US3740291A

US3740291A - Method and apparatus for applying a coating to a tubular member

Info

Publication number: US3740291A
Application number: US00108020A
Authority: US
Inventors: J Mallard
Original assignee: Individual
Current assignee: SOUTHWEST GROWTH POOL Ltd A TEXAS LP; Shaw Pipe Protection Ltd
Priority date: 1971-01-20
Filing date: 1971-01-20
Publication date: 1973-06-19
Anticipated expiration: 1990-06-19
Also published as: DE2150873A1; GB1309525A; NL7200710A; CA959744A; OA03946A; JPS5414608B1

Abstract

A METHOD AND APPARATUS FOR APPLYING A COATING UNDER COMPRESSION TO A TUBULAR MEMBER PERMITS IMPROVED ADHESION OF THE COATING TO THE TUBULAR MEMBER WITH IMPROVED CONSISTENCY AND STRENGTH OF THE APPLIED COATING,

D R A W I N G

Description

June 194, 1973 1. B. MALLARD v 3,740,291

METHOD AND APPARATUS FOR APPLYING A COATING TO A TUBULAR MEMBER INI/ EN TOR nous' willow f Malflaewl ATTORNE YS June 19, 1973 Filed Jan. 20, 1971 J. B. MALLARD METHOD ANI) APPARATUS FOR APPLYING A COATING TO A TUBULAR MEMBER 3 Sheets-Sheet 2 ATTORNEYS June 19,l 1973 J. B. MALLARD 3,740,291

METHOD AND APPARATUS FOR APPLYING A COATING To A TUBULAR MEMBER Filed Jan. 20, 1971 3 Sheets-Sheet 3 Y nu!! who@ MAMMA ff T'TRN YX United States Patent O 3,740,291 METHOD AND APPARATUS FOR APPLYING A COATING T A TUBULAR MEMBER .lames B. Mallard, 609 Ripple Creek, Houston, Tex. 77027 Continuation-impart of abandoned application Ser. No.

761,151, Sept. 20, 1968. This application Jan. 20, 1971,

Ser. No. 108,020

Int. Cl. B32b .i1/06; B651: 81 00 U.S. Cl. 156--392 4 Claims ABSTRACT 0F THE DISCLOSURE A method and apparatus for applying a coating under compression to a tubular member permits improved adhesion of the coating to the tubular member with improved consistency and strength of the applied coating.

CROSS-REFERENCE TO RELATED APPLICATIONS This is a continuation-in-part of my copending application Ser. No. 761,151, tiled Sept. 20, 1968 for Method and Apparatus for Applying a Coating Under Compression to a Tubular Member now abandoned.

BACKGROUND OF THE INVENTION (l) Field of the invention The present invention relates to methods and apparatus for applying a coating to a tubular member.

(2) Description of the prior art In the prior art methods and apparatus for coating tubular members, adhesion of the coating to the member was diicult to obtain. Consistency in the mixture of the ingredients of the coating often varied during application, decreasing the strength of the applied coating and making the exterior of the coating uneven and rough. Further, when the tubular member to be coated had a protective exterior coating, the ingredients of the coating often damaged the protective coating during application and failed to adhere to such protective coating. The coated tubular members had to be cured after coating prior to installation in order to allow the applied coating to harden. During installation, the uneven coating of the tubular members would often damage the installation equipment, particularly the rollers supporting the member in such equipment.

SUMMARY OF THE INVENTION Briefly, the present invention provides a new and improved method and apparatus for applying a coating to a tubular member. In the method and apparatus of the present invention, the tubular member is rotated and simultaneously moved longitudinally with respect to a placing head. A coating material is deposited or applied directly to the tubular member in such placing head while a strip of covering or wrapping material which is held under selectively controlled amounts of tension on a feed roll is conducted to such placing head and compressively wrapped with the deposited coating material against the rotating tubular member to form a covered coating layer on the tubular member. The tension in the wrapping material and the compressive wrapping of the coating material with the tubular member permit adhesion of the coating to the tubular member, and allow application of the coating material over a protective coating on the exterior of the tubular member with reduced damage to such protective coating. The coating material is vibrated and compacted While in the placing head so that the coating material is rm and substantially uniform in composition when compressively wrapped to the tubular mem- ICC ber. The uniform composition of the coating material forms a consistent density and absorption in the coating material, eliminating porosity in the coating and unevenly applied coatings and reinforcing Wire mesh may be compressively wrapped by the placing head into the coating material interiorly of the Wrapping material to further strengthen the coating material. The method and apparatus of the present invention provides continuous coating operations by abutting an end of a second tubular member with the end of a first tubular member as coating of the first tubular member nears completion and thereafter coating the abutting ends of such tubular members. Subsequently, the coating is removed from a portion of such abutting ends to provide access for ywelding or otherwise connecting the tubular members when such members are being installed or put into place for use.

The dry constituents of the coating material being applied are conveyed to a mixing station adjacent the placing head ywhere liquid is added to the dry constituents and the coating material is formed, so that only required amounts of the coating material are mixed, to reduce waste of the coating material should coating operations be unexpectedly interrupted. When the coating material is concrete, larger aggregate may be used with the method and apparatus of the present invention, reducing the amount of cement required to achieve the desired strength in the applied coating. The coated pipe may be stacked and stored after coating Without requiring curing, permitting earlier hardening and use of the coated pipe.

