US2090035A

US2090035A - Fuel supply unit for oil burners

Info

Publication number: US2090035A
Application number: US62971A
Authority: US
Inventors: Harrison E Fellows
Original assignee: Webster Electric Co Inc
Current assignee: Webster Electric Co Inc
Priority date: 1936-02-08
Filing date: 1936-02-08
Publication date: 1937-08-17
Anticipated expiration: 1954-08-17

Description

3 Sheets-Sheet lI H. E. FELLows FUEL SUPPLY UNIT FOR OIL BURNERSl Filed Feb. e, 193e Allg 17, 1937.y H. E. Fr-:LLowsy I 2,090,035

FUEL SUPPLY UNIT FOR OIL BURNERS Filed'Fe'b. 8,1936 5 sheets-sheet 2 v 122 163 .167164 165 @y 3 w illumini 1013565 M v 98 'Y 102 z zo .m 100 \"g 1125 I Y iimf" Aug. 17, l937 H. E. FELLows FUEL SUPPLY UNIT FOiR OIL BURNERS Filed Feb. a, 1936 -s 'sheets-smet s f Harrison E; fie/[aw By M, @M

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Patented Aug. 17, 1937 2,090,035 v FUEL SUPPLY UNIT Foa on. BURNERs Harrison E. Fellows, Racine, Wis., assignor to Webster Electric Company, Racine, Wis., a corporation of Wisconsin Application February s, 1936, serial No. 62,971 Claims. (ci. 137-153) The present invention relates to fuel supply units for oil burners, and is particularly concerned with fuel supply units preferably including a pump of the gear type, a strainer, and a sion of an improved strainer arrangement and construction which is capable of more economical manufacture than the devices of the prior art.

Another object of the invention is the provi- 6 pressure regulating valve. sion of a fuel unit arrangement which is equally 5 The pump may be of the single stage or double adaptable for use with a. two-pipe or a one-pipe stage type, but in the present embodiment only system, by merely changing the connections and the single stage pump has been illustrated: opening or closing a port or conduit formed in One of the objects of the invention is the pro the housing- 10 vision of an improved fuel supply unit in which Other objects and advantages of the invention l0 the regulating valve is of the type which bywill be apparent from the following description passes back to the tank or tojthe intake line any and the accompanying drawings, in which similar excess of fuel oil over that required to supply the characters of reference indicate similar parts burner, and in which the by-pass is effected throughout the several views.

through a port located in some part of the mov- Referring to the three sheets of drawings, l5 able bellows which is used to control a needle valve Fig. 1 is a diagrammatic view of an installation for the burner port. f embodying a fuel unit constructed according to Another object of the invention is the provithe present invention; sion of an improved fuel regulator valve of the Fig. 2 is an elevational view, partially broken class described, having a bellows for controlling away, showing the pump gears and conduits lead- 0 a by-pass valve and a burner valve which has the safety feature of permitting by-pass of any fuel oil which might leak through the bellows in case the bellows should fail.

Another object of the invention is the provision of an improved regulator valve of the bellows type in which valves are provided for the-burner port and a by-pass port, and which has a special. arrangement for effecting a quick closure of the burner port upon shutting down of the motor. on the plane of the line 5-5 of Fig. 4; m

When a burner is shut olf, the air supply to Fig. 6 is a fragmentary sectional view, taken the combustion chamber decreases very rapidly, von the plane of the line 6-,6 of Fig. 4; but unless some special provision is made, the Fig. '7 is a fragmentary sectional view, taken pressure in the regulating valve decreases quite on the plane of the line 'l-1 of Fig.v 5, looking in slowly, with the result that fuel is still supplied the direction of the arrows; 35 with an insuicient supply of air. This results Fig. 8 is a view of the regulator valve, similar g in inefficient combustion, causing excessive comto Fig. 3, -but showing the parts in the position bustion gases or smoke, and the excess gases which they assume immediately after the motor cause pulsating back pressures in the ues, which' has been shut down;

40 makes the furnace puff and rattles any loose Fig. 9 is a view in perspective of the type of 4" parts of the furnace.

One object of the invention is the provision of an improved regulating valve which eifects a quick cut-off at the burner nozzle after the motor current is cut off, thereby eliminating this inefficient combustion period and preventing the pulsating and puiiing of the furnace which result therefrom.

Another object of the invention is the provision of an improved form of packing or seal for the rotating shaft of the pump, by means of which the friction drag on the pump shaft is greatly reduced and the leakage of fuel along the rotating shaft is substantially prevented.

Another object of the invention is the proviing from the strainers through the pump to the radiator valve;

Fig. 3 is a vertical sectional view, taken on the plane of the line 3-3 of Fig. 4, showing the details of construction of .the parts of the unit;

Fig. 4 is a horizontal sectional view, taken on the plane of the line 44--Il of Fig. 3, showing the details of construction of the parts of the unit;

Fig. 5 is a fragmentary sectional view, taken spring preferably employed for assuring distention ofthe bellows and uniform contact between the sliding surfaces of the seal on the pump.

