US3873396A

US3873396A - Web splicing apparatus

Info

Publication number: US3873396A
Application number: US340262A
Authority: US
Inventors: Claude J Rice
Original assignee: Kendall Co
Current assignee: Kendall Co
Priority date: 1973-03-12
Filing date: 1973-03-12
Publication date: 1975-03-25
Anticipated expiration: 1992-03-25
Also published as: CA1012048A

Abstract

In a machine which applies a web as an outer coating to a length of pipe, the web being applied under tension, the machine including a web supply spindle and means defining a web delivery path from the spindle to the length of pipe, the improvement comprising retarding means disposed along the web path intermediate the spindle and the pipe operative to exert a retarding force on web delivered to the pipe, and a web splicing facilitator disposed along the web path intermediate the spindle and the retarding means. The web splicing facilitator is operative to stabilize a terminal portion of a first length of web thereby permitting splicing of that terminal portion to an initial portion of a second length of web.

Description

o g United States Patent 1191 1111 3,873,396 Rice Mar. 25, 1975 [54] WEB SPLICING APPARATUS 3,218,22l 11/1965 Burns 161/36 3,374,963 3/1968 C t' 242 58.4 [75] Inventor: Claude Bamsdan, Okla- 3,505,148 4/1970 148:1; 156 /36l [73] Assignee: The Kendall Company, Boston,

Mass. Primary ExaminerWi1liam A. Powell Filed Mar 1973 Assistant Examiner-Brian J. Leitten [21] Appl. No.: 340,262 [57] ABSTRACT 1n a machine which applies a web as an outer coating 52 us. Cl 156/392, 156/157, 156/162, to a length of Pipe, the Web being applied under 56/188. 56/195, 156/392, 156/4297 sion, the machine including a web supply spindle and 156/432 [56/494, 156/504 242/585 means defining a web delivery path from the spindle 511 1111. C1 B65h 81/00 to the length of Pipe, the improvement Comprising [58] Field of Search 156/157, 159, 187,188, tardihg means disposed along the Web P intermedi- 156190 191, 192 392, 428, 429, 5 504 ate the spindle and the pipe operative to exert a re- 195 494 162 6 138/129 tardi'ng force on web delivered to the pipe, and a web 5 5 75.2 splicing facilitator disposed along the web path inter- 1 mediate the spindle and the retarding means. The web 5 References Cited splicing facilitator is operative to stabilize a terminal UNITED STATES PATENTS portion of a first length of web thereby permitting splicing of that terminal portion to an initial portion of 2,724,426 11/1955 Bell et a1 156/159 3 Second length of web. 2,863,204 12/1958 T1mothy et a1. 3,024,157 3/1962 Beerli 156/504 8 Claims, 2 Drawing Figures PATENTED AR 2 51975 sum 1 0F 2 WEB SPLICING APPARATUS BACKGROUND OF THE INVENTION This invention relates to apparatus of the type which applies a web as an outer wrapping to a length of pipe.

To protect underground pipelines (e.g., natural gas or oil transmission lines) against damage due to corrosion, it is necessary to apply an anti-corrosive coating to the exterior surface of the pipe. In recent years, this coating has often taken the form of one or more layers of plastic tape wound in an overlapping fashion around the exterior of the pipe. For the background of this technique of pipe protection, the reader is referred to Hielema US. Pat. No. 3,700,520 issued Oct. 24, 1972.

The application of the tape to the pipe may take place on a continuous basis using over-the-ditch apparatus at the installation site or, using somewhat different apparatus, at a fixed location with subsequent transport of the pipe to the installation location. It is the latter situation to which the present invention is directed.

Typical apparatus for the application of tape to pipe in a fixed location provides for the movement of the pipe through or past the apparatus with translation and rotation of the pipe drawing the tape or tapes onto the pipe from fixed tape supply rolls.

It is a principal object of the present invention to provide improvements in apparatus of the type which applies a web to a moving length of pipe which will increase the efficiency of such apparatus. It is a further object to provide improvements which increase the production of the rate of the apparatus while maintaining operator safety.

SUMMARY OF THE INVENTION As mentioned above, the invention comprises improvements in apparatus which applies a web as an outer coating to a length of pipe, the web being applied under tension and the apparatus including a web supply spindle and means defining a web delivery path from the spindle to the length of pipe. In one aspect of the invention, the improvement comprises retarding means, disposed along the web delivery path intermediate the spindle and the length of pipe, operative to exert the retarding force on the web delivered to the length of pipe. A web splicing facilitator is also provided and is disposed along the web delivery path intermediate the spindle and the retarding means. The facilitator is operative to stabilize a terminal portion of a first length of web, thereby permitting splicing of that terminal portion to an initial portion of a second length of web.

