plurality of blades mounted on individual axes and spaced from one another when in open position to provide lines of closure at apl proximately the center of said conduit and at the sides of said conduit; and a fuel jet positioned approximatelyv in the center of said conduit at said` central line of closure whereby the fuel is discharged and atomized at a point substantially in the center of said conduit, said blades being arranged to close said jet when in closed position; and an idling jet to discharge fuel into said conduit when said blades are in closed position.

6. In a carburetor for an internal combustion engine, a conduit; a throttle in said conduit comprising a plurality of blades arranged to effect a closure along a line passing substantially through the center of said conduit; and a plurality of fuel jets positioned to discharge fuel adjacent said line of closure, one of said jets being positioned to discharge fuel on the downstream side of said throttle when the latter ls in open or closed position, and another of said jets being positioned to be open to the upstream side' of said throttle when the latter is closed whereby itis subject to substantially atmospheric pressure at closed throttle position, the latter jet being transferred from atmospheric pressure to the pressure downstream of said throttle by movement of said throttle toward open pomtion.

7. In a, carburetor for an internal combustion engine, a conduit; a throttle in said conduit comprising a plurality of blades arranged to enect a closure on a line extending substantially through the center of said conduit, each of the contacting edges of said blades comprising a notch and a half-cup section whereby in closed position said blades dene an aperture of predetermined size and a cup opening against the direction of uid flow; a fuel supply line; a jet connected t said line extending into the aperture formed between said blades, and a second jet connected to said line opening into said cup whereby in closed position of said throttle, theV first jet functions to induce a flow of fuel from said fuel supply line and a flow of air from said second jet.

il.l The combination claimed in claim 'l wherein means is provided to close said fuel supply line when said throttle is in closed position and the vacuum in the intake manifold is greater than 'predetermined normal idling vacuum compristhrottle, and when said throttle is cracked open a very slight amount, said orice is subject to a higher pressure by reason of the pressure existlng on the upstream side of said throttle.

9. In a carburetor having a conduit therein connected to the intake manifold of an internal combustion engine; a throttle comprising a plurality of separately pivoted blades spaced from one another when in open position, each of a size to close approximately one-half of said conduit and arranged to engage along a line passing through the center of said conduit; a fuel jet adjacent the closure line of said blades when in closed position whereby the flow of fuel from said jet is metered by said throttle; a fuel supply line to said jet; pressure responsive means to control said fuel supply line, said pressure responsive means being connected to said conduit by a second conduit having an orifice at a point. adjacent the closure line of said blades when the latter are in closed position and arranged to be exposed to the pressure in the intake manifold when the throttle is in closed position, said means being arranged to close the fuel supply line when the throttle is closed and the pressure in said intake manifold is below predetermined normal idling pressure, and to open said fuel supply line when said throttle moves toward open position and said orifice is subjected to higher pressure.

10. In a carburetor having a conduit connected to the intake manifold of an internal combustion engine; a throttle comprising a plurality of separately pivoted blades spaced frm one another and from the sides of said conduit when'in open position, each of a size to close approximately one-half of said conduit and arranged to engage along a line passing through' the center of said conduit whereby closing of said conduit along three lines is accomplished; a fuel jet adjacent .the central closure line of said blades, said blades being notched to form an aperture in closed position permitting ow of fuel from said jet to the downstream side of said blades; a fuel supply line to said jet; pressure responsive means to control said fuel supply line, said pressure responsive means being connected to said conduit at a point adjacent the central closure line of saidblades, said blades being formed to provide an aperture in closed position connecting said pressure responsive means to the engine vacuum and sealing said connection from the pressure upstream of said blades. a

11. In a carburetor for an internal combustion engine, a conduit; a throttle in said conduit; a plurality of fuel jets positioned upstream of said throttle, said throttle being provided with an aperture to connect at least one of said jets to its downstream side when in closed position, said aperture being positioned and of a size to closely fit about said jet when said throttle is in closed position to subject said jet to substantially the full effect of the pressure downstream of said throttle, ,the remaining jet being subjected to the pressure upstream of said throttle when the latter is in closed position.

being positioned and of a size to closely t about said jet when said throttle is closed; and a second jet upstream of said throttle connected to said fuel supply line and positioned to be subject to the pressure on the upstream side of said throttle when the latter is in closed position whereby in closed position of said throttle, said downstream pressure functions to induce a ow of fuel from said supply line and a flowof air from said second jet, both through said first jet. 13. The combination claimed in claim 12 wherein means is provided to close said fuel sup-- ply line when said throttle is in closed position and the vacuum in the intake manifold lof said engine is greater than predetermined idling vacuum comprising a pressure responsive device connected to said passage by a conduit having an orifice at a point immediately adjacent an edge of said throttle when in closed position whereby when said throttle is in closed position, said orifice is subject to the vacuum on the engine side of said throttle and when said 'throttle is cracked open a very slight amount, said orifice is subject to a higher pressure by reason of the pressure existing on the other side of said throttle.

