US2539484A - Vapor removing system for rotary fuel metering devices - Google Patents

Description

Jan- 30, 1951 A. P. scHNAlBLE Erm. 2,539,484

VAPOR REMovING SYSTEM Foa RoTARY FUEL METERING DEVICES ATTo/P/yfv Jan- 30, 1951 A. P. scHNAlBLE Erm. 2,539,484

VAPOR REMOVING SYSTEM FoR ROTARY FUEL METERING EvIcEs Filed April 2, 1945 2 Shees-Sheet 2 //3 :I i //7 59 //.5 EL., Z5

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ATTORNEY Patented Jan. 30, 1951 VAPOR REMOVING SYSTEM FOR ROTARY FUEL METERING DEVICES Albert P. Schnaible and Willard F. Blakeway, South Bend, Ind., assignors to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application April 2, 1945, Serial No. 586,224

7 Claims. (Cl. 15S-36.4)

This invention relates primarily to fuel-feeding devices of that type wherein the fuel supplied to a power plant or engine is measured or metered on the basis of engine speed which may be modified by one or more operating functions or characteristics indicative of mass air flow to the engine, or air consumption. Such adevice is illustrated in the copending application of Frank C. Mock, Serial No. 586,223, filed of even date herewith (common assignee), and now Patent No. 2,531,780 granted Nov. 28, 1950.

In fue1-feeding devices of this type, the fuel is conducted under pressure to a chamber embodying rotating parts which tend to impart a whirling motion to theY fuel in the chamber. Such parts in the device selected for the purposes of illustration in the present, instance comprise a pump rotor which draws fuel into the pump chamber, a fuel valve controlled by a centrifugal governor rotating in synchronism with the engine, and a cup-shaped member connected to the rotor and having a driving connection with the governor and functioning among other things to limit the throw of the governor weights.

In fuel-feeding systems operating on the prin-v ciple of speed metering pumps, vapor elimination from the fuel passing through the pump chamber and to the engine is essential to accurate metering, and accordingly an object of the present invention is to provide a vapor elimination system for speed metering pumps which is highly effective in operation and at the same time tends towards simplicity in overall pump construction.

Another object is to generally improve fuelfeeding devices of the type specified.

The foregoing and other objects and advantages will become apparent in view of the following description taken in conjunction with the drawings, wherein:

Fig. 1 is a schematic diagram of a speed metering pump in accordance with the invention;

Fig. 2 is a section taken substantially on the line 2 2, Figure 1; and

Figure 3 is an enlarged section of part of Figure 1.

Referring to the drawings, a main pump housing I has a portion shaped to define a fuel pump chamber II to which fuel may be supplied from a tank or other suitable source, not shown, through conduit I2. A fuel pump I3 has a rotor I4 formed with a center bore mounting a cam pin I5 and a series of radial slots mounting blades I6. The rotor is supported for rotation in an open sleeve or cage I'l terminating at its opposite ends in rings Ila which cam the blades radially inwardly against the cam pin I5. The right-hand end of the rotor is reduced to provide a drive shaft Ida which has a pinion gear I8 secured thereon to facilitate a driving connection with the power plant or engine to be supplied With fuel. The pump I3 takes fuel from chamber II and forces it under pressure into chamber I9 dened by a wall 20- shown as formed integral with the housing I0 and having portions 20a and 20h which are contoured to receive the rotor cage Il.

An end cap 2| removably secured to the housing I0 supports the sealing and bearing assembly for shaft Ida to which oil may be supplied through duct 22.

The left end of the rotor is rotatable in a stepped bearing and sealing ring 23 mounted in a boss 24 formed integral with the housing or casing I0, a bushing 25 serving to lock the bearing in place. The left end of the rotor is hollow to permit insertion of the cam pin I5, the latter being held against endwise displacement by an abutment member 26 provided with a sealing ring to prevent escape of fue1 from the rotor bore, said member being removably held in place by a snap ring 21.

