US2390204A - Combination booster pump - Google Patents

Description

ec. 4, 1945. R. R. cuRTls COMBINATION BOOSTER PUMP Filed May l2, 1944 4 vSheeS--Sheet l T22/'E1 Z 80.551511. Caer/s.

Dec. 4, 1945. R. R. CURTIS 2,390,204

COMBINATION BOOSTER PUMP Filed May l2, 1944 4 Sheets-Shea# 2 Dec. 4, 1945. R R. CUR-ns 2,390,204

COMBI NAT ION BOOSTER PUMP Filed May l2, 1944 4 Sheets-Sheet 3 Dec. 4, 1945. 4R. R. CURTIS 2,590,204

COMBINATION BOOS TER PUMP 19065544 E. 70er/6.

Patented Dec.v 4f 1945 UNITED STATES PATENT OFFICEl COMBINATION BOOSTER PUMP Russell R. Curtis, Dayton,

Pump Company, Dayton, Ohio, a corporation ol' Ohio Ohio, assignor to Curtis Application May 12, 1944, Serial No. 535,257

(Cl. S-11) 16 Claims.

This invention relates to multiple pump assemblies and specifically deals with assemblies having a single prime mover in selective driving relation with a plurality of pumps.

The invention Will hereinafter be specifically described as embodied in electric motor-driven submerged type pumps for airplane fuel systems, but it should be understood that the principles of this invention are broadly applicable to multiple pump assemblies, and especially assemblies hav- .ing a plurality of pumps selectively driven by a line in the fuel tanks tends to gasify and form bubbles of gas and vapor in the fuel lines, it is also desirable to provide a pump which rejects all nonliquid material and only pressures fully liquid material into the fuel. line. Centrifugal type booster pumps have been successfully used for bubble separation, and have been equipped with agitators to actually beat out bubbles of gas and vapor from the liquid fuel. Frequently, however, as, for example, at low altitudes, agitation of the fuel to beat out bubbles is not necessary and it is desirable to pressure fuel from the tanks into the fuel line at relatively high pressures for feeding fuel to the engine when the engine driven fuel pump is not operating. Thus, for example, in starting an airplane engine, the engine-driven fue] pump is idle, or turning only quite slowly, but the engine, to be quickly started, should receive highly pressured fuel. Also, if for any reason theengne-driven fuel pump should fail, highly pressured fuel feed is required for maintenance of operation.

Therefore, according to thisI invention, the combination pump unit is equipped with a positive-displacement type pump as well as a centrifugal bubble-separation type pump. Either pump can be selectively driven from the same prime mover.

The combination pump units of this invention can be equipped with reversible motors which, when operated in one direction drive the positivedisplacement pump and, when operated in the reverse direction, drive the centrifugal type bubbleseparating pump. Reversed roller or ball clutches can be interposed in the drive from the motor to each pump so that each pump will be selectivee 1y driven, depending upon the direction of rotation of the motor. The reversing motor drive can be replaced with a non-reversing motor drive and the pumps can be selectively operated by means of a controlled clutch interposed in the drive between the pumps. This clutch can conveniently be operated by a solenoid.

It is, then, an object of this invention to provide a single unit for separation of bubbles in airplane fuel systems and for pumping airplane fuel l without effecting bubble separation.

Another object of the invention is to provide a combination booster pump unit adapted to be submerged in an airplane fuel tank and containing a centrifugal type bubble-separating pump and a positive-displacement type pump selectively driven by a single electric motor.

A still further object of the invention is to provide a multi-pump and motor unit equipped with `an electric motor, a rotary vane type pump, a

centrifugal type pump, and means selectively connecting each of said pumps for corotation with said motor.

lA further object of the invention isto provide a submerged combination type booster pump adapted to be mounted on the bottom wall of a fuel tank and project into the fuel tank for receiving fuel directly therefrom to selectively pump this fuel by means of a centrifugal type pump, or -by means of a rotary vane type pump.

Another object of the invention is to provide a pump and motor unit having a single inlet, a single outlet, and a plurality of pumps each connecting the inlet with the outlet.

Another object of the inventionis to provide a multi-pump-electric motor unit having a centrifugal type pump arranged to directly receive liquid material from a pond and propel this liquid material to an outlet, and also having a rotary vane type positive-displacement pump receiving liquid from the centrifugal type pump and discharging the liquid to the outlet together with a valve which Yseals ,off communication between the outlet and theA centrifugal pump whenever pressure in the outlet is greater than pressure in the centrifugal pump.

A specific object of the invention is to provide a multi-pump-reversible electric motor unit having reversed one-way drive clutches between each pump and the motor.

Another specific object of the invention is to provide a multi-pump-electrie motor unit having a solenoid-operated clutch controlling driving of the pumps from the motor.

A still further object of the invention is to provide a submerged type booster pump assembly especially adapted for airplane fuel systems which assembly has a scavenging device for discharging liquid leaking past the` seal thereof.

