US2243970A

US2243970A - Furnace appliance

Info

Publication number: US2243970A
Application number: US102057A
Authority: US
Inventors: Nathan M Lower
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-09-23
Filing date: 1936-09-23
Publication date: 1941-06-03
Anticipated expiration: 1958-06-03

Description

N. M. LOWER FURNACE APPLIANGE June' 3, 1941;

6 Sheets-Sheet 1 Original Filed Sept. 255, 1936 INVENTOR.

/V//ar/ M. Loa/en 1 M f ATTORNEYS.

June 3, 1941. N. M. LOWER FURNAGE APPLIANQE v Original Filed Sept. 23, 1936 6 Sheets-Sheet 2 IVENTOR. Nathan M Lowe/1 ATTORNEYS.

June 3, 19,41. N, M, LOWER 2,243,970

FURNACE APPLIANCE Original Filed Sept. 25, 1936 6 Sheets-Sheet 5 INVENTOR. A/Valhn Loa/ef4 ATToRNEYs.

June 3, 1941. N. M. LOWER 2,243,970

` FunNAcE APPLIANCE original Filed sept. 2s, 1956 @sheets-sheet 4 INVENTOR. /VaZza/v M. Loa/ef4 ATTORNEY5.

June 3, 1941. N. M. LOWER FURNACE APPLIANCE Original Filed Sept. 23, 1936 6 Sheets-Sheet 5 INVENTOR. /Vlza/z M. Lou/ef7 ATTORNEYS.

June 3, 1941. N. M. LOWER 2,243,970

FURNACE APPLIANCE Original Filed Sept. 23, 1956 6 Sheets-Sheet 6 INVNTOR.

' ATTORNEYS/ Patented June 3, 1,941

FURNACE APPLIANCE Nathan M. Lower, Erie, Pa.

Application September 23, 1936, Serial No. 102,057 Renewed January 31, 1940 18 Claims.

My invention relates to improvements in furnaces and has for its main object the provision of an improved automatic furnace which does not require the services of an attendant.

A more specific object of the invention resides ln the provision of a stoker for a furnace arranged to deliver fuel through the normal nredoor opening of the furnace, the fuel Ifeed conduit of the stoker forming a hinging element about Which the door may be swung to opened or closed position.

Another object of the invention resides in the provision of improved means for distributing fuel evenly over all parts of the furnace grate.

The invention further contemplates the provision of simple, eflici-ent and compact means for oscillating the fuel trough of the fuel distributing mechanism and means for regulating the intensity of the fuel projecting blast.

Still another object of the invention resides in the 'provision of a novel door for a furnace firing opening arranged when opened to -carry with it the fuel discharge trough and the mechanism for oscillating the trough, leaving an unobstructed firing opening.

Another novel feature of the invention resides in the construction and relation of those parts of the stoker located in the firing opening whereby efcient cooling thereof is provided.

The invention also contemplates the provision of improved ash conveying means operated in timed relation with the stoker and by the same power that drives the stoker.

Another object of the invention resides in the novel ash pit construction beneath the furnace.

The invention has for another object the provision of novel variable speed reducing means between the ash and fuel conveyors and the Inotor `for driving them and means responsive to the boiler pressure automatically regulating the speed reducer for controlling the speed of the ash and fuel conveyors.

With the above and other objects in View, th-e invention consists of the novel details of construction and operation, and the novel combination .and relation of parts, hereinafter more fully described `and illustrated in the accompanying drawings, wherein Fig. 1 is a front elevation of the preferred arrangement of furnace and stoking and ash conveying apparatus, the furnace room floor being shown in vertical section;

Fig. 2 is a side view ofthe arrangement shown in Fig. l, with the furnace Iand furnace room floor shown in vertical section and the stoking apparatus and grate shaking means shown in elevation;

Fig. 3 is a sectional plan View through the upper portion of the furnace with the stoking apparatus and other parts sho-wn in top plan view;

Fig. 4 is a sectional View taken on the line 4 4 of Fig. 2;

Fig. 5 is a View of the drive mechanism of the stoking, ash conveying vand grate shaking mechanism, shown in vertical section with parts in side elevation;

Fig. 6 is a sectional view taken on the line 5 6 o'f Fig. 2;

Fig. 7 is a sectional View taken on Ithe line 1 1 of Fig. 5;