The pump rotor I4 has a driving connection with a governor assembly which, as will be more fully described hereinafter, is arranged to operate a poppet valve comprising an elongated valve or valve member 28 formed with a reduced stem 28a. The valve member 28 is mounted to slide in a bushing 29 having an attaching flange 29a secured to a flange 30 forming part of the wall of an unmetered fuel chamber to be described, said bushing being formed with a valve seat defining a valve port 3 I.

The reduced portion 28a of the valve stem 28 is encircled by a spring 32 which at its left end abuts a shoulder formed on the valve stem and at its opposite end bears against the inner race of a thrust bearing 33 held in adjusted position by end nut 34, the latter serving to adjust and correlate the governor and poppet valve assemblies.

The governor weights are indicated at 35; they are each secured on a shaft 36 and have formed integrally therewith clutch fingers 3l adapted to engage the thrust bearing 33 and urge the valve 28 toward open position, or to the right as viewed@ in Figure l, with a force depending uponthe speed of rotation and the resulting centrifugal effect of the weights 35. The shafts or pins 36 are anchored in yokes 38 forming part of a' hub 39 carrying the outer races of a bearing assembly 40, the inner races of the bearing assembly being mounted on the bushing 29 and held in place by endnutor collar 4 I.

A cup or cup-shaped member 42 is secured on the left end of the rotor I4 by means of a fitting 43 and'endnutor collar 44;'it functions among other things to reduce turbulence of the fuel in the chamber I9 and to limit the throw of the governor weights under certain conditions, as for instance, when there is no appreciable differential pressure across the metering head diaphragm, to be described. As will be obvious, this cup 1*.0- tates with the pump rotor and governor. A fuel baille or shield 42a is preferably mounted on the bushing 29 adjacent the valve port 3|; it directs fuel radially from the outer periphery of the governor chamber toward the poppet valve outlet port 3l. This baflie coacts with the cup 42 to assist in vapor elimination in a manner to be described, and it also reduces turbulence of the fuel in the region of the poppet valve.

A driving connection between the rotor I4 and governor is provided by means of lugs 45 projecting radially from the ange of the hub 39 and engaging in open slots 46 formed in the edge of the cup 42. This construction tends toward simplicity and it also facilitates assembly.

A governor head diaphragm is indicated at 41, Figure 1; it is clamped between the radial portions or flanges of bushings 48 and 49. Bushing 48 is slidingly mounted in a guide sleeve 50 supported by hub I, while bushing 49 has connected thereto a stem 52 adjustably locked in position by end nut 53. A cable 64 connects at one end with the member 52 and at its opposite end with the stem 28a of valve 28, note Figure 3. A bushing 55 steadies the cable 54, and to stiffen the cable sufficiently to prevent buckling due to idle spring thrust, a relatively light wire spring encircles the cable. An idle spring 51 engages the outer side of the diaphragm bushing 49 and applies predetermined pressure in an opening direction on the poppet valve 28 at low idling speeds to ensure suflicient metering head pressure for idling purposes, said spring being backed by an end plug 58 which is threaded into end cap 59 and is maintained in adjusted position by spring-pressed detent members 69. Since the spring 5l may require delicate adjustment, it

is important that the plug 58 be capable of easy adjustment while at the same time it should be held stable when once set or adjusted; and the detent members function advantageously in this respect.

A by-pass chamber 6I communicates with the fuel-intake chamber II; and controlling passage of fuel from the pressure chamber I9 to the bypass 6I is a relief valve 62 which seats on a valve cage 63 mounted in the upper transverse portion of the wall 20 and provided with ports 63a. The valve has a depending stem carrying a piston member 65 which slides in a vented cylinder 65a, said members 65 and 65a functioning as a dashpot to stabilize the action of the valve 62. A spring 66 is seated in a cup-shaped member 61 secured to the valve 62. A diaphragm 68 of substantially the same mean effective area as the seat of valve 62 is clamped between the member 61 and valve 62 and forms a movable wall of a balancing chamber 10. The spring 66 urges valve 62 onto its seat and allows it to open when the pressure in chamber I9 exceeds the pressure in chamber 19 by some predetermined amount dependent upon the strength of spring 66.

