US2690929A - Flame spray apparatus - Google Patents

Description

Oct. 5, 1954 s. s. JOHNS 2,690,929

FLAME SPRAY APPARATUS original Filed sept. 2o, 195o 4 sheets-sheet 1 aio O SG ATTORNEYS Get., 5, 1954 S. S. JOHNS FLAME SPRAY' APPARATUS Original Filed Slept. 20, 1950 "Jr- ;E El.. *"6

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FLAME SPRAY APPARATUS Original Filed Sept. 20, 1950 4 Sheets-Sheet 3 INVENTOR STANLEY S. `J'O-INS ATTORNEYS 5, 1954 s. s. JOHNS FLAME SPRAY APPARATUS original Filed sept. 2o, 195o 4 Sheets-Sheet 4 INVENTOR STANLEY S. JOHNS ATTOR NE YS Patented Oct. 5, 1954 UNITED OFFICE FLAME SPRAY APPARATUS Original application September 20, 1950, Serial No. 185,826, now Patent No. 2,634,703, dated April 14, 1953.

Divided and this application February 5, 1952, Serial No. 273,505

i claim. l

This invention relates to methods and apparam tus for processing the interior surfaces of tubular articles and the like and particularly to a flame spray apparatus and blast tube.

This application is a division of my copending application, Serial No. 185,826, led September 20, 1950, now Patent No. 2,634,703 of April 14, 1953.

The invention relates generally, but not necessarily, to the processing of tubular interiors in connection with conveyor line handling of such tubular objects, The invention will be described mainly in relation to the coating of welded seams of tubular articles, such as steel drums. The invention is not intended to be limited to the processing of such drums, however, and the application of the invention to many other types of articles will become fully apparent as the description proceeds.

The present invention is directed to a llame spray apparatus having a nozzle with a centrally positioned aperture through which a composition may be directly passed, and with a blast tube arranged at the exit of the nozzle for guiding the spray onto a surface which is to be coated.

It is a primary object of my invention to provide an improved means for producingr a llame spray from a powdered composition, such as a polyethylene composition, and to direct the spray to a predetermined portion of a surface.

Further objects and the entire scope of my invention will become apparent from the followingr detailed description of preferred embodiments of my invention. It is not intended that the particular embodiments, which are illustrated and described, shall limit my invention. These embodiments are described only for purposes of illustration.

The most complete understanding of the de scribed embodiments may be had with reference to the accompanying drawings, in which:

Figure 1 shows a side view of a combined bur rushing and coating apparatus.

Figure 2 is a view of the apparatus in Figure l taken on the line 2--2 of Figure 1.

Figure 3 shows a plan view of the apparatus in Figure 1.

Figure 4 Shows a detail View taken along the line 4--4 of Figure l.

Figure 5 shows a means of supporting the end of a blast tube, shown in Figure 1.

Figure 6 shows a modification of the structure shown in Figure 5.

Figure 'l shows my improved ame spray apparatua Figure 8 is an end View of the apparatus of Figure 'i taken along the line 8 8 of Figure 7.

Figure 9 is a cross-sectional view taken along the line 9-9 of Figure 8.

Figure l0 is a sectional view taken along the line l-I of Figure 9.

Figure 11 is a sectional view taken along the line H-ll of Figure 9.

Referring now to Figures 1-4, and primarily to Figure 1, an apparatus is illustrated in which a tubular article I@ is adapted to be reciprocated in a horizontal direction, and while being so moved, undergoes a processing operation along a previously welded seam by means of the processing apparatus indicated generally at l2. The reciprocating motion oi the container is automatically placed under the control of the motor driving unit, indicated generally as I4, and material which is to form part of a coating on the seam of the article I9 is delivered from a supply structure, indicated generally as It.

In greater detail, upstanding supporting members 29 are provided to which are attached longitudinal side rails 22 and 24. The rails 2?. and 24 are of an L-section having their lower sides extending horizontally and inwardly to provide horizontal surfaces 26 and 2l, respectively, upon which a carriage 28 may ride. The carriage 28 is supported for movement on the rails 22 and 2d by means of small wheels or rollers 36 mounted at substantially the four corners of the carriage. The carriage itself is made up of L-secu tion members as can be best observed in Figure 2.

On the carriage 28 are mounted two supporting bars 32 and 34, these bars being supported at their ends in the cross-wise or end I -sections of the carriage 28. These end sections are designated 36 and 38 in the drawings. Rotatably mounted on the bars 32 and 34 are wheels 36 employed to support the article IB for rotation about its axis. This can be best appreciated from the showing in Figure 2.