Referring to Fig. 1, I0 indicates in its entirety the fuel unit, which preferably includes a housing having housing parts for the regulator valve II, oil pump I2, and strainer I3. The device may be used with -a onepipe or a two-pipe system. In the two-pipe system the by-pass port I4 of the regulator valve is connected by a conduit I5 to the tank I6 to return the excess fuel to the fuelv l strainer is connected by a conduit 2l to the fuelV l the fuel unit I0 preferably consists of a. single casting formed with the housing parts for the valve, pump and strainer units.

The pump is preferably disposed in the middle between the valve and strainer units, since l5 it is adapted to receive fuel from the strainer and to deliver it to the regulator valve. Therefore, the middle part of the housing or the pump -housi-ng 24 is provided with a bore 25 for receiving a bearing sleeve 26 for the pump shaft 21.

20 The bearing sleeve 26 may comprise a metal member which is formed with a radially extending cylindrical portion or flange 28 which is adapted to fit in a counterbore 29. The cylindrical end portion 28 maybe provided with a 25 pair of intersecting

bores

30, 3| which form the chambers for the

pump gears

32, 33. These pump gears have their teeth in peripheral contact with the

bores

30, 3|, and are adapted to mesh with each other to'carry the fuel from 30 one side of the pump or intake to the other side or the output, thereby developing a pressure at the output side of the pump, due to the volume of fuel which is forced through the pump chamber by the gears.

v 35 The pump shaft 21 is preferably provided with an enlarged cylindrical portion 34 in the bearing sleeve 26, an annular shoulder 35, and a reduced cylindrical portion 36 extending through the seal or bellows packing.

40 A still smaller cylindrical portion 31 is located to engage in the bearing sleeve 38, and another smaller cylindrical end 39 is formed at the outside end of the shaft 21 for engaging in the bearing plate'40.

45 The gear 33 is supported upon a stub shaft 4|, which has one end passing through the bore 42 in the plate 28 and extended into a registering bore 43 in the body 24. The opposite end of the stub shaft 4| extends into a. bore 44 in the 50 bearing plate 40, and the gear 33 may be mounted for free rotation on'the stub shaft 4|.

Bearing plate 40 has another bore 45, which is suitably located to engage thereduced vcylindrical end 39 of the drive shaft 21, and the bear- 55 ing' plate is adapted to ilt in the-counterbore 23 and substantially fill the counterbore, its upper surface being flush with the outer at surface 46 on the body 24.

' The bearing plate 40 is secured in predeter- 60 mined position with respect to the pump housing plate 28 by pairs-of pins 41, which may have a drive fit in either of these members 28 or 4l, and which are secured in aligned bores to hold these parts in proper position.

65 The open end ofthe counterbore 29 lis closed by a cover plate 46,'which clamps a gasket 49 against the flat surface .46. by means of a plurality of screw bolts 50, which pass through the cover plate and are threaded into bores in the 70 body 24. The housing is provided with a portion 5| for enclosing the strainer and having a substantially cylindrical chamber 452. chamber 52 communicates with the intake side of the pump through a diagonally extending conduit 53,

75 which leads to the right hand side of the

gears

32, 33 in Fig. 2.v slot 54 extends longitudinally of the bearing sleeve 26 and communicates with the conduit 59, providing a conduit from the bellows seal chamber 55 to the pump intake for a purpose further to be explained.

'Ihe stub shaft 4| (Fig. 7) may be provided with a longitudinally extending conduit 56, adapted to equalize pressure on both ends of this shaft for the purpose of preventing any friction on the shaft 4I or gear 33, due to unequal pressure on any side.

The housing is also provided with a portion 51 which is adapted to house the regulator valve, and which is provided with a valve chamber 56. This valve chamber communicates with the output side of the pump through a diagonally eX- tending conduit 59 which leads to the left hand side of the gears in Fig. 2 from the valve chamber 58.

The shaft 31 may be provided with a transverse bore 60 extending through the shaft at the reduced cylindrical portion 39 and alpin 6| extends through the shaft into notches located in the gear 32 whereby the shaft 31 is adapted to drive the gear 32 and through this gear it also drives the gear 33. l

Referring to Fig. 4, the intake and outlet conduits 53 and 59 of the pump are there shown in dotted lines. Conduit 53 extends diagonally from the strainer chamber 52 to 'the counterbore 29. The sleeve 26 has an aperture registering with the conduit 53 and also has a drilled aperture 62 which extends parallel to the-axis of shaft 21 and connects conduit 53 with the inner face of the bearing plate 40.

In a, similar manner the outlet conduit 59 communicates with a drilled aperture 63 located in the sleeve 26 and extending to the face of bearing plate 40 on the other side or output side of the gears. These apertures can also be seen at 62 and 63 in Fig. 2, and it will be notedthat they do not yet communicate directly with

bores

30 and 3| surrounding the gears.