Fig. 8 is a sectional View taken on the line 8 8 of Fig. 1;

Fig. 9 isV a sectional view taken on the line 9 9 of Fig. 1 with the protecting plate shown in section;

Fig. 10 is a View showing the door in open position, the door and a portion of the boiler being shown in horizontal section with parts broken away;

Fig. 11 is a vie-w in elevation of the discharge end of the sto-ker distributor trough and distributor jet;

Fig. 12 is a View in section taken on the line I2 I2 of Fig. 2;

Fig. 13 is a View in section taken on the line l3 li3 of Fig. 12;

Fig. 14 is a view in section taken on the'line I4 I4 of Fig. 2;

Fig. 15 is a fragmentary diagram-matic View of the furnace and that portion of the stoker mechanism located at the furnace nring opening, with parts broken away and shown in section;

Fig. 16 is a view in section taken on the line Fig. 17 is a View in section through the firing opening of a furnace with a modified form of the invention shown applied thereto;

Fig. 18 is .a vertical section of a portion of the furnace taken on the longitudinal center line of the firing opening with a further modification of the invention shown applied thereto in similar section;

Fig. 19 is a view in elevation rof a portion of the structure shown in Fig. 18, with the furnace and redoor in section;

Fig. 20 isa sectional plan view through the ring opening of the furnace with the modified Ved therein is the casting 2l.

structure shown in Fig. 18 applied thereto, the redoor [being shown in an open position; and

Fig. 21 is a View in section on the line 2I-2I of Fig. 18.

In the drawings, a furnace is designated generally by the numeral I0, the irebox thereof is shown at Il :and the grates upon which the iirebed is supported are indicated at l2. The furnace front I'3 is provided with a firing opening Id above the level of the grates I2 and through .which `fuel may be manually or mechanically introduced into the rebox. For the purpose of mechanically delivering fuel from a- Asuitable sour-ce of supply, as from a fuelA blnv (not shown), and introducing it into the furnace,

a stoker of novel and practical construction is provided. The novel construction of-thestoker as well as the novel construction of the door I5 for the ring opening, which is particularly designed to accommodate the Stoker, will be described hereinafter in detail.

The stoker includes a transfer conduit I6 leading from the source of fule supply toward the furnace front I3 and mounted therein is a screw conveyor I1 for advancing fuel therethrough. The conduit I6 is preferably disposed in a depression IB formedV in the furnace room floor I9, so that the space above the oor is kept as free of obstructions as possible. For convenience in gaining access to the screw conveyor, the conduit I6, is preferably made U-shaped and isprovided with a separable cover 20, which when in place is flush with a furnace room floor I9. The depression vI8 in the floor I9 is somewhat enlarged subjacent the furnace front I 3 and mount- This casting 2I comprises a horizontal conduit section 22, forming a continuation of the transfer conduit I3, anda riser conduit section 23, offset at its lower end to one side of the horizontal conduit section 22 and being in communication therewith. Mounted in the riser conduit section 23 is a conveyor screw 2li arranged at its lower end to receive'the fuel delivered by the transfer conduit screw I7 and to elevate it through the riser conduit section 23.

As is best illustrated in Fig. 6, the conveyor screw I1 extends into the horizontal conduit section 22 and the flights and direction of rotation are so arranged that the fuel will be urged toward the riser conduit screw 24. The screw conveyor Il is provided with an extended shaft 25 which is journaled in a bearing 25a formed with the casting 2l and projects into a gear housing 2'1, also formed with the casting 2 l.

The riser conduit section 23 terminatesat its upper end subjacent one side wall of the firing opening I4. An annular flange or coupling 28,

encircles the upper end of the riser conduit section 23 for laterally supporting the same. A portion of the annular flange or coupling 28 extends above the upper end of the riser conduit 23fand is provided with a counterbore forming a seat 29. One end of an elbow-shaped conduit is received in the annular ange or coupling 28 and engages the seat 29 forming a continuation of the riser conduit 23. Upon its elbow portion, the conduit 3B is provided with a housing 3 I, the purpose of which is brought out further onin the description, and on the housing 3iv is formed a stub shaft 32 journaled in a bearing vi-which is rigidly secured to the furnace front i3. The stub shaft 32 is arranged` to .be in axial vertical alinezol ment with the coupling 28 so that the conduit 3f! is free to swing about a vertical axis. 1

The delivery end 3mi of the elbow-shaped conduit 36 is formed with and extends through the firedoor I5. Thus, that end of the elbow-shaped conduit mounted in the coupling 28, which will be termed the receiving end 3la,1since it receives fuel from the riser conduit 23, forms a hinge for the redoor I5, permitting the door to be opened for inspection of the re or other purposes without removing or dismantling any portion of the stoker mechanism. When the stoker is in operation, it is evident that the fuel is ineffect delivered through the hinge of the firedoor to the firebox of the furnace.

