Furnace

Application filed May 11,

The present invention relates broadly to liquid and gaseous fuel burners, and more particularly to burners of this type which are ordinarily designated “blow torches” or '· “furnaces”, and especially suitable for use by linemen, plumbers and the like where portable heating units capable of operation under adverse circumstances; are required, although the utility of the invention is not v limited in· this respect.

Throughout the specification and claims, apparatus of the general character herein contemplated will be described by the general term “furnaces”, it being understood A⁵ that the word is used as one of definition and not limitation, and is generically definitive of a general class of apparatus.

At the present time a number of different kinds of furnaces is available for perform20 ing the general functions herein contemplated. Such furnaces, however, have been objectionable for many reasons, most of which are concerned chiefly with the question of efficiency, the question of ease of op25 eration, adjustment and repair, and the question of safety.

As ordinarily constructed, furnaces of this general· nature have not been generally capable of use in unfavorable weather or high 22 wind conditions. _ The present invention has for one of its objects the provision of a furnace which may be efficiently used under such conditions, the invention contemplating among other things a restricted air supply 2 ^J as compared to that ordinarily permitted, and means for preheating the supplied air.

Another object of the present invention is to provide an improved burner of such nature that complete mixing of the fuel and -° air occurs in the lower part of the burner, thereby enabling higher temperatures to be obtained by the burner, which higher temperatures are desirable not only from the standpoint of the material being heated by the furnace but from the standpoint of fuel vaporization, and more particularly in cold weather.

With furnaces of usual construction, the temperature conditions during operation so have been such as to result in undue heating

1926. Serial No. 108,283.

of the fuel reservoir, whereby bulging and explosions not infrequently result. The present invention contemplates improved heat dissipating means intermediate between the burner and reservoir whereby the tempera- 55 ture of the reservoir can be maintained within a much lower range.

Another object of the invention is to provide a valve and burner assembly of such nature that the assembling operation is facil- eo itated and possibility of stripping threads is minimized.

Still another object of the invention is to provide a reservoir of improved construction whereby the strength thereof is increased, 65 the possibility of bulging is eliminated and the chances of rupture or bursting limited to a predetermined zone or zones.

Further objects of the invention are to provide an improved pump construction and 70 operating means therefor whereby operation of the pump is facilitated and the length of life thereof increased.

Still further objects are to provide a furnace construction in which access to the parts 75 for repair replacement or adjustment is facilitated.

Other objects of the invention will be apparent from the following specification and drawings constituting a part thereof, the so drawings showing for purposes of illustration only, certain preferred embodiments of the invention, it being understood that the drawings do not define the limits of our invention as changes in a construction and ⁸⁵operation disclosed therein may be made without departing either from the spirit of the invention or the scope of our broader claims.

In the drawings: ⁸⁰

Figure 1 is a side elevational view of one form of furnace constructed in accordance with the present invention;

Figure 2 is a vertical sectional view _8Sthrough a furnace constructed as shown in Figure 1, certain of the parts being shown in elevation or partly broken away for sake of clearness;

Figure 3 is a detail sectional view, on an 100

1,887,855 an annular portion 5 of relatively narrow width which is substantially straight and which departs rather sharply from the main curved body of the bottom. At the conclusion of the annular portion 5 the bottom is ₇₀provided with a reverse bend 6 terminating in a downturned flange 7 embraced within the upturned edge 8 of the top plate of the reservoir. In actual practice, we have found that a reservoir of the general characteris- 75 tics set forth will, in the event of extremely high pressure, tend to rupture substantially in the zone of the straight portion 5. This is by far preferable to having the reservoir rupture through the upper portion thereof, 80 inasmuch as this results in throwing the fuel downwardly away from the burner, with a corresponding decrease in the possibility of a serious explosion.

Eccentrically formed in the top of the res- 85 ervoir is an opening into which is secured an internally threaded bushing 9 adapted to receive the lower threaded end 10 of the valve body 11. This lower threaded end is also preferably internally threaded to receive a 90 fuel feeding tube 12 as understood in the art. The tube. 12 discharges fuel into a port 13 intersecting a laterally extending passage 14. This passage is shaped to constitute a seat for the conical end 15 of the controlling valve ⁰⁵16. Extending upwardly from the passage 14 is a second port 17 controlling the delivery of fuel to the lower end of a burner tube 18. This burner tube may conveniently be threaded directly into an extension. 19 on the ¹⁰⁰valve body, the lower threaded end preferably being tapered to provide a tight joint while permitting, a slight turn in either direction to properly position the burner.

