US3010010A

US3010010A - Apparatus for use in depositing weld metal as spiral, partially overlapping courses on the interior of a shell

Info

Publication number: US3010010A
Application number: US788431A
Authority: US
Inventors: Charles E Jackson; Gerald A Snow
Original assignee: Chicago Bridge and Iron Co
Current assignee: Chicago Bridge and Iron Co
Priority date: 1959-01-22
Filing date: 1959-01-22
Publication date: 1961-11-21
Anticipated expiration: 1978-11-21

Description

c. E. JACKSON ET AL 3,010,010 APPARATUS FOR USE IN DEPOSITING WELD METAL AS Nov. 21, 1961 SPIRAL, PARTIALLY OVERLAPPING COURSES ON THE INTERIOR OF A SHELL 6 Sheets-Sheet 1 Filed Jan. 22, 1959 J 0 o a 4 4! 4 5 4 7 4 3 v I a, a J J 5 v 00 m a d W 4 3 E z W. o 3 9 6 W 8 n 8 0 a 6 6 3 7s 6 5 /25, v H 5 z 6 b 5 r 8 6 B 4 7 4 6 8 w 1 a 4 I oo 4 3 u a w a a m m 1 l5 9 3 v 6 2 3 3 w 7" a 2 9 a 0 4 0 no m a m 4 f 6 9 7 4. 2 2 m 9 N o a a0 0 w; z a 1 I 6 l 7 5 7 0 a 0 d 7 9 4 H a I III, I I /,///d///////// l/Il/ l/l/l Nov. 21, 1961 c. E. JACKSON ET AL 3,010,010

APPARATUS FOR USE IN DEPOSITING WELD METAL AS SPIRAL, PARTIALLY OVERLAPPING COURSES ON THE; INTERIOR OF A SHELL Filed Jan. 22, 1959 6 Sheets-Sheet 2 132082221345: mles EJaciifcom Gemini :11 .Snow

c. E. JACKSON ET AL 3,010,010 APPARATUS FOR USE IN DEFOSITING WELD METAL AS SPIRAL, PARTIALLY OVERLAPPING COURSES ON THE INTERIOR OF A SHELL 6 Sheets-Sheet 3 a? w i m V 0 AM'\'\'\\\\ m x m '1".\

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Aw :1 a vi W Nov. 21, 1961 Filed Jan. 22, 1959 Nov. 21, 1961 c. E. JACKSON ET AL 3,010,010

APPARATUS FOR USE IN DEPOSITING WELD METAL AS SPIRAL, PARTIALLY OVERLAPPING COURSES ON THE INTERIOR OF A SHELL Filed Jan. 22, 1959 6 Sheets-Sheet 4 Nov. 21, 1961 c. E. JACKSON ET AL 3,010,010

APPARATUS FOR USE IN DEPOSITING WELD METAL As SPIRAL, PARTIALLY OVERLAPPING COURSES ON THE INTERIOR OF A SHELL Filed Jan. 22, 1959 6 Sheets-Sheet 5 Inventions.- C'aaflies E Jacfiflson, Geflaid d1 .Juow,

Nov. 21, 1961 c. E. JACKSON ET AL 3,010,010

APPARATUS FDR usE IN DEPOSITING WELD METAL AS SPIRAL, PARTIALLY OVERLAPPING COURSES ON THE INTERIOR OF A SHELL 6 Sheets-Sheet 6 Filed Jan. 22, 1959 6 4 a 5 a 5 n m 5 K 7 7 5 5 F 5 IHHLIIIIIH H H- W I 8 n u n n n u n 6 I 5 3 a //4 W 3 a 6 6 Q Y/// v////// rd 4O a M 4 6 w e 9 3 e a e w 6 a a 6 a w w K H H. n 7/A4 United States Patent O" 3,010,010 APPARATUS FOR USE IN DEPOSITING WELD METAL AS SPIRAL, PARTIALLY OVERLAPPING COURSES ON THE INTERIOR OF A SHELL Charles E. Jackson, South Portland, and Gerald A.

