US2051301A - Fuel supply unit for oil burners or the like - Google Patents

Description

Aug. 18, 1936.

FUEL SUPPLY UNIT FOR OIL BURNERS OR THE LIKE A. C. KLECKNER ET AL Filed March 14, 1934 5 Sheets-Sheet 1 Aug. 18, 1936.

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FUELSUPPLY UNIT FOR OIL BURNERS OR THE LIKE Filed March 14, 1934 3 Sheets-Sheet 3 116 117 125 1% J7 152 zZ J78 J50 J66 151 Patented Aug. 18, 1936 UNITED STATES PATENT I OFFICE Arthur G. Kleckner and Harrison E. Fellows, Racine, Wis., assignors to Webster Electric Company, Racine, Wis., a corporation of Wisconsin Application March 14,

/ 10 Claims.

The present invention relates to fuel supply units for oil burners or the like, and the present fuel supply unit comprises improvements over that disclosed in the prior application of one of the applicants herein, Arthur C. Kleckner, Ser. No. 604,834, filed April 12, 1932, for Multi-stage pumps and pumping systems. I

Among the advantages and objects of a fuel supply unit of the type covered by these applications are the following:

(1) The elimination of difficulties caused by fluid tight packings, by a substantial reduction in the fluid pressure to which the packing is subjected.

(2) Supply of liquid fuel to an oil burner at substantially constant pressure and volume in spite of the variations in suction resistance and/or nozzle resistance which might be caused by obstructions i either the nozzle or the suction pipes or by variation in head of the liquid in the supply tank. (3) Provision of a fuel supply unit which is self-priming, dependable, capable of immediately performing its functions on starting at any time, even though the tank and pipe lines have been completely emptied since the last operation of the fuel line.

Another object of the invention is the provision of an improved fuel supply unit of the type described which eliminates the difliculties sometimes encountered in the form of pump noise. The pump being of a gear type, the action of the gears causes periodic pulsations in the flow of the fuel oil, and these pulsations have a tendency to be carried back through the pipe to the tank. The tank acts under these conditions like a sounding board, producing, under some conditions, a sound which is distinctly audible and which would be a marked disadvantage in the case of an oil supply unit or pump which is intended to be used upon oil burners for homes, where noiseless operation is not only desirable but very essential if the unit is to meet with wide acceptance under all conditions.

Another object of the invention is the provision of an improved fuel supply unit for oil burners or the like which is adaptable to a one pipe or a two pipe system Without any external connections for this purpose, but also having no valves or other devices with which the ordinary householder could tamper.

Another object of the invention is the provision of an improved fuel supply unit for oil burners or the like which is adapted to eliminate the multiplicity of connecting pipes heretofore 1934, Serial N0. 715,441

found necessary in connecting various parts, such as pumps, strainers, regulating valves, etc., and the provision of a single unit device which-is capable not only of providing fuel under proper pressure and volume, but also capable of straining out any foreign matter which might clog the nozzle, and of regulating the pressure of the liquid fuel at the nozzle in such manner as to provide as far as possible a substantially constant supply of fuel at substantially constant pressure, in spite 10 of the various factors which might tend to diminish or increase the volume or pressure.

Other objects, features and advantages of the invention will be apparent from the following description and from the accompanying drawings, in which similar figures represent similar parts throughout the several views.

Referring to the drawings, of which there are three sheets:

Fig. 1 is a diagrammatic illustration ofa fuel supply system, including the present fuel supply un Fig. 2 is a vertical sectional view taken through the fuel supply unit of Fig. 1 on the planeof the line 2-2 in Fig. 4, looking in the direction of the arrows Fig. 3 is a sectional view taken through the fuel supply unit on the plane of the line 3-3 of Fig. 2, looking in the direction of the arrows;

Fig. 4 is a cross sectional view through the fuel supply unit, taken on the plane of the line 4-4 of Fig. 2, which is a horizontal plane with respect to Fig. 1;

Fig. 5 is a sectional view taken on the plane of the line 5-5 of Fig. 2, showing the shape of various parts and the'connection of various conduits of the fuel supply unit;

Fig. 6 is a fragmentary sectional view taken on the plane of the line 6-6 of Fig. 4, showing the shape of various parts of the pump and the connections of various conduits;

, Fig. '7 is a vertical sectional view taken on the plane of the line l! of Fig. 6, looking in the direction of the arrows, passing through the axes of the pump shafts, with the pump gears in elevation;

Fig. 8 is a transverse sectional view taken on the plane of the line passing through the axis of the drive shaft, showing the preferred type of oil seal;

Fig. 9 is a fragmentary vertical sectional view similar to that of Fig. 2, showing the preferred form of strainer and a silencer for preventing the singing noise that might otherwise go back to the tank in some installations.

Referring to Fig. 1, I9 indicates in its entirety the present fuel supply unit, which is preferably driven by an electric motor II, which may be the same motor that drives the fan or other mechanism connected with the oil burner in question. The complete fuel supply installation includes a tank I2, shown diagrammatically with a supply of fuel oil I3, and the suction pipe I4 leading to the fuel supply unit I0 is immersed in the liquid fuel I3. The return pipe I5, which is connected to the return port of the fuel supply unit I 0, communicates with the tank I2. Another pipe I8 conveys liquid fuel from the fuel supply unit I0 to an oil burner nozzle or other device for consumption of the liquid fuel.

While the present fuel supply unit is particularly adapted to be used for oil burners, it should be'understood that the device is also of general application and may be utilized wherever it is desirable to provide a supply of liquid at substantially constant pressure and volume with or without the strainer for cleaning the liquid out or the pressure regulator for maintaining close regulation of the pressure.