Referring to Fig. 6, this is a sectional view which shows the inner or upper surface of the bearing plate 40 of Fig. 4. It will be noted that the bearing plate has apertures' 45 and 44 to provide bearings for the

shaft portions

39 and 4|. cally extending

slots

64 and 65 which are so located that the outer ends of these slots register with the drilled apertures 62 and 63.

sides of the

gears

32 and 33 at points between the teeth of the gears, thereby communicating with the spaces between the teeth of the gears from the side of the gears.

Of course the

gears

32, 33 are'of the thickness as the depth of the

bores

30 and 3|, fitting closely against the inner surface of the bearing plate 40. The bearing plate 40 is also preferably provided with another conduit 66, which leads from the slot 65 diagonally over to the bore 45. Actually, this conduit 66 comprises a drilled aperture extending through the plate 40, and another slot 61 located on the outer surface and leading to the bore 45.

It should be noted that the outer end of the bore 45 is thus connected with the input side of the pump, and the pump is adapted to suck the fluid or fuel oil which may leakA ou-t to the end of shaft 21 back to the intake of the pump, thereby preventing the building up of any pressure under the cover plate 48 at this end of the shaft and keeping that pressure at about atmospheric The inner. ends of the slots 64 65 extend to points on the It is also provided with a pair of diametrimaking the conditions under which the shaft must be sealed by the bellows still much less rigorous than they would otherwise be. The

packing or seal need only seal against the leakage under a very low pressure, since the leakage is always carried back to the intake side of the pump.

l5 'I'he fuel unit is preferably provided with animproved seal for the shaft 21, which may be constructed as follows: A metal sealing ring 68 has a close frictional fit on the reduced cylindrical portion 36 of the shaft 31 against the annular shoulder 35.

The present fuel unit vis preferably provided with a counterbore 10 surrounding shaft 21 and communicating with bore 25, and counterbore 10 is adapted to slidably receive a second sealing ring 1|, having an outer cylindrical surface 12 for engaging the walls of bore 10. Sealing ring 1| preferably has an axially extending sleeve 13, and is provided with a bore 14 for passing the shaft portion36.

Shaft portion 36 preferably does notengage the walls of bore 14, the position of the ring being determined by its slidable engagement of its outer surface 12 in the bore 10. The sleeve 13 is preferably beveled at its inner edge, thereby providing a narrow flat engaging surfacev 15, which engages the flat end surface of the sealing ring 68. The periphery of the sliding ring 1| is formed with a plurality of steps, the outermost step 16 of which forms a seat fora compression spring 11 'located in the counterbore 10. The next step 18 on the ring 1| provides an annular seat and a cylindrical supporting surface for the end of a bellows 19.

The cylindrical end flange of the bellows 19 may be soldered, brazed, or otherwise permanently secured to the cylindrical end portion of the ring 1|. The spring 11 is preferably formed with a complete turn of one of its coils, engaging the seat 16 so far as possible for the purpose of equalizing the spring pressure on all sides of the ring 1| and preventing the ring 1| from having a tendency to cock. 'Ihe same is true of the opposite end of the spring 11 where it engages a seat 80 formedin a sheet metal cap member.

Referring to Fig. 9, this is a view which shows the spring in perspective, and it will be observed that the spring consists essentially of two closely coiled annular portions, one at each end, joined by the widelyspaced coils of the spring between them. These closely coiledA annular portions assure substantially equal spring pressure on all parts of the members which this spring engages.

The cap member 8| comprises a substantially circular metal member which is adapted to t in a counterbore 82 and which is provided with an aperture adapted to receive a portion of the bellows 19; that is, the c ap member 8l may be received between two of the Afolds lof the bellows on the outside of the bellows, and the last or uppermost fold may be soldered, brazed or otherwise permanently secured with a liquid-tight joint to the cap member 8|.

The cup shaped formation in the cap member 8| b enables the provision of a special annular seat 88 for the spring. The outermost portion ofthe ange of the cap member 8| rests against annular shoulder 83 in counterbore 82 and may rest against a suitable gasket to provide a :Huid-tight joint at this point. The bore 82 is adapted to slidably receive a substantially cylindrical clamping member 84, which may provide a self-lubricating bearing for the reduced cylindrical portion 31 of shaft 21. This clamping member preferably has an axially extending annular flange 85 projecting from its lower side wall. -The flange 85 engages the outerl and upper surface of the cap member 8| and clamps this member against the annular seat 83, thereby xedly securing one end of the bellows 19.l The opposite end of the bellowsl and the ring 1| are mounted for free axial movement, rotation being prevented by its securement to the housing by the flange 85. The actual sealing surface is between the end surface 15 of the annular sleeve 13 and the rotating ring 68.

It should be noted particularly that in this seal the spring is located outermost, and the sealing surface innermost with respect to the radial distance from the center of the shaft. Furthermore, the bellows is xedly mounted and prevented from rotating as distinguished from devices of the prior art where the bellows was mounted for rotation. Where such a bellows is mounted for rotation, there is a tendency,.if the bellows or its ring should get slightly olf center, for this defect to become accentuated by the action of centrifugal force. Therefore,.it is of great advantage to mount the bellows fixedly on the housing and to mount only the non-resilient and non-deformable metal ring 68 for rotation.