It is an object of the present invention to provide a new and improved method and apparatus for applying a coating to a tubular member.

It is an object of the present invention to provide a new and improved method and apparatus for depositing a coating material onto the tubular member and compressively wrapping the coating against the tubular member with a wrapping material to provide a coating under compression for such tubular member.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the coating apparatus of the present invention;

FIG. 2 is an isometric view of a tubular member with a compressive coating being applied in accordance with the present invention;

FIG. 3 is an isometric view of the placing head of the apparatus and method of the present invention;

FIG. 4 is a cross-sectional view of the placing head of FIG. 3;

FIG. 4A is a cross-sectional View taken along the line 4A-4A of FIG. 4;

FIG. 5 is a cross-sectional view taken along the lines 5-5 of FIG. 1; and

FIG. 6 is a cross-sectional view taken along the lines 6 6 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, the letter A designates generally the coating apparatus of the present invention performing the method of the present invention and compressively applying a coating material, such as for example concrete or the like, to a tubular member T which may be a steel or iron pipe or tube or the like, having a corrosion protective coating or other suitable coating if desired.

The apparatus A (FIG. l) includes a conveyor system C which rotates the tubular member T While simultaneously moving such tubular member T longitudinally past a platform P with which a placing head H is mounted.

A coating material conveyor system S conveys the dry constituents of the coating material to a mixing chamber M wherein water or other suitable fluid is added to the dry constituents of the coating material to form the coating material 81. A feed channel L conveys the coating material 81 from the mixing chamber M to the placing head H where such coating material is deposited onto the tubular member T. A plurality of storage reels R have mounted therewith rolls of a wrapping or covering material 61, which may be paper, plastic, impregnated paper or other suitable material, and a roll of reinforcing wire mesh 62, respectively. The Wrapping material `61 and the reinforcing wire mesh 62 are stored on the reels R and conducted therefrom under tension, in a manner to be set out hereinbelow, to the placing head H wherein the coating material 81 being deposited onto the rotating tubular member T is compressively wrapped against such rotating tubular member T with a strip of the wrapping material 61, and the reinforcing wire mesh 62 is compressively wrapped into the deposited coating material 81 interiorly of the strip of wrapping material 61 to strengthen the coating being applied under compression to the tubular member T.

The conveyor system C (FIGS. 1 and 5) includes an inlet conveyor system (FIG. l) and an outlet conveyor system (FIGS. 1 and 5).

A pair of horizontally extending support members or

braces

10a and 10b (FIG. 1) extend from the platform P a suitable length to accommodate the length of at least one tubular member T. The

supports

10a and 10b are mounted with suitable bracing or support structure above the ground or floor or surface to which the apparatus A of the present invention is mounted. An adjustable speed motor 11, which may be powered by electricity or other suitable energy sources, is mounted with the inlet conveyor system 10 and furnishes the power to rotate the tubular member T while simultaneously moving it longitudinally with respect to the platform P and placing head H. A drive pulley 11a transfers the energy from the motor 11 by a pulley belt 11b to a pulley 11c mounted with a drive shaft 11d. A pulley 11e transfers the energy from the drive shaft 11d by a pulley lbelt 11j to a pulley 11g to provide power to rotate and move the tubular member T. A universal joint 11h transfers the rotational movement of the pulley 11g through a drive shaft 11i to drive a suitable gear arrangement 11]l of the well-known type and provide rotational movement to a drive pulley 12a of a drive plattform 12.

The drive pulley 12a is mounted to a common axle with a drive wheel 12b, and the axle supporting the drive pulley 12a and the drive wheel 12b is supported by and rotatable within a pair of supports 1.2` which extend upwardly from a movable platform portion 12d of the drive platform 12. The drive wheel 12b has a rubber roller mounted at the periphery thereof to insure a rm and secure mounting of the tubular member T with respect to the drive platform 12 and drive wheel 12b and to provide rotational movement while simultaneously moving the tubular member 12 longitudinally towards the placing head H.

A pulley belt 12e transfers a portion of the force driving the pulley 12a to a second pulley 12j to drive a second drive wheel 12b, also having a rubber wheel mounted to the periphery thereof. The second pulley 12jc and the second drive wheel 12b are mounted on a common axle which is similarly mounted to rotate freely within a pair of upwardly extending vertical supports 12C which extend upwardly from the movable platform portion 12d of the drive platform 12.

An arcuate slot 12h is formed in the movable platform 12d extending therethrough to permit passage of a bolt or other suitable fastening means 121' which is mounted with the xed portion 12g of the platform 12, in order that the movable platform 12d may rotate with respect to the fixed platform 12g and in conjunction with the groter 1l vQntrQl the Speed of rQtatiQn Qt the tubular member T as well as the speed of longitudinal movement of such tubular member T by varying the speed of the motor 11 and the placement of the movable platform 12d with respect to the platform 12g and consequently varying the angle of the drive wheels 12b with respect to the longitudinal axis of the tubular member T.