We have found it to be desirable to con- ¹⁰⁵struct the valve body in the form of a brass forging due to the homogeneous nature thereof. In order, however, to reinforce this forging, and particularly the portion 19 receiving the lower end of the burner tube, ¹¹⁰there is threaded thereon a reinforcing sleeve 20 of cold rolled steel or other desired material.

This reinforcing sleeve at its upper end has an internal diameter preferably substantially equal to but slightly greater than the external diameter of the burner tube, whereby with the reinforcing sleeve in position- on the projection 19 it effectively serves not only as _i20a reinforcing means but as a guiding means lor guiding the burner tube accurately into engagement with the threads in the projection 19. Conveniently the projection 19 has its upper edge :21 downwardly and inwardly 125 beveled as clearly apparent from Figure 3 of the drawings for assisting in the guiding and engagement of the threads On the respective parts. In this manner stripping or splitting of the threads and splitting of the projection ISO enlarged scale, through a portion of the valve and burner assembly;

Figure 4 is a side elevational view of the pump;

Figure 5 is a detail view partly broken ⁵ away of a portion of the pump cylinder showing the clevis in position thereon;

Figure 6 is a detail sectional view on an enlarged scale, illustrating one of the fasteningmeans for the furnace guard;

¹⁰ Figure 7 is a top plan view of the structure shown in Figure 1;

Figure 8 is a top plan view of the heat dissipator;

Figure 9 is a transverse sectional view on ¹⁰ the line IX—IX of Figure 2 looking in the direction of the arrows; and

Figure 10 is a detail sectional view on an enlarged scale through a portion of the reservoir. .

In accordance with the present invention, there may be provided a furnace having a reservoir 2 adapted to contain a predetermined supply of fuel and forming a base ή? for effectively supporting the furnace. The “° reservoir is preferably of novel construction with respect not only to the material from which it is constructed but with respect to the contour thereof. This reservoir preferg₀ ably comprises an upper portion 3 comprising a single sheet of metal, the metal preferably being, or having the characteristics of drawn steel with a relatively low carbon content. The bottom 4, on the other hand, 35 is preferably constructed of spring steel having, a much higher carbon content, the carbon content of the bottom ordinarily being many times greater than that of the top.

The contour initially imparted to the plates from which the reservoir is constructed is preferably substantially that which parts of the dimensions generally indicated and of the characteristics described, will tend to assume, under high pressure ‘46 conditions within the reservoir. This contour is conveniently initially determined by constructing a reservoir of the desired metal and then creating a pressure therein sufficient to produce a slight bulging. This con‘^6 tour is then measured, and a second reservoir constructed having such contour. The pressure is then increased in this second reservoir to such an extent as to produce a bulging, and the contour again measured and a reservoir constructed. This operation is repeated until there is provided a reservoir having a contour conforming to the contour which the reservoir tends to assume under abnormal pressure conditions. We have '⁶⁰ found that such a reservoir has. materially greater strength than a reservoir the construction and curvature of which are arbitrarily produced.

The bottom 4, in accordance with the pres⁶⁵ ent invention is preferably shaped to provide

1,887,855 3 due to the taper of the threads on the burner is prevented.

The reinforcing sleeve 20 is preferably provided with an outturned flange 22 at its low_e er end forming a shoulder adapted to support a heat dissipating plate 23. This plate, as indicated in Figure 8 of the drawings, is preferably of generally circular contour having eccentrically formed therein an opening io 24 of a diameter permitting cooperation with the sleeve 20 and consequent movement of the plate 23 downwardly thereover into engagement with the shoulder 22. This plate throughout substantially its entire area is 15 formed with openings 25 preferably irregularly arranged relative to the contour of the dissipator as illustrated for example in Figure 8 of the drawings.

After the dissipator has been properly po20 sitioned, a spacing sleeve 26 is slipped over the reinforcing sleeve and a saucer 27 positioned around the reinforcing sleeve in such manner as to rest on the spacer. This saucer preferably has a diameter substantially equal 22 to the diameter of the dissipator 23 and has an upturned peripheral edge 28 whereby it serves to collect foreign matter and prevent the same from dropping onto the upper surface of the reservoir. This is particularly sc desirable in the case of burning fuel or other inflammable material which, if permitted to reach the reservoir and burn thereon, might result in undue temperature conditions, as well as sufficient heat to ignite vapor in the S5 reservoir with a resulting bulging or bursting thereof. The intermediate portions of the saucer 27 are preferably reinforced by means of a rib or corrugation 29.

