US2209856A - Fuel supply pump - Google Patents

Description

July 30,1940.. w, J, SMH-H ET AL 2,209,856

' n `FUEL spPPLY PUMP I Filed March 4. 1939 -4 Sheets-Sheet July 30,1940.` w. 3. SMITH fr@ 2,209,856

' FUEL SUPPLY P UMP v l A "Filed March 4, 1939 Sheeits-Sheet 3 ATIQRNEY4 l1940. w, J, sMn-H ET AL 2,209,856

- FUEL s UPPLY PUMP Filed March 4. 1939 v4 sheets-sheet 4 if-1E wmyvgNToR ATTORNEY Patentedlluly 30, 1940 UNITED s TATEs PATENT FFICE FUEL SUPPLY PUMP William J. smith and william W. slaght, Rocky River, Ohio, assignors to Cleveland Steel Products Corporation, Cleveland, Ohio, a corporation of Ohio Application March 4, 1939,v Serial No. 259,901

9 Claims.

This invention relates to fuel supply pumps and particularly to pressure pumps for use with oil burning apparatus.

One of the objects of the present invention 1s to provide a fuel supply pump for oil burning apparatus which is compact in its arrangement of parts, simple in construction and arranged to bel quickly and easily assembled.

Another object is to provide a fuel supply pump of such construction that it can be quickly oil.under pressure to the oil burner, which is of such construction that the oil is supplied under pressure to the lsecond gear set.

Another object, is to provide an oil burner fuel supply pump of the multi-stage type in which the primary stage pumping means serves as a booster for thesecondary stage pumping means and in which a portion of the load on one pumping means is borne by the otherpumping means.

A further object is to provide an oil burner fuel supply pump in which the pump casing is provided with integral strainer and pressure regulating chambers and in which the strainer means is of new and improved construction.

Referring to the accompanying drawings, which illustrate suitable embodiments of the present invention, v

Figure 1 is a plan view of the pump, showing the same mounted on a driving motor:

Figure 2 is an end elevation of the pump, a portion of the closureplate being broken away.

Figure 3 is an enlarged longitudinal section of the pump taken approximately on'the line 3 3 of Figure 2, showing the detailed construction of the pump interior;

Figure 4 is an enlarged transverse section taken on the line e-l of Figure 1, showing the strainer and' pressure regulating mechanism in particular;

. Figure 5 is a schematic diagram showing the passage of the oil during the pumping-operation;

Figure 6 is an enlarged section taken on line 5 6 of Figure 2;

. strainer cap;

Figure 7 is a transverse section taken on line 7--1 of Figure 6;

Figure 8 is a transverse section taken on line 8 8 of Figure';

Figure 9 is a plan view of the upper end of the Figure 10 is side elevation of the upper end of the strainer cap, a portion of the same being in section;

Figure 11 is a side elevation of the strainer, a

portion of the same being in section;

Figure 12 is a fragmentary section corresponding in part to Figure-3, showing amodified construction for use in an oil burner system of the two-pipe type; Y

Figure 13 is a view like Figure 12 in which .the modified construction is reversed for Vuse in a burner system of the one-pipe type, and A Figure 14 is a fragmentary upper plan View of the arrangement shown in Figure 13, a portion l of the same being shown in section.

In fuel pumps for oil burning apparatus -it is frequently the practice to employ a multiple stage apparatus in which one pumping means is employed to draw the oil from the oil supply tank and a second pumping means is employed to deliver the withdrawn oil to the oil burner nozzle.

In such constructions the withdrawn oil is at atmospheric pressure and the pressure of the oil delivered to the oil burner nozzle is produced entirely by the second pumping means.

Briefly, our invention is primarily directed to i the provision of an intermediate chamber or passage between the primary and secondary stages in which the oil supplied thereto from the source of supply is placed under a pressure above atmospheric pressure, and in which the pressure is controlled in such manner that it will not exceed a selectable predetermined pressure. vIn providing for this the primary stage gears or pumping means supplies the oil to this chamber and builds up the pressure therein, and the secondary stage gears or pumping meansv withdraws this oil which is under pressure and delivers it for supply to the oil burner under a predetermined higher pressure. y

' Assuming that the oil is to be delivered from the pumpto the oil burner nozzle underra predeterminedpressure, We have found that byfpr'oviding a pressure above atmospheric, on the oil intermediate the primary and secondary stages, a portion of the load on. the secondary stage pumping means is shifted to the primary stage vpumping means with the result that the pump will operate'more emciently-and will havelonger 4life than one of the same size not employing an intermediate pressure between the two stages. In this connection, the primary stage pumping means serves as a booster for the secondary stage 3 pumping means.