It is important that there be a substantially constant pressure drop across the valve 26, so that the various pressures in the system are balanced; also in fuel-feed systems where an injection nozzle is used, the metering needle is rendered less sensitive to variations in nozzle pressure. In the present instance, a constant drop across the valve 26 is brought about by connecting the balancing chamber 10 through duct or channel 1I, 1Ia with unmetered fuel chamber 12 into which the port 3| discharges fuel. The chamber 10 communicates with by-pass chamber 6I through restricted orifice or bleed 16 to permit complete filling of chamber 10 and to relieve vapor or excess pressure developed in said chamber by engine heat when the engine is stopped.

When the pump is initially placed in operation and suiicientv pressure is built up in the chamber I9 the valve 62 will open. When this valve opens, fuel is admitted to the chamber 6I, and after this chamber lls, fuel will pass through orice 15 into chamber 10. Since this latter chamber is in communication with the unmetered fuel chamber 12, the pressure on the top side of diaphragm 68 will be metering head pressure while that on the lower side of valve 62 will be equivalent to that in the governor chamber I9, and the differential between these chambers 10 and I9 or across the diaphragm and valve assembly 68, 62, and hence the drop across the valve 28 will therefore be maintained at a substantially constant predetermined value as determined by spring A66, irrespective of the volume of fuel delivered by the unit.

The valve indicated at BI, Figure 1, is an idle cut-off valve; it is used to completely cut off flow of fuel to the engine to stop the latter. The valve is provided with a stem 82 and a lever 83. In the position shown, the valve is open and fuel may flow through conduit 89, the latter being provided with a coupling member 65 for attachment of a suitable tube or fuel line leading to a spray nozzle, injection pump, burner ring or the like, depending upon what type of power unit is being supplied with fuel.

It will be noted that the conduit or duct 1l connects with its continuation 1Ia through a valve port 186 controlled by rotary valve 61 mounted on and rotatable with valve stem 82 and cut-off valve 8l. Thus when the idle cutoff valve is closed, valve 81 is likewise closed and communication between the chamber 12 and the chamber 10 is broken. The reason for this is that should the metering head pressure still obtain in chamber 10 after fuel flow is stopped and during further running of the engine due to momentum, the by-pass valve 62 would require so much pressure to unseat it as to produce dangerously high, pressures in the chamber I9.

A metering needle controls a metering orifice 9| denedby a seat or bushing located in the wall of chamber 12 and communicates said chamber with a metered fuel chamber 92, from which the fuel flows to discharge conduit 94. Needle 96 is regulated by an automatic control unit including a bellows 93 mounted in a housing 94 defining a chamber 95 to which charging pressure may be communicated through passage 96. The bellows 93 maybe evacuated to render it responsive to changes in pressure only, temperature compensation being had through a separate control element, subsequently referred to. An exhaust back pressure capsule or bellows 91, of reduced size with respect to the bellows |08, coacts with the latter to effect movement of the needle 90 as a function of manifold pressure modified by a certain increment of exhaust back pressure. The bellows 91 is vented to the atmosphere, since atmospheric pressure may be taken as an index of exhaust back pressure. For a more complete description of this automatic control unit, reference may be had to the copending application of Frank C. Mock, heretofore identified.

A variable pressure regulator control chamber 98 is in pressure communication with the one side of the diaphragm 41 and in restricted fiow communication with the chamber 12 by means of orice or bleed 99. A control orifice is indicated at it communicates chamber 98 with discharge chamber 92 through channels |0| and IOI'. A needle |02 regulates the area of orifice or bleed |00, said needle being adapted for either manual or automatic control, depending upon the type of engine or power plant to `which fuel is being supplied.

Assuming that the fuel-feeding system is to be used to supply fuel to the throttle-controlled airintake passage of van internal combustion engine, metering or feed of fuel is regulated by correlating certain variable factors of engine operation, namely, engine speed or R. P. M., manifold or boost pressure modified by a certain predetermined percentage of exhaust back pressure, for example one-sixth, and manifold temperature, to fulfill the following formula:

Fuel flowmanifold pressure-% back pressure manifold temperature XSPeed and driven thereby. Rotation of the pump rotor I4 causes fuel to be drawn in through conduit I2 from a suitable source of supply, such as a conventional fuel tank, and into the chamber I I, from which it is forced by the rotor blades or varies into the chamber I9. The relief valve 82 is set to maintain the fuel in chamber I9 at a predetermined pressure, over and above the pressure in unmetered fuel chamber 12. When this pressure is exceeded, the excess fuel is by-passed back to the chamber I| through the passage or chamber 6 I.