Snow, Falmouth, Maine, assignors, by mcsne assignments, to Chicago Bridge & Iron Company, Chicago, 111., a corporation of Illinois Filed Jan. 22, 1959, Ser. No. 788,431 17 Claims. (Cl. 219-76) The present invention relates to apparatus for use in lining the interior surface of a vertical shell of approximately circular cross section by depositing weld metal thereon as a generally spiral course with each course being a partial overlay with respect to the subjacent course.

While the invention is adapted for use with other structures, it is herein discussed primarily in connection with pulp digesters as best illustrating the problems involved andthe objectives of the invention and the novel features, and advantages of apparatus in accordance therewith. a

The liquors, and gases used in pulp digestion result in the corrosion and erosion of the digesters to the point where they. must be condemned as no longer fit for safe use. It has become the practice to avoid the heavy expense and substantial interruption of production entailed in digester replacement by cladding, with weld metal, the interiors of digesters that are approaching condemnation as no longer fit for safe service, with the weld metal applied as partially overlapping courses. It will be appreciated that, for such a lining to be satisfactory, there must be no gaps between courses and the courses must be reasonably uniform. These requirements are particularly troublesome in working in a chamber such as a digester and, in addition, the cost of providing such a lining and the time required for so doing are important considerations.

One practice has been to erect and suspend a support within the digester that is capable of serving as a platform for the welders. The platform had a peripheral way for carriages, typically three in number, each of which was driven therealong between two stations located 120 apart and common to appropriate ones ofthe other carriages. Each carriage supported a welding unit and the terminal ends of powerand material supply means. Manually operated means were also provided by which each welding unit was so raised, at the completion of a weld course, that the next course had a desired overlay with respect theretor Such apparatus had desirable features but was disad vantageous in some respects. Arnongthese may be noted that its use was attended by high labor costs and that difficulties were experienced in depositing a course in proper relation to a lower course and at the ends of the courses, in avoiding seams that were objectionable in appearance and sometimes the source of weld defects that had to be located and corrected.

In accordance with the present invention, the support includes an axial column on which there is mounted a section for rotation independently thereof and a drive for rotating that section. The section is provided with an arm for driving the carriages around the peripheral way. Each carriage has a welding unit consisting of agun and material and power supply means. The power and material supply means include portions carried by the rotatable section. In the case of electric circuits, the portions carried by the section preferably have brushes engaging fixed contact rings on the column. When the welding is done by the consumable electrode, inert gas process,the gas source may be located externally of the digester in which event the portionsof the gas supply that are carried by the rotatable section may be connected to the 3,010,010 Patented Nov. 21, 1961 supply by a rotatable joint and when the submerged arc process is practiced, the flux may also be fed to the wc1ding zone from outside the digester.

Each carriage supports-its welding unit by means operable to elevate the unit with respect thereto and each such means is actuated by engagement withcoacting means associated with the way whichis provided with a track for the carriages. The carriages are connected to each other and to the arm in a manner ensuring that each, may travel along the way with its position determined only by the supporting surface and guiding track. In ad dition, each welding gun is supported by its carriage for movement relative thereto in response to yieldable means engaging the shell and ensuring predetermined spacing between the welding gun and the wall on which weld metal is to be deposited. Eachcourse'is, accordingly,

' deposited accurately in relation to the previous course thus minimizing. defects therebetween.

As the weld metal is applied as a substantiallyspiral' course, joints exist only between the ends of the elec-- trodes which may befu'rnished in reels'or coils ofsub-' stantial length. The welding operation is accordingly ef-v fected with maximum speed and accuracy and with mini-' mum labor costs; As the carriages are coupled together, they may most advantageouslybe spaced so .closely to-l gether that they may be attended by a single operator located at a station with which the rotatable section is provided. I

Other objectives of the invention are concerned with means to enable the apparatus to be readily assembled within a digester. Limitations on the dimensions of parts are imposed not only by the size of the manhole of a digester but also by the structure.

