BACKGROUND OF THE INVENTION

[8001] This invention relates to an automated pipe wrapping apparatus for wrapping a pipe with a corrosion-protection layer.

[0002] It Is known to manually wrap an industrial-application pipe with a corrosion- protection material so as to prevent corrosion of such pipes during use. A strip of the corrosion-protection material is helically wrapped along the length of the pipe, with an overlapping of the strip of material over the previously laid material. This ensures that the whole pipe is seaiingly wrapped,

[0003] Manual wrapping is problematic in that it is labour-intensive, costly and lime- consuming,

|0Q04] There remains a need for an automated pipe-wrapping process. -Such a process, if presented, would have to ensure that it addresses some crucial problems encountered with manual pipe wrapping.

[0005] Firstly, the abovementionec! overlap would have to be uniform in order io achieve a sealing wrap while preventing wastage of the corrosion-protection material.

[0008] Secondly, pipes are sometimes formed from welding metal sheets together, resulting in weld seams that protrude from the surface of the pipe. During wrapping, the corrosion-protection material tents about the seam leaving air gaps on either side of the seam. These air gaps are undesirable as allow localised corrosion. [0007] Thirdly, the corrosion-protection material must be supplied in a continuous manner so that the automated process is not interrupted,

[0008] It is therefore an object of the present invention to address at least partially the aforementioned problems,

SUjyifvtARY OF INVENTION jQ0S9| The present invention aims to provide an automated pipe wrapping apparatus mainly to be used in the appiication of an adhesive strip to a length of pipe,

[0010] In a first aspect, the invention provides a pipe wrapping apparatus for wrapping a pipe with an adhesive strip, the apparatus including a conveyor upon which a length of pipe is conveyed in a first direction a feed source which supplies an adhesive strip in a second direction transverse to the first direction and an applicator interposed between the conveyor and the feed source which includes a support structure, a guide engaged with the support structure for guiding the adhesive strip from the feed source onto the pipe.

[0011] The guide includes a guide arm laterally extending from the support structure over which the adhesive strip passes from the feed source to the pipe, the arm is pivotally connected to the support structure to enable movement of the arm in an arc between an upper limit and a lower limit to laterally shift the adhesive strip along the arm to vary the angle at whic the adhesive strip is delivered to the pipe and so to vary an adherence pattern of the adhesive strip on the pipe. [0012] The adherence pattern may be a helical pattern, The adherence pattern may vary thus varying the extent of overlap of the adhesive material on the pipe.

[0013] The arm may be actuated to move to a predetermined position between the upper limit and the tower limit, which position is dependent upon the required adherence pattern,

[0014] The adhesive strip may include an adhesive layer and a carrier layer.

Ι0Θ15] The applicator may include a gathering device engaged to the support structure which gathers the carrier layer as it separates from the adhesive layer when the adhesive layer adheres to the pipe.

[001 S] The gathering device may include a spool and a motor which drives the spool

[0017] The gathering device may include a shredding mechanism which shreds the carder layer gathered by the spool.

[0018] The motor assembly may include a slip-clutch, interposed between an axle of the motor and the spool, to maintain tension in the carrier layer between the pipe and the spool.

[0019] The support structure may include a vertical adjustment mechanism to vary the height of the support structure, and thereby the guide, to cater for a variance in the diameter of the pipe.

[0020] In a second aspect, the invention provides a pipe wrapping apparatus for wrapping a pipe with an adhesive strip, the apparatus including a conveyor upon which a length of pipe is conveyed in a first direction, a feed source which supplies an adhes ve strip in a second direction transverse to the first direction and a flattening means, for flattening areas on the pipe where the adhesive strip has created an air pocket, which means includes a support, a pressing element and an extension arm which is pivotaily engaged, at one end, to the support and, at an opposed end, to the pressing element to present the element to, and bias the element against, the surface of the pipe.