When the engine is operating, the rotating governor weights and the idle spring 51 tend to open the valve 28 and fuel under pressure is passed through orifice 3| into unmetered fuel chamber 12. The fuel iiows through metering orifice 9| into metered fuel chamber 92 and throug-h conduit 84 to a fuel discharge nozzle for supplying fuel to an internal combustion engine, or burner for a gas turbine or jet propulsion engine'as the case may be. A small portion of the fuel fiows from chamber 12 through destriction 99 into regulator control chamber 98, thence through the variable orifice, |00 into metered fuel chamber 92 and then through conduit 84 to the nozzle along with the fuel flowing through metering orifice 9 It will be apparent that the pressure in the variable pressure regulator control chamber 98 will be of a value intermediate the unmetered fuel pressure in chamber 12 and the metered fuel pressure in chamber 92, and will tend to approach the pressure in chamber 12 as the effective area of orifice |00 is decreased by valve |02 and will tend to approach the pressure in chamber 92 as the effective area of orifice |00 is increased. For a given position of valve |02 the differential between the pressures in chambers 12 and 98 will remain a constant percentage of the differential between the pressures in chambers 12 and 92, the latter differential being the metering differential pressure effective across the metering orifice 9|. As the valve 28 opens or closes the fuel flow to the nozzle will tend to increase or decrease and the governor head and the metering differential will likewise increase or decrease. The governor head, thatis, the differential between the pressures in chambers 12 and 98, is effective on the governor head diaphragm 41 tending to move the diaphragm to the left and tending through cable 54 to move the valve 28 to the left in opposition to the force thereon of the governor weights '35.

The valve 28 will float toward open or closed position until the governor head acting on diaphragm 41 balances the force of the governor weights 35. Since the governor rotates in direct relation to engine` speed, the thrust of the governor weights is proportional to speed squared and therefore the balancing differential across diaphragm 41 is maintained proportional to speed squared and the metering head across the metering orifice 92 is also maintained proportional to speed squared. Assuming that the area of the metering orifice 9| is fixed, then flow therethrough would be proportional to the square root of the-pressure differential thereacross and hence proportional to engine speed. For a constant condition of manifold pressure and exhaust back pressure, theair flow to the engine will vary in direct proportion to the engine speed, and the control mechanism just described will correspondingly vary the quantity of fuel supplied to the engine or burner.

The mass rate of air now to the engine in addition to being dependent upon the engine speed is also dependent upon the manifold orl charging pressure modified by a predetermined increment or portion of the exhaust back pressure. In order to correspondingly vary the fuel fiow with changes in air iiow resulting from changes in manifold pressure or exhaust back pressure, the area of orifice 9| is controlled by the needle 90 and the latter is actuated in direct relation to manifold pressure modified by a predetermined increment of back pressure or atmospheric pressure. Thus as manifold pressure is varied, as by actuation of a throttle valve in the air-intake conduit of an internal-combustion engine or by variation in speed of a supercharger at a given throttle opening, such variations in pressure will be transmitted to the chamber 95 and imposed on the bellows 93. The pressure in this chamber 95 also acts on the back pressure bellows 91 which is internally vented to atmosphere or to the exhaust manifold and therefore modifies the travel of the bellows 93 in direct relation to changes in atmospheric pressure. The travel of the bellows and the contour of the needle are correlated to obtain the desired fuel orifice areas through the metering range.