It should be understood that a number of drive platforms, of like construction to the drive platform 12 set forth hereinabove, may be provided with the inlet conveyor system 10 and driven by suitable driving connections by the adjustable speed drive motor 11 in accordance with the length of the tubular member T to be coated, the desired speed of angular rotation of such tubular member T and the desired speed of longitudinal movement of the tubular member T With respect t0 the placing head H.

The outlet conveyor system 15 of the conveyor system C (FIGS. 1 and 5) includes a plurality of horizontally extending rails or braces 15a and 15b which extend from the platform P and placing head H on a side opposite the inlet conveyor system 10 and are mounted to a plurality of vertical support members 15C and 15d (FIG. 5), respectively, along the length thereof. The vertical support members 15C and 15d are mounted with horizontally extending lower support members 15e and 157, respectively, which rest upon a surface 15g on which the apparatus A is mounted.

A plurality of drive belt mountings 16 (FIGS. 1 and 5) are mounted to a corresponding plurality of fixed platform members 16a along the length of the rails 15a and 15b for a sufficient length to support the tubular member T after such member has been Icoated in the placing head H. The drive belt mountings 16 support the coated tubular member T and allow access to both ends of the coated tubular member T and permit removal of such coated tubular member T from the apparatus A for storage and curing.

Each of the extractor drive mountings 16 is rotatably movable with respect to its associated platform 16a by means of a pin 16b mounted with a movable base platform member 16e.` of such mounting 16 and extending downwardly through an aperture 16d formed in the platform 16a (FIG. 5 A pair of U-shaped supporting brackets 16e are mounted with the movable platform 16C and extend upwardly therefrom. to provide a mounting support for a plurality of axles 16g which support a plurality of drive wheels 16j and a plurality of slave wheels 116,1c (FIG. 5). The axles 16g are freely movable with respect to the support bracket 16e to allow rotational movement of the drive wheels 16f and slave wheels 1169c with respect to the brackets 16e. Driving energy is pro- .vided by suitable adjustable speed driving means and is furnished by a linkage 16h and conveyed through a universal joint to a drive pulley 161' (FIG. l) and a pulley belt 16j (FIGS. l and 5). The pulley belt 16j moves the drive wheels 16f (FIG. 5) to move an extractor drive belt 16k. The drive belt 16k rotates the coated tubular member T While simultaneously moving such coated tubular member T longitudinally after such member has passed beneath the placing head H and been compressively coated in a manner to be set forth hereinbelow.

A variable speed electric motor or other suitable adjustable speed driving means is provided to drive the linkages 16h and drive pulley 161', and such motor is separately controlled from the drive motor 11 for reasons that will be more evident herein-below.

The angular placement of the drive belts 16k with respect to the longitudinal axis of the coated tubular member T as Well as the speed of movement of such belt 16k are selectievly varied in the operation of the present invention, as will be more evident hereinbelow.

The platform P provides a support for the placing head H and other associated equipment, as set forth hereinbelow and includes a horizontally extending plate 20 of iron, steel, or other suitable material, which is mounted with the rails 10A and 10b of the inlet conveyor system, 10

and the rails a and 15b of the outlet conveyor system 15. A pair of mounting brackets or lugs a and 20b (FIG. 1) extend outwardly from the plate 20 in a direction transverse the conveyor system C and have mounted therebetween a mounting rod or -bar 20c, to which are mounted a pair of mounting sleeves 20d (FIG. l and 6) and 20e (FIG. l).

The mounting sleeve 20d is movable with respect to the longitudinal axis of the mounting bar 20c to allow a cut-off or removal saw 23 to be selectively positioned at different positions with respect to the length of the coated tubular member T passing across the platform P. The cutolf saw 23 and its associated drive motor 22 are mounted with a mounting plate 21a (FIG. 6) at an upper end of a rotatably movable cut-off arm or support arm 21 which is mounted at a lower end to the mounting sleeve 20d. The cut-off arm 21 and the mounting sleeve 20d are rotatably movable with respect to the mounting sleeve 20c (as illustrated by the arrow in FIG. 6) to allow the cut-01T saw 23 to be selectively engaged with the coated tubular member T and remove by means of an abrasive edge 23a thereof the wrapping material 61, the reinforcing wire mesh 62 and the coating material 82 compressively wrapped with the tubular member T (FIG. 6).

A short portion, for example approximately four inches, of the coating compressively wrapped to the tubular member T is removed form the coated tubular member T in order to provide access for connecting the tubular member to another tubular member when such members are being installed for use. lf the tubular member T is an iron or steel pipe, the end portions from which the coating has been removed by the cut-off saw 23 are accessible for welding of such tubular members. After welding, the tubular members may be hand packed and have a wrapped material and covering material applied by hand when such tubular members T are being installed.

The longitudinal movement of the mounting sleeve 20d with respect to the mounting rod 20c allows the placement of the saw 23 with respect to the tubular member T to be controlled and adjusted, and the length of the end portion from which the coating and covering materials are removed to be selectively varied in accordance with the amount of such end portion needed to be accessible in order to connect the tubular members as they are being installed, and thus selectively controls the amount of such accessible uncovered end portion, and reduces the amount of hand packing required when such tubular members T are being installed.