Other and further objects of the invention will be apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which, by way of preferred invention` On the drawings:

Figure 1 is a broken side elevational view, with parts in vertical cross sectionof a combination booster pump according to this inventionmounted on the bottom wall of a tank and projecting into the tank to be submerged therein.

Figure 2 is a transverse horizontal cross-sectional view taken along the line II-II f Figure 1 illustrating the centrifugal pump driving ball clutch.

Figure 3 is a transverse horizontal cross-sectional view taken along the line III-III of Figure 1 illustrating the positive-displacement pump driving ball clutch.

Figure 4 is a transverse horizontal cross-sectional view taken along the line IV-IV of Figure 1.

Figure 5 is a. horizontal transverse cross-sectional view taken along the broken line V-V'of Figure 1.

Figure 6 is a side elevational view, with parts in vertical cross section, of a modifled combination booster pump according to this invention.

Figure 7 is a broken side elevational view, with parts in vertical cross section, of another modified embodiment of combination booster pump according to this invention.

As shown on the drawings:

In Figures 1, 4 and 5, the reference numeral I0 designates generally a combination multipump-electric motor unit according to this invention. The unit I0 has a base plate with apertured mounting bosses ||a around the periphery thereof receiving cap screws I2 therethrough. The cap screws |2, as shown in Figure l, are threaded into a mounting ring |3 on the bottom wall |4 of a tank around anaperture I4a in the bottom wall. The screws I2 pass through the tank wall around the aperture and a gasket (not shown) can be interposed between the base |I and the tank wall to prevent leakage.

The base II has a tapered mouth ||b converging to a large opening ||c at a level below the tank wall |4. This opening llc is closed by a concave cap I5 bolted to the base I I as by means of cap screws |6. The cap I5 has a central boss portion defining a drain outlet closed by a plug I1.

The base II has an opening I Id therethrough in spaced lateral relation from the opening I le for a purpose to be more fully hereinafter described.

Three spaced upstanding portions including a leg I8, a wire conduit tube |9, and a leakage drain tube 20 are provided at spaced intervals around the tapered mouth IIb of the base II and support a centrifugal type pump casing 2| defining a volute chamber. The pump casing 2| has a peripheral discharge conduit-defining portion 2Ia integral with the tube 20 connected to and integral with an enlarged cylindrical casing 22 projecting laterally from the casing 2| and having an integral depending boss portion 22a integrally connected with the base I I around the aperture Hd. The casing 22 has an outer end portion closed by a removable cover 23 secured thereon as by means of cap screws 24 and sealed therewith by means of an O ring 25 carried in the groove 26a of a flange 26 around the casing 22.

The casing 22 also has an upstanding boss portion 22b.

As shown in Figures 4 and 5, a flange |9a is provided to connect the tube or pipe I9 with the casing 2|.

An upstanding conduit-defining portion 2l ining 3| carrying an end cap l. tegral with the casing 2| carries, in spaced relation above the casing 2|, a casing 28 for a rotary vane type pump. The casing 29 has a discharge conduit portion 28a intersecting and integrally connected with the upstanding boss 22b of the casing 22. The rotary vane type pump casing 2l is thus supported from the base by both the upstanding conduit'l 21 on the casing 2| and the upstanding boss 22b on the casing 22.

A reduced neck portion 29 projects upwardly from the top of the casing 29 and is integral with the bottom wall of a cup-shaped casing 3|) having an outturned flange 30a around the open top thereof. Ribs such as 29a can be provided at spaced intervals around the neck 29 to reinforce the neck.

A motor casing 3| is mounted on top of the flange 30a and secured to the flange as by means of cap screws 32.

As shown in Figure 1` a support ring 33 is mounted on the flange 30a and has an upstanding flange portion 33a snugly seated in the cas- 34 of motor structure which includes a side wall 35 carrying the ileld of an electric motor. Through bolts such as 36 extend through the ring 34 and are threaded into the ring 33 to hold the motor assembly together.

An 0 ring 31 is seated in a groove of the flange 30a to act on the ring 33 and prevent leakage from the casing 30 into the motor casing. A second 0 ring 38 is seated in a groove cut around the periphery of the ring 33 acting on the flange 30a and also on the casing 3| to prevent leakage into the motor compartglent.

vThe ring 34 carries a 'earing 39 rotatably supporting thebmotor shaft 40. 'I'his motor shaft 40 carries the armature of the motor.

As shown in Figure 1, the lower end of the tube 20 has a nozzle-like extremity 20a projecting into the slip stream beneath the tank I4 and facing downstream so as to cause a suction pull for scavenging material out of the chamber 4| betweenv the rings 33 and 34. lQlhus any liquid leaking past the seals into chamber 4I will be drained out of the unit. -A

The ring 33 has a thickened central boss portion receiving a stationaryseal ring 42 against an upper shoulder 33h thereof. This stationary seal ring 42 has a periphe al groove 42a around the under face thereof rec ing a resilient gasket 43 covered by a ber washer 44. A retainer collar 45 having radially extending outturned ears such as 45a is secured to the boss portion as by means of cap screws such as 46 and acts on the fiber washer 44 to cause the resilient washer 43 to sealingly connect the seal ring 40 with the boss.