Variation in the position of needle |02 will result in a given percentage change in the fuel supplied to the engine throughout the range of engine operation. Valve |02 therefore is well suited as a manifold temperature compensating device. For example, a neutral or intermediate control position of needle |02 may be taken at a point where the respective areas of the orifices 99 and |00 are equal and the pressure drops across each orifice are equal. Under. these conditions the difference in pressure between chambers 12 and 98 and hence the differential across diaphragm 41 is represented by the drop across orice 99 and is substantially equal to one-half of the total drop across orifices 99 and |00, the total drop being the metering differential across metering orice 9|. The differential across diaphragm 41 will retain this one-half relationship at all values of the fuel metering differential or metering orice areas. If now at a given governor or engine speed and a given area of metering orifice 9|, the area of orice |00 is increased as by raising the needle |02, thereby reducing the pressure in chamber 98, the differential across diaphragm 41 may, for example, become equal to six-tenths of the metering differential pressure instead of one-half. The differential across diaphragm 41 is then too large for balancing the force of the governor weights on valve 28 and the valve will partially close and decrease the fuel ow until the differential across diaphragm 41 is reduced one-sixth, to its former value, with a corresponding percentage reduction in the metering diierential across the orifice 9|. The quantity of fuel being delivered through orifice 9| to the engine or burner will accordingly be reduced to approximately the square root of vesixths of its former value, and this percentage reduction in flow through orifice 9| will be effective throughout the range of engine speeds and settings of needle |02. On the other hand, if the area of orifice is reduced as by lowering the needle |02, the pressure in chamber 98 will increase and the differential pressure across diaphragm 41 will decrease correspondingly. The

Aweights 35 will open the valve 28 an additional amount to increase the fuel now until the differential pressure across diaphragm 41 is restored to its former value to balance the force of weights 35. This will result in a percentage increase in the fuel ow through metering orice 9|, which percentage enrichment will obtain throughout the range of engine operation. Thus when the area of orifice |00 is at a maximum, the rate of fuel ow will be at a minimum, and when the area of said orifice is at a minimum, the rate of fuel flow will be at a maximum, for any given engine speed and a fixed position of needle |02. The pressure in chamber 98 thus may be selectively varied by needle |02 to accomplish an increase or decrease in the fuel metering differential pressure relative to the differential pressure across the governor head diaphragm, which in turn is maintained in balance with the force of the governor weights 35 by means of the valve 28 which opens or closes to increase or decrease the fuel flow until this balance is established. I

It is important that vapor be completely eliminated from the pressure chamber in which the governor and poppet valve assembly operate. Since fuel in vapor form is lighter than when in the liquid phase, it tends to gather in the central area of the governor chamber (due to the fact that the heavier liquid fuel is thrown outwardly by centrifugal force), where it (the lighter vapor) affects the buoyant action of the fuel on the governor weights and increases the effective throw of the latter, thereby increasing the meteringhead and tending toward a rich fuel/air ratio. If suicient vapor collects to more than ll the spinning cup and the governor chamber, it will pass through the system and result in a lean condition of the fuel/air ratio. Thus, as in other fuel systems, vapor formation tends towards unstable general.

In the present instance, a vapor elimination system is provided which takes advantage of the tendency of the vapor to centrifuge or move towards the central area of the governor chamber. The spinning cup 42 which houses the governor weights 35 is formed with a series of holes or openings |05 in the peripheral and end walls thereof, and the hub member 39 is also preferably formed with a series of openings |08, note Figure 3. The abutment member 26 in the end of the rotor |4 is formed with vapor escape openings I01through which vapor passes and thence through the space around the abutment member to discharge passages |08 formed in the rotor and extending on through the bearing 33 and terminating in an annular collecting chamber |09 formed in the boss 24. A vapor vent channel ||0 communicates the annular chamber |09 with a vapor vent chamber the latter being provided with a float l2 movable vertically in an inverted cup-like guide member ||3 and carrying a valve member |4 slidably on the lower end of a hollow depending stem providedwith a port 5, said valve ||4 controlling vapor discharge passage IIB, which may lead to a fuel tank, not shown, or to some other suitable point such as an air-intake conduit. The guide member ||3 is apertured as at ||1 to prevent entrapment of air or vapor therein.

