US2083787A - Combined carburetor and supercharger - Google Patents

Description

June 15, 1937. n.. LEFFLER COMBINED CARBURETOR AND SUPERCHARGER 5 Sheets-Sheet l Filed June l0, 1955 une 15, 1937. L. LEFFLER COMBINED CARBURETOR AND SUPERCHARGER Filed June jlO, 1955 5 Sheets-Sheet 2 `lune l5, 1937. L. LEFFLER ,COMBINED CARBURETOR AND SUPERGHARGER Filed June lO, 1935 5 Sheets-Sheet 3 Patented .lune 15, l??? UNTE@ STAES FTENT @FFME COMBINED CARBURETOR ANDl SUPER- CHARGER Application .lune 10,

9 Claims.

This invention relates to a combined carburetor and supercharger and more particularlyV pertains to a unitary device to atomize, carburet, and combine a hydrocarbon and air in suitable proportions for use as a fuel for internal combustion engines.

One object is to provide a carburetor in which it is possible to thoroughly mix hydrocarbon fuel and air to the end that the molecules of carbon, hydrogen and oxygen lwill be so distributed in the fuel mixture as to produce a combination that will be more completely combustible than it is possible to obtain with the velocity type of oarburetor.

Another object is to provide in a single unit a complete carburetor and super-charger.

Another object is to provide a carburetor unit which can be used on engines of Widely varying size and capacity without change except in capacity of jets and adjustment of air control shutters, thus eliminating the need for building and stocking numerous sizes and types of lcarburetors.

Another object is to provide a carburetor in which the fuel jets are so constructed and capable of being so adjusted as to compensate over the widest possible range for variation in load and duty of the engine on which the carburetor is installed and in which the correct relationm ship between air and fuel is maintained under the greatest variety of load and speed conditions.

Another object is to provide a carburetor that is practically insensitive to change of operating position; that will operate with equal facility at any angle in any plane, vertical or horizontal, upside down or in any location.

Another object is to provide a carburetor that is less sensitive to changes in altitude than the i velocity type of carburetor and in which the correct proportions of fuel to air content of the mixture can be maintained over the greatest possible range.

Another object is to provide a carburetor in which engine vacuum and centrifugal force are combined in promoting the delivery of fuel from the fuel jets to the end that maximum efficiency of fuel delivery may be obtained.

Another object is to provide a carburetor by which it is possible to bring about the delivery of a correct fuel mixture in larger volume under low speed hard pulling conditions of operation than is possible with the velocity type carburetor or with the velocity type carburetor in 1935, serial No. 25,854

(C1. zel-88) combination with the usual form of supercharger.

Another object is to provide a carburetor especially for aeronautical installation in which centrifugal force is employed in the operation of compensating jets in such manner as to preclude water fouling of jets with the resultant forced landings.

Another object is to provide a carburetor that can deliver a correct mixture of fuel and air without regard to speed of the engine to which it is attached.

Another object is to provide a carburetor which practically eliminates the hazard from re due to flooding when idling or standing; in which, when the throttle is closed the supply of fuel is automatically cut off and prevented from leaking and in which the supply of fuel is likewise cut olf and prevented from leaking at the instant that the engine stops.

Various additional objects and features of the invention Will appear and will be more fully understood from the following detailed description of a present preferred embodiment thereof, reference for this purpose being had to the accompanying drawings, in Which:

Fig. 1 is a View of the carburetor as seen in vertical section with parts in elevation.

Fig. 2 is a view in section and elevation as seen on the line 2 2 of Fig. 1.

Fig. 3 is a detail in section and elevation taken on, the line 3 3 of Fig. l.

Fig. 4 is a fragmentary sectional View taken von the line 4 4 of Fig. 3.

Fig. 5 is a view in section and elevation as seen on the line 5 5 of Fig. 1 in the direction indicated by the arrows.

Fig. 6 is a view in elevation as seen in the direction indicated by the arrow 6 in Fig. 1.

Fig. '7 is an enlarged sectional view of a portion ofthe fuel feed jets as seen on the line 7 1 of Fig. 5.

Fig. 8 is a detail in section of one of the fuel feed jets taken on the line 8 8 of Fig. 7.

Fig. 9 is a detail in horizontal section taken on the line 9 9 of Fig. 8.