In another aspect, the improvement comprises such retarding means disposed along the web delivery path intermediate the spindle and the length of pipe, in combination with a web stabilizer also disposed along the web delivery path and located intermediate the spindle and retarding means. The stabilizer includes a web accumulator comprising a web-storing enclosure and web drive means upstream along the web delivery path from the enclosure. The web drive means supply web to the enclosure at a rate which is faster than the rate at which the web is applied to the length of pipe. Thus, by operation of the web drive means for an appropriate period of time prior to the exhaustion of a first supply roll of web, a quantity of web will be accumulated in a relatively slack condition, with the retarding means, downstream of the accumulator, maintaining the necesssary web tension for proper application to the length of pipe. The accumulated web thus provides a continuous supply for wrapping the pipe, while the tail of web upstream of the accumulator remains stationary (thus stabilized), permitting a neat and safe splice to a fresh supply roll of web. In preferred embodiments of this aspect of the invention, the enclosure has a web entrance slot, a web exit slot, a depth less than twice the width of the web, and a height and width sufficient to contain therein a plurality of slack web loops; the drive means comprise a pair of rolls providing a nip through which the web passes, one of the rolls being driven by a motor; and the retarding means comprise a drum around which the web is trained and brake means for inhibiting the rotation of the drum.

In another aspect of the invention, the stabilizer comprises a splicing member which includes a pressure receiving surface disposed along the web delivery path intermediate the spindle and the retarding means, the surface being elongated in the direction of the path. In preferred embodiments of this aspect of the invention, the splicing surface has a length along the path at least equal to a plurality of widths of the web; the apparatus further includes barrier means disposed along the web delivery path immediately downstream from the splicing surface, the barrier means including a slot through which the web passes; and the retarding means comprise a drum about which the web is trained and brake means for inhibiting rotation of the drum.

DETAILED DESCRIPTION OF THE DRAWINGS Other objects, features and advantages of the invention will appear from the following description of a preferred embodiment taken in conjunction with the accompanying drawings.

DESCRIPTION OF PARTICULAR PREFERRED EMBODIMENTS In FIG. 1 there is shown apparatus ofthe general type suitable to apply, to a length of pipe, a protective coating in the form of a double wrapping of plastic web or tape. The pipe 10 enters the apparatus from the left (as shown in FIG. 1) and, while being conveyed from left to right is caused to rotate in a clockwise sense (as viewed along the direction of travel of the pipe 10 and as shown by the curved arrow in FIG. 1). The individual lengths of pipe 10 are supplied to the apparatus with the trailing end of one length of pipe abutting the leading end of the succeeding length of pipe so that the wrapping operation proceeds continuously despite the discrete nature of the pipe being wrapped.

The pipe first enters a cleaner 12 which may be of any conventional design (e.g., a plurality of rotary cylindrical brushes having axes parallel to the pipe). The pipe 10 next enters a primer station 14 where any conventional primer coating may be applied. The pipe 10 then receives a first layer of plastic web 16 supplied along a web delivery path which makes an acute angle A with the pipe 10. The angle A and the width of the web 16 can be varied, as is well known, to provide a proper overlap of the turns of the web 16 on the pipe (e.g., a /3 overlap) for any given pipe diameter and rate of both translation and rotation. The first web 16 is typically an 8 to mil thick polyethylene tape having a 2 to 10 mil coating of adhesive. The tape is supplied from a supply roll 18 supported on a spindle 20. The tape 16 passes through a splicing facilitator indicated schematically at 22. The spindle 20 is mounted on arm 24 which is supported for rotation on a frame 26. A second spindle 28 is also mounted on the arm 24 for supporting a second roll of tape 30. After a manual start-up, the web 16 is drawn onto the pipe 10 by the motion of the pipe. As further described below, retarding means are provided to maintain tension in the web 16 as it is delivered to the pipe 10.

. A second or outer plastic tape 32 is supplied from a roll 34 mounted on spindle 36. As with the first web 16, a standby'roll 38 is supported on spindle 40. Both spindles are mounted on an arm 42. The arm is pivotally mounted for rotation upon a frame member 44. A splicing facilitator 46 is provided along the web delivery path. The path makes an angle B (where B=A) with the pipe 10.

The tape 32 is typically a heavier (e.g., 40 mil) polyethylene tape without an adhesive backing. Adhesion is secured, as described in detail in the previously mentioned US. Pat. No. 3,700,520, by the extrusion of a bead 48 of molten polyethylene along one edge of the tape 32 by a unit 50.

To facilitate the high speed, uninterrupted coating of pipe 10, the wrapping with

tape

16 and 32 is continuous despite the discontinuous nature of the pipe 10. A cut-back device 52 is provided along the path of travel of the pipe 10 downstream of the wrapping-operation which removes the tape adjacent to, and overlapping, the leading and trailing ends 54, 56, respectively, of the lengths of pipe.