The oil supply unit I0 preferably comprises a housing I1 which may be made of cast metal, and which is preferably provided with a pair of laterally extending attaching flanges I8, I9 provided with bores 20 for receiving attaching bolts. The attaching flanges I8, I9 are carried by the rear wall 2I of the central part of the housing, which also carries a substantially cylindrical wall 22 surrounding the pump shaft 23. The wall 2| is provided with a cylindrical bore 24 forming a bearing for the pump shaft 23, and the cylindrical wall 22 surrounds the counterbore 25 for housing a spring and seal.

ing the screw bolts I81.

Referring to Fig. 8, this is a similar fragmentary view of an improved and preferred form of oil seal, which is preferably used in the devices embodying the invention. In this case, the plate 2I is formed with an annular wall 22 for housing the oil seal, and with an inwardly extending sleeve I80, which is reduced in size at I8I for providing an annular seat I82 for the spring I83.

The drive shaft 23 is located in the cylindrical bore 24 and projects from the cover plate I84 through an enlarged aperture I85. The cover plate I84 is substantially frusto-conical in form and provided with a radially outwardly extending attaching flange I88, having apertures for receiv- The attaching flange I86 also has a cylindrical flange I88 which embraces the reduced cylindrical end I89 of the annular wall 22 and is also adapted to receive a pair of gaskets I90, I9I which are located on the opposite sides of the diaphragm I92.

The diaphragm I92 is apertured, as are the gaskets I90, I9I, to receive screw bolts I81, and by means of the attaching flange I86, gaskets, and screw bolts, threaded into the bores in the annular wall 22, the diaphragm I92 has a fluid-tight connection with the end of the annularwall 22.

The diaphragm I92 supports'a metal sleeve I93 having a flat end surface I94 and having radially outwardly extending flange I95. The diaphragm is provided with a suitable aperture for receiving sleeve I93, and sleeve I93 is clamped on the diaphragm by means of a metal ring I96. The

' sleeve I93 may be spun over to secure the ring I96 in place, or the sleeve I93 may be soldered or otherwise permanently secured to the diaphragm I92. A coil spring I83, mounted on the reduced end I8I of sleeve I80, engages the diaphragm I92 face 20I.

and urges the sleeve I93 toward the right, in Fig. 8.

The sleeve member I93 engages a hardened threaded sleeve member I91, which likewise has a flat surface I98 on its end, and sleeve member I91 is mounted to rotate with the shaft 23. Sleeve member I91 is formed with a threaded outer surface I99 for receiving a complementary threaded sleeve 200, which has a frusto-conical inner sur- Sleeve member I91has a frusto-coni cal inner surface 202, and these two frusto-conical surfaces compress and engage a soft metal annulus 203, forcing it into engagement with the shaft 23 and fixedly securing the sleeve member I91 to the shaft with a fluid-tight joint between the sleeve member I91 and shaft 23.

The actual seal takes place at the engaging surfaces I94 and I98 which are resiliently kept in engagement with each other by the spring I83. The body of the end plate maybe provided with a bore 204 leading from the chamber 205 back through the low pressure suction side or low pressure output side. In case it is connected to the low pressure output side, the shaft is grooved at 206 to permit the oil, which is forced in to the chamber 205, to flnd its way back to the reservoir. Such an arrangement would be used where the fuel oil has lubricating properties. In case the fuel oil has foreign materials which might tend to affect the sliding seal at I94, I98 deleteriously. then the bore 204 should be connected to the suction sideof the low pressure stage to carry back to the pump such leakage as might take place along the shaft in the bore 24 to maintain the surfaces I94, I98 in a clean condition by means of the flow of fuel oil.

A cover plate 26 is provided with a reduced cylindrical portion 21 fitting in the counterbore 25 and with a bore 28 for receiving a bearing sleeve-29 having a radially outwardly extending flange 30. Cover plate 26 has a plurality of bores 30 and counterbores 3I for receiving the bodies and heads of the securing screw bolts 32, which are threaded into registering bores 33 formed In the wall 22. A suitable gasket 34 may be interposed between the cover plate 28 and the plane gasket seat which is provided by the outer end of wall 22. Cover plate 28 is preferably substantially circular, conforming to the outer surface of the cylindrical wall 22.

Within the counterbore 25 pump shaft 23 is preferably surrounded by a helical spring 35 which is compressed between the washers 36, 31, each of which engages a fluid tight packing 38, 39 of leather, rubber, soft metal, or other suitable material.

It should be noted that the seal which is shown in Figs. 3 and 4 is of an alternate type as compared with that disclosed in Fig. 8, and while either of these seals may be employed, that disclosed in Fig. 8 is preferred.

Referring again to Fig. 2, the housing I1 may be conveniently described by referring to the three parts, namely, the regulator valve housing 40, the pump housing 4|, and strainer. housing 42, although the major portion of all three of these divisions is comprised in a single integral casting.

These housings contain chambers which may be designated as the valve chamber 2, the pump chamber comprising counterbores 92-95 in the gear housing 58 and the strainer cham-' ber 43.

The strainer housing portion 42 at the right, as shown in Figs. 2 and 4, comprises a substantially cylindrical formation having its major axis extending vertically in Fig. l or at right angles to the pump shaft 23. This cylindrical strainer housing 42 is preferably formed with a substantially cylindrical strainer chamber 43, which is provided at the lower right hand of Fig. 2, with an inlet port 44 formed in a laterally extending lug 45, and provided with pipe threads for receiving the suction pipe M. It is also preferably provided with a threaded clean-out opening 46 centrally located in the bottom of the strainer housing portion 42 and provided with pipe threads for receiving the closure plug 41.