The motor shaft 40 projects freely through the stationary seal ring 42 and also through a rotating seal ring 41 having a top end face in sliding sealing engagement with the bottom end face of the stationary washer 42. A rubber sleeve 4B embraces the rotating seal ring 41 and is held thereon by means of a metal cup 49 spun over a shoulder of the rotating seal ring 41. The sleeve 48 is secured to the shaft 40 as by means of clamping wires 50.

A coupling member 5I depends from the motor shaft 40 in the casing 33 and is secured to the shaft by means of a pin 52. A retainer 53 is seated on top of this coupling 5| and lbottoms a coil spring 54 surrounding the cap 49 and acting on a shoulder of the cap to urge the cap and seal ring 48 against the stationary seal ring 42. The cap 49 has inturned tangs 49a engaging upstanding tabs 53a on the retainer 53 so that the cap will be drivenfrom the coupling l to insure rotation of the seal member 41 with the shaft 40. The retainer 53 has the skirt or side wall thereof overlying the ends of the pin 52 to prevent inadvertent removal of the pin.

The coupling 5I carries a plain bearing 55 rotatably supporting the reduced upper end 56a of a pump shaft 56: This pump shaft 56 extends from the casing 30 containing the couplingA 5l through the casing 28 into the open central portion of the casing 2l. The shaft has a collar 5617 riding on a plain bearing 51 carried in the lower end of the casing 28. A reduced-diameter threaded end portion 56o on the lower end of the shaft 56 projects beyond the bearing 51.

The coupling 5I has superimposed ball clutches 58 and 59 therein. The clutch 58 includes an outer clutch ring 58a keyed by means of key 60 to the coupling 5l and having cam tracks 58h around the inner periphery thereof for balls 58C. When the coupling 5l is driven by the motor shaft 40 in a counterclockwise direction, the cam tracks 5817 will act on the balls 58e to wedge the balls into driving engagement with a collar 6I pinned onto the pump shaft 56 as by means of a pin 62. Thus, counterclockwise rotation of the motor shaft 4|] will cause the clutch 58 to drive the pump shaft 56.

The clutch 59 has anouter clutch ring 59a keyed by means of the same key 60 to the coupling 5I and having cam tracks 59b for the balls 53e. Clockwise rotation of the coupling 5l by the motor shaft 4D drives the clutch ring 59a in a clockwise direction and the cam tracks 59h wedge the balls 59C against the top hub 83a of a pump rotor 63. The rotor 63 includes a bottom hub 63h. The hubs 63a and 63h of the rotor are rotatablymounted in plain bearings 64 and 65 carried by the casing 28. A tube 66 loosely fitting around the shaft 56 permits free rotation of the shaft within the rotor.

Clockwise rotation of the motor shaft 40 will thus cause the ball clutch 59 to engage the hub 63a of the rotor 63 and drive this rotor. Clockwise rotation of the ball clutch 58, on the other hand, will free the clutch from the collar 6l and the pump shaft 56 will not be driven. When the motor shaft 40 is driven in a counterclockwise direction the ball clutch 58 drives the pump shaft 56 and this counterclockwise rotation frees the ball clutch 59 from engagement with the pump rotor 63. Therefore, reversed rotations of the motor shaft 40 will selectively drive the pump shaft 56 or the pump rotor 63.

The clutches 58 and 59 are held in the coupling 5I by means of a cover 51a on the coupling and are separated from each other by means of a partition washer 61.

The casing 28, as best shown in Figure 4, has a pump liner 68 press-fitted therein and defining a pump chamber 68a with inlet ports 68h communicating with the passageway provided by the conduit portion 21, and outlet ports 68o communicating with the passageway provided by the conduit portion 28a. The rotor 63 is eccentrica]- ly mounted in the liner 68 and has radial slots 63C slidably supporting pump Vanes 69 acting cn the inner wall of the liner 68.

When the motor shaft 48 is driven in a clockwise direction the rotor 63 will be driven to cause the Vanes 69 to pump liquid from conduit portion 21 into the conduit duit portion 28a has a relief valve associated therewith adapted to open automatically under portion 28a. The con.

abnormal pressures and discharge materials in the co duit 28a back to the interior of the tank. As sho n in Figures 1 and 4, a spider 28h is formed in a side wall of the conduit 28a and provides a central boss in which the stem 10a of a relief valve 10 slides. This valve 10 has a head 10b on the outside of conduit 28a acting on a seat 28e formed on the outer face of the conduit. Facing material 1l may be carried by the head 10 to act on the seat and provide a seal. A coil spring 12 surrounds the valve stem 10a and is held under compression between the spider 28D and a retainer 13 carried by the valve stem. The spring 12 is effective to urge the valve head 10b againstl the seat 28e. A plug 14 is threaded in the conduit 26a opposite the spider 28h to give access to the interior of the conduit for mounting the spring on the stem 10a.