[0021] The pressing element includes a body and a plurality of rollers engaged with the body which rollers are presented to the surface of the pipe to press the adhesive strip thereon to depress the air pockets, [0022] The body may include a cavity within which at least a part of each roller is mounted,

[0023] Each of the rollers may be mounted within the cavity to move from outwardly biased position to an inwardly forced position to accommodate irregularities on the surface of the pipe. [0024] The support may have a vertical adjustment mechanism to vary the height of the support, and thereby the pressing element, to cater for a variance in the diameter of the pipe.

[0025] In a third aspect, the invention provides a pipe wrapping apparatus for wrapping a pipe with an adhesive strip, the apparatus including a conveyor upon which a length of pipe is conveyed in a first direction, a feed source which includes a support frame upon which at least one roll of the adhesive strip is horizontally supported, an applicator which aids in applying the adhesive strip to the pipe and at least one guide roller interposed between the feed source and the applicator which is orientated so as to cause the adhesive material received from the roil to twist from the vertical plane towards the horizonta plane before feeding the strip to the applicator in a second direction transverse to the first direction for application of the strip to the pipe, 002S] Preferably, the feed source includes a plurality of rolls of the adhesive materia! vertically stacked in horizontal support on the support frame.

[0027] The plurality of rolls may be interconnected, with an inner end of a tower roll attached with an outer end of a higher roll

[0028] The apparatus may include a plurality of guide rollers which are aiigned in plan, extending in the second direction,

|0 29] The support frame may include an alignment mechanism which causes the support frame to move In an arc to keep the adhesive material at a feed end section of the roll aligned with the second direction,

£0030] The support frame may be placed on wheels to reduce the force that is required to move the support frame in the arc,

[0031] The alignment mechanism may include a linear actuator, a sensor, a controller and at least one connector rod,

[0032] The actuator may be connected to the support frame by means of the at least one connector rod, J0033] The actuator may be connected, at one end _t to a first fixed point, and at an opposed end to the connector rod. [0034] The frame may be connected to a second fixed point spaced from the first fixed point,

[00351 T e sensor may be an optical sensor that senses a radial reduction in the spool and communicates the radial reduction to the controller which is in communication with the actuator,

[0036] The controller may actuate the actuator to push or pull on the rod to move the frame into a position in the arc which maintains alignment of the feed end section of the roll in the second direction,

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The invention is further described by way of example with reference to the accompanying drawings in which:

Figure 1 is a side view of an embodiment of the invention, which is a pipe wrapping apparatus;

Figure 1A diagrammafically represents a gathering device of the apparatus;

Figure 2 is an illustration of a profile of a wrapping material to be used with the invention;

Figure 3 is an illustration of the pipe and conveyer bed of the apparatus of Figure 1 , Figure 4 is a side view of a support frame of the apparatus of Figure 1 ;

Figure 5 is a plan view of a support structure showing the different angles of the roller arm of the apparatus of Figure 1.

Figure 8 is an illustration of a weld line material press of the apparatus of Figure 1 ; Figure 7A is an illustration of a welded pipe wrapped without the weld locator of Figure 8; Figure 7B is an illustration of the operation of the weld line material press of Figure 8 on the welded pipe of Figure 7A; and

Figure 8 illustrates an alignment mechanism of a dispenser to be used with the invention.

DESCRIPTION OF PREFERRED B BQPirvtEMT

[0038] An embodiment of the invention is described with reference to the accompanying drawings.

F003S] "Wrapping" refers to application of the adhesive layer around a pipe

[0040] There is therefore provided, according to the invention, a pipe wrapping apparatus 10 as shown in Figure 1.

[0041] The terms "wrapping material" and "wrapping sheet" are used interchangeably to refer to a double-layered material 12 shown clearly in Figure 2, in sheet farm, comprising a carder film 12A and a doubte-sided adhesive layer 12B attached thereto. The carrier film 12A is used as a carrier for the adhesive layer 12B, to support the adhesive layer and to prevent this layer from deforming when under tension.

[0042] The apparatus 10 comprises two major parts; a feeder assembly 14 and a wrapping section 18.

[0043] The feeder assembly 14 includes a dispenser 18 which includes a frame 17 which carries a vertical array of feeder spools 20A _t 20B and 20C of the wrapping mate ial 12, and a plurality of guide rollers, respectively designated 22A _f 228 ....22N, which support and guide the wrapping material from the feeder spools to the wrapping section 18.