The wall 42 of the strainer chamber is preferably provided at its top with a plane surface 48 forming a seat for a suitable gasket 49, which is compressed against the surface 48 by the cover plate 50. Cover plate 50 may comprise a substantially circular casting of the same size as the cylindrical strainer housing 42 and provided with a reduced cylindrical portion 5| adapted to fit within the cylindrical bore 52 of the strainer housing. through the cover plate 50 and are threaded into the wall of the strainer housing 42 to secure the cover plate firmly in place. The cover plate 58 may also be provided with a centrally located threaded bore 54 with a threaded closure plug 55 having a non-circular end 56 for receiving a wrench. This closure plug is convenient for use in observing the inside of the strainer chamber 43 at the top and for connection of a gauge, if desired.

The strainer housing portion 42 is integrally joined to the pump housing 4|, but separated therefrom, by the wall 5'! which forms a part of the strainer housing. The pump housing 4|, which forms an integral casting with the strainer housing 42 and regulator valve housing 48, may comprise a substantially oval portion of the casting which is provided with an inner gear housing 58 spaced from the outer wall 59 of the pump housing and forming an intermediate oil chamber 60. Various oil chambers and conduits in the oil supply unit are, of course, formed by coring out these portions of the casting, and the gear housing 58 must, of course, be suitably joined to the pump housing 4| by sections of metal 6| at the left and 62 at the right, where it is desired to locate conduits extending to the valve chamber and strainer chamber respectively.

The strainer housing portion 42 has its wall provided with an inwardly projecting annular shoulder 63 preferably having a flat upper surface for engaging a sheet metal partition 64. Sheet metal partition 64 is substantially circular in shape and may be in close frictional engagement with the wall of the bore 52 in the strainer housing 42, or it may fit loosely, being held by wire 66. Above the annular shoulder 63 and spaced sufiiciently from the upper surface of annular shoulder 63 to permit insertion of the partition 64, is an outwardly extending annular groove 65 in the wall of the strainer housing 42. A resilient spring wire 66 of steel or other suitable material is coiled into circular form and sprung outwardly into the groove 65, the groove 65 being so located that the wire 66 locks the partition 64 in place. Partition 64 is provided with a centrally located bore 61 which is adapted to receive the end 68 of a perforated metal tube 69. Tube 69 is threaded into the bore 81 and secured in place by a threaded locking member 10, which is threaded home on the end of the perforated tube 69 against the partition 64.

A plurality of screw bolts 53 pass The lower end of the tube 69 may be closed by any suitable means, such as an end plate, welded, soldered, or otherwise secured to close the end, but is preferably provided with a pair of axially extending lugs H which pass through the end plate 12 and are bent over to secure the end plate. The tube is in communication with the interior of the strainer chamber 43 through a plurality of apertures I3 located at random in the side of the tube Q, or apertures 13 may be suitably spaced to reg ster with annular chamber 88.

Removably supported upon the perforated tube 69 are a plurality of strainer units 14. These strainer units may be removed and replaced when they become clogged or otherwise disabled, and they preferably comprise strainer units of the type shown in the prior application of Harrison E. Fellows, Serial No. 603,734, filed April '7, 1932, for Strainers and methods of making strainer units.

In some embodiments of the invention, the features of the strainer may correspond in all of their details to those described and shown in the abovementioned Fellows application.

For example, each of the strainer units 14 is identical in construction with the upper one which is shown in section and which comprises upper and lower discs 15 of wire screen supported on a pair of metal collars 16 in spaced relation to each other. The collars 16 are annular stamped sheet metal members having a substantially cylindrical central portion I1 with anv outwardly extending annular flange 18. The cylindrical portion I1 is provided with a plurality of spaced apertures l9 communicating with the interior annular chamber 88 and thence with the apertures 13 of tube 69.

The two collars 16 are identical and their flanges l8 engage each other, the collars extending in opposite directions. At the outer end of each collar there is provided an inwardly extending flange 8|, which is bent outward upon itself at 82 to clamp the wire screen disc 15 to the collars 16, the wire screen disc having an aperture to receive the collar.

After the collars are so secured to the wire screen discs, they are provided with a circular wire loop 83 which is spaced slightly from the,

outer edge of the discs and which serves to hold the discs spaced from each other adjacent their outer edges. The outer edge portions 84 of the screen discs 15 are forced into engagement with each other, as shown, and secured by soldering said outer edge portions firmly to each other in position, shown in Fig. 2.

Referring to Fig. 9, this is a fragmentary view similar to Fig. 2, showing a modified form of strainer unit which is also provided with a silencer for preventing the singing noise which otherwise goes back to the tank from the pump.

In this embodiment the strainer housing 42 is screen, which are clamped by the spacing col-' lars I1 and forced to frusto-conlcal form.

The spacing wire 2), however, is located flush with the periphery of the screens 299, 299, and the edge space between the screens and the outer surface of the wire 2"! is filled with solder 2. The apertures 13 in the supporting sleeve 69 are preferably located to register with the apertures in the spacing members 11.

In this embodiment the wing nut 19 has been removed and there has been substituted a silencer, which comprises a spring pressed one-way check valve, indicated in its entirety by the numeral 2 I2. This check valve permits the fiow of liquid in the proper direction through the strainers to the pump, but places a predetermined suction resistance on the line, such as, for example, from five to ten inches of mercury, and it is found that this device efiectively silences the singing noise of the pump, which would otherwise go back to the tank and be magnified by the tank acting as a sound box.

This suction on the line is believed to cause the gasiflcation of the volatile elements of the liquid fuel, and these volatile elements or gases effect a cushion action between the teeth of the gears of the pump which prevents the singing noise, which would otherwise be present.