The mounting sleeve 20e (FIG. l) is mounted with the support rod 20C and extends upwardly therefrom, receiving therein a downwardly extending portion of an L- shaped tubular support arm 25 with which the placing head H is mounted. The downwardly extending portion of the L-shaped support arm 25 is mounted within the upwardly extending mounting sleeve 20e (FIG. l) and is rotatable therein in order that an outwardly extending portion 25a of the support arm 25 with which the placing head H is mounted (FIGS. 1 and 3) may be rotated in order to selectively adjust the position of the placing head H with respect to the longitudinal axis of the tubular member T (FIG. 1). The position of the placing head H with respect to the tubular member T is varied in accordance with the diameter of the tubular member T, the thickness of the coating material 81 to be applied to the tubular member T, the width of the strip of reinforcing mesh 62, the rate of longitudinal movement of the tubular member T with respect to the platform P and placing head H, and the speed of rotation of such tubular member T. Suitable means, such as a clamp or brace, are provided to hold the arm 25a and placing head H firmly in place with respect to the tubular member T during coating operations.

An inwardly extending mounting lug 26 (FIG. l) is mounted with the upwardly extending mounting sleeve 20e intermediate the ends thereof, and extends inwardly from the exterior of the platform P towards the tubular member T to provide a support for a bracing wheel 27 (FIGS. 1 and 3) which engages an exterior surface 29a of the tubular member T (FIG. 3) and holds such aubular member T firmly in place against the placing head H while a coating is being applied under compression to such tubular member. The bracing wheel 27 is preferably of rubber or other suitable resilient material to provide firm engagement with the tubular member T, and is mounted with an axle 26a in order to be freely rotatably movable with respect to the mounting lug 26 and roll along the exterior surface 29a of the tubular member T as such tubular member is rotated and simultaneously moved longitudinally with respect to the placing head H and the coating material S1 and wrapping material 61 and reinforcing mesh 62 are applied under compression to the tubular member T in the placing head H in a manner to be more evident hereinbelow.

A pair of mounting brackets 31 (FIG. 3) have apertures 31a formed therein through which the outwardly extending portion 25a of the support arm 25 may be inserted so that the placing head H may be mounted with the platform P. A pair of mounting flanges 3lb (FIG. 3) are formed in the mounting brackets 31 adjacent the apertures 31a, and bolts 31C or other suitable fastening means are inserted through such ange 31h to mount the placing head H with the support arm 25 of the platform P. The placing head H may be moved to different positions along the support arm 25a in accordance with the diameter of the tubular member T being coated by the placing head H, and other factors previously set forth. A support bar or brace 31d is mounted between the brackets 31 to provide further strength for such brackets.

A support member 31e is mounted at one end to an exterior surface 31f (FIG. 3) of the support bracket 31 and extends from the placing head H in the direction of the storage reels R. A guide bar or rod 31g is `welded or otherwise suitably mounted beneath the support member 31e in order to guide and properly position the reinforcing wire mesh 62 as such wire mesh is being conducted from the storage reel R into the placing head H to be compressively wrapped into the deposited coating material 81 interiorly of the `wrapping material 61 while such coating material is being compressively wrapped with the tensioned strip of wrapping material 61. The position of the guide bar 31g with respect to the placing head H and tubular member T may be varied to adjust the arc or angle through which the wire 62 travels in the placing head H during application. By moving the guide bar 31g upwardly and inwardly with respect to the placing head H (FIG. 4), the arc or angle of travel is increased, increasing the compression of the coating being applied and thereby increasing the weight and strength of such coating on the tubular member T.

The placing head H (FIGS. 1, 3 and 4) is box or chutelike in configuration and includes a first of front wall member 32 (FIGS. 3 and 4) which is adjacent the front or leading edge of the portion of the exterior surface 29a of the tubular member T currently being compressively coated in the placing head T, a second or rear wall member 35 (FIG. 3) which is adjacent the rear portion of the exterior surface 29a of the tubular member T currently being coated in the placing head I-I, an inner or center Wall member 34 (FIG. 4) which is positioned above the center of the tubular member T as such tubular member T moves beneath the placing head H to be coated, and an outer wall 33 (FIGS. 3 and 4) which is mounted to the front wall 32 and rear wall 35 opposite the inner wall 34.

A blade 37 of rubber or other suitable resilient material is mounted with an upper end 34a of the inner wall member 34 and assists in prevention of splashing or spilling of the coating material 81 as such coating material is deposited into the placing head H from the feed channel L. The lblade 37 is made of a resilient material to allow the feed channel L and the placing head H to be moved with respect to each other for cleaning, repair, inspection and like purposes. A second blade 37a is mounted with a lower end 34b of the inner wall member 34 and rides and engages the exterior surface 29a of the tubular member T (FIG. 4) as such exterior surface moves into position beneath the placing head H and prevents undesired debris and particles from moving the surface 29a into the placing head H and further assists in preventing the coating material 81 from leaking or escaping from beneath the lower end 34b of the inner wall member 34.