[0044] The guide rollers are illustrated in Figure 1 as all lying on a horizontal plane. This is for ease of illustration. Practically, the guide roller 22A is presented aslant the horizontal at, say, 45°, with each successive roller in the series being presented at an increasingly acute angle until towards the roller 22 , the rollers are horizontal. This relative positioning of the rollers in the series guides the wrapping material 12, as it emerges from the spool 20, from a vertical planar alignment to a horizontal pianar alignment

[0045] At roller 22A, the wrapping material 12 is starts to twist from a vertical planar orientation, leaving the feeder spools 20, to a horizontal planar orientation.

[9048] Each spool 20 is supported on a respective pisiform 24 in a horizontal orientation so as to avoid sagging and deformation of the spool. The platforms are mounted at spaced vertical intervals on an axle 28. A motor 28 drives the axle to rotate and, in turn, the platforms 24 with supported spools.

[S047] The feeder assembly 12 also includes a control mechanism 30 which controls positioning of the frame 174 with the rollers 22. The control mechanism includes an optical sensor 32, a linear actuator 34 and rods 38 and 38 (see Figure 8). The working of the control mechanism will be described below when referencing Figure 8.

[Θ048] The wrapping section 18 includes a support 40, on which is mounted first, second and third roller arms, respectively designated 42A, 42B and 42C, each of which guide the material 12, received from the feeder assembly 14, in an over and under pattern as Illustrated in Figure 1 ,

[0049] Also mounted to the support 40 is a locator arm 44, to a free end of which is attached a materia! press 46, The press 48 is more clearly illustrated in Figures 6 and 7B and will be described and its role explained below,

[Θ05Ο] The arm 44 and press 48 optionally can be standalone parts as shown in dotted outline in Figure 1.

[0051] Aside the support, the wrapping section 18 further includes a conveyor bed 48 on which a section of pipe 50 is supported between a pair of side rollers 52A and 52B which pipe is to be wrapped by the adhesive material 12 received from the roller arms 42. This wrapping of the pipe is shown in greater detail in Figure 3.

|0052| A pair of guide rollers 54 are mounted to the support 40, beneath the roller arms 42, These rollers receive the carrier film 12A, peeled from the wrapping material 12 as will be more fully described below, and guide the film to a shredder 58, also mounted to the support 40, which receives and shreds the carrier film. 0083] Wrapping of the pipe 50 proceeds in two stages: a manual start-up stage and an automated wrapping stage which follows the start-up stage.

[SSS4] In the manual start-up stage, the wrapping materia! 12 is pulled at a leading free end though the guide rollers 22 in a direction "A" as shown in Figure 1. The material 12 is oriented such that the carrier film 12A faces upwardly with the adhesive layer 12B beneath. fOOSS] The matenai 12 is then fed under the first refer arm 42A, over the second roller arm 42B and under the third roller arm 42C, The second roller arm 428 has a non-stick surface which prevents the adhesive layer 12B from sticking to this arm.

[ 0S6] The leading end of the wrapping material is th n pulled manually from the arms 42 over and around the pipe 50, As the leading end emerges from an underside of the pipe 50, the adhesive layer 12B i separated from the carrier film 12A and the adhesive layer is adhered to the pipe 50. The leading end, now only comprising of the carrier film 12A, is fed through the rollers 54 and engaged with the shredder 58.

[0057] The automated wrapping stage can now start,

[00S8] The conveyor bed 48, s de rollers 52 and the shredder 58 are electrically turned on causing the pipe to move in a direction perpendicular or aslant to the direction "A" (the "travel direction") whilst rotating in a direction "S". This movement of the pipe results in the pulling of the material 12 from the respective dispensing spool 20, through the guide rollers 22, over and under the roller arms 42 to meet a top side 58 (see Figure 7). Sticking to the surface of the pipe 50, with the pipe rotating and moving in the travel direction, the adhesive layer 12B helically wraps the pipe 50 as is illustrated in Figure 3.