Our invention is also directed to an improved arrangement of parts, and particularly to an improved means for easily converting the pump for operation in a one-pipeor a two-pipe oil burner system, and to the strainer device for freeing the oil of dirt and sediment, as will hereinafter appear. s

Referring to the accompanying drawings in which like numerals referto like parts through- 13 out the several views, first, describing the pump body, the entire pump is housed within a single body member or casting having a strainer chamber 2i., a discharge or pressure regulating chamber 22, a pressure chamber 23 at one end which is closed in by a cover plate 24 secured to the body casting 20 by suitable cap screws 26, and a seal chamber 26 at the opposite end. Referring to Figures 4 and 6, in particular, it is to be noted that the strainer and pressure 'regulating cham- 25 bers 2i and 22', respectively, comprise bores having parallel vertical axes arranged at opposite sides of the common horizontal axis of the pressure and seal chambers 23 and 26, respectively, and adjacent the seal chamber 26, thus providing 3,0 a compact integral arrangement.,

The body casting 20 is provided, as shown in Figures 3 and 6, with a bore 21 coaxial with the seal chamber 26 and opening at one end into the l seal chamber 26, the opposite endbeing formed 5 v with an eccentrically arranged counter-bore 28. Disposed within the bore 21 is a flanged shaft bushing 29 which is inserted from the seal chamber end of the body casting 20.

The pumping unit, which will now be described, is assembled from the pressure chamber end of the body casting 20, before the cover plate 24 is assembled, and comprises a shaft 30, primary stage gears 3|, secondary stage gears 32, a crescent plate 33 and a crescent plate 34. Referring to Figures 3, 6 and '1, the crescent plate 34 is formed with a closed end bore 36 in theface 36 thereof, which forms a journal forone end of the shaft 30, and with a crescent 31 projecting from the face 36. Fixed to the shaft 50,30 by means of a key 38 is the gear 32a of the secondary stage gear set 32 which engages with the face 36 and the radially inner face 39 of the crescent 31. The other gear 32h of the gear set 32 is of the internal type, having its teeth meshed lwith the gear 32a and rotatably engaged with the radially outer face 40 of the crescent 31.

The crescent plate 33 is formed with a laterally `extending crescent 4i on its face 42, a shaft bore 43 and with a counter bore 44 in its other '60 face 45. The face 45 seats against the face 36 f the crescent plate 34, with the counter bore`44 surrounding the secondary stage gear 32h in close running engagement. The primary stage gear 3Ia of the gear set 3i is fixed' to the shaft o5 33 by means of a pin or key 43 and engages with the face 42 and with the radially inner face 41 of the crescent 4i, and, similar to the gear 32h, the gear 3|b of the primary stage gear set 3i -is of the internal type and has running engagement 70 With the radially outer face 43 of the crescent 4I.

In the assembly, the shaft 3il extends through the journal 29 and gear 3ib is disposed within the counter bore 28 with' close running engagement, the face 42 of the plate 33 engaging the face 48 ofthe body casting. The sub-assembly4 just described is secured to this face 48 by suitable cap screws extending through the plates 33 and 34, and, in the assembly, the gears of the two sets have substantially sealed running engagement with the faces of the parts described 3 so as to prevent substantial leakage. During operation the gears 3ib and 32h rotate around the gears 3ia and 32a respectively. It is to be noted that shaft 30 extends beyond the journal bushing 28 and into the seal chamber 26. Y l0 The pump passages, which will now be described, comprise inlets and outlets for each stage. The inlet for the primary stage gear set 3i comprises .a passageway 6i (Figure 4) communicating at one end with the upper end of the strainer l5 chamber 2| and at its other end with one end of a passageway 62 (Figures 3 and 4) disposed in the pump body casting above the shaft 30, the axis of the passageway 62 being parallel with the axis of the -shaft 33, and opening through the 20 face 49 into communication with a passageway, 63 formed in the face 42 of the crescent plate 33 and opening to the primary stage gears 8ia and 3ib at the left and Just above one end of the crescent 4i, as shown in Figure '1.