The venting system operates as follows:

During periods of operation, a continuous flow of liquid fuel and/or vapor occurs from the centra] portion of the governor chamber through ports |01, |08, annular collecting chamber |09 and passage ||0 to the float chamber In the absence of vapor, the liquid fuel entering chamber lls the chamber and the oat valve ||4 closes port ||5. Fuel thereafter supplied to chamber escapes through passage ||1 and restriction ||8 to the by-pass chamber 6| which communicates with the pump inlet chamber Any vapor resulting from low pressures, agitation or other causes which enters or is formed in the chamber I9 will, due to centrifugal action, move inwardly through the holes |05, |06 in the wall of the cup 42 and the hub 39 and also through the space between the forward edge of the cup and said hub; and this vapor will converge around the axis of the governor and valve assembly and thence pass through the holes |01 in the abutment member 26 and outwardly through the channels or vents 08, annular chamber |09 and channel ||0 to the float chamber The baille 42a ensures that only the heavy liquid fuel from the periphery of the governor chamber reaches the valve port 3| and thus facilitates centrifuge of the fuel in the governor chamber.

Normally, when there is little or no vapor or air in the float chamber the valve port ||5 is held closed by the valve ||4; but when vapor or air enters said chamber, it depresses the liquid fuel level, the float drops and the valve ||4 uncovers port H5, permitting the vapor and air to escape back to the fuel tank through conduit H6. As the vapor escapes, liquid fuel entering chamber raises the fuel level therein and moves the oat upwardly to close port I5.

The cupI42 is not essential to effective operation of the venting system; it does however provide a convenient means for limiting the throw oi' the governor weights and lt also has a quies and unsatisfactory operation in cent action on the fuel in the region of the spinning weights.

With a vapor elimination system as herein disclosed, it is practically impossible to completely vapor-lock the pump for pressurizing the fuel, and hence if the system is used on high-altitude aircraft, fuel tank pressurization or boost pump equipment in addition to the pump I4 may not be needed. Vapor-lock in conventional pumps is usually caused by slugs of air being carried around by the Pump vanes, and if these continue to accumulate without being passed off, the pump locks completely or becomes inoperative to pressurlze the fuel. With the present invention, however, air and vapor is discharged on the high pressure side of the pump and does not have a chance to circulate back through the relief valve to the inlet side of the pump.

Obviously, the vapor elimination system will operate in any fuel metering device where the fuel is centrifuged due to a whirling action or movement irrespective of the particular means which causes such movement; hence the inventive concept is not limited to any specific type of fuel-feeding or charge-forming device or parts thereof but only by the scope of the appended claims.

We claim:

1. In a fuel-feeding system for an engine wherein fuel is metered as a function of engine speed, a fuel conduit having a regulating valve therein and a govenror operatively connected to said valve, means for rotating said governor in synchronism with the engine including a member located axially of the conduit and a bearing in which said member is mounted; rotation of the governor imparting a whirling action to the fuel and centrifuging the heavier constituents of the fuel toward theiperiphery of the conduit and the lighter constituents including vapor inwardducting fuel under pressure to said chamber, a a

metering orifice in said conduit, a valve controlling ilow of fuelfrom said chamber to said orifice, a centrifugal governor mounted in said chamber and operatively connected to said valve,

means for rotating said governor in synchronism with the engine, rotation of the governor imparting a whirling action to the fuel and centrifuging the heavier constituents of the f'uel toward the periphery of the conduit and the lighter constituents including vapor inwardly toward the axial portion of the chamber, a vaporcollecting chambex` having a float-controlled valve therein permitting escape of vapor under predetermined pressure from said latter chamber, and a conduit for conducting fuel and entrained vapor from the axial portion of the governor chamber to said vapor-collecting chamber.

3. For use in a fuel-feeding system for an engine wherein fuel is metered as a function of engine speed, a metering device provided with a governor chamber, a fuel pump including a pump rotor mounted in said chamber, a valve controlling flow of fuel from said chamber, a centrifugal governor mounted in said chamber and having an operative connection with said valve,

means providing a driving connection between the rotor and governdr, rotation of the rotor and governor imparting a whirling action to the fuel and centrifuging the heavier constituents of the fuel toward` the periphery of the chamber and the lighter constituents including vapor inwardly toward the axial portion of the chamber, a vapor-collecting chamber, said rotor being provided with an axial passage adapted to receive fuel and entrained Vapor, and a vapor-removing conduit communicating said passage with said vapor-collecting chamber.