Another possible way of eliminating this singing noise is to bleed air into the suction side of the pump to cause a cushion action on the teeth, but this is considered bad practice from the point of view of reduction of the volume of the pump and permitting air to get into the fuel line.

Another theory advanced by certain engineers regarding the silencing action is that due to the restriction at the silencer there is a marked change in the velocity of the oil at the point where it passes through the restriction and that this abrupt change in velocity breaks up any vibrations which may be traveling back through theoil, and thereby prevents the sound from reaching the tank.

The silencer 2I2 may consist of an internally threaded outer sleeve 2I9, the threads of which engage the end of the strainer sleeve 69. At its upper end this silencer sleeve 2 I9 has an annular shoulder on the inside for receiving the outwardly extending flange 2 carried by a valve sleeve 2I5. The valve sleeve 2I5 has an inwardly extending flange 2 I 6 surrounding an aperture which receives but does not pass the ball valve 2II, and the ball valve 2" is pressed by a spring 2I9, the other end of which is seated upon a plate 2I9 having an inwardly turned edge 229. The outer end of sleeve 2I3 is spun' over to secure the plate 2I9 and flange 2I4 in place, and the sleeve 2I5 is sufiiciently spaced from the internally threaded sleeve 2I9 so that strainer sleeve 69 may be threaded into the sleeve 2I9. Sleeve 2I9 acts as a nut to secure the strainer sleeve 69 in place on the partition 64.

The wire screen discs thus assume a substantially frusto-conical shape which gives them greater stifiness and increases the effective screen area over that of any other shape of strainer unit. The liquid in the strainer chamber 49 passes in at the inlet port 44 and surrounds the strainer units I4 passing through the screen to the interior .of each strainer unit, thence to the apertures I9 and apertures I9 into the tube 69 and out the tube 69 into the upper chamber 96 of the strainer housing.

The wall 51 between the strainer housing 42 and pump housing II supports a downwardly and laterally extending metallic formation 92 which is connected to the gear housing 99. This metallic connection is provided with a cored conduit 99 which communicates with the chamber 99 at the port 91 and which extends into the gear housing 59 to a point 99 at the right side of the gears in Fig. 2.

The gear housing 59 is provided with a pair of transversely extending bores 99, 99 forming bear lugs for the pump shaft 29 and pump shaft 9|. At each end of the bores 99 and 99 there is formed the counterbores 92, 99, 94, 95. Counterbores 92, 93 are adapted to receive the relatively narrow high pressure gears 96, 91 of the pum while counterbores 99, 95 are adapted to receive the low pressure gears 99, 99 which are adapted to pump up an excess supply of liquid fuel from the tank I2 to feed the high pressure gears 96, 91. Counterbores 92 to 95 inclusive closely fit the periphery of the toothed gears 96-99 inclusive, and counterbores 92-95 inclusive are formed with fiat end shoulders I99 for engaging the fiat end surfaces of the gears.

The depths of the counterbores 92-96 correspond respectively to the thickness of the gears so that the outer ends of the gears flatly engage the corresponding fiat surfaces on the end plates 2|, IN, and the gears substantially fill their respective chambers with exception, of course, of the spaces between the teeth and the bores in the gears, which bores are filled by the pump shafts 23, 9|.

The gear 99 is preferably keyed or otherwise secured to the shaft 23 by means of the removable pins I92, while the pin I 99 causes the gear 91 to rotate with shaft 29. Gear 96 may be loosely mounted on shaft 9|, being driven by gear 9] and the gear 99 may be loosely mounted on shaft 9|, being driven by gear 99. The shaft 9| comprises a short stub shaft having a central cylindrical portion I 94 of larger size fitting in the bore 99, and having the reduced end portions I95 fitting in the complementarybores in the gears 96, 9,9, and the ends of the shaft being plane surfaces at right angles to the axis of the shaft.

The shaft 29 may comprise a substantially cylindrical shaft. with a flattened end I96 for engagement with driving devices, and likewise having an enlarged portion I 91 fitting within the bore 99. the reduced portions I99, I99 of shaft 29.

Referring to Figs. 4 and 6, these are sections which show the connection between the inlet conduit 96 from strainer to pump and the gear chambers.- Inlet conduit 96 leads to a point 91 between the upper and lower low pressure gears 99, 99, and at one end of the gears. In Fig. 4 the low pressure gear 99 is seen'from above and the conduit 99 is in communication with the space between the gears at the right hand side and at one end of the gears through a slot II9 extending from end 91 of conduit 96 in a direction parallel to the axes of the shafts 29, 9|.

The right hand side of the low pressure gears 99, 99 in Fig. 4 is the suction side, shown by the arrows, and the left hand side of the gears 99, 99 in Fig. 4 is the low pressure output.

Referring now to Fig. 2, it will be observed that the gear housing 59 is also supported at the left hand side of the pump housing 4| by the inwardly extending lug 6|, back of which is located a conduit I II communicating at the left end with the cored reservoir space I24. Conduit III also extends toward the right in Fig. 4 to a point be- The gears 91 and 99 have bores fitting on tween the upper and lower gears 99, 99, but at one side thereof and is in communication with the toothed spaces between gears through the slot H3 which extends in a direction parallel to the axes of the shafts 23, 9| and parallel to the direction of the teeth. The output from the low pressure gears is, therefore, through the slot H3 and conduit III into the low pressure chamber I24, 60, I20. I

The left hand wall I I 4 between the pump housing H and the pressure regulator valve housing 40 supports a lug H5 which may be substantially rectangular in elevation, as shown in Fig. 2, and is provided with a semi-cylindrical end H6, as shown in Fig. 5.