The casing 2l has a central opening therethrough and a volute chamber 19 surrounds this central opening. An impeller 15 has a central boss portion 15a secured on the threaded end 56e of the shaft 56. Vanes 15b extend radially from the boss portion 15a in spaced relation around the boss portion as shown in Figure 5. These vanes 15b carry a cylindrical collar 15c in spaced radial relation outwardly from the boss portion 15a. This collar 15e has an outturned flange 15d from which depends a plurality of curved impeller` Vanes 15e in spaced peripheral relationship. These impeller Vanes 15e have outer edges in close operating clearance relationwith an inlet ring 16 secured in the bottom end of the casing 2l as by means of cap screws 11. This inlet ring 16 defines an opening 16a above the sump S defined by the tapered mouth I Ib and concave closure cap t5 onthe base l I.

The vanes 15e have inner edges converging from aligned relationship with the wall defining the opening 16a into spaced relation beneath the Vanes 15b. vThe outer edges of the vanes 15e, as explained above, have close operating clearance with the inlet ring 16 and have radially extending portions 15f projecting into an annular opening 18 of the volute chamber 19 provided by the casing 2|. These Vanes 15e and vane portions 15f are effective, when rotated, to centrifugally discharge liquid from the opening 16a into and through the volute chamber 19 to the conduit 21a and casing 22.

Flap valve is pivotally mounted on a ring 8| seated in the casing 22 around the mouth of the conduit 21a. A weak spring 82 acts on the valve 80 to urge the same into position for closing the mouth lof the conduit 21a.

When the impeller 15 is driven, pressure of liquid in the volute chamber 19 will be sufficient to open the flap valve 86 and discharge the liquid under pressure into the casing 22. This casing 22 communicates with the fuel line (not shown) to the engine-driven fuel pump and, for this purpose, has a conduit fitting 83 mounted on the upper end of the boss 22D. This conduit fitting has a spider 83a therein providing a threaded boss 83h receiving, in threaded relation, a bolt 84 passed through a cap 85 closing the opening Hd in the base H. The bolt B4 has a head 84a bottoming the cap 85. The fitting 83 is interchangeable with the cap 85 so that liquids from the casing 22 can be discharged to a conduit inside the tank or a conduit outside of the tank, as desired.

When the motor is operated to drive the motor shaft 40 in a counterclockwise direction the ball clutch 58 will drive the shaft 56 to rotate the impeller 15. counterclockwise movement of the coupling 5l will disengage the ball clutch 59 from the rotor hub 63a. The impeller l15 is effective to centrifugally discharge liquid from the sump S through the volute chamber 19 into the casing 22 for feeding under pressure to the feed conduit supplying the engine-driven fuel pump (not shown). At the same time, the vanes e, being radially outward from a central open space in the impeller 15, create a centrifugal separation of liquid from gases and vapors. The fully liquid material, being heavier than the gases and vapors, will be thrown outwardly by centrifugal force, while the lighter gases and vapors will rise through the center of the impellerto be discharged by the vanes 15b back into the pond of liquid in the tank. Therefore, the impeller acts as a separator and liberates bubbles of gas and vapor from fully liquid material, returning the bubbles to the tank and only pumping the fully liquid material.

Liquid under pressure in the casing 22 cannot flow back through the conduits 28a and 21 into the volute chamber 19 because the positive-displacement pump in the casing 29 is inactive when the impeller is being driven, and the rotor and vanes of this pump effectively seal off the conduits 21 and 29a.

When the motor is driven in a clockwise direction, the coupling 5| releases the ball clutch 60 from driving engagement with the shaft 56 and engages the ball clutch 59 in driving engagement with the rotor hub 63a to operate the positive-displacement pump. This pump receives liquids from the tank through the pump opening 16a and through the openings between the vanes 15b. The liquid flows from the volute chamber 19 through the conduit 2 1 tothe inlet 68h of the positive-displacement pump. The pump will presure the liquid from the inlet thru the outlet llc into the conduit 28a. Since the conduit 28a communicates with the boss 22h and with casing 22, liquid will be maintained in this casing 22 under pressure. This pressure will hold the flap valve 80 in closed position so that the liquid is not recirculated back to the interior of the tank unless it is under pressure sumcient to open the relief valve 10.

ISince the entire assembly I0 is submerged in the tank, and since it is desirable to seal the motor compartment from the fuel in the tank and from the fuel in the pump, the seal arrangement above described has been provided on the motor shaft 40, and the sealing gaskets have been provided for the motor casing.

From the above descriptions it will be understood that the unit |0 is readily mounted in a fuel tank and is preferably suspended from the bottom wall of the tank. The unit 0 includes a. centrifugal pump which is effective to separate gases and vapor from liquid fuel in the tank returning the separated vapors to the tank and pressuring only the fully liquid fuel into the fuel line. This pump is driven when the inotor is actuated in one direction. A second pump of the positive-displacement type is driven when the same motor is actuated in the reverse direction.