In orderY to facilitate advancement of fuel through the upright or receiving portion 32a. of the elbow-shaped conduit 30, there is mounted therein a short screw section 3&1. The riser conduit Z3, as it extends downwardly from the conduit 39, slopes laterally toward one side of the furnace, see Fig. 1, and rearwardly away from the furnace front I3, see Fig. 2, so that the riser conduit 23 is out of axial alinement with the receiving portion 39a of the conduit Si), thus necessitating a universal connection 35', see Fig. 13, between the riser screw section 24 and the short screw section 34'to provide; an operative driving connection therebetween. Offsetting the lower end of the riser conduit 23 in this manner permits the Stoker to be applied to the conventional type of furnace. It is apparent, however, that by making slight changes in the furnace construction, as by reducing the size of the ash door 36 and'by recessing the furnace front to provide more space between itl and thelower end of the riser conduit 2.3, the riser conduit 23-could be disposed in axial alinementwith the receiving portion of the conduit 3E)-J thus eliminating the universal joint 35.-

As explained above, the elbow-shaped conduit 36 is formed with andy opens through the nredoor l5. A portionofthe delivery end Sbof the conduit 30 projects through the redoor I5 terminating approximately at the center of the Fuel is conveyed through the defiring opening. livery portion 3th ofthe elbow-shaped conduit Sil by a conveyor. screw38 which is operatively connected to the] conveyor screw 34' bygearingV mounted in a casing 31 formed integral with the elbow conduit 33; Theadjacent offset ends'of the

screws

36 and 38,1are keyed' to thecros'sed shafts 39 and 4Q, respectively, journaledY in suitable bearings in the casing 315 The shaft 3S `carries a spiral gear 4I which meshes withA a nace front. Means for continuously oscillating the trough d3 through an arc isprovided, which.

will bey described indetailfurther on'in the description.

rThe troughY 43 is preferably in the formv of a hollow casting, horseshoe-shaped` in horizontal cross section andi including'. in', addition to the o bottomwall 47, the,upstandingfcurved'outer wall;v

48, the downwardly and inwardly sloping inner side walls 49 and 50, the downwardly and inv wardly sloping rear wall '5| and the front Wall 52. These walls enclose the chamber 53 through which a cooling fluid, as for example air, may be circulated. Air is drawn from without the furnace through the opening 54 in the redoor I into the chamber 53 of the trough 43 through the opening 55 in the curved outer Wall 49 thereof and is drawn into the rebox through the apertures 56 in the front wall 52 of the trough 43. At the sides of the opening 54 and adjacent the inner surface of the iredoor l5 are

vertical pins

51 and 58 mounted in the lip 59 and ledge 44.

Shield plates

60 and 6| are pivotally mounted on the

pins

51 and 58, respectively, and extend forwardly one to each side of the trough 43. The free ends of the

shield plates

60 and 6| are maintained in contact with the outer wall 48 of the trough 43 by a spring 62. The

shield plates

60 and 6| together with the top plate 63 and theledge 44 enclose a passage between the

openings

54 and 55 so that substantially all the air drawn in through the opening in the flredoor passes directly into the chamber 53 of the trough 43.

Fuel is projected from the trough 43 in aerial paths over the flrebed on the grates l2 by fluid under pressure issuing from a distributor head 64 seated in a recess 65 formed in the sloping rear wall 5| of the trough 43. The distributor head 64 is provided with a hollow pivot pin 66 mounted axially in the boss 45 of the ledge 44; thus with the pin 66 as an axis, the distributor head 64 is free to swing with the trough 43. The front face of the distributor head 64 is provided with a pair of laterally spaced nozzles 68 and 69 communicating with the cored passage 19 in the head 64. The cored passage 10 extends into the pivot pin. 66 and openings 1| in the pivot pin 66 provide communication between the passage 1|) and the cored passage 12 in the ledge 44. A flexible hose 13 leading from a source of fluid under pressure communicates with the cored passage 12. An angular baille plate 61 made preferably of a material having high heat conductivity, is mounted with one leg thereof against the furnace wall beneath the firing open-v ing, the other leg extending into the firing opening beneath the ledge 44 and trough 43 to protect the fuel distributing mechanism from the heat in the iirebox.