Referring to the drawings more specifically A indicates generally the carburetor casing which as here shown houses a pair of spaced cylindri cal axially aligned chambers B and C formed respectively With parallel end walls lil-ll and l2 l3 with the adjacent end walls Il and l2 of the chambers spaced apart.

The end walls I0 and ll of the chamber B are united by a cylindrical wall I4 and the Walls l2 and I3 of the chamber C are united by a cylindrical wall I5. The chambers A and B are intercommunicated by a spirally extending passage D which leads from the upper peripheral portion of the chamber B at one side of the vertical diameter thereof, as shown in Fig. 5, and

leads to an intermediate portion of the chamber C, through an opening I6 in the side wall I2 of the latter, as shown in Figs. 1 and 2.

10 Leading from the chamber C tangentially there-V of is a discharge tube E the outer end of which is adapted to be connected to the intake manifold of an internal combustion engine and which tube is equipped with a throttle valve I1 carried on a shaft IB extending through the tube E and fitted with a crank I9 on the outer end thereof; the crank being connected by a link I9 to an arm on a rock shaft 2| leading over the upper portion of the housing of the chamber B and 20 journalled in bearings 22 and 23 formed on the walls of the passage D. The outer end of the rock shaft 2| is fitted with a crank arm 24 adapted to be connected to any suitable manually operated control mechanism.

g5 VExtending axially through the end walls of the chambers B and C is a revoluble shaft journalled in ball bearings 26 and 21 on the outer end walls I3 and I3 of the chambers B and C. The end of the shaft protruding through the end wall I3 of the chamber C is fitted with a pair of separate over-running ball clutches 28 and 29 each of which is tted with a peripherial V-groove 30 for engagement with a driving belt in a usual manner.

'35 One of the clutches is designed to be driven from an engine crank shaft and the other from a second or auxiliary drive such as an electric motor in a manner not necessary to be here shown; the pair of clutches serving as a means 4() for enabling driving of the shaft 25 through either of two separate sources of power and in a fashion whereby the load will be automatically taken up by whichever of the two drives is Ifastest.

Mounted on the shaft 25 within the chamber B is a sleeve 3I on which is carried a plurality of radially extending fuel delivery jets F; there preferably being a series of such jets arranged in a row extending longitudinally of the shaft and sleeve with a plurality of such rows spaced equi-distant apart around the periphery of the sleeve. Each of said jets embodies a tube having an enlarged inner end portion 32 which is inserted into a recess 33 formed in the sleeve 3 i. The bottom wall of each recess 33 is formed with an epening 34 registering with a radial passage 35 formed in the shaft 25 leading to an axially extending passage 36 formed in the end portion of the shaft extending through the chamber B. The passage 36 constitutes a fluid fuel feed conduit for directing fuel to the several jets F from a suitable source of supply.

As here shown the passage communicates with a valve chamber 31 formed in the outer end portion of the shaft 25 in which is arranged a valve 38 which normally rests on a seat formed at the intersection of the passage 3G with the valve chamber 31; the valve 38 being normally7 maintained closed in a manner presently to be described, but being held open during operation of the carburetor.

The outer end portion of the shaft 25 extends through a packing gland G which embodies a packing nutv 3B screwed into a boss 4G formed 75 on a plate 4I carried on the end wall I0 of the chamber B; the gland further embodying a packing material 42 and a crowding ring 43 against which latter the end of the nut 39 abuts. The inner end portion of the nut 39 is formed with annular channels 44 and 45 on its outer end inner peripheries respectively, as particularly shown in Fig. 3, which channels are in open communication with each other through radial passages 43. The inner channel 45 is in cornmunication with the valve chamber 31 through `openings 41 formed in the side wall of the latter,

and connecting with the outer passage 44 through the boss 43 is a fuel feed pipe 43 leading from any suitable source of hydrocarbon fuel supply.

Means are providedfor automatically regulating the extent of opening of the valve 38 relative to the extent of opening of the throttle valve I1, which means is here shown as embodying a reciprocal stem 53 leading through a packing gland 5i on the nut 39 and having its inner end connected to the valve 38 The outer end of the stem 5i! is formed with an annular channel 52 engaged by a yoke 53 on the end of a lever 54 pivoted on a pin 55 carried on a bracket 56 projecting from the boss 40. The upper end of the lever 54 connects through a pivot pin 51 with a slide bar 58 extending through and guided by a pair of spaced lugs 5.9 and 60, and has its inner end abutting against a turnable disk 6I journalled on the boss 40 and slidably contacting the outer face of plate 4I; the bar 53 normally abutting against the plate 6I under the urge of a spring 62 interposed between the lug 59 and a collar 53 on the bar 58.