Surrounding the lug H5 is an annular space III which forms a part of the pressure regulator valve chamber H2. Further commurzation between the pump housing chamber 66 and the pressure regulator valve chamber I I2 is provided through the conduits or bores H8, I I9 which extend axially of the lug H5, the latter bore H9 communicating with the bored reservoir I20 (Fig. 2). The bores H8, H9 and space I20 constitute a part of the fuel returned from the pressure regulator valve to the pump reservoir 60 and, as previously stated, all of the space inside the pump housing 4|, with the exception of the gear housing 58 and its supporting lugs 6|, 62, is cored out to provide a reservoir 60.

This reservoir 60 practically completely surrounds the gear housing 58 so far as it is possible to do so, and it constitutes a sound deadening liquid enclosure about the gear pump; that is, the spaces 60 and I20 in Figs. 2 and 3 are part of the oil reservoir above and below the gear pump. The space I2I at the right of the gear housing 50 in Fig. 2 is a further part of the oil reservoir enclosing the gear housing at the right. The cored spaces I22, I23 at the bottom and top of Fig. 6 also constitute portions of the oil reservoir surrounding the gear pump, and the cored space I24 in Fig. 4, which is behind the lug BI, provides communication between the lower part of the reservoir I20 and the upper part 60 past the In a similar way at the right hand side of Fig. 2 the cored space I2I provides communication between the lower cored opening I20 and the upper cored opening 60, on the right hand side of the gear pump in Figs. 2 and 4, extending past the lug 62 which encloses pump intake conduit 86.

It will thus be observed that the reservoir 60, I20, I2 I, I24 completely surrounds the gear pump housing 58 and insulates, so far as possible to do so, the gear pump from the outer casing. This reservoir also constitutes an enlarged space in the fuel line between the first or low pressure stage of the pump and the pressure regulator valve chamber into which the liquid fuel must pass, and it reduces the pulsations in the liquid fuel which are caused by the gear pump. Each tooth of the gears naturally causes a pulsation or pressure wave in the liquid fuel which it impels, but as the liquid fuel passes into this reservoir its velocity is diminished, since the same volume of liquid flows through every cross section of the liquid path. Thus the velocity is diminished in this reservoir and the pulsations are absorbed by the mass of liquid in the reservoir.

The oil surrounding the gear pump also deadens the transmission of sound to the air; and the increased mass of the metal surrounding the gear pump also serves to absorb the sound. It is practically impossible to determine the exact theory upon which the noise or tone due to the gear pump is eliminated but the improved structure as shown herein accomplishes this result and is a marked improvement over the devices of the prior art.

Referring now to Fig. 4, the supply of liquid fuel which is pumped up into the reservoir 60, I20, I2I, I24 is conducted to the high pressure gears through a cored conduit I25 which extends into the space between the upper and lower shafts 23, 9I adjacent the left end of the shafts in Fig. 3 and at the lower end of the shafts in Fig. 4. This conduit I 25 is in communication with the toothed spaces between the high pressure gears 96, 91 through a slot I26 which extends in a direction parallel to the axes of the shafts and parallel to the teeth. Conduits I25, I26 constitute the high pressure intake for the gears 96, 91.

Another conduit I 21 provides communication between the pressure regulator valve chamber I I2 and the high pressure output side of the gears 96, 91. Conduit I21, Fig. 4, extends to the right to a point between the upper and lower shafts 23, 9I and communicates with the high pressure output side of gears 96, 91 through the axially extending slot I28. Thus the high pressure stage of the gear pump, comprising gears 96, 91, takes the liquid fuel from the reservoir surrounding the gear pump through the conduits I25, I26, and discharges it through the conduits I28, -I 21 into the pressure regulator valve chamber H2.

In order to provide access to the interior of the pump reservoir 60, I20, I2I and to provide for the return of surplus liquid fuel to the tank in a two pipe system, the pump housing M is provided at its lower side with a threaded outlet bore I29. If a one pipe system is desired, this outlet bore I 29 may be closed by a threaded plug like the plug 41, in which case the plug I30 in the bore I3I of partition 51 should be removed so as to provide direct communication between the strainer chamber 43 and the reservoir I2I Instead of returning excess liquid fuel to the tank, it is returned from the reservoir I2I under these conditions, with a one pipe system, to the strainer chamber 43, thereby reducing the amount which is sucked up through the suction conduit I4.

The preferred form of use of the invention, however, comprises the use of a return pipe I5, and the purpose of the removable plug I30 is merely to adapt this preferred form of fuel supply unit to one pipe systems as well as two pipe systems to meet both types of conditions which might be encountered in old installations.

With a two pipe system, the threaded bore I29 receives a threaded pipe connection I32 which has an upwardly extending tube or pipe I33 projecting into the reservoir I2I to the point I34, which is the end of the pipe. The conduit I5 communieating with standpipe I33 is the return conduit for the excess liquid fuel which is pumped up into the reservoir I2I by the low pressure stage. Since the end I34 of the return pipe extends up into the reservoir, liquid cannot flow back from reservoir I2I until it covers the end of the return pipe, and there will always be a supply of liquid in the reservoir 60, I 2I which extends to the point above the intake slot I26 of the high pressure gears.

The present pump is self-priming by virtue of the substantial removal of output resistance from the low pressure output or suction stage of the pump. Since the suction stage merely pumps up liquid which is provided with a free return I5 to the tank from the reservoir 60, I 2I, as soon as the pump starts the low pressure stage is capable of discharging air back to the tank I2 and thereafter sucking up liquid which is discharged into the reservoir 60, I2I. This makes the pump self-priming under practically all conditions, even when all of the liquid is exhausted from the pump, and a supply of liquid fuel is provided for the high pressure stage from the reservoir 60, I2I as soon as the pump starts. The standpipe I33 is a useful auxiliary feature which further aids the immediate supply of liquid to the high pressure stage by retaining in the reservoir 60, I2I a level of liquid up to the end of the standpipe for immediate use.