[0059] With the shredder 58 rotating, it pulls on the carrier film 12A, thereby aiding rotation of the pipe and the wrapping process whilst keeping the wrapping materiai 12 taught. At the same time, the shredder collects and shreds the carrier film to waste, [0080] The apparatus 10 therefore provides an automated wrapping process. The movement, at a predetermined yet changeable speed, of the pipe 50 along the conveyor bed 48 ensures application in a uniform helical pattern of the adhesive layer 12B to the pipe sectors 50 in which the extent of the overlap zone 80 is kept to a minimum, maximising the coverage provided by the adhesive layer.

[0061] Ideally, a slip-dutch 81 (see Figure 1A) is coupled with a drive means 83 of the shredder 58. The slip clutch decouples the shredder from the drive means when tension in the carrier film 12A tends to rise beyond a predetermined maximum, and re-establishes the coupling when the tension reduces below a predetermined minimum. This respectively prevents breaking of the carrier film 12A due to high tension and excess slack in the carrier film 12A,

[0082] The pipe wrapping apparatus 10 provides for the wrapping of pipes with a range of diameters.

[0DS3] As was mentioned in the background, pipes 50 are sometimes manufactured by forming a tube from an arcuate metal sheet and welding together the adjoining edges, A weld seam 82 that results often protrudes from the pipe surface. Figures 7A and 7B illustrate this. The pipe is Illustrated in Figure 7A wrapped with adhesive layer 12B. However, "tenting" has occurred over the seam producing gaps 83 between the surface of the pipe and the adhesive layer. f0064J Also gaps occur at an adhesive layer edge 64 in the overlap zone 80,

[TOSS] The press 48 addresses this issue of tenting, The press, shown in greater detail in Figures 6 and 7B, consists of a body 88 which partly houses a plurality of balls, respectively designated 8BA to 68D. Each ball is mounted to the body to enable it to universally rotate and also move resiliency inwardly and outwardly relatively to the housing. This resilient movement is indicated by a bi-directional arrow designated Έ". Each ball is made ol or are coated with, non-stick material

[0 S6] The press 46 is optimally positioned over a top side 58 of the pipe SO, offset between 10 ^c and 4Q ^a from the vertical, depending upon the diameter of the pipe. The arm 44, being pivotal!y connected to the frame 40, allows the press to ride over ridges created by the adhesive layer edges 84 and the weld seam 62 as the press encounters these ridges on each rotation of the pipe.

[0987] The workings of the press 46 are now described with reference to the weld seam 62 merely for ease of explanation.

[00S8] As the pipe 50 rotates and is wrapped with the adhesive material 12B, the balls 84 of the press 48, under downward force imposed on the press by the downwardly biased arm 44, press on the wrapped surface of the pipe 50. When seam 55 arrives at the press 48, the balls 84, each in turn, press down on the material 12B, which is tenting the gaps 83, onto the surface of the pipe, eliminating or substantially reducing the gaps. The gap 83 A is closed first. Each ball 84 rides over the seam 62 by resiliency recessing into the body 86 before returning to an outward biased position, closing the gap 83B.

[0089] The frame 40 on which the locator arm 44 is mounted can have height adjustment means (not shown) to adjust the height bi-directionally as represented by arrow "B" in Figure 4. This adjustment mechanism can be automatic or manual. If therefore a smaller or bigger diameter pipe is introduced to be wrapped, the frame 40 can be moved respectively down or up and the arm, if located on the frame, can be positioned at the ideal height.

[0070] Alternatively, it is the locator arm 44 which can be rnoveabiy mounted on the frame 40, adjustable to move up or down to accommodate varying pipe diameters.

[0071J As has been said, the pipe 50 is moved along the conveyor bed 48 in direction that is either perpendicular or aslant to the direction "A", spinning in a direction "S" (see Figure 1), thereby collecting along its surface, and being so wrapped by, the adhesive material 12B. It is ideal that this wrapping is done such that the adhesive material 128, being in sheet form, partially overlaps upon itself in the overlap zone 80 as it spirals along the pipe 50. Ideally, this overlap zone is between 10mm and 15mm 0S?2J To achieve this overlap, the angular orientation of the "master" roller arm 42C relatively to the upright frame 40, over which the wrapping material 12 passes, can be varied pivotally upwardly to an upper position, and pivotalSy downwardly to a tower position. This arcuate variation in the positioning of the roller arm 42B is illustrated in exaggeration in Figure 4, Figure 5A to 5C also illustrates Irs plan the upper (Figure 5B) and lower positions (Figure 5C) of the roller arm 42C and how it affects the movement of wrapping material, again exaggerated.