An arcuate arrangement of spur teeth 64 is formed on the outer margin of the disk EI which teeth mesh with a toothed segment 55 rigidly fixed to the rock shaft 2| wherebyirocking movement of the latter will be imparted to the disk '3l so as to move a cam 66 on the latter in and out ofy engagement with the inner end of the slide bar 58 to effect reciprocal movement of the latter in cooperation with the spring 62 and thereby eifect reciprocal movement of the stem 5i) through the medium of the lever 54.

The jets F are designed to effect delivery of a regulated supply of gasoline or hydrocarbon into the chamber B on rotation of the shaft 25, and for this purpose each of the jets is provided with a compensating valve embodying a ball 61 which normally seats on an adjustable plug 53 screwed into engagement with internal threads formed on the inner end portion 32V of the jet and which plug is forme-d with a central passage 39 normally closed by the ball 61. The ball 61 is normally maintained in its seated position by a spring 10 which bears between the ball and the inner end of an outer tube section 1I carried on the outer end of the inner tube section 32.

Means are provided for varying the extent of Y opening of each of the ball valves (51 in each of the jets of a row of the latte-r which means is here shown as comprising a tubular stern 12 which is mounted on the inner end of the tube 1I andY projects interiorly of the spring 10 with its inner end terminating in spaced relation to the ball 61; the stems 12 in the several jets of a row of the latter being spaced from the balls 61 therein at progressively increasing distances leading from the jet at one end of the row to the jet at the other end thereof, as particularly shown in Fig. 7.

As a further means of varying the fuel discharge capacities of the several jets in each row thereof the tubes 1I are formed of progressively decreasing internal diameters from the tube at one end of the row having the shortest range of valve opening to the tube at the other end of the row having the greatest range of valve opening.

In order to insure the discharge of a thin hollow column of the liquid fuel from the jet F, rather than a solid stream, the outlet orifice I3 of each jet opens laterally thereof in a direction counter to the direction of rotation of the shaft 25, or travel of the jet, and extending into the orifice I3 from the inner end thereof is a metering pin I4 carried on an adjustable plug 'I5 screwed into the forward wall of the jet tube member 1I, as particularly shown in Fig. 8; the outer ends of the pin terminating inwardly from the margin of the orice. The pins 'i4 in the several jets may be of varying diameters relative to the diameters of the discharge orifices 'I3 thus permitting further refined regulation-of the discharge characteristics of each of the several jets.

As a means for augmenting flow of the fuel from the jet orifices the outer end portions of the jets are formed of streamline or tear-drop contour in cross section, as particularly sho-wn in` Fig. 9, with the jet orifice opening through the trailing edge thereof.

It will now be seen that by forming the jet in the manner described the shaft 25 may be equipped with a multiplicity of jets each of which, or any group of which, may have different fuel discharging capacities than the others and whereby a wide range of variation in the quantity of the fuel discharged collectively by the jets on rotation of the shaft 25 may be attained, so that variations in fuel supply will be effected with varying speed of rotation of the shaft 25.

Projecting radially of the shaft 25 intermediate the rows of jets F are blades H which are here shown as supported at their inner ends on the sleeve 3l and have their side and outer end margins proximating but slightly spaced from the inner faces of the end walls lil and II and circumfere-ntial wall I4 of the chamber. Each of the blades H is formed intermediate its ends with a transversely elongated opening 'I6 covered by a screen ll. The openings I5 in the several blades are disposed at different spaced relations from the outer periphery of the sleeve 3l so that the openings of adjacent blades will be off-set or staggered relative to each other.

Mounted on the shaft 25 within the chamber C is a series of radially extending blades I here shown as mounted on a sleeve 'II affixed to the shaft 25 and Which blades have their side and outer end margins proximating but spaced slightly from the inner faces of the end Walls I2 and I3 and the circumferential Wall I5 of the chamber B. Each of the blades I is formed with an opening IB covered with a screen 79, which opening is elongated transversely of the blade and is arranged so that the openings in adjacent blades will be off-set relative to each other.

