US2305005A - Coating machine - Google Patents

Description

Dec 15, 1942. R, HEN Y 2,305,005.

comma MACHINE Filed April 25, 1941 3 Sheets-Sheet 1 INVENTOR. fe/nmel ZZZ/e221" BY 7% R. E. HENRY 2,305,005

COATING MACHINE Filed April 25, 1941 3 Sheets-Sheet 2 Dec. 15, 1942.

Dec. 15, 1942. I R. E. HENRY 0 COATING MACHINE Filed April 25, 1941 3 Sheets-Sheet 3 Patented Dec. 15, 1942 COATING MACHINE Rommel E. Henry, Longview, Tex, assignor to Pipe Line Service Corporation, Franklin Park. 111., a corporation of Illinois Application April 25, 1941, Serial No. 390344 13 Claims. (01. 91-32) This invention relates to machines for applying coating materials to pipe and the like, and

has for its principal object the provision of a machine that will apply to the pipe a coating that is devoid of holidays, pinholes or other imperfections.

The principal object of the invention is the provision of a coating shoe for'forming a bath of coating material that is free from entrapped .gas and in whichthe pipe is immersed.

the provision of a shoe which is adjustable so,

that the thickness of the film of coating materi applied to the pipe may be varied.

Still another object of the invention lies in the provision of arrangements for supplying the shoe with coating materials that are free from entrapped gas bubbles and the like.

Further objects of the invention, not specifically mentioned here, will be apparent from the detailed description and claims which follow, reference being had to the accompanying drawings in which a preferred embodiment of the invention is shown by way of example and in which: Figure 1 is an elevational view of a portion of a machine, partly in section, showing the coating shoe and mounting therefor;

Figure 2 is a cross-sectional view, taken substantially along the line 2-2 of Figure 1, and

drawn to an enlarged scale; and

Figure3 is an elevational view, partly in sec tion, showing the coating shoe construction.

Pipes, pipe lines and the like, are frequently protected from corrosion and electrolysis by an application of a coating material. In certain instances, a wrapper or wrappers are applied over the coating material before the same has set, with the result that the wrapper is imbedded in the coating material and thereby bonded to the pipe to afford additional protection. In other instances, the coating material alone is relied upon to protect the pipe.

The coating material is usually applied hot and on cooling forms a fairly solid film or sleeve around the pipe and to be effective, it is necessary that thesleeve so formed be free from holl-' days, pinholes -or other imperfections through which moisture may enter and come into contact with the pipe. In instances where a wrapper is applied immediately on top ofthe coating and before the coating has cooled. the tension under which the wrapper is applied trowels the coating and tends to squeeze out of it any entrapped gas and also tends .to move the coating into holidays that may have been left by thecoating shoe. In installations where no wrapper is used, this trowelling action is not present, and if the coating is to be free from imperfections, the coating shoe itself must be capable of applying a holiday free mm on the pipe. v

. It has been found that a goodly portion of the holidays in the coating material are the result of gas entrapped in the coating material supplied to the shoe. This is particularly true when the coating material contains solvents which vaporize at or near the temperature at which the coating material is applied. It has been the practice heretofore to supply coating material to the shoe from a tank of material by pumping the same to a point above the pipe and then allowing this material to flow over the pipe. In-cert'ain instances, the shoes used embrace only the lower half of the pipe and in other instances, a full shoe encircling the pipe is employed and the coating material is dropped into a funnel-like projection on the top of the shoe. It has been found that permitting the coating material to drop into the shoe or on to v the pipe causes a certain amount of air to be entrapped in the material and that this entrapped air may cause bubbles to be formed in the coating on the pipe.

In accordance with the teachings of the present invention, the flow of coating material is reversed, that is, the pump forces the material through a suitable supply line that leads into the bottom of the shoe, the material flowing upwardly through the shoe and excess material escaping from the shoe through an overflow port located on the top thereof. The pump is arranged to draw coating material from the bottom of the tank and is protected so that it cannot pick up coating material which has just fallen back into the tank. with this arrangement, air or gas entrapped in the coatingmaterial by the overs. flow falling back into the pool of such material is allowed to escape before the material is recirculated through the system, with the result that the stream of material flowing from the pump to the coating shoe is free from gas or second or so-called travelling type machine wherein the pipe remains fixed and the machine travels therealong to produce the relative movement between the shoe and pipe by which the coating is applied to the pipe. The coating shoe or the instant invention may be used equally well in machines of either type. Most static a type machines, and some travelling type mat-- chines, apply a wrapper immediately over the coating material and when the shoe of the present invention is used in such a combination, the work turned out by the machine is improved and when subjected toelectrical tests for detecting holidays, fewer imperfections are found.