The rear wall 35 has a blade or funnel member 35a mounted at an upper end 35b adjacent the feed channel L to prevent spillage or escape of the coating material 81 as such coating material passes and moves into the placing head H to be deposited onto the exterior surface 29a of the tubular member T. The mounting brackets 31 are mounted with the exterior of the upper end 35h of the rear wall member 35 of the placing head H.

A lower portion 35C of the rear wall member 35 has a blade 38 of rubber or other suitable resilient material mounted therewith by bolts 35d or other suitable means. The blade 38 and lower portion 35e of the Wall member 35 have a slight helical taper from an upper end 38a (FIG. 3) of the blade 38 to a lower end 38b of such blade, with such taper being in the direction of rotational movement of the tubular member T with respect to the placing head H, in this embodiment clockwise (FIG. 4). The slight helical taper of the blade and wall portion 35C provides a channeling or funneling action and convey and assist in compacting the coating material 81 being deposited onto the tubular member T in the placing head H.

The front wall member 32 is mounted along an edge with the inner wall member 34 and has a slight helical taper from an upper end 32a to a lower end 3211 in a direction opposite the direction of rotation of the tubular member T to provide a further channeling and funneling compacting action with respect to the coating material 81 being deposited onto the tubular member T in the placing head H.

The outer Wall member 33 is pivotally mounted at an upper end 33a between the lower wall portion 35a` of the rear wall member 35 and the lower portion 32b of the front wall 32. Outer wall member 33 is pivoted inwardly to a work position (shown in phantom in FIG. 4) to support the coating material 81, wrapping material 61 and reinforcing mesh 62 as such materials are applied to the tubular member T. The spacing of the Wall member 33 with respect to the tubular member T when the wall member 33 is pivoted inwardly to the work position determines the thickness of the coating to be applied by the placing head H.

A bar or block 33b of metal or other suitable material is mounted at a lower end 33a of the wall member 33 adjacent the rear wall member 35. When the outer wall member 33 is pivoted inwardly to the work position, the bar 33b engages the reinforcing mesh 62 to the desired depth in the coating material 81 and displaces the coating material 81 inwardly with respect to the tubular member T. 'Ihe inward displacement of the coating material by the bar 33b forms a shoulder (FIG. 4A) at the trailing edge of the coating being applied to the tubular member T in order to form an overlap of reinforcing mesh 62 within the coating applied to the tubular member T.

A vibrator 39, or other suitable means for introducing motion, is mounted with the outer Wall member 33 and is energized by an air pump or other suitable motor through a conduit 39a to vibrate the placing head H, causing a compacting and vibrating force to be applied to the coating material 81 within the placing head H being deposited onto the tubular member to cause the coating material 81 to be rm and substantially uniform in composition while auch material is being compressively wrapped against the tubular member T. The uniform composition of the coating material 81 and compressive application of such, as will be set forth hereinbelow, obtain consistent density and absrption in the coating material 81, eliminating porosity therein `and providing evenly coated, smooth tubular members T of increased strength. The firmness of the deposited coating material 81 eliminates the likelihood that the coated tubular members T require curing, permitting earlier handling, installation and use of the coated members T.

An angle iron member 33d, or other suitable structural member, is attached to the lower portion 35e of the rear wall member 35, the outer wall member 33, and the lower portion 32h of the front wall member 32 to strengthen the placing head H against the vibratory forces induced in such placing head by the vibrator 3-9, and to limit pivotal movement of the outer wall member 33.

A guide roller 41 (FIGS. 3 and 4) which is rotatably movable with respect to the lower portion 35e of the wall member 35 and the lower portion 32b of the front Wall member 32 is mounted between such Wall members and guides and conducts the strip of wrapping material 61 from the reels R where such material is held in tension, as will be more evident hereinbelow, into the placing head H in order that the wrapping material `61 may compressively wrap the coating material 81 against the tubular member T within such placing head H.

A pair of plates 42a and 42b are mounted with the upper portion 35b of the rear Wall member 35 and the upper portion 32a of the front wall 32 and extend therebetween to form a guide chute for the strip of reinforcing mesh 62 being compressively wrapped into the deposited coating 81 interiorly of the wrapping material 61 in the placing head H. A pair of metal rods 43a and 43b are similarly mounted between the

wall members

32 and 35 and form a pair of guide bars for the strip of reinforcing mesh 62 to further assist in maintaining such strip of mesh in proper position while such strip of mesh is being compressively wrapped into the deposited coating 8 1 in the placing head H.

A bar or rod 44 (FIG. l) is mounted to a frame or other suitable structure (not shown) at an elevated position with respect to the guide bar 31g and conveys and guides the strip of wrapping material 61 and the strip of reinforcing mesh 62 across such bar 44. Suitable spacing rods or other structure are provided to insure that the reinforcing mesh 62 and the covering material 61 are maintained spaced with respect to each other as such pass over the bar 44. The bar 44 is elevated with respect to the reels R and th'e placing head H to assist in conducting the reinforcing mesh 62 and wrapping material 61 under tension from the reels R to the placing head H in order that the wrapping material 61 and reinforcing mesh 62 may compressively wrap the deposited coating material 81 against the exterior surface 29a of the tubular member T.