The positive-displacement pump is adapted to pressure liquids received from the tank through the inlet of the centrifugal pump. The positivedisplacement pump does not include the vaporseparating feature of the centrifugal pump, but is adapted to deliver fuel at higher pressures without substantial agitation of the fuel. The

positive-displacement pump is useful at 10W altitudes.v and especially when starting the engine or when the engine-driven fuel pump is inoperative. The centrifugal pump is useful at higher altitudes to prevent vapor lock in the fuel system. The positive-displacement pump develops higher pressures than the centrifugal pump but has lower pumping capacity than the centrifugal pump. Because of the very high pressures required for starting and emergency duties, the positive displacement pump has been made quite small to minimize power requirements and this power requirement is Abalanced with the power requirements of the centrifugal pump when operated at high delivery rates and low pressures.

In the embodiment shown in Figure 6, a pump and motor unit has a base 9| similar to the base described in Figures 1 to 5 adapted to be mounted on the bottom of an airplane fuel tank. 'I'he base 9| supports a centrifugal type Dump casing 92 in spaced relation thereabove, and this casing 92 has an upwardly projecting head portion 93 forming a bottom end cap for a motor casing 94. The motor casing 94 has a top cap 95 carrying a casing 96 in which is mounted a rotary vane-type positive-displacement pump 91 similar to the pump described in connection with' Figures 1 to 5.

An electric motor in the casing 94 has a drive shaft 98 projecting into both casings 93 and 96. The portion of the shaft 98 projecting into the casing 93 has a coupling 99 pinned thereon. A one-way drive roller clutch |00 operating in the identical manner as th'e ball clutch 58 selectively connects the coupling 99 with a pump shaft |0| rotatably mounted in the lower end of the casing 93 and drivingly connected with a centrifugal impeller |02 operating in the identical manner as the impeller 15 described in Figures 1 to 5. The casing 92 has an inlet ring |03 defining an inlet opening |04 and vanes 02a of the impeller discharge liquid material from the opening |04 into and through a volute chamber |05 defined in the casing. This volute chamber |05 communicates with a discharge conduit |06 connected with a cylindrical casing |01 receiving a conduit fitting |08 at the upper end and closed at the lower end by means of a cap |09. As explained in connec` tion with Figures 1 to 5, the iltting and cap are interchangeable. A flap valve ||0 is mounted in the casing |01 and is spring urged into closed position.

The volute chamber |05 also communicates with' a fitting connected through a hose I2 with a fitting ||3 communicating with the inlet 91a of the rotary vane pump 91.

The outlet 91b of this pump 91 receives a T- fltting ||4 having one leg connected through a hose H 5 to the fitting |08 and having another leg connected to the fuel line to the engine-driven fuel pump (not shown) The upper end of the motor shaft 98 is pinned to a coupling ||6 containing a one-way drive roller clutch l 1 operating in the same manner as the ball clutch 59 described in Figures 1 to 5.

When the motor in the casing 94 is driven in a counterclockwise direction, the roller clutch |00 drivingly engages the pump shaft 0| to rotate the centrifugal impeller |02 and centrifugally discharge fuel from the tank through the volute |05 into the conduit |06 for acting on the flap valve ||0 to open the same. The fuel enters the casing |01 where it is discharged into th'e fuel line through the hose H5. As explained above, the impeller 02 is effective to separate liquid material from gases and vapors, and the gases and in the bearing vapors are returned back to the tank. This counterclockwise driving of the motor disengages the roller clutch ||1 so that the pump 91 is idle.

When the rotor of ing, it is effective to seal the outlet 91h thereof from the inlet 91a thereof, and fuel under pressure in the coupling ||4 cannot return through the hose ||2 and coupling back to the volute chamber |05.

When the motor in the casing 94 is driven in a clockwise direction, the coupling 99 disengages the roller clutch and the coupling ||6 engages the roller clutch ||.1 to drive the rotor of the pump 91. This causes the pump 91 to operate and receive liquid from the tank through the inlet; |04, volute chamber |05, fitting hose H2, and fitting ||3. The liquid will be discharged through the outlet 91h into the fitting ||4 to th'e fuel line (not shown). Flap valve I |0 will be closed since the pressure in the casing |01 will be greater than pressure in the volute chamber |05,

Thus driving of the motor in one direction causes operation of the centrifugal pump While driving of the motor in the reverse direction causes operation of the positive-displacement pump. Y

In the embodiment sh'own in Figure 7, the unit has a base |2| carrying, in spaced relation thereabove on legs |2 la, a centrifugal pump casingv |22 having upstanding conduit-defining portions |23 and |24 carrying a, top flange |25. The top ange |25 has a depending cup-shaped portion |25a. A casing |26 is mounted on top of the flange |25' and has a laterally projecting conduit portion |21 connected with an upstanding conduit tting portion |28. The fitting portion |28 has a depending mouth |28a on the fiange |25. A flap valve |29 is mounted in the depending mouth portion |28a of the fitting |28 and acts on .the flange |25 as a seat to close the conduit |24.