The self-lubricating bearing 86 comprises a substantially cup-shaped metal member having a. cylindrical outer wall which ts in the counterbore 82. It is closed by a. closure plate 86 which;

may have a pressed t in the top of the cup, and

both it and the closure plate 86 have a centrally located aperture for receiving the bearing sleeve The bearing sleeve 38 may consist of a porous bronze bushing which isadapted to transmit lubricant that is contained within the reservoir 81, which maybe filled with felt or other wicking impregnated with liquid lubricant orsemi-solid lubricant, such as vaseline.

The depth of the self-lubricating bearing member 84 is such that it projects slightly above the gasket seat 88 when the parts are assembled.

Therefore,a gasket 89 may be employed below a cover plate 90, which is secured to the housing by a plurality of screw bolts 9| passing through the cover plate and threaded into the body. The gasket 89 is sufficiently compressible so that when the screw bolts 9| are driven home the self-lubricating bearing member 84 is forced into its bore, and flange 85 engages cap member 8| and compresses its gasket so as to provide a fluid-tight seal between the cap member 8| and the body of the housing.

A washer 90' may be located on the reduced portion of the shaft 31 at the annular shoulder 9| inside the bearing 38, thereby providing a thrust bearing for preventing axial movement of the shaft outward and preventing fmal thrust from acting upon the bellows 19.

The Apressure on both ends of the shaft is, however, substantially equalized bythe action of the bleeding conduits which lead to the intake of thepump and prevent ,the building up of any pressure on the end 39 of the shaft. The member 92 surrounding 4the portion of the housing which forms the Wall of counterbore 82 comprises a supporting member for the pump, which is secured to the pump body by a plurality of screw bolts 93.

Referring to Fig. 3, the general shape of the housing 24 is that of a central cylindrical portion 94 having its axis in a horizontal plane, and attached to vertically extending cylindrical portions 51 and 5| which form the chambers for the strainer and regulator valve respectively. The strainer housing portion is preferably provided with an inlet port 95'at the top which leads to the chamber 52. Chamber 52 may comprise a substantially cylindrical bore, the lower end of lwhich is provided with a threadedclean-out l5 opening 96 closed by a screw plug 91, and the upper end of whichis threaded as at 98. The threads 98 preferably extend down past the inlet conduit 95 and below the auxiliary conduit 99 which leads to the upper threaded portion of the valve chamber 52.

The purpose of the auxiliary conduit 99, which is closed by a slotted screw plug |00 disposed in the threaded end |0| of conduit 99, is to adapt the device for one-pipe and two-pipe systems. In

the one-pipe system the by-pass outlet |02 of the valve chamber 58 is closed by a plug, and the plug |00 is removed from the auxiliary conduit 99. The excess of oil which is by-passed then passes through the conduit 99 back to the strainer, and

thence to the inlet side of the pump, where it may be pumped over again. It is, therefore, unnecessary in such a system to use the return conduit I5 because the excess liquid fuel is returned to the supply of oil in the strainer chamber 52.

The strainer assembly is indicated in its entirety by the numeral |03,\ and it comprises a threaded supporting plug or plate |04 which supports the strainer members and is adapted to be supported in the strainer chamber 52 by being threaded home in the threaded portion 98 of the chamber.

The threads are so arranged that when the plug |04 is threaded to the lower limit of the threads the strainer unit |03 is properly situated in the chamber, and the plug |04 is below the .

conduits

95 and 99.

Plug |04 is provided with a plurality of depending annular ribs |09. The number of annular ribs provided would depend upon Athe number of strainers used in the unit. In the present embodiment two such ribs are used with four round strainer members. Each of the ribs |09 has a multiplicity of cylindrical bores ||0 drilled through it to provide communication between the space I above the plug and the proper parts of the strainer unit in the chamber52.

The reduced cylindrical portion |01 of the rod |06 supports a second strainer plate ||2 which has a centrally located aperture for receiving the rod portion |01. This lower strainer plate ||2 has aplurality of upwardly projecting concentric annular ribs |3, which are two in number in'the present embodiment, since the four strainers may be located on the opposite sides of the two ribs.

The ribs ||3 are preferably tapered from both sides toward the top so that as the plate ||2 is inserted into the strainer members, and the assembly is secured by tighteningthe nut |08 on rod portion |01, the ribs I3 cam the strainers into their proper position. The ribs are, however, provided with outer and inner cylindrical surfaces I4 for engaging the strainer members.

The strainer members ||5, ||6, ||1 and |I8 comprise cylindrical members of fine wire meshv screen which are formed by bringing parts of the screen adjacent two opposite edges into contact with each other to form a cylinder and soldering these edges together in that form. The upper and lower edges of these cylindrical screens are protected by being dipped into solder so as to provide these edges with a border of soldered vmember H8v fits against the innermost wall of ribs |09, ||3, and screen ||1 fits against the outer wall of the innermost rib. f v

The screen plate ||2 is provided with sufficient body projecting beyond the outermost r'ib ||3 at ||9 to form a seat for the outermost screen ||5. The plate |2 is also provided with suitable oil apertures |20 located at the central portion of the plateA inside the screen |8 and located between the ribs ||3 so as to provide communication to the space between screens ||6 and ||1.