The outlet for the gears 3ia and 3Ib is at the right and just above the other end of the crescent 4i as viewed in Figure 1 and is through a discharge passageway 64 in the face 42 of crescent plate 33, which passageway 64 opens directly 30..

through the periphery of the plate 33 into the pressure chamber 23.

The inlet passages for the secondary stage gear set 32 include a pwageway 66 formed in the crescent plate 34, opening at one end through 35.

the periphery of the plate 34 (Figure 8) to the pressure chamber, and at the other end in a port 66 to the gears 32a and 32h at the left and just above the end of the crescent 31, as viewed in Figure 8. 40,

, The outlet passages for the secondary stage gear set 32 include a port 61 opening from the l gears 32a` and 32h at the right and just above the otherv end of the crescent 31, as viewed in Figure s, into a passageway sa m the plate u which ter- 45' minates in a port 68 that opens into a passageway 68 in the plate 33, which passageway 60 (Figures 3 and 8) opens in turn into a passageway 3i in the body casting 20, the latter passageway being below the shaft 30 and parallel thereto. The 60' passageway 6i communicates with a passageway 62 in the body casting 26 which'opens into the pressure regulating chamber 22 near the lower end thereof, as shown in Figure 4.

Referring now to Figures 4, 6, 9, 10, and 11, the 65 strainer chamber 2i is closed at its lower end by a threaded plug 33 having an opening 64 therethrough which is threaded at 66 for` the reception of an inlet pipe fitting and inlet pipe 36a, (Figure 2) which leads to the supply tank (not shown), 80.

and at'66 with a counter bore to form a sump or well. The strainer proper comprises a relatively deep cup shaped lower end piece 31 preferably in the form of a. sheet metal stamping, an upper inverted cup-shaped end piece 33 in the form 65 n of a metal stamping, and an endless strainer screen 33 having its open ends fitting within said end pieces 31 and 33. The screen 36, instead of v being cylindrical, as is the usual practice, is formed with a plurality of longitudinally extend- 70 ing corrugations or indentations 13, thereby forming a plurality ofgenerally radial4 screen surfaces 1i, as shown in Figure 6. The upper end piece 63 is formed with apertures 11 corresponding in number to the number of indentations 10, and '75, l

each aperture is without or exteriorly of the screen 69A and disposed between the adjacent screen surfaces 1| that form one indentation 10. Secured within a central opening in the lower end piece 61 is a vertically rising tube 13 having openings 14, therethrough near its upper end, as shown in Figure 4.V As shown in this view, the strainer assembly just described is positioned within the chamber 2| with the end pieces 61-'and 68 engaging the wall thereof and with the lower end piece resting on the closure plug 63. In this position the upper end piece is slightly below the outlet to the pump inlet passageway 5|. A closure -tube 13 and thence outwardly through'the openings 18 into the space within the screen 88. The

oil then passes through the screen walls 1| and l upwardly through the apertures 11 into the space above the end piece 68 from which the pump inlet 5| opens.

The lower end piece 61 forms a sump or settling chamber into which the sediment collects.

In order to clean the strainer, the plug 15 and spring 16 are removed, and the assembly is removed by the use of a suitable hooked instrument, after removal, the parts can be separated and cleaned. In this connection all of the sediment removed from the oil by the screen 89 collectsin the sump provided by the cup-shaped lower end piece 81, so that upon removal of the screen, none of the sediment will fall back into the suction line.- 'v

Referring now to Figure 4, the lower end of the pressure regulator chamber 22 is closed by a threaded plug 18, there being a gasket 19 of layers of suitable material of variable thickness between the flange of the plug 18 and the body casting. 'Ihe plug 18 is formed with a threaded aperture for reception of a suitable outlet fitting and outlet pipe 80a (Figure 2) which leads to the oil burner (not shown), and the portion extending into the chamber 22 is counterbored at 8| to receive a valve member 82 having a discharge port 83 therein. The pressure regulating mechanism comprises a tubular member BLitted tightly within the chamber 22 and having its lower end slightly above the outlet part of the discharge passageway 62. Reciprocably mounted wit'sin the member 84 is a cup-shaped member 85 having at its lower closed end 88 a valve needle 81 for cooperation with the discharge port 83. The valve needle 81 is urged to its port-closing position by a compression spring 88 having one end within the cup-shaped member 85 and its opposite end engaged with an abutment iiange 89 formed on a screw member 90 which is threadably carrried by a closure plug 9| that is threaded into the upper end of the chamber 22. The upper end of the screw member 80 projects into a counterbore 92 formedinthe upper side of the plug 9|. In order to conceal this end of the screw member, a threaded closure element 83 is provided to close the counter bore 92. It is apparent that by adjusting the screw 90 that needle 81 can be made to move from its seat at any desired pressure.