Formed in the end Wall Ill of the chamber B is an air intake opening J which leads through the end plate 4I and over a portion of which opening the disk I6I extends, whereby on turning of said disk under action of the throttle control rock shaft 2l the extent of the` air intake opening will be automatically varied to regulate the volume of air intake relative to the volume of hydrocarbon fuel fed to the jet F, and relative to the volume of fuel mixture discharged from the chamber C determined in part by the extent of opening of the throttle valve I'I.

When the throttle valve I'I is in its closed position as indicated by the dotted lines a in Fig. 2, the rock shaft 2| Will then be disposed at the starting position of its stroke in which position will then also be positioned to substantially cover the air intake opening J. On initially operating the rock shaft 2| to open the throttle valve I'I the disk 6I is turned to move the cam 66 clear of the slide bar 58 thereby effecting opening of the valve 38 and also of the air intake opening J.

On starting the engine to which the carburetor is applied in the usual fashion one of the clutch disks 28-29 is driven by the engine and at the same time the other clutch disk is driven by a supplemental source of power, such as an electric motor, thereby effecting rotation of the shaft 25 together with the jet and blade element carried thereon.

The shaft 25 is rotated in a direction opposite the direction of opening of the jet orices 13 whereby by reason of the streamline cross sectional contour of the outer end portions of the jets negative pressure is established at the jet orifices which together with centrifugal force generated by rotation of the shaft and also the partial vacuum induced by the engine in the carburetor chambers urges the fuel along the tube and effects discharge thereof from the orifices into the air stream then being moved by the blades I-I projecting between adjacent rows of the jets.

The resultant mixture is advanced by the plate H until it is delivered into the passage D communicating with the secondary or final mixing chamber C into which the mixture is advanced and is there further agitated by the blades I, and finally delivered into the throat formed by the tube E communicating with the intake manifold and then to the cylinders of the engine where the mixture is compressed and combusted and its energy employed in driving the engine in a Well known manner.

By providing the several fan blades with the screened openings portions of the vapors delivered by the jets between any adjacent pair of 1 the blades will be caused to pass successively into the chambers between succeeding pairs of blades which flow will be substantially along a spiral path by reason of the offset arrangement of the screened openings. A thorough agitation and intermixture of the fuel mixture will thus be accomplished.

The several jets operate in progressive stages controlled by the pressure of the springs 7D acting on the ball valves 61 according to variav tions in speed of rotation of the shaft 25. The volume capable of being delivered by each jet is controlled partially by the relative size of the jet orifice 'I3 and the metering pin 14, co-operating with the compensating ball valve B'I and partly by the engine vacuum and centrifugal force due to the speed of rotation; the volume discharged by each jet increasing through the centrifugal force as speed increases until the maximum is reached and the stage is cut out and fio CAD

the next stage cut in. It is manifest however that the several -jets may be designed to operate simultaneously in corresponding fashions but in order to obtain variations in the volume of fuel feed progressively, as engine speed and fuel demand warrants, it is desirable that the jets be designed to operate differently under Varying conditions.

To this end each stage of jets is provided with lthe valve seating springs 10 of different sizes and strength, with light springs on the rst stage and heavier on succeeding stages. Centrifugal force and engine vacuum act on the check valves 61 to lift them from their seats and cause them to continue to lift against the spring pressure; the .succeeding jets coming in in series due to variations in tension of the springs 10. When the speed of rotation is high enough to cut in the first jet of the second stage the springs on the rst stage willfhave been compressed sufficiently so that the ball valve acting on it will seat over the tube 'l2 and thereby cut off the now of fuel through the oriiice of that tube. The same operation progresses through the various stages until only the large passage jets of the last stage are in operation. Relative spring strength and adjustment and relative lengths of the tubes 12 determines the progressive opening and closing of the jets either as speed increases or decreases. The tension of the spring 'l0 of either of the jets is regulated by adjusting the threaded plug 68 in its screw connection with the jet tube section 32.

Complete closure of the throttle I1 instantly cuts off the fuel supply through the action of the valve 38 so there is no objectionable loading while engine is slowing down due to the high vacuum effect of the closed throttle. In this instance the mixture in the fan chambers continues to be agitated and is ready for prompt acceleration Without loading when the throttle is again opened.