In the accompanying drawings, there is shown an illusspace between it and overhead trative embodiment of the invention from which these i and other of its objectives, novel features, and advantages will .be readily apparent. In thedrawings,

FIG. 1 is a partial vertical section through a digester in which there is installed apparatus in accordance with the invention,

FIG. 2 is a section taken approximately along the in-' dicated lines 2-2 ofFIG. 1,

' FIG. 3 is a top plan view, on an increased scale, of one of the carriages,

FIGS. 4 and 5 are, respectively, side and end views thereof,

13, and a head or dome 14 having an 'axially located;

.-- and as much as fifty feet in height.

flanged manhole 15. Digester dimensions vary consider-j ably and they may be as much as twelve feet in diameter The diameter of the manhole may be as little as eighteen inches and the distance between it and the overhead structure may be I as little as four feet and sometimes less.

Apparatus for use in lining the interior of a digester i must be adapted to be assembled within the digester from parts that are dimensioned to be worked into position between the digester and overhead structure and lowered through the manhole 15 and in accordance with the invention, a column 16 is employed that has ribs 17 to which end cap arms 18 are bolted. Wire ropes 12 or other suitable supporting members are connected to brackets 20 bolted to the flange of the manhole 15 and the wire ropes are connected to the arms 18 by jacks 21 or other means adapted for use in raising, lowering, and

holding the apparatus in a Wanted position within the digester 10.

, The column 16 is shown as consisting of an upper section 16 to whose upper end the end cap is bolted, an intermediate section '16 and a bottom section 16. The section 16 has

tubular ends

22 and 23 welded therein. The end 22 is dimensioned to receive the machined lower end 24 of the section 16 and is locked thereto by bolts 25. The end 23 is dimensioned to receive the machined upper end 26 of the bottom section 16 and is locked thereto by bolts 27, see FIG. 6.

The lower end of the column section 16 is provided with ribs 28 to which corresponding ends of braces 29 are bolted in an upwardly and outwardly inclined position. Horizontal, radially disposed arms 30 are similarly secured to the section 16 and the upper end of each brace 20 is so cut that a plate 30 relative thereto is horizontal. A triagular frame comprising supports 31, having their ends beveled as at 32 and the arms 30 are connected to appropriate ones of the plates 30 Each plate 30 has a vertical arcuate flange 33 to which are bolted the ends of appropriate ones of the three frame members 34 each shown as defining an arc of 120. Flooring 35 is laid on the upper surface of the frame established by the supports 31 and the members 34 to establish a suitable platform.

Each frame member 34 has sockets 36 welded to its inner face and these receive posts 37. The upper end of each post 37 is slidably entrant of a depending socket 39 on the under surface of each of the three flat surfaced sections 40 each of which defines an arc of 120. At each end of each section 40, there is a depending flange 401, see FIG. 2, enabling the sections 40 to be bolted together to provide an elevated, peripheral way, generally indicated at 41, provided with a guide rail 4-2 and a series of arcuately spaced contact pins 43. Secured to the under surface of each section 40 are a series of jack screws 44 and a like series of jack screws 45 are carried by the frame members .34 for steadying engagement with the wall of the digester. 7

Below the platform, there are blocks 46 welded to the column section 16 and to which is bolted a mount 47 for an electric motor 48, a first speed reducer 49, a second speed reducer 50, and a flexible overload coupling 51 between the two speed reducers. The driven shaft of the speed reducer 50 has a pinion 52 meshing with a gear 54 bolted to the bottom ring 55 of a housing generally indicated at 56.

The housing 56 comprises the ring 55, an upper ring '57 joined thereto by tie bars '58 and the cover sections 59, see FIG. 7, whose side flanges are attached to the bars 58. The'section 16 has a ring 61 between which and the ring 55 is a ball bearing unit 62 while between the upper ring 57 anda ring 63, fast on the upper end of the section 16 there is a ball bearing unit 64. The ring 63 has .a series of ports 65 to enable cables to be passed downwardly therethrough for connection with appropriate ones of the contact rings 66 provided with connectors 68 and mounted on non-conductive spacers 69 secured to the section 16 The rotatable rings 55 and 57 are provided with holders 70 for the insulated shafts 71 for the ring engaging brush holding units 72. The housing is provided with a mount 73, see FIG. 2, to which the forked end 74 of an arm 75 is detachably connected by transverse pivot means 76. The arm 75 extends radially with'its free end overlying the way 41. \An arm support 77 is connected to the free end of the arm 75 bytransverse pivot means 78 and has a way engagin'g, supporting wheel 79.