It is preferable to limit the pressure at which the oil passes through the discharge port 83, and in order to provide for this, a relief passage within the sleeve 84 and above th'e sleeve.

94 is provided in the bore of the sleeve 84 and openings 95 are provided through the cylindrical wall of the cup-shaped member 85. In operation. the pressure of the oil within the space between the closed en'd 85 and valve plate 82 causes the member 85 to slide in the sleeve 84 and lift the needle to open the port 83. As the pressure increases, the member 85slides upwardly within the sleeve 84 against the compression of spring 88, and when a predetermined pressure is reached the closed end 86 of member 85 clears the relief passage 84 so that the excess oil will pass through the passage 98 and the openings 95 into the space Thus, the action of the pressure of the oil below the member 85 and the counter-acting pressure of the spring 88 together with the relief passage 90 allows only a predetermined pressure on the oil flowing through port 83 to be reached.

A relief passage 86 is provided in the body casting which opens into the space adjacent the upper closure plug 9| for the regulating chamber 22, and which communicates as shown in Figure 6 with a pressure relief chamber 91 (Figures 3, 4, 6 and 7). While adjustment of the regulating valve mechanism is obtained by means of the screw 90,v adjustment for the cut oif differential is obtainable by removing desired thicknesses of the laminated gasket 19 to vary the position of the valve member` 32. I

With respect to the pressure chamber 23 and with reference to Figure 3, it has been previously described that the primary stage pumping means 3| -pumps oil into the pressure chamber 23 and that the secondary stage pumping -means 32 pumps oil from this chamber. In accordance with the present invention a pressure is maintained so that the secondary stage gear set 32 y draws the oil from a zone which is under a pressure above atmospheric. This is accomplished by providing the pressure chamber with a relief valve mechanism so that a predetermined pressure will be maintained therein but which will not exceed a desired maximum. In this connection 89 is tapered to form a valve seat |0|, surrounding the end of opening 98, for engagement therewith of a valve ball |02. 'I'he ball |02 is urged to closed position by a compression spring |03 which is held in compression by a cap |08 threaded into the counter-bore 89. The gasket |85 for the cap |04 is of the laminated variable thickness shim type so that the spring may be adjusted for'the desired compression Wherebyto predetermine the pressure at which the .valve |02 will move from its seat |0| and permit oil to ilow into the pressure relief chamber 91 when the predetermined pressure in chamber 23 is reached. By removing different thicknesses of the gasket material |05 thedesired compression may be placed in the spring |03.

It isthe practice in some oil burner installations toemploy what' is commonly known as a two pipe system or a one pipe system. In two pipe systems, the excess or by-pass oil is re turned through a pipe to the storage tank, and` in one pipe systems the excess oil is returned tothe suction side of the pump. The fuel supply device of the present invention is arranged to be usedwith either a two pipe system or a one pipe system by merely opening one psageway and closing another. We have shown variationsof this arrangement in the drawings. In the construction shown in Figures 3 and 7, it is to be noted that the pressure relief chamber 91 extends around one side of the pump body casting from the top to the bottom thereof and that this chamber opens through the bottom of the casting in a threaded port |06 which is closed by a plug |01. It is also to be noted that the relief chamber 91 at the upper side of the pump body casting is formed with a lateral extension |08. This extension connects with the intake passageway 52 (Figure 3) through a vertical passage |09.

When the pump is used in a one pipe system,

the closure plug |01-is left in place and the excess or by-pass oil from the pressure chamber 23 and the pressure regulating chamber 22 which passes into the relief chamber 91 returns to the suction side of the primary stage pumping means through the passage |09.

When, however, the pump is used in a two pipe system, the closure plug |01 is removed and a pipe (not shown) leading to the fuel supply tank (not shown) is connected to the threaded port |66 in its place', and the passage |09 closed, in which case the excess or by-pass oil flows fromthe relief chamber 91 through the return pipe described to the fuel supply tank.

In Figure 3, the closure means for the passage |09 under the condition described comprises a valve needle mounted on or forming a part of a screw element threaded in an opening ||2 through the body casting 20, which opening is coaxial with the passage |09 and which may be closed by a closure plug I3. By threading jacent the passage |09, 'which opens into the reliefchamber 91. When the two pipe system is used these two passages |09 and I4 are closed that is secured tothe body casting by a screw ||1, the solid surface of the gasket and the one side face of the member H6 sealing and closing off these passages as shown in Figure 12.