The liquid fuel is, therefore, supplied under pressure through the conduit I21, to the pressure regulator valve chamber I I2, and any excess over that utilized by the oil burner may be discharged back to the reservoir 60, I2I through the conduit I which is controlled by valves, hereinafter to be described.

The pressure regulator valve housing 40 is substantially cylindrical in plan and is provided with an outlet or burner port I35 located in a downwardly extending lug I36. This outlet port is threaded to receive the threaded metal plug I31, having a cylindrical counterbore I38 communicating with a port I39. Plug I31 has a non-circular outer portion I40 which is threaded home against the end of the lug I36, with a gasket I4I interposed.

The lower end I42 of plug I31 is threaded to receive the usual nipple I43 which is rotatably mounted on the burner supply conduit I6. Mounted in the counterbore I38 is a shouldered metal sleeve I44, having its lower cylindrical end in close frictional engagement with the interior of bore I38. An outwardly extending shoulder I45determines the final position of sleeve I44, and sleeve I44 is provided with a bore I46 communicating with bore I39. The upper end of bore I46 may be made frusto-conlcal to provide a seat for the needle valve I41, which is mounted upon the lower end of the piston I48.

Piston' I48 is provided with a peripherally extending groove I49, which is adapted to provide communication between the port I50 and port I5I in the sleeve I66 when the groove I49 is in registry with ports I50, I5I. Groove I49 is so located, however, that it is out of registry with the ports I50, I5I when the needle valve I41 is upon its seat so that the needle valve port I46 is opened first and afterwards, on further movement of the pi ton I48, the ports I50, I5I are placed in communication with each other.

Piston I48 comprises a substantially cylindrical member provided at its lower end with an enlarged aperture 22I for permitting movement of a needle valve I41 therein. The needle valve I41 has a ball 222 located on its inner end, and the ball 222 engages a complementary socket in a plug 223 located inside the bore 224 in the pis- .I55, having an aperture of sufficient size to receive the bellows, and projecting laterally into the counterbore I56 in the housing 40.

Counterbore I56 is threaded to receive a threaded cover I51, and the annular plate I may be clampedbetween the end of the plug or the cover plug I51 and the annular shoulder I58.

Cover plug I51 is also provided with a threaded bore I59 for receiving the threaded screw bolt I60, which may be secured in place by lock nut I6I. The cover plug is also preferably provided with a threaded lug I62 surrounding the screw bolt I for receiving the cap I63. The lower end of screw bolt I60 bears against a spring plate I64 which has a centrally located semi-circular portion and an outwardly extending flange I65, forming a seat for a compression spring I66a.

The spring I660 engages the end plate I53 In the bellows I54 and tends to hold the needle valve I41 closed, but the valves may .be opened by fluid pressure acting upon the bellows I54 in the housing 40. The tension of the spring I66a may be adjusted by means of the screw bolt I60 so that the bellows will be opened at any predetermined pressure desired. The sleeve I66 -may comprise a metal member of metal dissimilar from the piston I48. For example, the piston may be made of steel and the sleeve of brass, and the sleeve I66 has a close frictional fit in the bore I52 in lug H5. The ports I50, I5I are adapted to register with the ports III, II! in the lug II5. considered as a part of the by-pass ports H8, H9, I50, I5I, in which is located the piston I48 for controlling the by-pass port, and the needle valve I41 is likewise located in the burner outlet port I 46.

The housing 40 is preferably provided with a threaded outlet port I69, which is closed by the threaded plug I10, which may be utilized for an auxiliary outlet or inlet, if desired, or for observing the action of the valve, without completely disassembling it. i

The port II9 communicates with the reservoir space I20, I2I surrounding the pump, and the piston valve I48 is thus adapted to by-pass back to the reservoir such amount of liquid fuel as is not required to feed the burner.

The course of the fuel through the device is as follows: Fuel is drawn in through the suction pipe I4 from the supply I3 in the tank I2, passing into the chamber 43 of strainer housing42. The liquid fuel passes through the strainers 14 into the tube 69, thence into the chamber 85 and out through conduit 86 (Fig. 4), slots IIO, to the intake side of the suction stage of the pump, comprising the gears 98, 99.

The liquid fuel is discharged from the gears 98, 99 at slot H3 and passes through conduit I24 into the space I22, I23, I20, I2I, 60, surrounding the pump housing 58. From this space it is fed into the high pressure stage of the pump, comprising the gears 96, 91, through the slot I26, and is discharged through slot I28 at the oppo site side of the gears into conduit I21. Conduit I21 leads into the chamber II2 of the pressure regulator valve housing 40, and the liquid fuel under pressure acts against the bellows I54 to compress the bellows. When the pressure has reached a suillcient amount to compress the bellows, the needle valve I41 is opened and the Bore I68 in sleeve I66 may be 25 pressure continues to rise until it has reached the portsI50, I5I and any excess of oil is by- 70 passed back through ports H8, H9, I50, I5I to the reservoir 60, I20, I2I, I23 surrounding the pump.

The standpipe I33 projects up into the liquid fuel in the reservoir and prevents flowing back of fuel except when it rises above the end I34 of the standpipe, but 'any excess of fuel above this level is permitted to flow back freely through pipe I33 and pipe l5 to the tank I2. If it is desired to use this unit with a one pipe arrangement, then the port I29 may be plugged up and the plug I30 removed so that any excess oil may be discharged back from the suction stage into the strainer chamber 43.

The present unit is thus equally adapted for two pipe systems or one pipe systems, and may be used with or without a free return to the tank.