4. A pump as claimed in claim 3, wherein said rotor is mounted in a bearing having an annular collecting chamber communicating with said axial passage through ducts formed in the rotor and said vapor-removing conduit communicates at its intake end with said annular chamber.

5. For use in a fuel-feeding system for anfengine wherein fuel is metered as a function of engine speed, a metering device provided with a pressure chamber, a fuel pump including a rotor mounted in said chamber, a valve controlling flow of fuel from said chamber, a centrifugal governor having governor weights mounted in said chamber, said` governor having an operative connection with said valve and a driving connection with said rotor, a cup-shaped member rotatable with and surrounding the governor weights and limiting the throw of the latter, rotation of the rotor and governor imparting a. whirling action to thev fuel and centrifuging the heavier constituents of the fuel toward the periphery of the chamber and the lighter constituents including vapor inwardly toward the axial portion of the chamber, a vapor-collecting chamber, said cup-shaped member having a plurality of holes in the Wall thereof to expedite flow of vapor toward the axis of the governor chamber and said rotor having an axial passage adapted to receive fuel and entrained vapor. and a vapor-removing conduit communicating said axial passage with said vapor-collecting chamber.

6. For use in a fuel-feeding system for an engine wherein fuel is metered as a function of engine speed, a metering device provided with a pressure chamber, a by-pass and a relief valve controlling passage of fuel from the pressure chamber to the by-pass, a. metering orifice downstream of said pressure chamber, a valve port and a fuel valve controlling flow of fuel from the pressure chamber to said orifice through said port, a fuel pump including a rotor mounted in said pressure chamber, a centrifugal governor having governor weights operatively connected to said valve, a baille disposed between the governor and valve port functioning to ldirect the fuel radially of the pressure chamber prior to passing through said port, a cup-shaped member surrounding the governor to limit the throw thereof, said latter member also providing a driving connection between the rotor and governor, rotation of the rotor and governor imparting a whirling action to the fuel and centrifuging the heavier constituents of the fuel toward the periphery oi' the pressure chamber and the lighter constituents including vapor inwardly toward the axial portion of the chamber, a vaporcollecting chamber, a float valve controlling escape of vapor from said latter chamber, a. vapor-removing passage communicating at its inlet with the axial portion of said pressure chamber and at its outlet with the vapor-collecting chamber to conduct fuel and entrained vapor from said pressure chamber` to said vapor-collecting chamber, and a restricted ow passage communicating the vapor-collecting chamber with said by-pass to maintain the liquid fuel in said latter chamber at a predetermined level.

'1. In a fuel feeding system for an engine, a'

fuel conduit having a metering restriction therein, means for creating now of liquid fuel through the conduit, a valve for controlling the rate of ow through said restriction, rotatable governor means in said conduit for controlling said valve, said governor means also acting to impart a whirling action to the fuel during its flow through that portion of the conduit in which the governor means is located, a vapor collecting chamber exterior of said conduit, and a duct having its inlet end located to receive the lighter constituents of the whirling body of fuel and its discharge end communicating with said chamber.

ALBERT P. SCHNAIBLE.

WILLARD F. BLAKEWAY.

12 REFERENCES CITED The following references are of record in the le of this patent# UNITED STATES PATENTS Number Name Date 1,345,895 Segvin July 6, 1920 1,906,334 Rathbun May 2, 1933 2,238,502 Muir et al. Apr. 15, 1941 2,275,355 Finken Mar. 3, 1942 2,368,528 Edwards Jan. 30, 1945 2,368,529 Edwards Jan. 30, 1945 2,368,530 Edwards Jan. 30, 1945 2,412,289 Pugh et al. Dec. 10, 1946 FOREIGN PATENTS Number Country Date 526,988 Great Britain Sept. 30, 1940 630,932 Germany June 9, 1936

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