The member ||6 has an annular groove IIB in its opposite side face and the gasket ||5 has openings l |I9 therein spaced the same as the passages |09 and 4, so that when the pump is to be used in a one-pipe system, it is only necessary for the installation man to align the gaskets openings H9 with the passages |09 and ||4 and mount the member ||6 in place with the grooved side in engagement with the gasket I5, as shown in Figure 13. In this case the excess or by-pass oil will flow from the chamber 91 through pas- -sage ||4 to the groove |8 and thence through passage |09 to the pump inlet passageway 52. It is obvious that other well known means for closing and/or connecting the passages 09 and ||4 may be provided.

With further reference to Figure 3, a suitable seal is provided for the shaft 30, which comprises a bearing plate engaged-with the end of bushing 29, a second annular member |2| pressed on the shaft which engages plate |26 and a shouldered non-rotatable collar |22 closely surrounding the shaft 30 and having end thrust vengagement with the member |2|. Mounted between the collar |22 and a washer-like member |23 carried on `the collar |22 is a flexible disk |23 of suitable oil vsealing material which seats on a shoulder formed in the seal chamber 26. The flexible disk |24 is securely clamped between the washer |23 and collar |22 and against the shoulder |25 by means of a cup-shaped element |26 having its peripheral edge engaged with the peripheral portion of the disk |24, between which member |26 and the washer |23 there is a spring |21 under compression. A

vplate |28 surrounding the shaft 30 is secured to the body casting by screws |29 and abuts the 4element |26 to clamp the flexible disk |24 between shoulder |25 and element |26 and to compress the spring |21 to thereby clamp the disk |24 between the washer |23 and collar |22.

A running seal is thus provided which prevents leakage of oil from the seal chamber 26 which might leak therelnto from the shaft bearing.

As shown in Figure 6, a passage |30 is preferably provided between the seal chamber 26 and strainer chamber 2| so that the suction will draw excess oil from the seal chamber 26.

Suitable mounting flanges |3| may be provided on the body casting 20 for. mounting the pumpen a motor |32, shownin Figure l, the motor and pump shafts having suitable interlocking parts to provide a drive connection.

If desired, the body casting 20 may, as shown in Figure 3, be provided with `a passage |33 leading to the discharge passage 6| so that a gage (not shown) may be attached theretoto determine the pressure being produced. 'Ihis passage |33 is normally closed by a closure plug |34.

In order to more clearly show the passage of oil through the fuel supply device described and in order to more clearly set forth the operation of the device, a schematic arrangement of the parts and passages is shown in Figure 5. Referring now to Figure v5, and bearing in mind that the primary stage and secondary stage gear sets are driven by the same shaft, and assuming that the device is in operation, the primary stage gear set,'of course, creates a suction withthe result that oil is withdrawn from the fuel supply tank through pipe 65a. This oil is drawn upwardly through the pipe 13 within the strainer chamber 2| and strainer screen 69, passes through the strainer screen 69 and thence through passageways 5I, 52 and 53 an'd the inlet port A. 'I'he oil is discharged under pressure through the discharge port B and the outlet passage 54 into the pressure chamber 23 wherein a predetermined pressure is created. The secondary stage gear set 32 likewise creates a suction and theoil in chamber 23, which is under pressure, is withdrawn through the intake passage 65 and intake port C. 'I'he oil is discharged under pressure through the discharge port D and thence throughpassageways 60, 6| and 62 into the pressure regulating chamber 22 for discharge through the controlled` discharge port 83 to the pipe 80a which leads to the oil burner nozzle, the pressure of the oil causingmember 86 to lift needle 81 from the seat. Should the pressure of the oil exceed a predetermined maximum, the excess pressure raises the member 86 to clear the edge of the by-pass passage 94 and a portion of the oil passes through the by- Apass 94, rises in chamber 22 and flows through passageway 964 to the relief or by-pass chamber anism in the regulating chamber 22 thus* funct 91. The spring 88 and attendant valve mechtions to maintain a predetermined pressure on the oil iiowing through the outlet port 83 toY the oil burner and to by-pass oil whenever the oil pressure tends to exceed the predeterminedpressure. a

Also, the pressure of the oil in the pressure chamber 23 is limited to a predetermined value, and should the pressure tend to increase beyond this value the ball |02 opens the port 98 to bypass oil through passage |070 to the relief or by-pass chamber 91.