A protruding arm 38 is xed to the carriage 28 along the left-hand side of the carriage (as viewed in Figure 2), and this arm extends downwardly of the carriage for connection to a drive chain at a point 60. The drive chain, designated as 42, runs over idler sprockets 44 and 46 which are rotatably mounted on upright supporting members 4t and 59. These supporting members extend between the upper side rail 24 and lower horizontal drive supporting rails 52 and 54.

The drive unit, previously indicated generally as l 4, is supported on the rails 52 and 54 by means of a transverse plate 56. The drive unit I4 is made up of a preferably reversible motor H driving a reduction gear box l l2, the latter having an output drive sprocket II4. The chain 42, previously described as extending over the idler sprockets 44 and 46, is then alsol trained over the drive sprocket H4 and any additional idler sprockets as may be desired.

From the apparatus as thus far described, it will be apparent that as the motor H0 is operated in a forward direction, the arm 38 connected to the chain 42 at point 40 will cause the carriage 28 to move forwardly (to the left in Figure 1) and cause the article l0 to move relative to the processing devices indicated generally as l2. When the motor H0 is reversed, the carriage and container will be returned to their original position.

The processing devices, indicated generally as I2, are in the illustrated embodiment comprised of a burnishing motor 2li) and a flame spray apparatus indicated generally as 2I2. These units are intended. to burnish and then coat a previously welded seam of the article l0, such a seam may take the form as indicated at 2|.4 (Figure 2).

The motor 2|!) and thel spray unit 212 are mounted on an I-beam.` 2I6, the latter being mounted in cantilever fashion from two upwardly extending beams 2l8v supported by the previously described framework. The motor 2I0 is mounted at the free end of the cantilever beam 2 I6 on a parallelogram arrangement so that the motor can be raised and lowered with respect to the lower interior surface of the article It. This parallelogram mounting consists of two upper conventional variety and is arranged to reciprocate the operating rod 223 along the axis of the latter. It will thus be apparent that as the rod 228 is reciprocated to the right (Figure 1), the motor 2l0 will be raised.

The motor 2H) is equipped at its lower end with a drive shaft 232 and mounted on this shaft is a burnishing brush 234.

The flame spray unit, indicated at 212, comprises a nozzle section designated as 236 and a blast tube section designated as 238. rlhe nozzle unit 236, which will be described in more detail below, performs the function of spraying a molten substance into the upper end of the blast tube 238 and this tube directs the spray toan outlet end 240.

The details of the end 240 of ther blast tube 238 may be best understood with reference to Figures 5 and 6. The spray which proceeds down the blast tube 238 may be created from a polythene powder (which will be more fully discussed below in connection with the nozzle 236). This spray will form a coating on the seam 2M. as indicated at 242 in Figure 5. It will be realized, of course, that the coating may be any other suitable composition, including all types of paint and the like. The blast tube 238 is terminated a relatively great distance above the seam 2 I4 at the rim 244. A surrounding tubular sleeve 246 is then mounted on the end of the blast tube 238 by means of four set screws 248, the latter clamping on the tube 238 adjacent the rim 244 thereof. The screws 248 provide adjustment of the sleeve 246 relative to the tube 238, this being desirable because the tube 238 itself is rmly attached to the I-beam 2&6-, The: lower edge 250 of the sleeve 24Er is positioned closely adjacent the inner surface of the article l0 and will thus serve to substantially prevent the spreading of the coating material beyond the confines of sleeve 246. The upper end 252 of the sleeve 245, however, extends substantially above the lower opening of the tube 238 (at rim 244) and thus provides an upwardly erected exhaust channel for escaping gases which accompany the molten coating material. An effective means is thus provided for directing and conning the coating material within apredetermined area, and at the same time, permitting unused gases to escape upwardly about the tube 238.

To closely control the clearance of the lower sleeve edge 250 from the surface of the article I0, the sleeve 246 may be provided with rollers 254 (Figure 6) which will ride on the interior surface of the article I0. The sleeve 246 maybe further mounted on the tube 238 by means of a pivotal support pin 25h` which connects an arm 258 extending from the blasting tube 232) with an arm 260 extending from the sleeve 24E. With the use of this pivotal mounting, the set screws 248 may be loosened and while the blast tube is within the length of the article I0, the wheels 254 will support the sleeve 246. The rim 244 will serve to engage the loosened set screws 248 to limit the downward movement of the sleeve 246 about the pivot 255 when the article ID is removed from proximity with the blast tube 238.

As an equivalent arrangement, the set screws 248 may firmly clamp the sleeve 246 to the tube 238 and the tube itself may be pivotally mounted on the I-beam 2|.G for limited movement.

The` nozzle unit 235 is adapted to be supplied with a powdered composition from the supply means I6 through a suitable conduit 262, and to be supplied with necessary fluids under pressure through the connections indicated generally at 263. The supply means IG may be controlled by a vibratory means (not shown) which, in the case of powder, will control the flow thereof through thev conduit 262.