The way 41 supports carriages of which two are shown in the drawings and which are generally indicated at 80, see FIGS. 3, 4 and 5. Each carriage consists of a base 81 supported by an intermediate way engaging wheel 82 and provided with end brackets 83 each having a way engaging wheel 84 having its axis intersecting the axis of the column 16. The end brackets 83 are also provided that have pairs of rotatable followers 85, each pair receiving the guide rails 42 between them. The carriages are interconnected by couplers, generally indicated at 86, as may be seen in FIG. 2, and these are shown as comprising end links 87, each connected to a carriage by a vertical pivot 88, and an intermediate link 89 connected to the end links 87 by transverse pivots 90. A generally indicated coupler 91 connects the arm support 77 to the leading carriage and preferably consists of an intermediate link 92 connected to end links 93 by transverse pivots 94. The end links 93 are connected to the leading carriage and the arm support, respectively, by vertical pivots 95.

Each carriage base 81 has a mount 96 for vertical guide rods 97 and these are located on opposite sides of a hub 98 in which there is a ball bearing unit 99 for the spindle 100 on whose lower end there is a sprocket 101 and which is provided with a collar 102. Above the collar 102, the spindle is threaded to establish the upper spindle portion as a screw 103. The collar 102 has a flange 104 overlying a ball 105 in the hub 98 shown as being backed by a spring 106. The guide rods 97 slidably guide the mount 107 and have their upper ends interconnected by a header 108 in which the upper end of the screw 103 is journalled with its stem 109 being provided with a hand wheel 110. The mount 107 includes a fixed nut element 111 through which the screw 103 is threaded.

On the undersurface of each carriage base 81 there is a stud 112 carrying a star wheel 113 and a sprocket 114 connected to the sprocket 101 by a chain 115 having one course trained about the idler 116 on the stud 117. The stud 117 is carried by one arm of the bell crank 118 pivotally attached to the base 81 and has a pin 119 on its other arm extending through a slot 120 in the base 81 to which it is locked as by the wing nut 121 threaded thereon. The star wheel 113 is shown as arranged to be moved a quarter turn each time a carriage passes a contact pin 43 thus to elevate its mount 107 to a predetermined extent relative to its base 81.

The mount 107 carries a welding unit, generally indicated at 122. In the embodiment of the invention shown in the drawings, such a unit consists of equipment of the type using the inert gas, consumable electrode process and as such equipment is conventional, it is not herein detailed other than to indicate the stainless steel wire electrode at 123, its feed at 124, and a source of supply at 125 carried by a support 126 attached to' the housing 56. The gun is indicated at 127 and controls at 128 with the power supply being indicated by the electric cable 129 whose leads are connected to appropriate ones of the brushes 72.

The gas supply conduit 130 to each welding unit 122 is shown as being connected to a ring 131 rotatably connected to a hub 132 secured to the tubular end 22 of the column section 16 The ring 131 has an annular channel 133 into which one end of a conduit 134 in the hub 132 opens. The other end of the conduit 134 is connected to a gas conduit 135 in comunication with a source outside the digester 10.

It will be noted that each mount 107 has a bracket 136 provided with a pair of pivots 137 for the parallel arms 138 connected to a support 139 by pivots 140. The gun 127 is supported by a bracket 141 attached to a plate 139 by locking bolts 142 extending through slots 143. At the free end of the bracket 141 there is mounted a wheel 144 whose function it is to engage the digester wall and to maintain the tip of the gun 127 in predetermined position relative thereto. For that reason, a spring 145 is provided to urge the guide wheel 144 outwardly into such contact.

From the foregoing, it will be appreciated that the weld metal deposited by each gun is an approximately spiral course accurately applied in relation to the next subjacent course and as each gun is operative through 360, the length of each spiral course is dependent only on the length of the wire electrodes.

While only two carriages are shown in the drawings, additional carriages may be employed but it is preferred that the carriages be coupled closely together. One reason for that preference is that each carriage then may follow freely the track or guide rail 42. Another reason is that the closely coupled carriages can be serviced by a single operator with maximum ease and convenience and it reduces the size of his stand 146 shown as including a seat 147. In any event, carriage spacings of less than 180 with a single arm, usually a towing arm, are requirements. The housing 56, the support 126, the stand 146, and the seat 147 comprise the rotatable section of the apparatus.