The housing 3|, preferably formed as an integral part of the iiredoor I5, encloses mechanism for horizontally oscillating the trough 43. This mechanism is operatively connected with the Stroker conveyor screws, thus coordinating the rapidity of 4oscillation of the trough with the amount of fuel being conveyed by the stoker con-l veyor screws.

In the housing 3| and keyed to the shaft 39 is a pinion 15 meshing with a gear 16 keyed to the vertical shaft 11. A large cam 18 is mounted on the shaft 11 and is arranged to rotate with the gear 16. A lever 19 pivotally mounted at one end in the housing 3| on stub shaft 86 carries a rotatable roller 8| which is maintained in contact with the cam 18 by a compression spring 82. The other end of the lever 19 is pivotally connected with a shaft 83 carrying a rack member 84. One side of the rack member 84 is received in a grooved roller 85 rotatably mounted in the housing 3|, while the teeth 81 on the other side thereof engage the spur gear 88. The spur gear 88 is keyed to a hollow shaft 89 rotatably mounted in and extending through a bearing 98 within and formed with the housing 3|. A curved arm 9| is secured at one end to the end of the shaft 89 projecting through the bottom wall of the housing 3| and at its other end to the trough 43.

In operation, when the stoker conveyor screws are rotating in a direction to advance fuel to the trough 43, the cam 18 will rotate in the direction of the arrow shown on Fig. 14. Still referring to Fig. 14, it is clear that when the cam is in the position illustrated, the discharge mouth 92 of the trough 43 will be directed along the longitudinal center line of the iirebox. Now, as the cam rotates, the rack member 84 will be moved toward the right because of the gradually increasing radius of the cam between the points a and b thereof, and the operative connections between the rack and the trough will swing the trough so that the discharge mouth thereof will be directed toward the left side of the rebox.

Continued rotation of the cam 18 will cause the trough to swing back to the position shown in Fig. 14, since the gradually decreasing radius of the cam between the points b and c permits the spring 82 to force the rack member to the left. Between the points c and d of the cam, the radius is still further decreased causing the rack member 84 to move still further toward the left and in turn causing the trough to swing so that the discharge mouth thereof will be directed toward the right side of the iirebox. Between the points d and a of the cam, the radius thereof increases, causing the rack member to reverse its movement and in consequence reverse the movement of the trough 43 so that it will return to the position shown in Fig. 14.

The oscillating mechanism is of such design that the trough 43 is oscillated a sufficient degree to each side of the longitudinal center line of the furnace to discharge the fuel substantially parallel to the plane of the inside wall of the furnace front. It will be seen, therefore, that the trough 43 oscillates continuously from side to side, thus permitting fuel to be discharged directly to all parts of the iirebox and in proper amounts to each individual area of the rebed to provide a level iirebed.

The shaft 89 and curved 9| are preferably provided with the communicating

passages

93 and 94, respectively. The passage 93 communicates with the interior of the housing 3| through the registering

openings

95 and 96 in the shaft 89 and bearing 96, respectively, and the passage 94 opens through the end of the arm 9| at 91. The housing 3| is providedwith an opening 98 in a wall thereof exteriorly of the firebox and is provided with a cover 99 forming a closure therefor. Apertures |98 in the cover 99 permit air to be drawn from without the iirebox into the housing 3| and then through the

passages

93 and 94 into the rebox. The draft in the rebox causes a constant iniiow of cool air from outside the furnace, providing cooling means for those parts within the rebox.