Referring to FIG. 2, the pipe 10 is supported on eonveying apparatus which includes wheels (indicated at 58) for producing the necessary rotation of the pipe 10 to draw the

webs

16, 32 onto the pipe. For each

web

16, 32, the frame 26, 44 (which supports both the

arm

24, 42 and the splicing facilitator 22, 46) is itself pivotally supported as at 60, 62 so that the angles A and B may be varied as desired.

Referring now to the supply of tape 16, it will be seen that the facilitator 22 includes a roller 64 and a pair of nip rolls 66, 68, the roller and the nip defining a straight horizontal segment of the web delivery path. Disposed adjacent and immediately below that portion of the path is a web stabilizing splicing member 70, including a flat, upper, pressure-receiving surface 72, mounted on the frame 26. The surface 72 is elongated in the direction of travel of the web 16 and preferably has a length of at least twelve inches. Immediately downstream of the member 70, there is provided a barrier means 74 in the form of a vertically disposed plate having a slot 76 therein aligned with the path of the web between roller 64 and nip 66, 68. Downstream of the nip, the web is trained about drum 78 which includes an internal braking device 80 of any conventional design. The outer surface 82 of drum 78 is coated with slip-resistant material such as rubber. Roller 84 is disposed downstream of the drum 78 and aligns the web 16 for travel to the length of pipe 10.

Rollers

64, 66, and 68 are coated with a conventional release material 4 to prevent excessive sticking of the adhesive layer of web 16.

The arm 24 which supports the

spindles

20, 28 is rigidly affixed to a sprocket 86. The sprocket 86 may be driven by a chain (not shown) so that the orientation of

spindles

20, 28 with respect to the roller 64 may be reversed when desired, as further discussed below.

The splicing facilitator 46, associated with web 32, includes a rectangular web enclosure 88 having a web entrance slot disposed adjacent nip rolls 90, 92 and a web exit slot disposed adjacent nip rolls 94, 96. The enclosure 88 has a depth which is less than twice the width of the web 32 and a height and width sufficient to enclose a plurality of slack web loops 98. The enclosure 88 is constructed to provide for the visual inspection of the loops 98 within the enclosure (e.g., it may have walls of transparent plastic, wire mesh, etc.). A motor 100 is mounted on the enclosure 88 and is connected by a belt 102 to drive the nip roll 90.

Rolls

104 and 106 are also mounted on the enclosure 88 and define a web path between the supply roll 34 and the nip rolls 90, 92. A member 108 is supported along the web path between the supply roll 34 and the roll 104 and includes a surface 110 disposed adjacent and parallel to the web path.

Rolls

112 and 114 define the web path between the nip rolls 94, 96 and a large drum 116 having an internal brake 118 and an outer surface 120 which comprises a slip-resistant material such as rubber. Roll 122 defines the final length of path of the web 32 for proper delivery to the pipe 10. The arm 42 is fixed to, a sprocket 124, which may be rotated by means of a chain (not shown), for reversing the positions of the

spindles

36 and 40 with respect to the roll 104.

The operation of the splicing facilitator 22 is as follows: After an initial manual start-up, web 16 is continuously drawn by the translating and rotating pipe 10 from the supply roll 18. The retarding influence of the drum 78 maintains the tension in the web 16 which is necessary for proper application to the pipe 10. In a typical wrapping operation, the web 16 travels across the upper surface 72 of splicing member 70 at a rate suffcient to permit a manual splice of the self-adhesive tape 16. The splice is achieved by manually unwinding a sufficient length of tape from the roll 30 so that the free end of that roll may be held above the pressure receiving surface 72 of the splicing member 70. With his other hand, the operator merely severs the web 16 between the roll 64 and the supply roll 18 (or, alternatively, waits until the roll 18 is exhausted of web) and immediately presses the free end of roll 30 onto the trailing portion of the web 16 as it travels across the stabilizing surface 72 of splicing member 70. The adhesive incorporated on one surface of the web forms an instant splice so that the supply of web 16 to the pipe 10 may be continuous. The barrier 74 is provided to prevent an accidental drawing of the operators hand, with the web 16, toward nip rolls 66, 68. The barrier plate extends sufficiently (e.g.. three inches or more) above the slot to effectively mask the rolls 66, 68. After the splice is achieved. the orientations of

spindles

20 and 28 may be reversed as discussed above and a fresh roll of tape mounted on spindle 20 preparatory to the next splice.