14. In n internal combustion engine, a carburetor ha ng a passage for conveying fuel and air tp the engine; main and idling fuel supply means; a throttle for opening and closing Jsaid passage; means for shutting off the idling fuel supply means when said throttle is at closed position and the engine develops a vacuum in excess of predetermined normal idling vacuum, and for automatically opening said idling fuel supply means when said throttle is opened, said lastmentioned means comprising a pressure responsive device connected to said passage by a conduit having an orice at a point immediately adjacent an edge of said throttle when in closed position whereby when said throttle is in closed position, said orifice is subject to the pressure `on the engine side of said throttle and when said throttle is cracked open a very slight amount, said orifice is subject to a higher pressure 'because of the pressure existing on the other side of said throttle.

15. In combination with a carburetor comprising a conduit and a throttle in said conduit; idling fuel supply means; means whereby said idling fuel supply means is shut off whenever at closed throttle the pressure downstream of said throttle falls below predetermined normal idling or closed throttle pressure, said means comprising pressure responsive means connected to said` carburetor conduit by a conduit having an orice subject to substantially intake manifold vacuum when said throttle is closed and positioned immediately adf valve type; an idling fuel jet adjacent one edge of said throttle whereby in closed and nearly yclosed position the flow of fuel from said jet is meteredby said throttle; an idling fuel supply line to said jet; and pressure responsive means 5 to close said idling fuel supply line, said pressure responsive means being connected to saidvcarburetor conduit by a conduit having an orifice immediately adjacent an edge of said throttle when the latter is in closed position and arranged 10 to be subject to the pressure in said intake when saidthrottle is in closed position, ysaid means being arranged to close said idling fuel supply line when said throttle is closed and at a pressure in said intake less than the predetermined normal 15 idling pressure, and to open said idling fuel supply line as said throttle moves away from closed position and said orifice is thereby subjected to higher pressure.

17. In acarburetor for use with an internal 2o combustion engine, a throttle; means' adjacent an edge of said throttle when in closed position to provide fuel when said engine is idling or operating under light load; means to shut, oif the supply of fuel when said throttle is in closed position 25 and the vacuum downstream from said throttle exceeds that of predetermined normal idling vacuum, and means to connect said shut-off means to said carburetor adjacent an edge of said throttle when in closed position, the adjacent edge of said throttle being formed as a relatively thin section relative to the thickness of the remainder of said throttle to increase the sensitivity of 'said fuel shut-off means.

18. A carburetor for an internall combustion engine comprising a passage for conducting fuel to said engine; a throttle in said passage; a conduit having an orice opening into said passage immediately adjacent an edge of said throttle when in closed position to supply fuel at idling 40 and under light load; means connected to said passage to shut oil' the flow of fuel to said supply means when said passageis closed by said throttle and the engine develops a vacuum in excess of predetermined normal idling vacuum, said throttle being positioned to control said shutoff means and to meter the fuel mixture from said supply conduit.

19. A carburetor for an internal combustion engine comprising a passage for conducting Vfuel to said engine; a throttle in said passage for controlling the iiow of fuel therethrough; a jet to supply fuel at idling and under light loads opening into said 'passage ata point adjacent an edge of said throttle when in closed position to be controlled by said throttle; means connected to said passage by a conduit having an orifice to shut off the flow of fuel to said jet when said passage is closed by said throttle and the engine develops a vacuum in excess of predetermined normal idling vacuum, said orifice being positioned immediately adjacent an edge of said throttle when in closed position so that operation of said means will be dependent upon the position of said throttle.

20. A carburetor for an internal combustion engine comprising a passage for "conducting fuel to said engine; a throttle in said passage for controlling the ow of fuel therethrough; a jet for supplying fuel to said engine at idling and under light load; and means to shut off the fuel supply ,o

ing an orifice at a point immediately adjacent n the downstream lip of saidthrottle when in closed position" whereby operation of said means will be dependent upon the position of said throttle.

21. A carburetor for an internal combustion engine having main'and idling fuel supply means; a passage for conducting fuel to said engine; a throttle for opening and closing said passage; and means for shutting oil* said idling fuel supply means when said throttle is at closed position and the engine develops a vacuum in excess of `predetermined normal idling vacuum and for automatically opening said idling fuel supply means when said throttle opens comprising a pressure responsive device connected to said passage by a. conduit having an orifice at a Apoint closely adjacent a portion of said throttle when in closed position whereby said connection is connected to the engine side of said throttle when said throttle is in closed position, and on movement of said throttle toward open position to create an opening in the order of 0.01 inch, said connection is broken suilcient to render said shut-01T means 10 inoperative.

WILLIAM E. LEIBING.

Images