Since the distance from the '.ring opening, in which is located the fuel distributing means, to the opposite wall of the furnace is generally greater than the distance from the firing opening to either side wall, provision has been made for varying the pressure of the iiuid blast as the distributor turns from one side to the other. One end of the housing 3| is provided with an opening 98a and a detachable head 99a forming a closure therefor. The head 99a has a hub |8841 fitting in the opening 98a and extending pushing the piston therethrough intothe housing 3l.. The head 99ay has a cored passage therein communicating with the horizontal cylinder I? formed inthe-hub itaf. with the outlet |93 in the head ll'a through a slotA will and one end of the flexible hose '|3.isl arrangedu to be received in the outlet |83. inlet '|5 of the cored passage SillV is in registering communication with a cored passageV |615 in the* stub shaft 32! and7 a iieiribler hose iiil connects the cored pas-sage ie'ii with a steam pipe |1581 leading from the-steam dome of the furnace Hl" or from other` suitable sources. Thus steam passes froml the steam dome through the pipei-S, flexiblehosel till, cored passage Hit, cored passage mi, slot lil, outlet It', flexible hose '3V and then into the` distributor mechanism as Y across the slot L'. VThe pressure of the steam against the other side of the piston its will move the same to the right when theV cam H! is in a position toV permit such movement. Thus it will be seen that as the earn lll rotates, the the piston ilQ reciprocates in the cylinder |52, gradually dii.-inishing the size of the slot Eil-l as. it moves toward the left and gradually enlarging the slot les as it moves toward the right; in'g into the flexible' hos 'i3 and thence to the distributorY alternately decreases and increases.

Now, since the elliptical cam which, as seen above, controls the blast of steam issuing from the distributor, and 'the cam 13, which controls Vthe oscillating movement of the trough d3, are both. keyed to the same shaft ll it is apparent that the pressure uuid blast and oscillation of the trough :i3 are coordinated. With the trough @S in the position shown in Figure 3 and I4 it is clear that the fuel must be thrown a greater distance; so that, as shown in Fig. 14, theV piston i3@ is at one extreme position to entirely uncover the slot ist', thereby allowing a :full volume of steam to reach the distributor. .As-the trough i3 turns, it is evident from Fig. 3 that the fuel should be. projected a continuously 'lesser distance, at the same. time the cam iii is to continuously cover the. slot maso that a continuously Vervolume of steam is being delivered to distributor, thus projecting the fuel a continuously shorter distance. Fuel is therefore projected withk a greater velocity toward the more remote. wall of the frebox than toward the side walls whereby fuel is distributed evenly over all parts of the irebed in the furnace.

The Stoker` is operated by a suitable source of power, such as the motor H2, through a speed' The passage |l |'l communicates Thel It follows that the volume of steam passinY the lower2 portion of the casing ||4 is connectedwithA themotor drive shaft |20 by a flex-- ible' connection `|2'|. Inl the upper portion of t-hecasingY isV aV shaft |22 rotatably'mounted in bea-ringsH |23= andv |2132" Y Mounted on the lower shaft is a relatively small coneV pulley |25'v and on the upper shaft |922- a relatively'large cone pulley |26 tapered in the opposite direction. A square shaft |21 li'esY between the lower shaft and the upper sha-ft i122 and is mounted in the casing bea-ring i2@ and the'casingcover bearing |29. A Vnarrow endless vulcanized rubber belt |39 passesV aroundv the pulleys |25 andl |2Swhereby motion is transmitted from the shaft to the shaft |22, the speed of the shaft |22 being lessiV than that of the shaft because of the dilerence in the circumference of the parts of the pulleys |25; and |26 over which the belt |36) travels. Because of the taper off the pulleys |25` and |26 thespeed ofthe shaft IH may be varied with respect tothe speed of the shaft |22 by endof a lever |32 arranged' to swing upwardly and' downwardly'in response to the steam pressure inthe boiler of the furnace lil, and is at- In consequence, the belt shifter |33 is moved to the'left and with it the belt |30' whereby the shaft i'22. is caused to rotate ata slower rate. Since power for operating the Stoker is transmitted 'through the shaft |22, itis evident that as the steam pressure in the furnace boiler increases the speed of the stokerdecreases, thus delivering lessrfuel to the 'rebox.

Conversely, if the steam pressure in the boiler drops-the free end' of the lever |32 is lowered, causing slack in the cable EEE' and permitting the compression `spring iii to shift the square shaft [2l andY belt shifter |33 to the right. Shifting of the belt shifter |33 to theright moves the belt i3@ to the right whereby the` shaft |22 is caused to rotate faster andv it follows that the Stoker isopereted at a more. rapid rate, delivering` more fuel. to. the rebox. The delivery of fuel. to the fi'rebox by the Stoker is` thus automatically regulated. by the boiler steam pressure.