While the means, shown in the drawings, for elevating each gun relative to its carriage, as that carriage travels around the way, causes the successive turning of the elevating screws, each step is usually such a small fraction of an inch that the course does not show any well defined steps but rather appears a true spiral. When the limits of the gun elevating screws are reached, welding is interrupted until the apparatus can be repositioned and the guns adjusted to continue their accurate depositing of weld metal courses. j i What we therefore claim and desire to secure by Letters Patent is:

1. In apparatus for use in lining the interior of a cylindrical metal shell by depositing weld metal thereon in courses with'each course being disposed approximately as a. spiral and as a partial overlay with respect to the subjacent course, a support including an axial column and a peripheral way, carriages supported by said way and coupled together, a section carried by said column for rotation independently thereof and including an arm connected to one of said carriages; a drive for rotating said section about said column, a welding unit for each carriage including a gun and power and material supply means, said power and material supply means being provided with portions carried by said section, and connecting meansbetween each carriage and the Welding unit therefor operable to elevate the welding unit relative thereto, the connecting means for each carriage and said way including coacting parts operable to effect the oper ation of each connecting means to a predetermined extent oneachlap of its carriage.

2. In apparatus for use in lining the interior of a cylindrical metal shell by depositing weld metal thereon in courses with each course being disposed approximately as a spiral and as a partial overlay with respect to the subjacent. course, a supportincluding an axial column; carriages supported by said way and coupled together, a section carried by said column for rotation independently thereof and including a towing arm connected to the leading one of said carriages; a drive for rotating said section about said column, a welding unit for each carriage including a gun and power and material supply means, said power and material supply means being provided with portions carried by said section, and connecting means between each carriage and the welding unit therefor operable to elevate the welding unit relative thereto, the connecting means for each carriage and said way including coacting-parts operable to effect the operation of each connecting means to a predetermined extend on eachlap of its carriage. I

3. In apparatus for use in lining the interior of a cylindrical metal shell by depositing weld metal thereon in courses with each course being disposed approximately as a spiral and as a partial overlay with respect to the subjacent course, a support including an axial column and a peripheral way provided with a series of'arcuately spaced elements;carriages supported by said way and coupled together, a section carried by said column for rotation independently thereof and including an arm connected to one of said carriages; a drive for rotating said section about said column, a welding unit for each carriage including a gunand power and material supply means, said power and material supply means being provided with portions carried by said section, and connecting means between each carriage and the welding unit therefor operable to elevate the welding unit relative thereto and including an actuator engageable by said elements successively as said section turns.

4. In apparatus for use in lining the interior of a cylindrical shell by depositing weld metal thereon in courses with each course being disposed approximately as a spiral and as a partial overlay with respect to the subjacent course, a support including an axial column and aperipheral way, carriages supported by said way and coupledtogether as a train whose length is less than 180, a section carried by said column for rotation independently thereof and including an arm connected to one of said carriages and a station for the operator between the ends of said train; a drive for rotating said section about said column, a welding unit for each carriage including a gun and power and material supply means, said power and material supply means being provided with portions carried by said section, and connecting means between each carriage and the welding unit therefor operable to elevate the welding uni-t relative thereto, the connecting means for each carriage and said way including coacting parts operable to eifect the operation of each connecting means to a predetermined extent on each lap of its carriage.

5. In apparatus for use in lining the interior of a cylindrical metal shell by depositing weld metal thereon in courseswith each course of one wire being disposed approximately as a spiral and as a partial overlay with respect to the subjacent course, a support including an axial column, and a peripheral way, carriages supported by said way and coupled together, a section carried by said column for rotation independently thereof and including an arm connected to one of said carriages; a drive for rotating said section about said column, a welding unit for each carriage including a gun and power and material supply means, said power and material supply means being provided with portions carried by said section, at least one of said means including a source located outside said shell and a joint comprising a part carried by said column and a rotatable part carried by said section, and connecting means between each carriage and the welding unit therefor operable to elevate the welding unit relative thereto,-the connecting means for each carn'age and said way including coacting parts operable to eifect the operation of each connecting means to a predetermined extent on each lap of its carriage.