It is found that the pump noise present in ordinary gear pumps is eliminated by means of the present arrangement and the pulsations or vibration in the liquid fuel are not carried back through the pipe to the tank. The interposition of the reservoir in between the low pressure stage and the high pressure stage causes the flow of oil to slow up or lose its velocity and breaks up the vibration. The oil surrounding the pump also deadens the transmission of sound to the air and the increased mass of metal and oil act as sound absorbers, making the present pumping arrangement substantially noiseless for all practical purposes.

While we have illustrated a preferred embodiment of our invention, many modifications may be made without departing from the spirit of the invention, and we do not wish to be limited to the precise details of construction set forth, but desire to avail ourselves of all changes within the scope of the appended claims.

Having thus described our invention, what we claim is new and desire to secure by Letters Patent of the United States, is:

1. In a fuel supply unit for oil burners or the like, a casing having two laterally spaced cylindrical portions with the axes of said cylindrical portions extending parallel to each other, said cylindrical portions being joined by an integral medial housing portion of partially cylindrical form having its axis extending at substantially right angles to the axes of the first-mentioned cylindrical portions, one of said cylindrical portions forming a strainer housing, and the other of said cylindrical portions forming a regulator valve housing, a web disposed between said strainer housing and said medial portion. and a second web disposed between said regulator valve housing and said medial portion, an integral inwardly projecting lug formed in said medial housing, said lug supporting a pump casing substantially surrounded by a space communicating with said strainer housing and adapted to be substantially filled with fuel oil to absorb the pump noise, and said lug having a discharge aperture extending from the interior of said pump housing to said regulator valve housing, end plates on said medial housing portion for closing the same, and cover means for each of said cylindrical portions, said strainer housing having a transversely extending partition, a downwardly extending perforated tubular member and a plurality of wire mesh wafers carried by said tubular member.

2. In a fuel supply unit for oil burners or the like, a casing having two laterally spaced cylindrical portions with the axes of said cylindrical portions extending parallel to each other, said cylindrical portions being joined by an integral medial housing portion of partially cylindrical form, having its axis extending at substantially right angles to the axes of the first-mentioned cylindrical portions, one of said cylindrical portions forming a strainer housing, and the other of said cylindrical portions forming a regulator valve housing, a web disposed between said strainer housing and said medial portion, a sec- 5 0nd web disposed between said regulator valve housing and said medial portion, an integral inwardly projecting lug formed in said medial housing, said lug supporting a pump casing substantially surrounded by a space communicating with said strainer housing and adapted to be substantially filled with fuel oil to absorb the pump noise, said lug having a discharge aperture extending from the interior of said pump housing to said regulator valve housing, plates on said medial housing portion for closing the same, cover means for each of said cylindrical portions, said regulator valve housing having an inwardly projecting lug provided with a conduit communicating with the space in said medial housing portion 20 surrounding said pump housing, a piston valve slidably mounted in a bore transversely to said conduit, said piston valve having a circumferentially extending slot providing communication between parts of said conduit when in predetemiined position, a conical valve member universally mounted on the end of said piston valve for controlling an outlet port to a burner, and a pressure responsive bellows for controlling both of said valves.

3. In a fuel supply unit for oil burners or the like, a casing having two laterally spaced cylindrical portions with the axes of said cylindrical portions extending parallel to each other, said cylindrical portions being joined by an integral 35 media] housing portion of partially cylindrical form, having its axis extending at substantially right angles to the axes of the first-mentioned cylindrical portions, one of said cylindrical portions forming a strainer housing, and the other of said cylindrical portions forming a regulator valve housing, a web disposed between said strainer housing and said medial portion, a sec- -ond web disposed between said regulator valve housing and said medial portion, an integral inwardly projecting lug formed in said medial housing, said lug supporting a pump casing substantially surrounded by a space coimnunicating with said strainer housing and adapted to be substantially filled with fuel oil to absorb the pump noise, said lug having a discharge aperture extending from the interior of said pump housing to said regulator valve housing, and plates on said medial housing portion for closing the same, cover means for each of said cylindrical portions, one of the cover plates for said medial housing having a laterally projecting seal housing, a pump shaft projecting out of said seal housing, a cover plate for said seal housing, a diaphragm having its outer edge clamped between said cover plate and seal housing and having a metallic fitting surrounding said shaft and provided with a fiat end surface, a collar having a complementary surface and having a fluid-tight connection with said shaft, said collar 66 having a sliding contact with said fitting for preventing leakage along said shaft.

4. In a fuel supply unit for oil burners or the like, a pump comprising an inner housing having bores for receiving pumping gears, low pressure 70 stage gears and high pressure stage gears in said inner housing, an outer housing comprising a metal shell in spaced relation to said inner housing, said outer shell being joined to and supporting said inner housing by a pair of joining lugs. and said lugs having intake and outlet conduits formed therein communicating with the low pressure stage inlet and the high pressure stage outlet respectively, and conduits providing communication from said low pressure stage output to the space between said housings and from 1 said space to the intake of said high pressure stage.

5. In a fuel supply unit for oil burners or the 10 like, apump comprising an inner housing having bores for receiving pumping gears, low pressure stage gears and high pressure stage gears in said inner housing, an outer housing comprising a metal shell in spaced relation to said inner housing, said outer shell being joined to and supporting said inner housing by a pair of joining lugs, and said lugs having intake and outlet conduits formed therein communicating with the low pressure stage inlet and the high pressure stage outlet respectively, and conduits providing communication from said low pressure stage output to the space between said housings and from said space to the intake of said high pressure stage, and an upwardly projecting conduit located in said space and providing a free return conduit from said space to a supply tank.