Since the screens ||6, ||1 are so close together, there is a possibility that these two screens might collapse, and therefore a helical spacing spring |2| has been placed between screens ||6 and |1 to prevent collapse and insure spacing of these screens at all points.

The screens are assembled with their supporting plates by first putting the screens on the plate |04, with the spring and the rod |05 in proper position, and then placing the lower plate ||2 on rod |06 and locating the ribs ||3 between the proper screen members by means of the beveled camming surfaces on these ribs. The nut |00 may then be threaded on rod portion |01 toclamp the plate ||2 against the ends of the screens and force the ends of the screens toward the plug |04, thereby forming a cylindrical removable unit. p,

The plug |04 is provided with a transverse slot for receiving a screw driver, and the complete screen assembly may be inserted into the screen chamber 52 by inserting the screen rst and then threading the plug down from the top of the threads 98 until it reaches the position of Fig. 3. v f

The top of the chamber 52 and space is closed by a suitable screw plug |22, which preferably has a laterally. projecting ange overlying the border of the .threaded bore 98 and engaging a suitable gasket which is -clamped against the gasket seat` |23.

The course of travel of the liquid fuel through this strainer is as follows: The liquid fuel is sucked inv at the intake conduit 95, and passes downward through the aperturesv ||0 between screens ||1 and ||8 and between the screens ||5 and ||6. The liquid fuel passes through these screens and is discharged into the space 52 surrounding the screen unit and through the aperturesk |20. which lead from the spaces., between l v Sclens H6 and In and from the interior of screen H8.

' cut away at |36 in registry with the slot |29 so The strainer chamber 52 communicates with Ithe pump through the conduit 53, which leads to the intake side of the pump, and thus all of the fuel supplied to the pump is first strained by the strainer unit |03. Should the strainer unit become clogged at any time, it may be removed and cleaned by taking off the strainer members and brushing them or subjecting them to air pressure, and the sediment may be removed at any time by means of the clean-out opening'96.

Referring, now, to the regulator valve unit of Fig. 3, the regulator valve housing 51 is preferably formed with a laterally protruding boss at the top, having a threaded bore for an intake opening 02.

The housing chamber 5B has an upper threaded portion |24, which extends substantially below the intake opening |02 and below the auxiliary conduit 99 so that the bellows supporting plug may be in position to avoid interference with these conduits.

The regulator valve chamber' 58 is preferably formed with an inwardly projecting annular shoulder |26 near the bottom toprovide a support for a piston valvesleeve |21 which slidably receivesthe piston valve |28. The annular shoulder |26 has a cylindrical bore passing through it so that it is adapted to receive the sleeve |21 which is secured in the bore by a close frictional fit. The right hand portion of the annular shoulder |26 is provided with a slot or aperture |29 extending from the lower space |30 of the regulator valve chamber to the upper space I3! This communication between the parts of the valve chamber permits the liquid fuel underpressure to act not only on the bellows. |32 but on the piston |28, and also provides means for conducting the liquid fuel to the burner outlet port |33.

'I'he sleeve |21 may have a radially projecting flange |34 at its lower edge for determining its final position in the bore of the 'shoulder |26.

The lower en d of the stem |39 is provided with a frusto-conical point |4|, forming a valve surface which is adapted to seat in a complementary valve seat |42 formed in the end of a ferrule |43. Ferrule |43 may be made of brass, bronze, or other suitable material, and may have a pressed or screw t in a tting plug |44, which is threaded into the threaded lower end |45 of the housing space |30, and has a non-circular portion for engagement of a wrench.

Fitting |44 also has a threaded tubular portion |46 for engagement with suitable fittings and pipes. The piston |28 has its bore |41 threaded at the upper end for reception of a supporting plug or body |48. This plug or body may be provided with a partially spherical socket |49 at its lower end for engaging the ball |40, and it comprises a substantially cylindrical threaded member having a radially extending flange I 50 at the top and having a slot |5| for engagement with a screw driver. It may also have a counterbore |52 in the top flange, forming a seat with a confining shoulder for the compression spring |53.

The radial ange |50 also serves the purpose of clamping the end plate |54 of the bellows |32 to the piston |28. The plug |48 is also preferably hollowed out or provided with an inner conduit |55 for the purpose of discharging bypassed fuel through the bellows, and after the plug |48 is in place and the bellows plate |54 is clamped to the piston, the plug may be locked in place by drilling the discharge aperture |56 through the wall of the piston |28 and plug |48, as appears at the right side of the piston in Fig. 3.