Referring now to the drawings in more detail, particularly Figure 1,- a frame 9 with a tank 2 v is disposed beneath the frame and connected thereto by suitable supports 3. The frame may well be a part of the travelling type coating machine shown in Patent No. 2,188,001 issued to Duaei, et a1., January 23, 1940, or the stationary machine of the type shown in Patent No. 2,048,557 issued to Michelson and Duaei July 21, 1936. The details of frame construction form no essential part of the present invention and the frame has been shown diagrammatically herein, reference being had to the foregoing patents for such details as needed.

The coating shoe consists of a pair of rings 3 and 5 between which is a sheet metal wall i5 forming with the rings a generally cylindrical shoe that embraces the pipe. The rings and walls are preferably welded together, as indicated at i, so as to form a rigid structure capable of with standing the rough usage to which it will be subjected.

In order to permit the shoe to betakenoif of and put on the pipe line and to permit it to ride over welds or other obstructions thereon, the

rings 4 and 5 and the wall d are formed in a these sections contains ears 8 and the two upper ones contain co-operating ears 9, these cars being pierced to permit pins iii to be projected therethrough to form a hinge connecting the three sections together. Projecting outwardly from the two upper sections of the shoe are bosses ii to which supporting links by which the shoe is supported on the frame are attached.

In the embodiment shown in the drawings, a shaft i2 is supported upcn the frame 5 by suitable bearings and carries cell crank levers i3 fixed thereto. Pivoted to these levers are generally L-shaped it which support at their free ends links I5 that are connected to the ears ii on the shoe. Each link contains a spring it so as to render the same resilient and permit the shoe to move a limited distance vertically oi the frame. The particular construction of linkage shown in the drawings is shown by way of example and may be modified within the teach ings of the invention.

Shaft I2 also carries a crankarm it and when it is desired to lower the shoe away from the pipe, this arm is rotated in clockwise direction,

I aecaocs Figure 1, moving the shaft and link to lower the pivotal connection between the bell crank levers and links it. This movement lowers the links it causing the shoe first to open and then to drop away from the pipe into the position in which it is shown in dotted lines in Figure 2. The rotation of crank it in the opposite direction will raise the shoe and reengage it with the pipe.

As will be seen best in Figure 3, the ring 5 is rounded to form an entrance port ii leading into the shoe, this ring being of such size that the innermost edge of the port engages the pipe fairly snugly to center the pipe therein. The ring l contains a similar flared edge leading out of the shoe. This ring is slightly larger than the ring 5 so that the exit port 18 has a diameter equal to the outside diameter of the pipe, plus twice the thickness of the minimum thickness of coating that the shoe is designed to apply.

In order to center the shoe upon the pipe, two spacing screws 28 are located in the bottom member of the shoe adjacent the ring 5, and a plurality of spacing screws 2| are disposed adjacent the ring t. As shown, six screws 2i are employed although this number may be varied. Screws 2U engaging the bottom side of the pipe relieve the bottom portion of ring 5 of wear which would be occasioned by the tension of the springs 96, pulling the shoe upwardly and the lower ones of the screws 2i perform a similar function. By

v proper adjustment of the screws, the shoe is centered on the pipe so that the coating applied thereto is of uniform thickness around the pipe.

The bottom section 36, Figure 2, of the wall 5 contains a nipple 3i located near the forward end of,the shoe, that is, near the end ring 5. The nipple is attached in any preferred manner such as by welding and communicates with the inside of the cylindrical shoe.

Located within the tank 2 is a pump 32 having connected to its outlet side a flexible hose 33 that is connected to the nipple ii. The pain which may be of any preferred type, forces material from the tank 2 through the pipe 33 into the shoe, where this material encircles the pipe and is confined in the shoe by the end rings d and 5. Rising out of the top of the shoe at the junction of the two sections thereof' is a generally rectangular box-like member 3'3 forming a reservoir into which the coating material travels. It will be noted in Figure 1 that the end walls of the reservoir 36 are higher than the central section of the sidewalls, this arrangement forming a weir 35 through which the excess material in the reservoir overflows, falling down over the outer surface of the shoe and into the tank 2.