The shaft |22 isv connected by a flexible coupiing. 36 to a. shaft ist mounted ina casing |38 carried by the stoilier conduit casting 23. Mounted'` on the shaft` t3? within the casing |38 is a worm |33.- m'eshing withV a gear ilil mounted on a verticalv shaft lill.. The veitical` shaft IM eX- tendsf downwardly through the casing |38 into the gea-r housingxZ-land carries at. its lower'end within the housing 2.1 a beviel gear M2 engaging the teeth ofv a bevel `gear |43; mounted on |22 is increased' since thel the shaft extension 25 of the transfer conduit screw |1 for operating the same. Mounted on the same vertical shaft v|4| below the bevel gear |42 is a gear |44 meshing with a helical gear |45 mounted on the extended shaft |46 of the inclined riser screw 24 for operating the same.

The grates |2 are arranged to be shaken in timed relation with the operation of the stoker by mechanism hereinafter described in detail with particular reference to Figures 2, 5, 6 and 16. Pressed on or otherwise suitably secured to the shaft extension 25 of the screw conveyor I1 and within the gear housing 21 is an eccentric |41. A dog |48 is mounted on the eccentric |41 so that rotation of the eccentric |41 will cause reciprocation of the dog |48. The free end of the dog |48 rests against the teeth |49 of a ratchet wheel |50 by reason of gravity and direction of rotation of the shaft extension 25. The ratchet wheel |50 is secured on one end of the shaft and a casing |52, preferably secured to the gear housing 21, houses the ratchet wheel and the end of the shaft |5| on whichthe ratchet wheel is secured. The teeth |49 of the ratchet wheel |59 are cut at an angle so that movement of the dog |48 in one direction will cause engagement of the free end of the dog with one of the teeth of the ratchet wheel, rotating the ratchet wheel and consequently the shaft |5| a fraction of a turn; retrograde movement of the ratchet wheel, when the dog |48 moves in the opposite direction, is prevented by the formation of the teeth |49 which permits the free end of the dog |48 to slide over the teeth |49.

The ashes drop through the grate |2 into a l pit |53 in the furnace floor beneath the furnace. The sides defining the pit |33 slope downwardly and inwardly toward each other, so that the pit resembles an inverted pyramid. YCommunicating with the pit `|53 from a point at one side and exteriorly of the furnace is a short inclined conduit section |64. A conduit |65 extends upwardly at one side of the furnace from the conduit section |54, to which it is connected, preferably though not necessarily by a universal connection |36. One or more chutes |51, two being shown in the drawings for purposes of illustration, communicate with and extend downwardly at an angle from the upper end of the upright conduit |55 and empty into ash receptacles |58. Ash is conveyed from the pit |53 through the conduits |64 and |65 by conveying means including a screw conveyor |99 extending upwardly from the bottom of the pit along a vwall thereof and through the conduit section |64, and a screw conveyor in the upright conduit |65. A universa] joint |1| connects the screw conveyors |39 and |10 so that one may be driven by the other.

In Fig. 17 there is shown a modification of the stoker mechanism adjacent the firing opening in the furnace front 8|. In the preferred form of the invention, as described before, the stub shaft 32 is arranged in axial vertical alinement with the coupling 28 so that the conduit 30 and redoor |5 are free to swing about a vertical axis. In this modified form of the invention, the stub shaft |82 and the coupling |83 are in axial alinement, but the axis is inclined from the vertical so that the door |84 upon being opened swings outwardly and upwardly about the conduit |85 yas an axis. Since the door is swung slightly upwardly upon being opened, the weight thereof makes it self-closing upon being released.

As previously described, in the preferred form of the invention the fuel receiving trough 43 is carried by the redoor |5 on a ledge 44 formed with and extending inwardly from the redoor I5, so that upon opening the door I5 the trough 43 is withdrawn from the firebox. In the modied form of the invention, as shown in Figures 18, 19, 20 and 21, the ledge |85 is generally the same as the ledge 44, but instead of being formed with the redoor, it is provided at its end outside the rebox with a pair of depending legs |81 through which the ledge |86 is secured to the furnace wall |88 by suitable means, such as bolts |89. As has also been described, in the preferred form of the invention the trough 43 isoscillated by mechanism mounted in the housing 3| through the curved arm 9|.' In the modified form of the invention, as best shown in Figures 18 and 21, the curved arm |90 is disengaged from the shaft |9| throughV a cutaway, as at |92, in the shaft |9I. Thus in this form of the invention, when thei door is swung open, the trough |94 remains in its position in the firing opening |93 by reason of its being supported by the furnace wall |38 through the ledgel and by reason of the disengageable nature of the arm |90 and shaft |9|`.

the arm |90 and shaft |9| are in position to be disengaged, permitting the door to be opened.