The casing |26 has an upwardly projecting collar portion |26a on which is carried a motor casing |30. A motor in the casing has a drive shaft |3| extending through collar |26a and through casing |26 terminating in a reduced lower end portion |3|@ having diametrically opposed elongated keys |3|b thereon.

The shaft |3| projects through a stationary seal ring |32 and through a rotating seal ring |33 in face engagement with the stationary seal ring |32. A rubber sleeve |34 embraces the rotating seal ring |33 and is held thereon by a cup member |35. The cup member is acted on by a coil spring |36 bottomed on a retainer |31 disposed around the shaft |3| and held against longitudinal movement away from the cup memberv by means of a lock wire |38.

.The casing |26 has a bottom shoulder |26`b on which is mounted a bearing |40. A pump liner |4| for a rotary vane type positive-displacement pump is bottomed on this bearing |40 and has an inlet opening |4|a communicating with the conduit |23 and an outlet openingI |4|b communicating with the conduit |21- A second bearing |42 is mounted on the liner |4| and is secured thereagainst by means of a sleeve |43 slidable in the casing. A gasket |44 is seated in the groove provided around the upper end of the sleeve |43 and the stationary seal |32 is bottomed on this gasket. A'fcover ring |45 acts on the stationary seal |32 and is secured to the casing A rotor |41 has a hub |26 by means of cap screws |46.

|41a rotatably mounted the pump 91 is not operat- 42 and a second hub |41b rotatably mounted in the bearing |40. A tube |48 is freely disposed around the shaft |3| and projects through both hubs |41a and |41b.

The rotor |41 carries pumping varies |49 slidably mounted in slots thereof and acting on the liner |4| to propel liquid from the inlet |4|a to the outlet |4417.

The hub |4117 has depending dogs |41c in spaced relation therearound for a purpose to be more fully hereinafter described.

The cup shaped depending portion |25a of the flange |25 has a bearing |50 bottomed on`a bottom shoulder |2511 thereof. A A spacer ring |5| is mounted in the cup on the bearing |50 and supports a second bearing |52. The bearings |50 and |52 are plain carbon or graphite bearing rings and are secured in the cup |25a by means of a plug ring |53 threaded into the top of the cup.

The bearings |50 and |52 rotatably support a shaft |54having a well |54a in the top thereof receivingv the end of the shaft portion |3|a. A well |54b is formed in the bottom of the shaft |54 and receives therein a stub shaft |55a of a centrifugal impeller |55 identical with the impeller 15 described in connection with Figures 1 to 5. A pin |56 secures the stub shaft |55 for corotation with the shaft |54.

The shaft |54 has a flange |540 underlying the bearing |50 and riding on a raised end face |50a of the bearing.

A sleeve |51 is mounted around the top of the r shaft |54 and secured thereon by means of a locking pin |58. This sleeve has a flange |51a riding on a raised end face |52a of the bearing |52.

Aand lowering The upper end of the sleeve |51 has dogs or vertical teeth |51b.

A clutch element |60 is slidably keyed on the portion |3|a of the shaft |3| and has upstanding dogs or teeth |60a for meshing with the dogs or teeth |410 on the rotor hub |41b together with depending dogs or teeth |60b for= meshing with the dogs or teeth |51b of the sleeve |51. The clutch element |60 is loosely embraced by a lever |6| pivoted as at |62 to the casing. |26. The clutch element |60 rotates freely in an aperture defined by rib |6|a on the lever |6|. The clutch element |60 has a concave peripheral wall |60c adapted to be engaged by the rib |6|a for raising the clutch element |60.

The end of the lever |6| remote from the pivot |62 has an elongated slot |6|b receiving a pin |63 on the core |64 of a. solenoid |65 carried in the casing |26. A spring |66 acts on the core |64 to urge it downwardly thereby causing the pin |63 to tilt the lever |6| downwardly for moving the clutch element |60 into position for engagement of the clutch teeth |60b with the sleeve teeth |51b. In this position of the clutch the shaft |3| drives the clutch element |60 through the keys |3|b and the clutch |60, in turn, drives the shaft |54 through the sleeve |51. The shaft |54 rotates the impeller |55 to actuate the centrifugal pump. The impeller |55 is effective, as explained above in connection with Figures l to 5, to receive liquid gasoline or other fuel in the tank, centrifugally separate the fully liquid material from gases and vapors, pump the fully liquid material through the volute chamber into the discharge conduit |24 under pressure suflicient to open the flap the material into the tting |28. The separated gaseous material is forced back` to the interior valve |29 and dischargeA of the tank by the vanes in the top ofthe impeller. Gasoline under pressure in the conduit |28 will not flow through the conduit |21 when the positive-displacement rotary vane pump is idle since the rotor and vanes of this pump separate the outlet |4|b from the inlet |4|a.

When the solenoid |65 is energized, thev core |54 is drawn into the solenoid coil against pressure of the spring |66 to raise the lever |6| and thus move the clutch element |60 outuof engagement with the sleeve |51 and into engagement with the rotor hub |41b through intermeshing relation between the dogs or teeth ISUa and |410.