6. In a liquid fuel supply unit for oil burners,

the combination of a housing provided with a pump chamber, a valve chamber and a strainer so chamber, said strainer chamber having an inlet port adapted to be connected to a source of liquid fuel supply and having an outlet port communicating through said housing with the pump chamber inlet port, a strainer unit in said strainer chamber and interposed between the strainer inlet and outlet ports, said pump chamber having an outlet port communicating with said valve chamber, pressure responsive means in said valve chamber and subject to the pressure of liquid fuel supplied from said pump outlet port, said valve chamber having a burner outlet port and a by-pass outlet port, valve means actuated by said pressure responsive means for controlling said burneroutlet port and said by-pass outlet port whereby the by-pass outlet port is adapted to discharge from the valve chamber any excess of liquid fuel above that passed by the burner outlet port, conduit means within the housing leading from the. by-pass outlet port and having the pump and with a pipe leading to the source of fuel supply, and'closure means for selectively closing one or the other of .said communications whereby said fuel supply unit may be used in a one pipe or two pipe supply system.

'I. In a liquid fuel supply unit for oil burners, the combination of a housing provided with a pump chamber, a valve chamber and a strainer chamber, said strainer chamber having an inlet port adapted to be connected to a source of liquid fuel supply and having an outlet port communicating through said housing with the pump chamber inlet port, a strainer unit in said strainer. chamber and interposed between the strainer inlet and outlet ports, said pump chamber having an outlet port communicating with said valve chamber, pressure responsive means in said valve chamber andsubject to the pressure of liquid fuel supplied from said pump outlet port, said valve chamber having a burner outlet port and a by-pass outlet port, valve means actuated by said pressure responsive means for controlling said burner outlet port and said by-pass outlet port whereby the by-pass outlet port is adapt- .ed to discharge from the valve chamber any excommunication respectively with the inlet port of cess of liquid fuel above that passed by the burneroutlet port, conduit means within the housing leading fromthe by-pass outlet port and having communication respectively with the inlet port of the pump and with a pipe leading to 5 the source of fuel supply, and closure means for selectively closing one or other of said communications whereby said fuel supply unit may be used in a one pipe or two pipe supply system, one of said closure means comprising a threaded o plug provided with a tool receiving, formation and located in a threaded bore inside said housing in substantial alignment with an external port whereby a screw driver or other tool may be inserted through said latter port to remove 15 said threaded plug.

8. In a liquid fuel supply unit for oil burners, the combination of a housing provided with a pump chamber, a valve chamber and a strainer chamber, said strainer chamber having an in- 20 let port adapted to be connected to a source of liquid fuel supply and having an outlet port communicating through said housing with the pump chamber inlet port, a strainer unit in said strainer chamber and interposed between the strainer 25 inlet and outlet ports, said pump chamber having an outlet port communicating with said valve chamber, pressure responsive means in said valve chamber and subject to the pressure of liquid fuel supplied from said pump 'outlet port, said valve chamber having aburner outlet port and a by-pass outlet port, valve means actuated by said pressure responsive means for controlling said by-pass outlet port whereby the by-pass outlet port is adapted to discharge from the valve chamber any excess of liquid fuel above that v passed by the burner outlet port, conduit means pump chamber and a valve chamber, with pumping means in said pump chamber adapted to 50 pump a volume of liquid fuel inexcess of that required for the burner, said housing having an inlet port communicating with the inlet side of the pump chamber and adapted to be connected to a source of liquid fuel supply, and said hous- 55 ing having a pump chamber outlet port communicating with said valve chamber, pressure responsive means in said valve chamber and subject to the pressure of liquid fuel supplied from said pump outlet port, said valve chamber hav- 5o ing a burner outlet port and a by-pass outlet port, valve means actuated by said pressure-responsive means for controlling said by-pass outlet port, whereby the by-pass outlet port is adapted to discharge from the valve chamber the ex- 55 cess of liquid fuel supplied to said valve chamber from the pump chamber in excess of the liquid fuel passed by the burner outlet port, said unit having selective conduit means within said unit leading from the by-pass outlet port and having communication respectively with the inlet port of the pump chamber and with an outlet adapted to be connected to the source of fuel supply, and closure means for selectively closing one or the other of said communications whereby said fuel supply unit may be arranged to return excess liquid fuel to the intake port of the pump or to the source of fuel supply.

10. In a liquid fuel supply unit for oil burners, the combination ofa housing provided with a pump chamber and a valve chamber, with pumping means in said pump chamber adapted to pump a volume of liquid fuel in excess of that required for the burner, said housing having an inlet port communicating with the inlet side of the pump chamber and adapted to be connected to a source of liquid fuel supply, and said housing having a pump chamber outlet port communicating with said valve chamber. pressure responsive means in said valve chamher and subject to the pressure of liquid fuel supplied from said pump outlet port, said valve chamber having a burner outlet port and a by-' pass outlet port, valve means actuated by said pressure-responsive means for controlling said by-pass outlet port, whereby the by-pass outlet port is adapted to discharge from the valve chamber the excess of liquid fuel supplied to said valve chamber from the pump chamber in excess of the liquid fuel passed to the burner outlet port, said unit having selective conduit means within said unit leading from the by-pass outlet port and having communication respectively with the inlet port of the pump chamber and with an outlet adapted to be connected to the source of fuel supply, and closure means for selectively closing one or the other of said communications whereby said fuel supply unit may be arranged to return excess liquid fuel to the intake port of the pump or to the source of fuel supply, one of said closure means comprising a threaded plug provided with a tool receiving formation and located in a threaded bore inside said housing in substantial alignment with an external port whereby a tool may be inserted through said latter port to remove or install said threaded plug.

ARTHUR C. KLECKNER.

HARRISON E. FELLOWS.

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