The coating material returning to the tank may entrap gas or air and to prevent material containing gas or air from being drawn into the pump, the tank 2 is provided with a bafiie as extending from the top edge of the tank and above the upper surface of the coating material therein down to a line near the bottom of the tank. Bubbles formed in the material by the overflow of the shoe are confined in the section of the tank. away from the pump and it is there by assured that the pump will supply to the shoe only gas free material.

It will be understood that the tank 2 may be provided with suitable arrangements for applying heat to the material contained therein. but since these arrangements form no part of the instant invention, they have been omitted from 4and the p portion otthe pipe. 1

:2 and a may be fixed to n M M ierred mannerysuch as by weldingi andf. may

7 to the left. To preve links, such as chains];

venting the coatingsh asoaoos aroundthe the avoid an unnecessary complicationthereoi. G d a .1 52 d Coating materials that the:shoejoi the present invention must handle vary; considerably at ap- I plication temperatures. Certain of these. materials, known generally as enamels, are of the g consistencyof cream. atproper application temperature, whileothers, such as No-Oxid'? ror example, are much thinner having consistency morenearly' that 01' water,

, It willbeob served' that coating material To control the flow'oi material under these 1 1 conditions, a baille or bailies 22 may beattached to the bottom section "of the wall [of the shoe. This bamemeans extends into juxtapositionlto'thepipe andexte'nds'slightly beyond the Junctions oi the bottomsection '30 with the up- 'per sections of the shoe. Each upper section A carries'a similarfibame means 23 whi h overlaps the bai'iie 22, as shown in Figure :extend t Ew thm'amt m i seam an inch 01' the 7 With bodie 22 and-1234 "quid ing the shoe through nip wardly around? the ..fpipe .g1thou gh "a' "liinited amount -01 it sows" slon theipipe horizontally through the space betweenjthe' baiiie and the pipe. The pressure occasioned by the velocity oi thejliquid' 'enteringthe pipe is thus blocked of! from the ring 4 along thebottom'portion oi the pipe and the liquid against 'this ring is, in

r a nine in the space between ur mia: wall loiths shoe and the pipe, the pump being rui'i'iasten'ough to supply. suflicient material to ,keep the shoe iull, and overflowing at all times.

As the shoe moves along the pipe, or the pipe. moves through the shoe, the coatingmaterial in which the pipe is submerged adheres to the pipe and a certain amount of this material flowsfout oi the shoe in the space between the ring 4 I and the pipe. .The adjusting screws 2| areset Jso that the amount of material so escaping from o i The movement-ct the coating material upwardly in the shoe scrubs the pipe iree of air 'eii- I the shoe will be correct forthe desired thickness of coating.

trapped in pits or irregularities in the surface. Thisv is P rticularly noticeable on reconditioned pipewhpse surface is apt to contain pits in which air has been entrapped'with shoes or the .prior Air brought into the shoe oithepresent inventionis scrubbed onto! the pits into the coatingmaterial and allowed to escape from the: shoe in the overflow. Since the air is lighter than the coating material, it naturally tends to risetherehand the upward movement of the material aim rather than hinders'this natural movement. v Should a or other obstruction appearjhg. the pipe, it engage the rounded face or the 3 entry port I1 and force the shoe'opensufliciently to permitit to; embrace the weld. ,As will be seen inFigure 2, the adjacent ends of the three sec- [flows mainly upi tions'of the shoe are provided with overlapping plates 40 and 4|,whichclose the-gaps between the sections as theshoe opens to permit passing a weld,'therebv .preventingyan. excessive loss of a material fr'omtheshoe; Plates 40 located at, the

ends 'oi' thefreservoir 34 extend-from the top J thereoifidowninto close proximity to the pipeandj f are. attachedlto'on'e section of. the reservoir wall and overlap the abutting section. If desired, the

- tree endorthese'platesM may be bevelled, as

at 42 so thatthey will cut through the material-in the reservoir as-the shoecloses.

the main, only under the pressure of the. hydrostatic head, and the amount offliquid passing f the device, after" the coatbrought to application pis started with the coatcoating shoe intoathe'flcoating material so as'to more quickly bring it up to proper temperature. I Alter the hot coating material has flowed through the shoe sufliciently to prepare it for. operation,

crank l8 isoperated toengage the. shoe with the pipe. a e .vA relative movement between the shoe and pipe is'then setup either by moving the machine along the pipefor by moving the pipe 7 through the machine As' viewed in Figurel,

this movement is as e pipe 3'! were" moving the coating shoe from being dragged along'wi {the pipe, suitable drag .m moving to the left. Gas free coating material 'iorcedthrough the d 1 rom thepipe. In certain instances it mayfbefadvantageous to lower the are attached to the shoe O "the arrangement pre- 45 out of the shoethroushjthe ring] is "limited. f -,While only one ba'ifle 22 and 23 is shown, a pmrality of similar baiiies may be used, forming; in f efiect, a labyrinth packingalong the pipe. This may be advisable-in extreme cases although ordi-.