While I have shown and described a specic embodiment of my invention it is manifest that various changes may be made inthe parts and their construction and arrangement Without departing from the spirit and scope of the invention and accordingly I do not limit myself to the exact construction shown but may make such changes andmodifications as occasion may require coming within the meaning of the terms of the claims.

I claim:

l. A unitary device to atomize, carburet and combine air and a hydrocarbon in suitable proportions for use as a fuel for internal combustion engines comprising a housing having an air intake opening, an adjustable shutter for controlling low of air through said opening, a hollow shaft in said housing through which a hydrocarbon may be fed, a plurality of radial tube members communicating with the hollow portion of said'shaft, compensating valves in said tube members adapted to regulate the supply of hydrocarbon owing through said tube members, and a plurality of radially 'extending blades carried on said shaft Within said housing.

2. In a combined carburetor and supercharger, a housing having a mixing chamber therein Yformed with an air intake opening, a revoluble hollow shaft extending through said chamber, a series of tubular jets carried by said shaft communicating with the interior of the latter having orifices opening to said chamber in a direction opposite the direction of rotation of said shaft,

said jets being of tear drop contour in cross section with said orifices opening through the trailing edge thereof.

3. In a combined carburetor and supercharger, a housing having a mixing chamber therein formed with an air intake opening, a revoluble hollow shaft extending through said chamber, a series of tubular jets carried by said shaft communicating with the interior of the latter having orifices opening to said chamber in a direction opposite the direction of rotation of said shaft, and fluid control means in said jets for regulating the volumetric iiow of fuel through the several jets relative to each other.

4. In a combined carburetor and supercharger, a housing having a mixing chamber therein formed with an air intake opening, a revoluble hollow shaft extending through said chamber, a series of tubular jets carried by said shaft communicating with the interior of the latter having orices opening to said chamber in a direction opposite the direction of rotation of said shaft, a spring pressed ball valve in eachof said jets for regulating flow of fuel therethrough arranged to be opened under the action of centrifugal force on rotation of said shaft.

5. In a combined carburetor and supercharger, a housing having a mixing chamber therein formed with an air intake opening, a revoluble hollow shaft extending through said chamber, a series of tubular jets carried by said shaft communicating with the interior of the latter having orices opening to said chamber in a direction opposite the direction of rotation of said shaft, a spring pressed ball valve in each of said jets for regulating flow of fuel therethrough arranged to be opened under the action of centrifugal force on rotation of said shaft, and means in said jets for adjusting the extent of opening of said valves.

6. In a combined carburetor and supercharger, a housing having a mixing chamber provided with an air intake opening, a revoluble hollow shaft extending through said chamber, means for directing a supply of hydrocarbon to the interior of said shaft, a series of tubular jets carried by said shaft communicating with the interior of the latter and having orifices opening to said chamber, aplurality of blades carried by said shaft in said chamber, said blades being formed with openings to permit passages of gases and vapors therethrough.

'7. In a combined carburetor and supercharger, a housing having a mixing chamber provided with an air intake opening, a revoluble hollow shaft .extending through said chamber, means for directing a supply of hydrocarbon to the interior of said shaft, a series of tubular jets carried by said shaft communicating with the interior of the latter and having orifices opening to said chamber, a plurality of blades carried by said shaft in said chamber, said blades being formed with openings to permit passage of gases and vapors therethrough, the openings in adjacent of said blades being radially off-set relative to each other.

8. In a combined carburetor and supercharger, a housing having a plurality of mixing chambers with a passage communicating said chambers, one of said chambers having an air intake opening and the other of said chambers having a discharge outlet, a rotary shaft extending through said chambers, a series of blades on said shaft in each of said chambers and means for directing a hydrocarbon through said shaft into the chamber formed with an air intake opening, comprising a series of jets carried by said shaft and projecting between adjacent of said blades.

9. In a combined carburetor and supercharger, a housing having a plurality of mixing chambers With a passage communicating said chambers, one of said chambers having an air intake opening and the other of said chambers having a discharge outlet, a rotary shaft extending through said chambers, a series of blades on said shaft in each of said chambers and means for directing a hydrocarbon through said shaft into the chamber formed with an air intake opening, comprising a series of jets carried by said shaft and projecting between adjacent of said blades, said jets having orifices opening opposite the direction of rotation of said shaft, and the blades in each of said chambers being formed With openings leading therethrough, and screens extending over said blade openings.

LANDRETH LEFFLER.

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