Rotation of the rotor |41 will impel liquid from the inlet |4|a to the outlet MIb. The conduit |23 supplies the inlet |4|a from the volute chamber. The positive-displacement pump pressures the liquid from the conduit |23 through the conduit |21 into the fitting |28 and, when pressure in the fitting |28 is greater than pressure in the conduit |24, the flap valve |29 will be closed, so that the liquid will not be recirculated back to the volute chamber.

In the pump |20 the motor shaft 3| is driven in one direction only, and the solenoid |65 selectively controls sequential driving of the positivedisplacement pump or the centrifugal type pump.

From the above descriptions it Will be understood that the invention now provides multipump and motor units adapted to be submerged in airplane fuel tanks wherein one pump is of the centrifugal type effective for separating gases from the liquid fuel and for pressuring the fully liquid fuel into a pipe line, while the other pump is of the positive-displacement type and pressures the fuel without separating gases and vapors therefrom, A single electric motor is arranged for selectively driving either pump, and clutch means are included in the unit to control the selective driving. The positive displacement pump will pressure fuel at relatively high pressures to an airplane fuel line and serve to take the place of the engine-driven fuel pump during starting and emergencies. It will maintain engine operation sufiicient for sustaining fiight when the main pump or engine-driven fuel pump is totally inoperative. 'I'he centrifugal pump separates gases and vapors from the liquid fuel and pressures the fully liquid fuel into the fuel line and serves as a high altitude booster.

It will also be understood that the units of this invention can be completely inoperative without stopping fiow of fuel from the tank to the fuel line, since fuel can always flow through the impeller and casing of the centrifugal pump. The weak spring urging to closed position the flap valve in the discharge conduit of the centrifugal pump will readily permit the valve to open Whenever there is a suction pull in the fuel line as when the engine-driven fuel pump is operative and the booster pump unit is inoperative.

It will, of course, be understood that Various details of construction may be varied through a Wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention:

1. A pump and motor unit comprising a plurality of pumps having a common inlet and a common outlet, a motor for driving said pumps,

vclutch means selectively connecting said pumps with said motor for sequential operation of the pumps, and means between said outlet and said inlet preventing back fiow from the outlet through an inoperative pump.

2. A booster pump adapted for attachment to the fuel tank of an aircraft fuel system which comprises casing means having a mounting fiange for attachment to a tank and providing a pumping chamber for a centrifugal pump with an inlet for open communication with the interior of the tank, said pumping chamber having a first outlet and a second outlet in open communication with said inlet, an impeller rotatably mounted in said casing means cooperating with said pumping chamber to pressure fluid to said second outlet, means on said impeller for eliminating bubbles from fluid being pumped, a positive displacement type pump having an inlet communicating with the first outlet of said pumping chamber and an outlet communicating with the second outlet of said pumping chamber, a single prime mover for driving said impeller and said positive displacement type pump, and clutch means selectively connecting said prime mover with the positive displacement type pump or with the impeller.

3. A booster pump unit adapted for aircraft fuel systems comprising a centrifugal pump, a rotary vane pump, said pumps having a common inlet and a common outlet, an electric motor for driving said pumps, mechanism for selectively connecting the pumps with said motor, and means preventing back fiow from the outlet through an inoperative pump.

4. A pump and motor unit adapted to be submerged in a pond of liquid in a tank comprising a mounting base adapted to be attached to a tank wall, a centrifugal. pump casing having an inlet above the base, said base beneath said pump inlet defining a sump receiving liquid from the pond for supplying said inlet, said centrifugal pump casing having a main outlet and a secondary outlet, an impeller in said casing arranged for pressuring liquid from the inlet to the main outlet, chamber defining means on said base communicating with said main outlet to receive liquid therefrom, a vaned rotor type pump mounted adjacent said centrifugal pump casing having an inlet receiving liquid from said secondary outlet of the centrifugal pump casing and an outlet discharging liquid to said chamber defining means, an electric motor, and clutch means drivingly connecting said electric motor with said fmpeller and said vaned rotor.

5. A submerged type booster pump assembly comprising a mounting plate defining a sump, a centrifugal pump casing secured on said mounting plate in spaced relation above said sump, said casing having a central opening therethrough and a peripheral pumping chamber around said opening in communication therewith, an impeller rotatably mounted in said central opening having pumping vanes around the periphery thereof for discharging liquid received from the sump into said pumping chamber together with additional vanes in the top thereof for discharging vapors out of the central passageway, a pump shaft driving said impeller, a second pump casing having an inlet communicating with said pumping chamber, a rotary vane type pump including a vaned rotor in said second casing, a single motor on said unit, and clutches for selectively connecting said single motor with said pump shaft and with said vaned rotor.

6. A combination booster pump comprising a unit including a centrifugal type pump having a first pumping chamber and means associated therewith for separating gases from liquids and for pressuring fully liquid material, a positive displacement type pump having a second pumping chamber, said first and second pumping chambers having a common inlet, a single electric motor, and means for selectively connecting said motor and said pumps in driving relation.