.narily one set ot baiiies will be sumcient. Y

-material. Preferably the shoe sections are formed so that Plates 4| are-flxed'upon rings 4 and I onone side "of th butting ends .oi the sections thereof and overlaptheothersections. These platesextend i'rom'theouter wall 8 ofthe shoe into close proximity, oi the pipe. Each plate :4l is fixed to one 5 section and overlaps the adjacentise'ction and the free ends of the plates; are. bevelled as areplates 40 to cut through the :material as the shoeis 'being closed. By this arrangement, it is assured that the coating material in the shoe will completely surround the pipe at all times and a weldv passing through theshoe will becoated with'the the adjacent ends, abut tightly together when the shoe is set toapply. a minimum thickness coating on the pipe. 'Whenthe shoe is adjus ed .i'or applying. a thicker coating, the ends will be spaced apart slightly and the plates 40 and 41 serve to preventexcessive-loss or coating materiali'romtheshoe.

Whenever it isnecessaryto stop the relative movement or the pipe and shoe, as will be the 7 permit replenishing'thesupply oi wrapping material to the machine, aswell as case frequently to for other causeathe shoe may be dropped away flexible pipe as into thehdtto or the shoe hows rrom the pipe and, if desired, the pump mayigbe .stoppedswithout impeding the work:

things are in readiness to resume operatio the pum is-started and u suflicient hot material has been pumped throughrthe pipe 31 to be sure that the same free 01'. the shoe maybe w res elevated into engagement with the pipe and work The shoe of the present invention is possessed of many advantages} Through its operation of feeding coating materiaffrom. the bottom of a tank' upwardly through the shoe under pressure l generated by'the pump, holiday free coatings may be applied to thepipe even though the material used contains solvents which are vaporized in whole or in partat the temperatures employed in the-process. Air trapped in pits in the pipe is scrubbed outof the pits and carried out of the shoe with the excess material. Excess material returning to the. tank will entrap a certain amount of air which, being lighter than the material, escapes therefrom long before the materail again enters the circulatory system; The shoe may be readily lowered from the pipe when it is necessary to clear an obstruction orwhen it is necessary to shut down'the machine and the. danger of 'freezingthe shoe on the pipe by the solidification of inated.

While I have chosen to show my invention by illustrating and describing a preferred embodiment. of it, I have done so by-way of example only, as there are many modifications and adaptations which can be made by one skilled in the art within the teachings of the invention;

Having thus complied with the statutes; and shown and described a preferred embodiment of coating material therein is elimmyinvention, what I consider new and desire to have protected by Letters Patent is'pointedcut in'the appended claims; What is claimed'is:

1; In a machine for applyin coating material to a. pipe during a relative movementjofthe machine and'pipe, a generally cylindrical shoe en- .oirciing the pipe, a'supply line leading into the llnttom'of said shoe, means for forcing coating material through said lirie and shoe and around said-pipe, and overflowmeans at the top of said shoe for permitting excess material to flow out of said shoe and over the outside thereof.

' -2, In a machine for applying coating material to a pipe during a relative movement of the machine and pipe, a tank disposed beneath the pipe 'that'is to be coated and-containing'a supply 'of coating materiaL'ia shoe, means for-supporting said shoe above said tank in engagement-with the pipe, means for supplyin gas free coating material to said shoe, comprising, a' pump submerged in thec'oating material and a feed pipe leading out of. the pump and into the bottom'of said shoe through which the pump forces material upwardly through the shoe and out ofthe .upwardly through the shoe and out of the top thereof, and bafiie means guarding said pump from coating material dropping from said pump into said supply of coatingmaterial.

4. In amachlne for applying coating material to pipes and the like during a relative movement the pipe that is being coated, a shoe encircling said pipe, a tank disposed beneaththe pipe, a shaft on said frame, apair of bell crank levers on said shaft, link means connecting said levers to said shoe to support the shoe on the frame, means connected between the shoe and frame for steadying the shoe with respect to the frame during the relative movement of the machine and pipe, a pump in said tank, and flexible pipe means connecting the pump to the bottom of the shoe to permit the pump to force coating material from the tank upwardly through the shoe and around the pipe that is being coated.