The burner itself is conveniently construct40 ed substantially as disclosed in the patent to Flitcroft No. 1,283,133 of October 29, 1918, in that there is provided a casing 30 supported by the tube and preferably cast therearound and carrying an inlet 31. The out45 let nipple 32 of the burner tube is, however, located a greater distance from the inlet 31 than disclosed in the Flitcroft patent. The casing 30 has openings 30' therein to admit air to the burner. In the drawings, the burn50 er parts are shown substantially one-half full size, thereby providing a distance between the burner nipple and the inlet 31 which is great enough to permit complete mixing of the fuel in the lower part of the casing 30 in 55 a manner not obtainable with the Flitcroft burner as constructed. This enables the creation of a higher temperature at the outlet of the burner and a better vaporization of the fuel in the burner tube. Surrounding the up60 per end of the casing 30 and extending around a substantial portion of the casing is a removable air preheating bell 33.

Secured in any desired manner to the top of the reservoir 2 is a bearing bracket 34 hav¢5 ing bearings therein for a pintle 35 extending through openings in lugs 36 carried by the lower end of a guard and flue 37. This guard and flue at its lower edge is slotted, as indicated in dotted lines in Figure 2, to provide a recess 38 to accommodate the valve stem 16 when the guard and flue is swung into and ⁷⁰out of operative position about the pintle 35. At its front side the guard and flue car- . ries a door 39 which may be slid into open or closed position at will in the guide grooves 40 provided therefor in the guard and flue. ··

Carried by the guard and flue at its upper end is a top plate 41 which is conveniently provided with a flange 42 for the reception of a hood 43, a portion of which is indicated in _ dotted lines in Figures 1 and 2. This hood ⁸⁰tends to protect the melting pot or other articles mounted on the plate. To accommodate the plate to articles of different shapes and contours, as well as size, it may be provided ₈₅with stepped supports 44, these supports be- ing effective for not only centering the pot but for preventing slipping or tilting thereof. F ormed in the top plate 41 substantially centrally thereof so as to overlie the burner ₈₀is an opening 45 having a diameter which is preferably substantially equal to the external diameter of the upper portion of the casing 30 whereby the passage of excess air into the guard and flue 37 is prevented. Sur- ₀₅rounding the central opening 45 is a series of comparatively small openings 46 and 47, these openings, providing the necessary draft for operation under normal conditions and being small enough to prevent any disturb- ₁₀₀ance with the operating conditions, in the event of extreme blasts of cold air having a tendency to travel downwardly in opposition to the natural draft, and thereby unduly chill the casing to an extent sufficient to in- ₁₀₅terfere with vaporization and proper burner operation. It will be apparent that should any air pass downwardly through the series of openings 46 it will come into contact with the air preheating bell 33 kept heated by ₁₁₀flames emanating from the openings 33' whereby its temperature is materially raised to such an extent as to prevent interference with vaporization.

For maintaining the guard and flue in _il5position on the reservoir to prevent accidental swinging movement thereof, it may be provided with any desired number of clips 48 having a pivotal connection 49 with the guard, and slotted to pass around bolts 50 carrying Ϊ20 clamping means preferably in the form of wing nuts 51. In order to prevent loss of the wing nuts the bolts 50 may be drilled and retaining means 52 inserted through the openings. When it is desired to swing the 125 guard and flue to inoperative position, the wing nuts may be loosened, the clips swung away from the bolts by means of the thumb pieces 53, and the guard and flue moved as desired. With the combined guard and flue 130

1^887,855

4έimposition; the furnace is ready for use, or may'be carried from point to point by means; of ^!a.bail 54· carried by suitable, trunnions 55 on the top plate.

The reservoir may have the usual filling 5^; opening: closed by a: drop forged steel filler plug: 56 and may also be provided with a pump 57 having; a general·construction disclosed in Flitcroft Patent 1,030,465 of June 25,.1912. Conveniently, however, the pump ¹⁰ cylinder has mounted therein a. piston rod 57', the upper end of which carries an operating.handle 58 extending laterally whereby it may be conveniently gripped by an operator. For holding the parts normally in a ¹⁵’position illustrated in full lines in Figures 1 and 2, there may be.provided a clevis 59 carrying a coiled spring; 60 adapted to cooperate with a depression 61 in the handle. The clevis is conveniently carried by trun²⁰ nions 62 formed integrally with the pump forging which carries the pump cylinder and projecting laterally therefrom. These trunnions are preferably internally threaded to receive screws 63 preventing the clevis from ²⁵ accidentally becoming disengaged from the. trunnions, while permitting removal and replacement of the clevis when desired. The upper· end of the pump forging is preferably externally threaded to cooperate with a main ³⁰ nut 64 adapted to receive a secondary nut 65 threaded thereinto and removable independently thereof. This secondary nut is preferably extended into the pump cylinder, as ₃₅ shown, to provide a guiding and wearing; extension 66 for the piston rod 57' duringoperation of the pump.