7. A combination booster pump unit comprising a base adapted to be mounted on a tank, upstanding casing structure on said base adapted to be submerged in a tank, said structure including a centrifugal type pump casing having an inlet adjacent said base and a plurality of outlets, a positive displacement type pump casing having an inlet connected with one of said outlets of the centrifugal pump casing and an outlet communicating with the other of said outlets of the centrifugal pump casing, an electric motor, an impeller in said .centrifugal pump casing, a vaned rotor in said positive-displacement pump casing, and clutch means for drivingly connecting said motor with said impeller and said vaned rotor.

` 8. A combination booster pump unit comprising a mounting plate adapted to be suspended on the bottom wall of a tank, upstanding means on said mounting plate adapted to project into the tank, an electric motor and a plurality of pumps on said upstanding means, and said upstanding means having passageways joining lsaid pumps to provide a common inlet and a common outlet.

9. A combination booster pump unit adapted for aircraft fuel systems comprising a low altitude booster pump having a first pumping chamber, a high altitude booster pump having a second pumping chamber, said first and second pumping casing and extending therefrom, said second casing defining a clutch chamber, a positive-displacement type pump chamber, and a centrifugal type pump chamber, said centrifugal type Dump chamber having an inlet, a first outlet communicating with the positive displacement type pump chamber, and a second outlet, an impeller in said centrifugal pump casing, a vaned rotor in said positive displacement type pump casing, a pump shaft driving said impeller and extending through said vaned rotor into said clutch chamber, said vaned rotor having a hub extending into said clutch chamber, a coupling in said clutch chamber connected to said motor shaft, and separate clutch means interposed between said coupling, said pump shaft and said hub for selectively. connecting the motor shaft indriving relation with said impeller and said vaned rotor.

12. A combination booster pump comprising a unit adapted to be submerged in a pond of liquid and including an electric motor casing, a clutch casing, a positive-displacement type pump casing,

chambers having a common inlet and a common outlet, an electric motor, and means for selectively connecting said pumps with said electric motor to be driven thereby.

l0. A combination booster pump comprising a mounting base, upstanding legs on said base, a centrifugal-type pump casing supported on said legs in spaced relation above the base having a central vertical opening therethrough, a volute pumping chamber around said central opening in communication therewith, a laterally extending discharge conduit, and an enlarged cylindrical casing at the end of the discharge conduit, an impeller rotatably mounted in the central opening of the casing having pumping vanes around the periphery thereof cooperating to separate liquids from vapors and pump the liquids into the volute pumping chambers together with vanes at the tops thereof for propelling the separated vapors through the open top of the opening, a second pump casing above said centrifugal pump casing having an inlet conduit depending therefrom and communicating with the volute pumping chamber together with an outlet conduit extending laterally therefrom and communicating with the enlarged cylindrical casing, a vaned rotor rotatably mounted in said second pump casing, an electric motor mounted on top of said second pump casing having a drive shaft depending therefrom, a pump shaft carrying said impeller and extending through said vaned rotor, a rst clutch connecting said pump shaft with said motor shaft, and a second clutch connecting said vaned rotor with said motor shaft.

1l. A combination type booster pump comprising an electric motor, a casing surrmmding said motor, a second casing secured to/the motor and a centrifugal type pump casing together with conduits providing a common inlet and a common s outlet for the casing, an impeller in said centrifugal pump casing, a vaned rotor in said positivedisplacement pump casing, clutch means in said clutch casing, a pump shaft secured to said impeller extending freely through said vaned rotor, saidmotor having a drive shaft depending into said clutch casing, said vaned rotor having a hub extending into the clutch casing, and said clutchmeans selectively connecting said hub and said pumpshaft with motor shaft.

13. In a unit including an electric motor and a plurality of pumps, a drive shaft for one pump, a rotor for another pump receiving the drive shaft freely therethrough, and one-way drive clutches for drivingly connecting the motor selectively with said drive shaft and with said rotor.

14. A combination pump unit comprising an electric motor having a casing projecting from opposite ends thereof, a centrifugal type pump in one of said casings, a positive-displacement type pump in the other of said casings, said centrifugal type pump having a single inlet and a plurality of outlets, said positive-displacement pump having a. single inlet and a single outlet, conduit means connecting one of the centrifugal pump outlets with the inlet of the positive-displacement pump, and second conduit means connecting the other outlet of the centrifugal pump with the outlet of the positive-displacement pump.

15. A multi-pump-single motor unit comprising a prime mover, a plurality of pumps driven by said prime mover, and a single solenoid-operated clutch selectively connecting the pumps with said prime mover.

16. A combination booster pump comprising an electric motor having a driveshaft extending therefrom, a vaned rotor loosely embracing said drive shaft, casing means for said rotor cooperating therewith to provide a rst pumping chamber, a pump shaft aligned with the end of the drive shaft, an impeller on said pump shaft, casing means for said impeller cooperating therewith to provide a second pumping chamber, and a solenoid-operated clutch selectively connecting the drive shaft with said pump shaft and with said vaned rotor.

RUSSELL R. CURTIS.

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