The piston is also preferably provided with a longitudinally extending bleeder aperture |51, by merely flattening the piston |28 from a cut-off shoulder |58 adjacent the lower outer edge of the piston to a point |59, which is above the aperture |56. The purpose of this bleeder slot will be explained in greater detail hereafter, as it affects theoperation of the valve and permits Vthe burner port to be closed more quickly by means of 'the valve |4| than is accomplished by the devices of the prior art.

'I'he bellows |32 comprises a flexible sheet metal member. which is responsive-"to pressure when properly closed at its ends. It is mounted on the bellows plate |54 by having one of Vits horizontal folds engage the upper surface of thev plate and one of its outer bends hooked outside the edge of the circular plate |54. The plate |54 and bellows |32 may be secured together permanently by soldering, brazing` or any convenient fastening means which will assure a liquidtight joint at this point. The opposite end of threaded bore |24. It has a bore i6| extending through it for passing the spring |53, and when the plug |25 is threaded 'home in the bore |24 the bellows supporting plug |25 and bellows |32 are properly positioned in the chamber 58, below conduits |02 and 99.`

Plug |66 may be similar in construction to plug |22 in that it has a radially extending flange for extending the top of the housing and clamping a gasket against the housing. The adjustment screw |64 has a slot |61 for receiving a screw driver, and the upper end lof bore |85 may be closed by a cap screw |68 which is threaded into the bore. 'I'he adjustment of the screw |64 5. determines the state of compression of the-spring |53, and therefore determines the pressure at which the valves controlled by bellows |32 will open.

'I'he operation of the regulator valve is as fol- 10 lows: When the motor driving the burner fan and pump is started, fuel is drawn in through the strainer chamber to the pump and discharged under a suitable high pressure into the I valve chamber 58. When the pressure has built up to a predetermined point, which is determined by the adjustment of the spring |53, the

uid under pressure acts on the bellows |32 and area of piston |28 and causes the piston to rise. This opens the burner port |33 first, and oil u nder pressure is supplied to the burner, and the piston continues to rise until the by-pass aperture |56 is opened and until the excess of oil is by-passed through this aperture from the chamber 58.

The bellows and piston achieve an equilibrium when suicient oil is by-passed to reduce the pressure in the chamber to that equal toan amount necessary to move the piston to its nal position.

In the case of a one-pipe system,` the aperture |02 is plugged up, and the plug |00 is removed so that the by-passed fuel passes back through auxiliary conduit 09 to the strainer chamber 52,

where it is used over again by the pump. 40 In 4both cases, however, liquid fuel is by-passed through the bellows |32; and should the bellows spring a leak, the liquid fuel leaking through such a break in the bellows would merely be carried back to the tank or to the intake side of the pump, and there would be no possibility of pressure building up in the bellows chamber behind the bellows in such manner as to close the valves and cut off while the motor is running. This is a safety feature which is of the utmost importance.

Where the bellows is not opened to the by-pass as in the present case, there is always a possibility that if the bellows springs a leak the pressure inside and outside of the bellows would be equalized, and the spring would close both the by-pass port and the burner port, thereby shutting off theburner, but the motor would still continue to run, and since there was no outlet through to the burner or by-pass, under these conditions pressure'l would build up in the valve and conduits leading from the pump to such an extent' that something would have to break. Such an accident would never occur with the r present construction, as the interior of the bel-I 6. lows is at all times in communication with a free by-pass outlet and Aconduit back to th'e'tank or the intake side of the pump.

The bleeder aperture |51 acts as follows: 7 When the pump motor is shut down,- the supply of air to the burner stops quite quickly, but the motor and pump usually run for a short time thereafter, supplying oil to the burner, with insufficient oxygen in the devices of the 75 Prior art.

' pass.

In the present device the decrease in pressure of oil in the valve chamber causes the piston |28 to be extended by spring |53, rst closing the by-pass aperture 51 and then closing the burner port |33. This action is accelerated, and the pressure in the valve chamber is reduced to atmospheric by reason of the bleeder aperture |51, which becomes open to the lower part |30 of the yalve chamber as soon as the shoulder |58 passes the lower edge of sleeve |21. Of course, this fiattened portion is opened to the upper part of the chamber 3| by reason of the lflattening above the aperture |56, and consequently the pressure in the chambers |30, |3| does not remain above atmospheric, but such liquid fuel as is in these cham.

bers has a free opening through aperture |51 'and by-pass aperture |56 to the by-pass port |02. The result is that the fluid pressure in the valve chambers is quickly reduced to atmospheric when the pump motor is stopped and the burner is shut off practically as quickly as the air fan, thereby preventing any further burning of fuel with insufiicient oxygen.

This is of great importance in the operation of such a device, because the devices of the prior art are very noisy when the motor shuts down, due to the fact that the combustion with insuiiicient oxygen results in a puiiing or pulsating action in the combustion chamber. Thispulsating or puffing action reverberates throughout the entire heating system and is very annoying, as it occurs every time the burner is shut off in the devices of the prior art.