6. In apparatus for use in lining the interior of a digester or like chamber having a manhole by depositing weld metal thereon in courses with each course being disposed approximately as a spiral and as a partial overlay with respect to the subjacent course, an axial column to be lowered through said manhole, a support including upwardly and outwardly inclined brace members detachably connected to the lower end of said column, transverse supporting members detachably interconnecting the upper ends of said brace members, a plurality of arcuate lower frame members detachably connected to said upper brace ends, a plurality of arcuate upper frame members detachably interconnecting said upper and lower arcuate members, all of said members, when detached from one another being dimensioned to pass through said manhole, and a section carried by said column for rotation independently thereof, said section including a detachable arm, and a drive for rotating said section about said column, said drive being detachably connected "to said column below the plane of said lower arcuate members and dimensioned to pass throughlsaid manhole.

"7. In a device for use in lining the interior surfaces of a cylindrical shell by depositing weld metal thereon in courses with each course being disposed approximately as a spiral and as a partial overlay with respect to the .subjacent course, a support including an axial column to be suspended within the shell, and a peripheral way,

carriages supported by said way and coupled together as a train, a section carried by said column for rotation independently thereof, and including an arm connected to said train, a welding assembly for each carriage including a gun movable towards and away from said shell, a spring urging said gun towards said shell, and a shell engaging follower limiting the movement of said gun in response to said spring, and connecting means between each carriage and the welding assembly therefor operable to elevate the welding assembly relative thereto, said connecting means and said way including coacting parts operable to elfect operation of each connecting means to a predetermined extent on each lap of its carriage.

8. In a device for use in lining the interior surfaces of a cylindrical shell by depositing weld metal thereon in courses with each course being disposed approximately as a spiral and as a partial overlay with respect to the subjacent course, a support including an axial column to be suspended within the shell, and a peripheral way including a guiding rib concentric with the column, carriages supported by said way, each including rollers straddling said rib, a section carried by said column for rotation independently thereof and including a towing arm, a welding assembly for each carriage including a gun movable toward and away from said shell, a spring urging said gun toward said shell, and a shell engaging follower limiting the movement of said gun in response to said spring, and connecting means between each carriage and the welding assembly therefor operable to elevate the welding assembly relative thereto to a predetermined extent on each lap thereof and couplers between said carriages and between the leading carriage and said towing arm, each of said couplers including a central link and end parts, each end part including a transversely pivoted section and a vertical pivot between each end part and said link, said vertical pivots being all spaced approximately the same distance from said column.

9. In a device for use in lining the interior surfaces of a cylindrical shell by depositing weld metal thereon, a support including an axial column to be suspended within the shell, and a peripheral way, carriages supported by said way, coupling means interconnecting said carriages, a section carried by said colunm for rotation independently thereof, a towing arm, transverse pivot means connecting said arm to said section, a welding assembly for each carriage including a gun movable toward and away from said shell, a spring urging said gun toward said shell, and a shell engaging follower limiting the movement of said gun in response to said spring, connecting means between each carriage and the welding assembly therefor operable to elevate the welding assembly relative thereto a predetermined distance on each lap, said towing arm including an end provided with a way engaging wheel, transverse pivot means connecting said end to said arm, and coupling means between said end and the leading carriage, said coupling means including vertically and horizontally pivoted sections.

10. In apparatus for use inlining the interior of a cy-' lindrical shell by depositing weld metal thereon in courses with each course being disposed approximately as a spiral and as a partial overlay with respect to the subjacent course, a support including an axial column to be suspended within the shell and a peripheral way, carriages supported by said way, coupling means interconnecting said carriages, said column including upper and bottom sections, and an intermediate section including female ends, the proximate ends of said upper and bottom sections being male ends fitting and being bolted to. said female ends, said support being attached to said bottom section and coupled together, a section attached to said intermediate section for rotation independently thereof and including an arm connected to one of said carriages; a drive for rotating said section about said column and being attached to said bottom section, a welding unit for each carriage including a gun and power and material supply means, said power and material supply means being providedwith portions carried by said section, and connecting means between each carriage and the welding unit therefor operable to elevate the welding unit relative thereto, each connecting means and said way including coacting parts operable to elfect the operation of each connecting means to a predetermined extent on each lap of its carriage.