The apparatus as thus far described can be arranged for automatic operation in the following manner: Assuming, initially, that the carriage 28 is at its outermost or right-hand position (Figure l), an article Ill is first placed upon the rollers 36, either by being placed thereon manually or by suitable lifting means (not shown) for lifting from an adjacent conveyor line. A foot switch 3l() is then closed by the attending operator and the closing of this switch establishes a circuit through suitable relay contacts to energize the windings of motor HU to drive this motor in a forward direction. This circuit which is established may also energize the vibrator associated with the supply means IG to permit a flame spray to proceed through the tube 238, and may also energize the motor 210 to rotate the brush 234. At this time, the solenoid D will not be energized and the brush 234 will be in position to engage the article Ill. The operation of the motor in a forward direction will move the pin 42 to cause the carriage 28 to move to the left (Figure l), and, therefore, the brush will burnish the seam and the blast tube 238 will subsequently produce the rst layer of a coating on the seam.

The carriage in its right-hand position (Figure 1), is arranged to engage a limit switch 3I2 and, while thus engaged, to hold this switch in an open position. Switch 3I2 may be connected in parallel with foot switch 3 I 0 and as soon as the carriage 28 has moved to the left a sucient distance to permit switch 3| 2 to close, then switch SI (l may be opened and the previously mentioned circuits will remain closed through switch SI2.

When the carriage 2B reaches its most lefthand position (Figure 1), it will engage and close a normally opened limit switch 3I4. The switch 3I4 may be connected to energize the operating coil of a relay of which the previously mentioned relay contacts form a part. The operation of this relay may cause the windings of the motor lit to be connected to reverse the rotation of this motor, while at the same time, the operation of the relay may (l) energize solenoid 234 to raise the brush 234, (2) cut 01T the supply means I6 if only one layer of coating is desired, and (3) close holding contacts which will hold the relay in operated position after the carriage 28 has moved toward the right (Figure l), and the switch 3I4 has reopened. Due to the action of the holding contacts, the carriage 28 will return to its original position and reopen the switch SI2 before movement is stopped. Upon opening the switch 3I2, the relay holding circuit will be opened and the circuit thus set for another cycle operation upon the subsequent closing of the foot switch 3M).

From the foregoing circuit description, it will be apparent that the carriage 28 will initially move the article IU so that the seam thereof is nrst burnished and then a coating applied thereto. Upon the return movement of the carriage, the burnishing brushes moved out of the way to prevent destruction of the coating, and at the same time, a second layer of coating may be applied. It will, of course, be understood that a second layer may be dispensed with, or on the other hand. if more than two layers are desired, a suitable relay system could readily be provided to permit further reciprocations of the article I4 with the burnishing brush held in its uppermost position during this operation.

I have additionally discovered that in the processing of surfaces, such as the interior welded seam in steel drums, that a very effective coating consists of resins of polythene (polymerized ethylene). The use of such a coating derived fro-m the powder has been diicult, however. with previous methods of flame .spraying the powder or composition on the metal surface. By the use of the spraying nozzle, about to be described, however, a very satisfactory naine spray may be obtained.

The nozzle is the unit previously mentioned above and indicated by the numeral 236. A detailed understanding of this nozzle may now be had with reference to Figures 7-11.

The nozzle is built up around a centrally positioned aperture 4 I 4 which extends generally from a connection at 4I2 to the supply conduit 262 to its other end 4M located adjacent to the blast tube 238. The powdered composition is drawn from the supply conduit 262 and caused to be rapidly discharged from the end 4I 4 by means of air pressure introduced into the central aperture 4m by means of a converging channel M5. As best shown in Figure 9, the converging channel 4I6 causes the .air to be directed into the central aperture 4m in a direction nearly parallel to the direction of the particles moving from the conduit 262. It will be thus apparent that a blasting action takes place which rapidly accelerates the powdered composition through the nozzle. The straight through powder feed has been found to be a very decided improvement over prior art devices having elbows which clog easily.

The converging channel 4 I 8 is structurally provided for by having the central aperture 4I!) made up of a rearward section 4 I B and a forward section 420. Each of the sections 4I8 and 420 have abutting iiange members 422 and 424, respectively, 4and the latter flange is cut away, as at 426, leaving a shoulder 428 of section 420 to engage the outermost area of the ange 422 of the rearward section 458. The shoulder 428 thus creates a spacing between the inner diameters of the anges of sections 4 i 8 and 424 and, accordingly, creates the channel 4I6. The air under pressure is supplied to the channel 4IE by means of four apertures 43D extending from the inner edge of the shoulder 426 forwardly in a direction substantially parallel to the central aperture 4I ll.