I claim:

l. In a Stoker for feeding fuel to a furnace,.a trough opening into said furnace, means for delivering fuel to said trough, means for issuing a continuous blast of iiuid under pressure for continuously projecting the fuelfrom said Ytrough into the furnace, means for continuously horizontally oscillating said trough, means for continuously varying the intensity of said pressure fluid blast and means common to said trough oscillating means and said blast intensity varying means for actuating the same in synchronism.

2. In a stoker for feeding fuel to a furnace, a trough opening into said furnace, means for delivering fuel to said trough, means for issuing a continuous blast of uuid-under pressure for continuously projecting the fuel from said trough into the furnace, a supply line for continuously delivering fluid under pressure to said last named means,l means for contin-uously horizontally oscillating Vsaid trough, means operable in said supply line for continuously varying the supply of fluid under pressure to said blast issuing means, and means common to said trough oscillating meansl and said blast intensity varying means for actuating the same in synchronism.

3. In a Stoker for -feeding fuel to a furnace, a trough opening into said furnace, means for delivering fuel to said trough, a jet nozzle for issuing a continuous blast of fluid under pressure for continuously projecting the fuel from said trough into the furnace, a supply line for continuously delivering fluid under pressure to said jot nozzle,

means for continuously `horizontally oscillatingV said trough, said jet nozzle being carried by said trough and being Voscillatable therewith, means operable in said supply line for continuously varying 'the supply of fluid under pressure to said jetinozzle, and means common to said trough os'- cillating means and said blast intensity varying means for actuating the same in syn-chronism.

,4. In combination with a furnace 'having a rlng opening in a Wall thereof, a firedoor for said opening, a ledge formed With Ysaid redoor and extending inwardly ofthe Vfurnace through the lower portion of the firing opening, said ledge having an annular upstanding boss disposed in approximately the plane of the inside surface of the furnace wall, a fuel trough positioned on the inner side of`said redoor and carried by of said hollow-Walled trough having an air ad-v mission yopening and the exterior front wall of said hollow-Walled trough having air emission apertures, an opening in said redoor, and means forming'a passage from the opening in said'firedoorto the opening inthe rear wall of said hol low-trough. i

6. In combination with a furnace having a'ring opening in a Wall thereof, a fired-oor forV said opening, a hollow-Walled fuel trough in said firing opening .spaced from ,said firedoor, the exteriorrear Wall of said hollow-Walled trough havinganA air admission fopening and the exterior front Wall of said hollow-walled trough having air emission apertures, an opening in said firedoor, and means forming a passage from the opening in said firedoorto the opening in the Vrear Wall of said hollow trough, said trough and passage forming means being` supported by and arranged to move with the firedoor when said door is opened and closed.V

7. As an article of manufacture a fuel discharge trough for a stoker, said vtrough having a bottom wall, an upstanding'curved ex-terior Wall U-shaped in section parallel to said bottom Wall, interior Walls converging from the upper rim of said upst'anding exterior WallY to said bot- 'tom Wall, a front Wall connecting the contiguous front edges of said bottom, interior and exterior Walls, said front, interior, exterior andV bottom Walls forming in said trough a chamber.

8. As an article of manufacture a fuel discharge trough for a stoker, said trough having a bottom Wall, an upstanding curved exterior Wall U-shaped in section parallel to said bottom Wall, interior Walls converging from the upper rim of said upstanding exterior Wall to said bottom Wall, a front Wall connecting the, contiguous front edges of said bottom, interior and exterior Walls,

said front, interior, exterior and bottom Walls forming in said trough a chamber, a plurality of apertures in said 'front Wall communicating with the chamber in said trough and an opening in 'said exterior Wall Yopposite said front Wall communicating With said chamber. Y