Each of the storage reels R (FIG. 1) include an upwardly extending at metal plate 51 which is mounted with a frame member 52 to a support member S3. The support member 53 is mounted with a post 54, the top of which is shown (FIG. l), above the ground or surface on which the apparatus A is mounted. An axle 55 is centrally mounted with respect to the plate 51 and extends outwardly therefrom. A reel or roll of wrapping material 61 is mounted on the axle 55 adjacent the metal plate 51 on a rst storage reel R-l and a reel of reinforcing mesh 62 is mounted in a like manner to a second storage reel R-2.

An outer plate 56 is mounted onto the axle 55 exteriorly of the plate 51 on the reel R-l containing the wrapping material 61 and the reel R-2 containing the reinforcing mesh 62 and is selectively compressed against the reel mounted thereon by adjusting the tension placed against the plate 56 by a nut 57 or other suitable means threaded onto the exterior Q15 the axle 55.

An arm 56a is mounted with each plate 56 and is engaged against the surface adjacent the reels R-l and R-Z by initial rotational movement of such reels and is forced into engagement against such surface during further rtational movement of such reels to further assist in providing a tensile force on the reinforcing mesh 62 and wrapping material 61 as such materials are conducted from the reels R into the placing head H to be compressively wrapped onto the tubular member T and compress the coating material 81 against such tubular member. Additional axles S and metal plates 51 are provided for storage of additional reels of wrapping material and reinforcing mesh to be used in the coating operations of the present invention.

An additional support arm 45' (FIG. 1) is mounted at an elevated position adjacent the rearmost reel R-2 containing the reinforcing mesh 62 and conducts such reinforcing mesh to a position elevated with respect to the reel R-l containing the wrapping material 61 to prevent the mesh 62 from contacting the wrapping material 61 and tearing such, as such materials are conducted from the reels R into the placing head H. i

The amount of tension applied to the reinforcing mesh 62 and the wrapping material 61 by the reels R in order to position the reinforcing mesh at the desired radial relationship within the coating, and the desired tensioning of the nut 57 with the axle 55 to achieve such tension are selectively varied in accordance with the speed of rotation and longitudinal movement of the tubular member T, the thickness of coating material 81 being deposited thereon, the desired position of the reinforcing mesh 62 within the coating 81, and the amount of compressive force to be applied to the coating 81 by the wrapping material 61.

The coating material conveyor belt system S (FIGS. 1 and 5) includes an endless conveyor belt 70 of the well known type which conveys the dry constituents of the coating material, in this embodiment cement and gravel, from a position, adjacent storage hoppers of the well known type, at which the cement and gravel are deposited onto a lower end of the belts 70 and transported by such belt 70 to an upper end 70a (FIGS. 1 and 5).

The ldry constituent materials of the coating material 81 are deposited from the upper end 70a of the belts 70 into a funnel shaped upper end 71a (FIG. 5) of an inlet tube or conduit 71 and fall and pass through such conduit 71 into the mixing chamber M. The tube 71 is mounted at a lower end 71b to the mixing chamber M and supported by such mixing chamber.

A plurality of angle iron members 73 are each inserted through L-shaped apertures on diametrically opposed sides of th'e tube 71 and extend through the interior of the tube 71 in a helical or revolving pattern in order to mix and intermingle the dry constituents of the coating material as such constituents fall and pass through the tube 71 to the mixing chamber M.

The mixed and intermingled dry constituents of the coating material pass through the lower end 71b of the tube 71 and an opening in a top member 7 5a of the mixing chamber M into a chamber 78 of the mixing chamber M formed by a cylindrical wall member 75b (FIGS. l and 5) and a frusto-conical shaped lower wall member 75C.

Liquid, in this embodiment water, is added to the dry constituents of the coating material in the chamber 78 of the mixing chamber M by being sprayed from a plurality of apertures 77a formed in the interior of an annular ring or pipe 77 mounted within the chamber '78. An outlet conduit 6a conveys the liquid to be added to the dry constituents of the coating material in the mixing chamber M to such mixing chamber, and a valve 6b controls and regulates the flow of such liquid from the inlet conduit 87a t0 the annular spray ring 77 in the chamber 78 in order to selectively control and regulate the mixture of the liquid and the dry constituents being mixed in the chamber 78.

By adding liquid to the dry constituents in the mixing chamber after such constituents have been conveyed from their respective storage hoppers, rather than conveying the mixed material on conveyor belts, the amount of mixed coating material is kept to a small amount. Thus in the event of equipment stoppage or malfunctioning, the number of parts of the apparatus A from which the coating material must be removed before it hardens and the amount of coating material to be removed, is kept to a minimum reducing loss and waste of such coating material.

The constituents of the coating material fall through an opening 75b in the mixing chamber M into the feed chamber L after the liquid is added in the chamber 78. To assist movement of the coating material through the feed channel L, the mixing chamber M is mounted on suitable supports at a slightly higher elevation than the upper or inlet end of the placing head H.