The present device is therefore adapted to operate in a substantially noiseless way, and is nottop of the piston. When the air is forced out so that the pump receives solid oil, the volume de'- `llvered to the regulator valve is greatly in excess of the amount which can leak through the opening |51, as will beevident from the fact that a special by-pass conduit is usually employed. Therefore, the pressure will build up in the valve chamber and the by-pass piston will rise. As the piston rises the opening of the bleeder |51 at shoulder |58 is closed, and therefore the piston will continue to rise until a suflicient amount of the aperture |56 is exposed to maintain a pre-' determined pressure. V

This construction causes the piston to rise sufciently to lift the cut-off needle'valve |39 well off its seat to prevent throttling at this point.

The operation of thepresent device 'should be carefully distinguished from devices in which asmall groove has been cut inthe by-pass valve so that,there is always a. denite leakage to the bytrie to increase the opening at A|56 for regula- ,tion, and the bleeder would tend to prevent the of the oil to the nozzle.

When the burner is shut ofi',v pressure in the In such cases the piston would rise only a regulator valve decreases slowly, and not in procombustion gases. The excess gases cause pulsating back pressures in the flues and rattle any loose parts in the furnace. It is, therefore, desirable that the pressure in the regulator valve chamber decrease Yas quickly as possible to accomplish a quick cut-off at the burner nozzle after the motor current is shut off.

The flattened portion or groove in the by-pass piston will open at |58 as the piston moves downward, permitting oil to escape and accomplishing a quicker cut-off at the nozzle than if the cr'l could only escape through the opening at |59. This cut-olf position of the regulator valve is shown in Fig. 8.

It will thus be observed that I have invented an improved fuel oil unit having a regulator valve which is adapted to give a quick cut-off and a wide range of movement of the cut-off valve so as to prevent throttling when thc cut-off valve is opened.

The present unit is adaptable for one-pipe or two-pipe systems, and its oil seal on'the rotating shaft has a very low friction, due to the improved structure and arrangement of the parts.V The oil seal is also substantially leak-proof and requires no repair, not only due to the specific construction, but to the arrangement with the pump whereby leakage to the oil seal chamber vis carried back to the pump.

The strainer unit is simple and inexpensive and easy to clean out and assemble, and the entire system. is so arranged that it will quickly eliminate any air in the system when the pump is started. The cut-off valve closes so quickly on stopping the pump motor that there is none of the pulsating or puiiing action in the furnace due to ineiicient combustion at that time, such as is experienced with the devices of the prior art.

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

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, 'isz l. In a fuel unit for Voil burners, the combination of a supporting body having a chamber formed therein, a burner outlet in said chamber, an inlet to said chamber, a by-pass outlet in said chamber, a pressure responsive bellows located in said chamber having the space around one side of said bellows communicating with the inlet port of the chamber and the space adjacent the other side of the bellows communicating with the by-pass outlet, valve means controlled by said bellows for controlling said burner outlet port, and by-pass valve means controlled by said bellows for controlling a port leading from one side of the bellows to the other side of the bellows whereby oil is discharged from the burner outlet port at a predetermined pressure and the excess is by-passed through the bellows to the by-pass outlet, and in the event of leakage of said bellows the leakage is carried away through said by-pass outlet port, said by-pass comprising a piston having an aperture communicating with the interior of the bellows and with the space exterior of the bellows when the by-pass port is opened.

2. In a regulator valve, the combination of a housing having a by-pass outlet, having a pressure inlet and a burner outlet, a pressure regulating bellows located in said bodv and having its interior in communication with said by-pass outlet, valve means controlled by said bellows for controlling said burner outlet and for controlling a port leading from thev exterior of said bellows to the interiorof said bellows whereby excess oil is by-Dassed through saidbellows to said by-pass port and any leakage of the bellows is merely discharged through the by-pass outlet without danger of pressure building up in the housing, said valve means comprising a `.needle valve for controlling the burner outlet and a piston valve for controlling the by-pass port, and bleeder means for said piston adapted to be cut off promptly upon opening of the burner port valve to assure a wide opening of the burner port valve.

3. In a regulator valve, the combination of a housing having a by-pass outlet, having a pressure inlet and a burner outlet, a pressure regulating bellows located in said body and having its interior in communication with said by-pass outlet, valve means controlled by said bellows for controlling said burner outlet and for controlling a port leading from the exterior of said bellows to the interior of said bellows whereby excess oil is by-passed through said bellows to said by-pass port and any leakage of the bellows is merely discharged through the by-pass outletwithout danger of pressure building up in the housing, said valve means comprising a needle valve for controlling the burner outlet and a piston valve for controlling the bypass port, and bleeder means for said piston adapted to be out off promptly upon opening of the burner port valve to assure a wide opening of the burner port valve, said bleeder means being also arranged to be opened upon closure of said burner port valve in order to relieve the pressure in the valve chamber and effect a quick cut-oil'.