5. In a machine for applying coating material to pipes and the like during a relative movement of the machine and pipe. frame disposed above the pipe that'is being coated, a tank below the pipe, a coating shoe suspended from said frame and encircling the pipe, a baflie in said tank extending from the top' of the same into juxtaposition to the bottom and dividing the tank into two compartments, a pump in one of said compartments, and a flexible tubing extending from said pump to the bottom of said shoe-to conduct coating material from the tank to and through the shoe,"said shoe being suspended over the second one of said tank compartmentsso that material dropping from the shoe into the tank falls into said second compartment.

. 6. vIn a machine for applying coating material to a pipe during a relative movement of the machine and .pipe, a generally cylindrical shoe encircling the pipe, a supply line leading into the bottom of said shoe, means for forcing coating mitting excess material'to' flow out of said shoe,

and over the outside thereof.

7 In a machine for applying coating material to pipes and the like,-a frame, acoevting shoe comprising aplurality of sections hinged together to form a generally cylindrical member through which the pipe that is .being coated extends coaxially, a resilient link attached to each of two of said shoe sections extending toward said frame, means on the frame engaging saidlinks to support the shoe with respect 1 thereto, saidmeans including over-center levers operable to lower the shoe to permit" the same to open and fall away from the p pe, at flexible pipe leading into the bottom of the shoe, means including a pump for forcing a coating material through said pipe and shoe and around the pipe, and overflow :means on the top of the shoe for directing excess coating material flowing outtof the shoe therethrough over the outside of the shoe.

8. 'In a coating machine, a shoe encirclingthe Q pipe that, is to be coated, and adapted to move with respect thereto, an end wall projecting radially inwardly from one end of said shoe and slidably engaging the pipe, an end wall projecting radially inwardly from the other end of said shoe and terminating on a circle spaced from the outer surface of the pipea distance equal to the thickness of the coating to be applied thereto, a plurality of spacing means projecting through said "shoe betweensaid end wallsand engaging 'said pipe to space said latter end wall uniformly therefrom, a tank containing coating material that is to be applied to the pipe, means includof the machine. and pipe, a frame disposed above 76 8 a pump for feeding said material into the botto flow from said shoe over the outside thereof i and to return to said tank.

9. In a machine for applying coating material to a pipe during a relative movement 01' the machine and pipe; a generally cylindrical shoe encircling the pipe, a supply line leading into the bottom of said shoe, means for forcing coating material through said line into said shoe, means for directing said material upwardly through said shoe and around the pipe, and overflow means at the top of said shoe for permitting excess material to flow out of and over the outside of said shoe.

10. A shoe for coating pipe comprising, a plurality of segmental members, means yieldingly holding said members together to form a. generally cylindrical member which surrounds the pipe,

means for spacing the shoe concentrically on the pipe, means for feeding coating material into the shoe at a point beneath the pipe, means for directing said material upwardly through the shoe and around the pipe, and overflow means for permitting excess material to escape from the shoe at the top thereof.

11. A shoe for coating pipe comprising a plurality of segmental members, hinge means yieldingly holding said members together to form a generally cylindrical member which surrounds members at uniform distance from the pipe, a

nipple through which coating material is fed into the shoe at a point beneath the bottom or the pipe, baflle means in the shoe for causing said material to flow upwardly through the shoe and around the pipe, and overflow means for permitting excess material to escape from the shoe at 1 the top thereof.

12. A shoe for coating pipe, comprising, three sections which are registered together to form a generally cylindrical body which encircles the pipe, hinge mean connecting said sections togather, a flexible tube connected to and leading through the bottom one of said sections into the shoe, means on the ends of said shoe extending into juxtaposition to the pipe for confining coating material in theshoe,;overflow means leading out "or the top of the and spacing means engaging the pipe and shoe for centering the shoe coaxially of the pipe.

13. A coating shoe comprising, three sections which together form a generally cylindrical body, hinge means swingly connecting two 01 said sections to the third, a nip' e depending from said third section to --receive a pipe through which coating material is supplied to the shoe, end walls projecting radially inwardly to form flanges which assist in confining coating material in the shoe, wall means projecting outwardly from each of said first and second sections, said wall means forming a reservoir, extending upwardly from the shoe through which excess coating material may flow and spill over the outside face of the shoe, means projecting outwardly from said flrst and second sections toreceive meansfor supporting and steadying the shoe, and spacing means extending inwardly from said sections for centering the shoecoaxially with a pipe.

REMMEL E. HENRY.

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