The air under pressure, which is applied through the channel 4m, is initially applied through a hose connection 432 and this air is rst used to cool certain associated structures. Without this novel cooling, the complete length of the central aperture will become overheated, with undesirable results. The hose connection 432 is mounted in a forward or enclosing section 434 of the nozzle structure, this section being provided with an annular channel 436 into which the air rst passes. Upon being distributed in the channel 432, the air next passes through four openings 438 into a forwardly extending cylindrical chamber deiined on its outside by a tubular wall 446 of the section 434, and dened at its inner side by a sleeve member 442. After proceeding from the channel 43S through the openings 438 and forwardly through the chamber dened by members 4453 and 442, the air then turns inwardly around the most forward end of the sleeve 442 and proceeds in a rearward direction through an annular channel dened on its outside by the inner surface of the sleeve 442, and defined on its inside by the outer surface of a combustion chamber sleeve 444. The air is then made available to the forward ends of the apertures 430 through a chamber indicated as 446, the latter being defined on its forward side by an extending flange section 448 of the sleeve 442, and on its rearward side by a central nozzle section 450.

From the structure as thus far described, it will be apparent that air being supplied through connection 432 rst proceeds forwardly through the outermost annular channel and then proceeds rearwardly through the next inner annular channel through the chamber 446 where it is made available to the apertures 430. From the latter apertures, the air is introduced into the converging channel 4i 6 via the cut away section 426 and the powdered composition supplied from conduit 262 accordingly blasted out through the end 4I4 of the central aperture M4.

To create a ame spray, suitable gases, such .as acetylene and oxygen, are introduced through piping connections 452 and 454, respectively, into an annular mixing and combustion chamber 45B. This mixture is then permitted to escape through four openings 454 into an annular chamber defined at its outer side by the inner surface of the tube 444, and defined at its inner side by the outer wall of the forward section 420 of the central aperture structure 4I0. The outer end 4:artisanat M4 of the central aperture structure 4H! is ycharacterized by a series of radially extending teeth 460 which abut .at their outer edges the junction of the sleeve 444 and the outer casing 440 to form a series of jets immediately surrounding the end 4M of the central aperture lili). The gases which are mixed in the chamber 4.56 and are burning in the chamber extending from the openings 458 to the jets 46.9 are accordingly directed outwardly of the jets in a direction substantially parallel .t-o the axis of the central aperture M9. The powdered composition which is being expelled from the central aperture is therefore completely heated and caused to assume a molten state.

As previously mentioned, the air pressure being supplied through the piping connection 432 passes over the outer surface of the sleeve member `lidi! and, accordingly, serves to cool this member.

The blast tube 233 is an important part of my invention. Without the use of such a tube I have found that a great deal of unmelted powder will issue from the nozzle, and, moreover, the spray will not be conned to a particular desired area of the surface to be coated.

The blast tube will become quite hot because of its proximity to the iiame, and this heats kand melts unmelted powder issuing from the nozzle. In some instances, it may be desirable to insulate the outer surface of the blast tube to build up the heat to high values, The size and length of the tube may also be selected to provide desired degrees of heat.

In the use of the apparatus described in connection with Figures 1 to 6, it is to be understood that the seam or other surface of the article may have been previously heated (as by a previous Welding operation) and the articles have then been naturally or articially cooled to a temperature level whereat the coating may be applied Without danger of blistering. In other Words, in utilizing the first described apparatus in the processing of the surfaces of the article, a rst step may comprise heating, and the coating operation is a later step in the process.

The detailed description has been made only for thepurposes of illustration and the true scope of the invention is to be determined from the appended claim.

I claim:

In a flame spray apparatus, a spraying nozzle, the nozzle comprising a centrally positioned aperture therethrough, means for supplying a spraying composition to the input end of said central aperture, means to supply pressure into the said central aperture to blast the said composition along the central aperture, a flame jet positioned adjacent the output end of the central aperture and arranged to direct a name substantially in the direction of movement of the oomposition blast issuing from the central aperture, a blast tube having one end positioned adjacent the output end of the said aperture and the other end positioned adjacent a surface to be coated, whereby the name-sprayed composition may be directed to a predetermined area of the said sur face to be sprayed, the end of the blast tube which is positioned adjacent to the surface to be coated being provided with an annular guiding sleeve supported on the said end of the blast tube, said sleeve at its lower end being adapted to move closely adjacent the surface, and adapted at its upper end to provide a gas escape passage in `a direction away from the surface being coated.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,072,845 Benoit Mar. 9, 1937 2,125,764 Benoit Aug. 2, 1938 2,229,631 Barker et al Jan. 28, 1941 2,397,165 Shepard Mar. 26, 1946 2,411,409 Ballard Nov. 19, 1946 2,427,448 Duccini et al Sept. 16, 1947 2,436,335 Simonsen Feb. '17, 1948

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