9. In a Stoker for feeding fuel to a furnace, a trough opening into said furnace, means for delivering fuel to said trough, means for projecting the fuel from said'trough into the furnace, a rotatably mounted shaft operatively connected with said fuel delivering means, a cam mounted on said shaft, means responsive to said cam for horizontally oscillating said trough, a second cam mounted onn said shaft, and means responsive to said second cam for varying 'the forceef said fuel projecting means. Y

l0. In a stoker for feeding fuel to a furnace, a trough opening into said furnace, means for delivering fuel to said trough, means Vfor projecting the fuel from said trough into the furnace, a rotatably mounted shaft operatively connected with said fuel delivering means, a cam mounted on said shaft, means responsive to said cam for horizontally oscillating said trough, a second cam mounted on said shaft, and means-responsive to said second cam for varying the force of said fuel projecting means, said cams being arranged to actuate said projecting means with maximum force when the discharge end 'of the trough is directed toward the remote lportions of the rebox, and With minimum force when the discharge end of the ltrough Ais directed. toward the near portions of the firebox.

1l. In a Stoker for feeding fuelrto a furnace,'

a trough opening into saidv furnace, means for delivering fuel to said trough, means for issuing a blast of fluid under pressure for projecting the fuel from said trough into the furnace, supply line for .delivering fluid under pressure to said means, a rotatably Y mounted shaft operatively connected with said fuel. delivering means, a cani mounted on said shaft, means responsive to said cam for horizontally oscillating said trough, a second cam mounted on said shaft, and means in saidsupply line responsive to said second cam for varying the supply of duid under pressure to a blast of duid under pressure for projecting the.

fuel from said trough into the furnace, a supply line for delivering fluid under pressure to said means, a rotatably mounted shaft operatively connected with said fuel delivering means, a cam mounted on said shaft, means responsive to said cam for horizontally oscillating said trough, a second cam mounted on said shaft, and means in said supply line responsive to said second cam for varying the supply of fluid under pressure to said blast issuing means, said cams being arranged to provide a blast of maximum intensity when the discharge end of the trough is directed toward the remote portions of the firebox, and a blast of minimum intensity when the discharge end of the trough is directed toward the near portions of the rebox. 13. In combination with a furnace having a firing opening in an upright Wall thereof, a movably mounted redoor for closing and exposing said firing opening, a fuel conduit comprising an upstanding -portion mounted for axial rotation and a portion extending laterally from the delivery end of said upstanding portion, said last named portion being formed with said redoor and opening therethrough to the furnace, said upstanding portion forming a hinging element for moving said redoor to close or expose said firing opening, a screw conveyor in said upstanding conduit portion, a screw conveyor in said laterally extending conduit portion, and means outside the conduit passage operatively connecting the adjacent ends of said screw conveyors.

14. In a. Stoker for feeding fuel to a furnace, a trough opening into said furnace, means for delivering fuel to said trough, means for projecting the fuel from said trough into the furnace, means for varying the force of said projecting means, means for horizontally oscillating said shaft, means responsive to said cam means for horizontally oscillating said trough and means responsive to said cam means for varying the force of said fuel projecting means.

16. In a Stoker for feeding fuel to a furnace,

a trough opening into said furnace, means forA delivering fuel to said trough, means for issuing la blast of fluid under pressure for projecting the fuel from said trough into the furnace, a supply line for delivering fluid under pressure to said means, a rotatably mounted shaft, cam means mounted for rotation With said shaft, means responsive to said cam means for horizont-ally oscillating said trough, and means in said supply line responsive to said cam means for varying the supply of fluid under pressure to said blast issuing means.

17. In combination with a furnace having a ring opening in a Wall thereof, a redoor for said opening, a ledge formed With said redoor and extending inwardly of the furnace through the lowerrfportion of the firing opening, a fuel trough carried by said ledge, said fuel trough and said ledge being provided, one with a vertical annular boss and the other with an annular recess receiving said boss, said boss and recess being disposed in approximately the plane of the inside surface of the furnace Wall, and means for horizontally oscillating said trough about the axis of said boss.

18. In combination with a furnace having a firing opening in a Wall thereof, a fredoor for said opening, a hollow-walled fuel trough in said firingopening positioned on the inner side ofv and spaced from said iredoor, the exterior rear wall of said hollow-Walled trough having an air admission opening, an opening in said redoor, means forming a passage from the opening in said iiredoor to the opening in the rear Wall of said hollow trough, said passage forming means including side Walls pivotally mounted at one end on vertical axes adjacent opposite sides of the opening in said redoor, and means for maintaining the free ends of said side Walls in contact with said trough.

NATHAN M. LOWER..