4. In a regulator valve, the combination of a body formed with a chamber therein, said chamber having a burner outlet, an inlet and a by-pass outlet, pres-sure responsive means located in said chamber comprising a bellows having the space on one side of said bellows communicating with the inlet port of the chamber and the burner outlet, and the space on the other side of the bellows communicating with the by-pass outlet, a piston valve actuated by said bellows, said piston valve having a by-pass port providing communication from one side of the bellows to the other side, valve means actuated by said piston for controlling said burner outlet port, said piston having a longitudinally extending slot communicommunication is'closed after the burner outletA valve means is opened a predetermined amount.

5. In a regulator valve the combination of a housing having an inlet, a by-pass outlet and a burner outlet, a pressure responsive bellows located in said housing and having its interior in communication with said by-pass outlet, valve means controlled by said bellows for controlling said -burner outlet and for controlling a port leading from the exterior of said bellows to the interior of said bellows whereby excess oil is bypassed through said bellows to said by-pass port and any leakage of the bellows is merely discharged through the by-pass outlet without danger of pressure building up in the housing, said valve means comprising a piston valve ixedly sev cylinder carried by said housing for controlling said by-pass port, and a second valve carried by 'said piston valve for controllingsaid burner port,

said piston and cylinder beingformed with a bleeder port adapted to be cut off promptly upon opening of the burner port valve to assure a wide opening of the burner port valve and said second valve comprising a needle valve having a limited sure inlet and a burner outlet, a pressure regulating bellows located in said body and having its interior in communication with said by-pass outlet; valve meansy controlled by said bellows for controlling said burner outlet and for controlling a portv leading from the exterior of said bellows to the interior of said bellows whereby excess oil is by-p'assed through said bellows to said by-pass port and any leakage of the bellows is merely discharged through the by-pass outlet without danger of pressure building up in the housing, said Valve means comprising a needle valve for controlling the-burner outlet and a piston valve for controlling the by-passport, and bleeder means for said piston adapted to be cut off vpromptly upon opening of the burner port valve to assure a wide opening of the burner port valve, said piston valve being slidably mounted in a sleeve carried by said housing and said housing having an inwardly extending flange for supporting said sleeve, said flange having a port providing communication betweenthe lower part of said housing and the bellows enclosing part of said housing.

7. In a regulator valve the combination of a housing having a by-pass outlet, a pressure inlet and a burner outlet, a pressure responsive bellows located in said housing and being subjected to the pressure of fluid in said housing, valve means controlled by said bellows for controlling said burner outlet, valve means controlled by said bellows for controlling said by-pass outlet, whereby excess oil is by-passed through said bellows to said by-pass outlet and the burner outlet is supplied with liquid fuel under substantially constant pressure, said first-mentioned valve means comprising a needle valve and said second-mentioned valve means comprising a piston slidably mounted in a cylinder in said housing, said needle valve having a substantially universal connection with said piston valve and being provided with a conical point adapted to seek a fluidtight Contact with said burner outlet by virtue of the universal movement of said needle valve, said piston being provided with a port communicating with the interior of said bellows and thence to the by-pass outlet, whereby any leakage of the bellows is merely discharged through the bypass outlet without danger of pressure building up in the housing.

8. In a regulator valve the combination of a housing having a by-pass outlet, a pressure inlet and a burner outlet, a pressure responsive bellows located in said housing and being subjected to the pressure of fluid in said housing, valve means controlled by said bellows for controlling said burner outlet, valve means controlled by said bellows for controlling said by-pass outlet, whereby excess oil is by-passed through said bellows to said by-pass outlet and the burner outlet is supplied With liquid fuel under substantially constant pressure, said first-mentioned valve means comprising a needle valve and said second-mentioned valve means comprising a piston slidably mounted in a cylinder in said housing, saidneedle valve having a substantially universal connection with said piston valve and being provided with a conical point adapted to seek a fluid-tight contact with said burner outlet by virtue ofthe universal movement of said needle valve, said piston being provided with a port communicating with the interior of said bellows and thence to the by-pass outlet, whereby any leakage of the bellows is merely discharged through the by-pass outlet without danger of pressure building up in the housing, said piston 'also having avilattened portion providing a bleeder outlet between the piston and its cylinder. 9. In a. regulator valve, the combination of housing having a by-pass outlet, having a pressure inlet and a burner outlet, a pressure regulating bellows located in said body'and having its interior in communication with said by-pass outlet, valve means controlled by said bellows for controlling said burner outlet and for controlling a port leading Afrom the exterior of said bellows to the interior of said bellows whereby excess oil is by-passed through said bellows to said by-pass port and any leakage of the bellows is merely discharged through the by-pass outlet without danger of pressure building up in the housing, said valve means comprising a needle valve for controlling the burner outlet and a piston valve for controlling the by-pass port, and bleeder means for said piston adapted to be cut oif promptly upon opening of the burner port valve to assure a Wide opening of the burner port valve, said bleeder means being also arranged to be opened upon. closure of said burner port valve in order to relieve the pressure in the valve chamber and effect a quick cut-off, said bleeder means comprising a port formed between a flattened portion of said piston and a cylinder carried by said housing and having cut-off edges adjacent the opposite ends of said cylinder.

HARRISON E. FELLOWS.