11. In apparatus for use in lining the interior surface of a cylindrical metal shell by depositing weld metal thereon, a centrally disposed stationary axle, an arm associated with said axle and rotatable thereon, a peripheral way supported by said axle substantially concentric with said shell, a carriage including welding means and supported by said way and movable therealong, connecting means between said arm and said carriage, means for rotating said arm to effect peripheral movement of said carriage, and means for elevating said welding means relative to said carriage proportional to peripheral movement of said carriage.

12. In apparatus for use in lining the interior surfaces of a cylindrical metal shell by depositing weld metal thereon, a centrally disposed stationary axle, an arm associated with said axle and rotatable thereon, a pee ripheral way supported by said axle substantially concentric with said shell, carriages supported by said way and coupled together and movable along said way, each carriage including welding means, connecting means between said arm and the leading carriage, means for ro. tating said arm to effect peripheral movement of said carriages, and means for elevating each of said welding means relative to its carriage proportional to peripheral movement of said carriage.

13. In apparatus for use in lining the interior surfaces of a cylindrical metal shell by depositing weld metal thereon, a centrally disposed stationary axle, an arm associated with said axle and rotatable thereon, a peripheral way supported by said axle substantially concentric with said shell, a carriage supported by said way and movable thereon, welding means including a screw feed connection with said carriage, connecting means between said arm and said carriage, means for rotating said arm to effect peripheral movement of said carriage, and means associated with saidway for actuating said screw feed relative to said carriage in predetermined increments proportional to peripheral movement of said carriage.

14. In apparatus for use in lining the interior surfaces of a cylindrical metal shell by depositing weld metal there: on, a centrally disposed stationary axle, an arm associated with said axle and rotatable thereon, a peripheral way supported by said axle substantially concentric with said shell, a carriage supported by said way and movable therealong, welding means including a screw feed connection with said carriage, connecting means between said arm and said carriage, means for rotating said arm to effect peripheral movement of said carriage, and means spaced along said way and coacting with said screw feed connection to elevate said welding means relative to said carriage in predetermined increments proportional to'peripheral movement of said carriage, and the spacing, of said last named means. 1

15. In apparatus for use in lining the interior surfaces of a cylindrical metal shell by depositing-weld metal thereon, a centrally disposed stationary axle, an arm associated with said axle and rotatable thereon, a peripheral way substantially concentric with said shell, a carriage including welding means and supported by saidway and movable therealong, connecting means between said arm and said carriage, means for rotating said arm, to effect peripheral movement of said carriage, and means for elevating said welding means relative to said carrige proportional to peripheral movement of said carriage.

16. In apparatus for use in lining the interior surfaces of a cylindrical metal shell by depositing weld metal thereon, a transverse arm, means supporting said arm for ro tation about the axis of said shell, a peripheral way substantially concentric with said shell and including a guide track, carriages supported by said way and peripherally movable thereon in engagement with said track, each carriage including welding means, connecting means between said arm and the leading one of said carriages and between said carriages, each of said connecting means including a central link and end parts, each end part including a transversely pivoted section and a vertical pivot between each end part and said link, said vertical pivots being spaced approximately the same distance from said axis, means for rotating said arm to elfect peripheral movement of said carriage, and means for elevating said welding means relative to said carriage proportional to peripheral movement of said carriage.

17. In apparatus for use in lining the interior surfaces of a cylindrical shell by depositing Weld metal thereon, a transverse arm, means supporting said arm for rota- 10 tion about the axis of said shell, a peripheral way substantially concentric with said shell and including a guide track, a carriage including welding means and supported by said way for movement therealong in engagement with said track, connecting means between said arm and said carriage and including vertically and horizontally pivoted sections, means for rotating said arm to effect peripheral movement of said carriage, and means for elevating said welding means relative to said carriage proportional to 10 the movement of said carriage along said track.

References Cited in thefile of this patent UNITED STATES PATENTS 2,839,663 McCallom June 17, 1958 15 2,839,666 Launder et a1. June 17, 1958 2,902,588 Zouck et a1. Sept. 1, 1959 FOREIGN PATENTS 743,555 Great Britain Jan. 18, 1952