The oil in theby-pass chamber 31 in` a onepipe system, such as shown in Figure 5, flows, due to suction pressure, through passageway |09, the valve needle il@ being away from its seat under this condition, and thence through inlet passageways 52 and 53 to the suction side of the primary stage gear set 3| for recirculation. If,

however, the system is a two pipe system, the passageway |09 is closed by the valve needle Hit,

and a pipe (not shown) leading to the fuel supply tank is connected to the outlet |06 in lieu of the closure plug |01, and under such condition, the oil in the by-pass chamber Si drains portion of the load, i. e., the creation of the discharge pressure is borne by the primary stage gear set, thus relieving the secondary stage gear l set of the burden of all the load. The load is thus distributed between the two gear sets with the result that there is greater efficiency and economy of operation and the/life of secondary gear set is prolonged.

Various other advantages resultfrom the fuel supply device of the present invention. The arrangement is compact and neat appearing andl the parts are so arranged as to provide for easy and rapid assembly. Also a new and advantageous arrangement is provided for freeing the oil of dirt and sediment before it enters the pump gears.

Another advantageous feature is that various passages for the gears are so arranged that the gears will remain wetted tn provide for self-priming.

While preferred embodiments of the invention have been illustrated and described, it is to be understood that various changesmay be made in the detailed construction and arrangement of the parts without departing from the spirit and scope of the appended claims.

What we claim is:

l. A uel supply pump for oil burners and the like comprising a pump body having a pressure chamber therein, primary stage pumping means carried by said body, inlet and outlet passages for said means,`said outlet passage opening into said chamber, a secondary stage pumping means carried by said body, inlet and outlet passages for said secondary stage pumping means, said last named inlet passage opening from said` therein, a return passage for said discharge chamber for bil-.Passing oil therefrom when the mum, a pressure relief valve associated with said pressure chamber for by-passing oil to said rst mentioned return by-pass from said pressure chamber when the pressure therein exceeds a predetermined maximum, and a by-pass chamber in said body, said return passage and return by-pass being independent of each other and communicating with said by-pass chamber whereby oil from said return by-pass enters said by--pass chamber independently of said pressure chamber.

l2. A fuel supply pump for oil burners and the like comprising a pump body having a pressure chamber therein, primary stage pumping means carried by said body, inlet and outlet passages for said means, said outlet passage opening into said chamber, a secondary stage. pumping means carried by said body, inlet and outlet passages for said secondary stage pumping means, said last named inlet passage opening from said chamber,`

a return by-pass leading from said chamber, said last named outlet passage terminating in a discharge chamber, pressure regulating means associated with said discharge chamber for maintaining a predetermined pressure therein, a return passage for said discharge chamber for by-passing oil therefrom when the pressure therein exceeds a predetermined-maximum, a pressure re-- lier` valve associated with said pressure chamber 'for by-passing oil to said first mentioned return by-pass from said pressure chamber when the pressure therein exceeds a predetermined maximum, and a by-pass chamber in said body said return passage and^return by-pass being independent of each other and communicating with said by-pass chamber whereby oil from said return by-pass enters said by-pass chamber independently of said pressure chamber, said body having a passageway therein communicating with said by-pass chamber and the rst mentioned inlet passage.

3. A fuel supply pump for oil burners and the like comprising a pump body having a pressure chamber therein, primary stage pumping means carried by said body, inlet and outlet passages for said means, said outletpassage opening into said chamber, a secondary stage pumping means A carried by said body, inlet and outlet passages for said secondary stage pumping means, said last named inlet passage opening from said chamber, a returnA by-pass leading from said chamber, said last named outlet passage terminating in a discharge chamber, pressure regulating means associated with saiddischarge chamber for maintaining a predetermined pressure therein, a return passage for said discharge chamber for bypassing oil therefrom when the pressure therein exceeds a predetermined maximum,` a pressure relief valve associatedA with said pressure chamber for by-passing oil to said i'irst mentioned return by-pass from said4 pressure chamb'er when the pressure therein exceeds a predetermined maximum, and a by-pass chamber in said body said return passage and return by-pass being independent of each other and communicating with said by-pass chamber whereby oil from said return by-pass enters saidby-pass chamber independently of said\pressure chamber, said body having a passageway therein communicating with said by-pass chamber and the rst mentioned inlet passage, and manual means for ciosing said last named passageway.