The feeed channel L includes a U-shaped or semicircular shaped conveyor channel S0 which extends from an inlet end a (FIG. l) beneath the mix chamber M to an outlet end 80b adjacent the open upper end of the placing head H (FIGS. 1 and 3). A pair of upwardly extending arms or flanges 80C are formed extending up wardly from the channel member 80 at the inlet 80a to enclose the opening 75d in the mix chamber M and prevent spillage and waste of the coating material 81 as such coating material passes from the chamber 78 into the feed channel L.

A metering auger or screw conveyor 83 transports and mixes the coating material from the inlet end 80a of the feed channel 80 to the outlet end 80h adjacent the placing head H. A motor 84 which is mounted with a platform 85a beneath the channel member 80 by a plurality of mounting arms 85b or other suitable mounting means provides the power to drive the metering auger 83 by means of a pulley belt 84a driving a pulley 84b and rotating such pulley to rotate the metering auger 83. The motor 84 is of the Well-known type whose speed is adjustably controllably in order that the speed of rotation of the metering auger 83 may be selectively controlled to control the thickness of the coating material being conveyed and mixed by the metering auger 83 and being deposited by the placing head H onto the tubular member T, as Well as to control the amount of such coating material being deposited onto the tubular member T.

In the operation of the present invention, the tubular member T is placed on the inlet conveyor system 10 and rotated and moved simultaneously longitudinally with respect to its longitudinal axis by means of the roller wheels 12b on the platforms 12 until a first end of such tubular member is adjacent the placing head H.

The dry constituents of the coating material 81 are conveyed by the belt 70 and deposited through the tube 71 into the mixing chamber M where the liquid constituents of such coating material are added, and the coating material 81 is thus formed in the mixing chamber M.

The coating material 81 after being formed in the mixing chamber M is moved by the metering auger 83 through the feed channel L while simultaneously being mixed by such metering auge'r 83. At the outlet end 80b of the feed channel L the coating material 81 passes into the open upper end of the placing head H (FIG. 4) and is deposited by the placing head H onto the tubular member T. By depositing the coating material 81 directly onto the tubular member T, the likelihood of snags, rips Jr tears to the strip of covering material 61 is reduced, and a more acceptable and longer lasting coated tubular member T is thus formed in the method and apparatus of the present invention. Further, damage to the protective coating on the exterior surface 29a of the tubular member T is prevented.

An initial wrap of coating mterial 81 is applied to the exterior surface 29a of the tubular member T, and the strip of reinforcing mesh 62 andthe strip of wrapping material 61 are conducted from their respective storage reels R-Z and R-l to the initial wrap of coating material 81 and applied with such coating material 81 to the tubular member T. The wrapping material 61 and reinforcing mesh 62 are passed through the placing head H as the initial hand wrapping of the tubular member T takes place.

After applying an initial wrap for one revolution of the tubular member T, the coating material 81 in the placing head H is deposited onto the tubular member, and the tubular member T is rotated and moved longitudinally with respect to the placing head H by the inlet conveyor system 10. Tension is maintained in the strip of the wrapping material 61 and the strip of reinforcing mesh 62 by the hand-applied initial wrap pulling against the tension maintained in the storage reels R by the tightened nut 57 and the outer plate 56 as the tubular member T is being rotated and simultaneously moved longitudinally with respect to its longitudinal axis by the inlet conveyor system 10.

The tension in the strip of wrapping material 61 and the strip of reinforcing mesh 62 compresses the coating material 81 against the exterior surface 29a of the tubular member T as such tubular member is rotating and moving longitudinally past the placing head H, and thus the coating being applied to the tubular member T in the method and apparatus of the present invention is applied under compression to such tubular member to strengthen and increase the service life of the tubular member T.

The tension in the wrapping material 61 and the compressive wrapping of the coating material 81 with the tubular member T allow use of larger aggregate in the concrete, permitting use of less cement to obtain the same strength concrete coating. The tension and compressive wrapping also obtain improved adhesion between the coating material 61 and the uncoated or protective coated exterior surface 29a of the tubular member T, as well as allow coating of tubular members of small diameters.

The inlet conveyor system continues the rotating and longitudinal movement of the tubular member T past the placing head H, and the coating material 81 deposited onto the tubular member T is compressively wrapped by the Wrapping material 61 and reinforcing mesh 62 against the exterior surface 29a of the tubular member T, forming a helical spiral wrap of such coating, reinforcing mesh and covering material about the tubular member T (FIG. 2).

As the application of the coating to the tubular member T proceeds, the belts 16k on the outlet conveyor system transport and support the coated portion of the tubular member T away from the placing head H. The belts 16k and the outlet conveyor systems 15 move at a slower speed than the drive wheels 12b in the inlet conveyor system 10 to equalize the torque on the tubular member T, since the coated portion of the tubular member T is larger in diameter than the uncoated portion.

As the trailing end of the tubular member T currently being coated in the placing head H approaches the placing head H, a second tubular member T is mounted with the inlet conveyor system 10 and conveyed by such conveyor system into position such that the leading end of the second tubular member abuts the trailing end of the rst tubular member T. As the abutting end portions of the two tubular members pass beneath the placing head, coating operations continue uninterrupted as coating of the iirst tubular member is completed and the coating of the second tubular member is begun, allowing increased eiciency and greater operating speed when coating such tubular members.