[0073] This movement between the upper position and the lower position has the effect of varying the angle of delivery of the material 12 to the pipe 50, as is illustrated In Figures 5A to 5C, changing the depth of the overlap zone 60 by tightening or loosening the helical pattern respectively. [0074] Considering the dispensation of the material 12 by the spools 20, it Is important that the material is dispensed in alignment with the rollers 22 as shown in Figures 1 and 8. The control mechanism 30 for the platform 24 maintains this alignment

[0075] Referring to Figure 8, a spool 20, illustrated as a bold circle, starts dispensing wrapping material 12 in alignment with the rollers 22. Only the roller 22A is shown for ease of Illustration. The materia! is guided in this alignment to the pipe 50, also left out in this diagram, via the applicator 18, This is the optimal orientation of the dispensed wrapping material reiatively to the guide rollers 22.

[0076] As the spoof 20 radially depletes this dispensation alignment is tost as the material 12, towards a core 70 of the spool, dispenses from an angle β-This is undesirable as distortion of the planar orientation of the material 12 can occur ai least at the roller 22A.

[007?] The control mechanism 30 of the feeder assembly 14 referred to above prevents this loss of this dispensation alignment in the following way:

[00TB] The optical sensor 32 monitors the depletion of the spool 20 and reports the extent of the depletion to a controller 72 which is in communication with the linear actuator 34. The output shaft of the actuator is connected to the frame 17 by means of the rod 38, The base of the actuator is connected to a first fixed swivel pivot 74 The frame 17is connected to a second fixed swivel pivot 78 through the use of a tethering rod 38,

[0079] The frame 17 is placed on one or more trolley wheels 78 to reduce the force that is needed to move the frame. [0080] On actuation of the actuator 34, the actuator will extend and push on rod 36 to move the frame to the optimal position relatively to the guide rollers 22 In direction "H". This movement ensures that the circumference of the spool 20 is aligned with the rollers 22, and eliminating the possibility of distortion of the planar orientation of the material 12 at the rollers 22,

[0081] The spools 20 are interconnected to ensure the continuous supply of material even when a spool is depleted. The interconnection process (illustrated in dotted outline on Figure 1} consists of Joining an inner end of the current spool 20A to the outer end of the succeeding spool 20B, The interconnection process can he used to ensure continuous material supply when two or more spools are used.

[0082] When the current spool 20A in completely depleted a changeover to the succeeding spool 20B will occur. During this changeover the optical sensor will report this to the controller 72 which is in communication with the motor 28 and the actuator 34. The motor will shut down during the changeover to retard the speed of the vertical axle 28 which is connected to the spools 20, The actuator 34 will retract, pulling on rod 38. to move the frame 1? to the optima! position relatively to the guide rollers 22 a direction "1" which is the opposite of direction Ή".

[0083] If the retraction is not done the spool 20B will remain in the position of the dotted circle creating a distortion of the planar orientation of the material 12 at the guide rollers 22.

[0084] The invention is expected to be employed as part of a large scale industrial pipe wrapping process, where intervals of non-stop pipe wrapping (production shifts) are anticipated. Therefore, to allow for non-interrupted production shifts, joining of spools 18 as described above will be ideal

[0085] Pipes 50 are fed on the rollers 52, end to end, A next-in-line pipe is allowed to move at a relatively faster speed towards a pipe then being wrapped. The next-inline pipe nestles against the pipe being wrapped, forming a joiner (spider) section between the pipes and allowing for continuous un-interrupte wrapping.

[0086] After wrapping, the pipes 50 can be separated by peeling off the masking coats previously applied on the last 100mm of their end parts.