Heretofore, considerable difficulty has been experienced in attempting to swing a hold40 ing clevis of the general type shown herein into inoperative position to permit operation of the pump. In accordance with.the present-invention such operation is facilitated by shaping the handle 58 so that it not only ex-; 45 tends laterally but also upwardly as clearly shown in the drawings. When so constructed, the act of swinging the handle from its full line position in either direction,, as indicated in clotted lines, will tend to cam off 50 the clevis and automatically throw it to inoperative position. At the same time, the handle will be brought around to such a posi-. tion that the pump.may be more expeditiously operated.

As is customary in furnaces of the general nature herein disclosed, there is provided a drip cup 67 preferably mounted above the saucer 27 and spaced therefrom by a sealing and packing washer 68 of asbestos or other :60 suitable material. After the drip cup is-in position, it may be held therein by a put 69 threaded onto the upper end of the reinforcing and guiding sleeve 20.

In actual practice we have found that the ,65 construction of the dissipating plate 23 with a plurality of openings irregularly positioned: with respect to the contour of the plate is extremely important and insures a better operation than can be obtained in a construction in which the openings are regularly ar- 70 ranged or in which the plate has a peripheral edge or border of regular or uniform characteristics. While we have? not been able to : definitely determine the reasons? for such improved operation, it is believed that the ir- ⁷⁵regular arrangement of openings more effectively breaks up and distributes the limited ' amount of air: which passes to the interior; of the combined guard and flue 37 through the· recess 38, through the space below: the door. ⁸⁰39, and below the combined guard and flue 37 at such points at-which tight contact with the top of the reservoir is not made.

It will be understood that ill starting; the burner in operation it is customary, to cause ⁸⁵a body of·fuel to accumulate within the drip, cup 67. Not infrequently this.· fuel is permitted to accumulate to a-point-substantially even with the top of the.cup, and occasionally the cup. is-permitted to overflow?. In such· ⁹⁰cases, when the fuel is ignited the resulting expansion or boiling of^: the fuel causes it to further overrun the edges, of the. drip cup. The possibility of an accumulation of fuel under, these conditions on the top of· a reser- ⁹⁵voir is prevented by-reason of the; saucer 27. The heat generated, however, if directly transmitted to tlie reservoir might produce atemperature, therein which would be objectionably? high. The dissipator? effectively co- ¹⁰⁰operates with the burner parts to directly dissipate heat therefrom* not only by reason. of the large radiating surface provided, but by reason; further of the intimate contact between the various portions thereof and the ¹⁰⁵entering air. It also prevents the existence of a comparatively still body of air below· the saucer capable of conducting heat downwardly therefrom.

An apparatus of the character herein con-, no template! must be capable of operation without: adjustment in weather and wind conditions of all different kinds ancl degrees.· The heat-dissipator is an important factor in insuring such operation* as ?it, to a considerable 115 extent, breaks up.the draft which would normally be produced by the combined flue and guard and effects delivery of air in broken-up condition only, and largely preheated to the burner. . 120

Certain ·features of the present- invention, and more particularly; the swinging guard and flue structure, are disclosed and -claimed in our copending ? application, Serial No. 48,978, filed August 8,1925, in which there is 120 also claimed the provision of a saucer and drip cup intermediate the-burner and reservoir. The present application constitutes a continuation in part of such copending: application. 130

1,88 _φ Certain advantages of the present invention arise from the improved reservoir construction and contour whereby greater strength and safety are insured.

- Other . advantages of the invention arise from the improved burner construction in which mixing is completed in the lower portion of the burner casing, and from the provision of heat dissipating means intermediate w ^tke burner and reservoir and preferably provided in addition to the safety, saucer.

Still other advantages arise from the improved top plate construction whereby the air supply is controlled, broken up and pre₁₅ heated.

Further advantages of the invention arise from the improved valve and burner assembly and from the improved pump structure in which increased bearing surface is pro•^:-j ^{Vlded and 3n} ^bich the pump handle is effective for earning off the clevis.