After the abutting end portions have been coated, the end portions pass from beneath the placing head H to a position adjacent the cut-off saw blade 23. The cut-olf arm 21 is then pivoted inwardly until the abrasive edge 23a of the saw blade 23 comes into contact with the coating applied t0 the irst tubular member at a position,

for example four inches, slightly in advance of the abutting end portions, and the motor 22 is energized so that the abrasive edge 23a of the saw blade 23 may cut through the covering material 61, the reinforcing wire mesh 62 and the coating material 81 to reach the exterior surface 29a of the tubular member T. Any residue of coating material clinging to the tubular member T and not removed by the saw 23 may be washed or hosed oif, if desired. Such cutting action removes the coating applied to the tubular member T from an end portion of the tubular member, and provides access to the tubular member T for welding or other installing operations as such tubular members are being installed. The cut-off arm 21 is movable longitudinally along the mounting bar 20c to allow the amounts of coating material removed by the cut off blade 23 to be controlled in order to reduce to a minimum the amount of tubular member T left exposed, thereby reducing the amount of handpacking or wrapping required when installing such tubular members.

In a like manner, the coating applied to the leading edge of the second tubular member abutting the trailing edge of the rst tubular memberl is removed to provide access to such tubular member for installation. The continuous coating of abutting end portions of tubular members as a rst tubular member is completing being coated and a second tubular member is to begin being coated, with subsequent removal of portions of the coating material, allows continuous operation and eliminates the requirements of having to hand wrap the leading and trailing end portions of each tubular member as such tubular member is being coated in the apparatus, in addition to reducing the amount of tubular member T left bare during coating operations.

After the coating has been removed from the abutting end portions of the two tubular members, the iirst tubular member T is in condition for removal from the coating apparatus A in order to be stored to cure the coating applied to such tubular member. The speed of the belt 16k in the outlet conveyor system 15 is increased in order to increase the longitudinal movement of the rst tubular member which has been completed, and thus move the first tubular member away from the second tubular member which is currently being coated in the placing head H. Movement of the coated tubular member T away from the member being coated provides access to the ends of coated tubular member T to allow the coated tubular member T to be removed from the outlet conveyor system 15 by a crane, or other suitable removing means to be stored or stacked or to be transported to a location for installation and use. When being installed for use, the smooth exterior coating of the tubular members T pass over the rollers of the installing equipment without damaging such installing equipment.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials as well as in the details of the illustrated construction may be made Without departing from the spirit of the invention.

What is claimed is:

1. An apparatus for applying a coating under compression to a tubular member which is being rotated and moved along its longitudinal axis adjacent the apparatus, comprising:

(a) conveyor means for rotating said tubular member and moving said tubular member along its longitudinal axis;

(b) a support frame positioned adjacent said conveyor means;

(c) reel means for storing a roll of wrapping material;

(d) placing head means mounted with said support frame, said placing head means including:

(1) a first wall member;

(2) a second wall member spaced from said rst wall member;

(3) means for depositing a coating material onto the rotating tubular member between said rst and second wall members;

(4) an outer wall member pivotally mounted with said first Wall member and said second wall member and movable relative thereto to a position to determine the thickness of the coating material deposited onto the the roating tubular member by said placing head means;

(5) means for compressively wrapping the deposited coating material against the rotating tubular member with a strip of the Wrapping material substantially simultaneously With the depositing of said coating material to form a covered coating layer on the tubular member; and

(e) means for conducting the strip of wrapping material under tension to the placing head from said reel means whereby the tension in the strip of Wrapping material compresses the coating material against tubular member.

2. The structure of claim 1 further including:

(a) a second reel means for storing a roll of reinforcing wire mesh; and

(b) said placing head means further includes means for compressively wrapping a strip of the roll of reinforcing wire mesh into the deposited coating interiorly of the wrapping material to strengthen the coating.

3. The apparatus of claim 1 wherein said placing head means further includes:

vibrator means for eompacting the coating material in the placing head While depositing such coating material onto the tubular member, wherein a substantially uniform composition of coating material is applied to the tubular member.

4. The apparatus of claim 1, further including:

(a) means for storing the dry constituents of the coating material;

(b) means for conveying the required amount of dry constituents of the coating material to a mixing station adjacent the placing head;

(e) mixing chamber means at said mixing station adjacent said placing head receiving the dry constituents from said conveying means for adding liquid to the dry constituents to form the coating material whereby only required amounts of such coating material are mixed as needed thereby reducing waste of such material when coating operations are unexpectedly interrupted; and

(d) means for further mixing and conveying said coating material from said mixing station to said placing head means.

References Cited UNITED STATES PATENTS 2,945,278 7/ 1960 Robertson 25-38 2,368,742 2/1945 Brend 91-14 1,961,974 6/1934 Kramer 138-175 2,269,032 1/1942 Moore 25-38 2,696,353 12/1954 Vessels 118-320 X 2,470,068 5/ 1949 Contenson 25-38 3,190,780 6/1965 McNulty etal. 156-392 X 3,245,856 4/ 1966 Morain 156-392 X DANIEL I. FRITSCH, Primary Examiner U.S. Cl. XR,