4. In an oil supply pump for oil burners and the like, "a body casting closed at one end and open at the opposite end to provide a chamber, said closed end having a shaft bore in alignmentl with said open end, said body casting -having a strainer chamber and a regulating chamber therein, a pumping unit, said pumping unit com- 'prising plate members, a primary stage gear set and a secondary stage gear set carried by said plate members, a common drive shaft for said gear sets and inlet and outlet passages in said plate members for each of said gear sets, said pumping unit being insertable through said open end as a unitary structure, means for securing said unit to said closed end with said shaft extending through said bore, the outlet passage of said primary stage gear set and thc inlet passage of said secondary stage gear set opening into said first mentioned chamber, a passageway in said body casting between said strainer chamber and theinlet passage of said primary gear set, a passageway in said body casting between the outlet passage of said secondary gear set and said regulating chamber, and closure means for said open end.

5. A fuel supply pump for oil burners and the like comprising a body member having astrainer chamber, a regulating chamber and a pressure chamber, primary pumping means within said body member connected with said strainer cham-- ber for delivering oil to said pressure chamber, secondary pumping means for drawing oil from said pressure chamber and delivering same to said regulating chamber, said body member having a return oil passage, a pressure relief means associated with said pressure chamber forlimlting the pressure therein and to deliver excess oil to said return oil passage, said regulating charm ber having a return port connected with said return oil passage and a main outlet port, and pressure regulating means in said regulating chamber and associated with said return port and main outlet port for delivering oil through said outlet port at a predetermined pressure and for delivering excess oil through said return port to said returnpassage independently of said pressure chamber when the pressure exceeds said predetermined pressure.

6. In a fuel supply pump for oil burnersand the like, a pump body having an inlet passageway and 4a pressure regulating chamber,. pumping means within said body connected with said inlet passagewayfor pumping oil to said regulating chamber, ra by-pass chamber having a pair of outlet ports opening through said body, said body having a return passage between said by-pass chamber and said pressure regulating chamber, said body having a thir'd port opening therethrough and communictaing with said inlet passage, said third port being relatively close to one of said outlet ports, a reversible member secured to said body over saidone port and said third port and having a passageway therein for connecting said last mentioned ports in one position and closing said ports in another position, and removable closure means for the other of said first mentioned ports.

7. In a fuel supply pump for oil burners and the like, a pump body having an inlet passageway and a pressure regulating chamber, pumping means within said body connected with said inlet passageway for delivering oil to said regulating chamber, a by-pass chamber, a by-pass passageway between said regulating. chamber and said by-pass chamber, a passageway between said bypass chamber and said inlet passageway, a port in said body opening to said by-pass chamber, a closure plug for said port, said by-pass passageway having a valve seat therein and a screw member threaded through said body and having a valve member thereon adapted to cooperate with said valve seat to close said by-pass passageway, said screw member being accessible from without said body.

8. A fuel supply pump for oil burners and the like comprising a housing member having a pressurelchamber therein, primary stage pumping `means carried by said body, inlet and outlet pas-4 sages for said means, said, outlet passage opening into said chamber, a secondary stage Dumping means carried by said body, inlet and outlet passages for said secondary stage pumping means, said last named inlet passage opening from said chamber, a return by-pass leading from said so y.

chamber, and a pressure relief means normally vclosing said by-pass for limiting the pressure in said chamber and for by-passing oil from said chamber when the pressure therein exceeds a predetermined maximum, said pressure relief means including a valve member for opening and' closing said by-pass, spring means urging said valve mem-ber to closed position, and a screw member accessible from without said housing lmember and engaging said spring means for varying at will the pressure exerted by said spring means on said valve member.

9. In a fuel supply pump for oil burners and the like, a pump body having an inlet passageway -and a pressure regulating chamber, pumping means within said body connected with said inlet passageway for pumping oil to said regulating chamber, a'by-pass chamber having a pair of outlet ports opening through said body, said body having' a-return passage between said by-pass chamber and said pressure regulating chamber, said body having a third port opening therethrough and communicating with said inlet passage, said third port being relatively close to one of said outlet ports, a member secured to said body and having a passageway therein connecting said one port and said third port, and closure means for the other of said rst mentioned ports.

. WILLIAM J. SMITH.

WILLIAM W. SLAGHT.

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