The splicing facilitator 46 for web 32 also includes a drum (drum 116) for applying a retarding force to the web and a web accumulator which comprises the enclosure 88, the nip rolls 90, 92, and the motor 100. Shortly before the splicing-in of a fresh roll of tape 38 is necessary, the motor 100 is turned on to drive the nip rolls 90, 92 by means of the belt 102. The drive speed is chosen to be substantially faster than the rate at which the web 32 is being drawn onto the pipe 10. The overfeed of web thus causes the formation of slack web loops 98 within the enclosure 88 and upstream of the retarding drum 116. With visually transparent walls for the enclosure 88, the operator can determine when the enclosure 88 is substantially filled with loops 98 and at that point turn off the motor 100.

The web will then be supplied to the pipe from the excess supply within the enclosure 88, while the web upstream of the enclosure 88, including that adjacent 110, will remain stationary, and thus be stabilized". This stabilization of the web 32 is necessary to achieve an adequate splice since, it will be recalled, the web 32 is not self-adhesive. With an adequately sized enclosure 88 (depending, of course, on the rate at which the web 32 is supplied to the pipe 10) substantial periods of time (e.g., up to a minute) may be provided, during which the trailing portion of web 32 is stabilized and stationary upstream of the roll 104 so that a splice can be accomplished by severing the web 32, unrolling the web from roll 38 a sufficient amount to reach the severed end of the web and making a splice in any conventional fashion (e.g., using a small piece of adhesive tape such as tape 16). The splice may be achieved using the surface 110 to facilitate the splicing operation. With an appropriately sized enclosure 88, however, there is adequate time for performing a manual splice even without a facilitating surface such as surface 110.

After the splice has been completed, the location of

spindles

36, 40 may be reversed. Upon exhaustion of the supply of web within the enclosure 88, the unwinding of web from the on-line supply roll will resume.

While particular embodiments have been described in detail, other embodiments are within the scope of the invention and the following claims.

l claim:

1. In a stationary machine which applies a selfadhesive web as an outer coating to a length of moving pipe, the web being applied under tension, the machine including a web supply spindle and means defining a web delivery path from said spindle to said length of pipe, the improvement comprising retarding means disposed along said delivery path intermediate said spindle and said length of pipe operative to exert a retarding force on the web delivered to said length of pipe,

and a splicing member including a splicing surface supported along said web delivery path intermediate said spindle and said retarding means, said surface being elongated in the direction of said path.

2. The improvement of claim 1 wherein said surface has a length along said path at least equal to about 12 inches.

3. The improvement as claimed in claim 1 further including barrier means disposed along said web delivery path immediately downstream from said surface, said barrier means including a slot through which said web passes.

4. The improvement as claimed in claim 3 wherein said barrier means comprise a plate having a slot therein for the passage of web therethrough and extending in a directiongenerally perpendicular to said surface for a distance of at least 3 inches.

5. The improvement as claimed in claim 1 wherein said retarding means comprise a drum about which said web is trained and brake means for inhibiting rotation of said drum.

6. The improvement as claimed in claim 5 wherein said drum has a slip-resistant outer surface.

7. The improvement as claimed in claim 6 wherein said outer surface is rubber.

8. In a stationary machine which applies an outer coating to a length of moving pipe, the coating comprising an inner self-adhesive web and an outer non-self adhesive web, each web being applied under tension, the machine including respective web supply spindles and means defining web delivery paths from said spindles to said length of pipe, the improvement comprisfor each web, retarding means disposed along said web delivery path intermediate said spindle and said length of pipe operative to exert a retarding force on the web delivered to said length of pipe, and a splicing surface disposed along said web delivery path intermediate said spindle and said retarding means;

said surface associated with said inner web being elongated in the direction of said path; and

a web storage unit associated with said outer web comprising a web container for storing slack web and web drive means upstream along said web deliver path of said container selectively operative to supply web to said container at a rate which is faster than the rate which said web is applied to said length of pipe.

Claims

1. In a stationary machine which applies a self-adhesive web as an outer coating to a length of moving pipe, the web being applied under tension, the machine including a web supply spindle and means defining a web delivery path from said spindle to said length of pipe, the improvement comprising retarding means disposed along said delivery path intermediate said spindle and said length of pipe operative to exert a retarding force on the web delivered to said length of pipe, and a splicing member including a splicing surface supported along said web delivery path intermediate said spindle and said retarding means, said surface being elongated in the direction of said path.

4. The improvement as claimed in claim 3 wherein said barrier means comprise a plate having a slot therein for the passage of web therethrough and extending in a direction generally perpendicular to said surface for a distance of at least 3 inches.

7. The improvement as claimed in claim 6 wherein said outer surface is rubber.

8. In a stationary machine which applies an outer coating to a length of moving pipe, the coating comprising an inner self-adhesive web and an outer non-self adhesive web, each web being applied under tension, the machine including respective web supply spindles and means defining web delivery paths from said spindles to said length of pipe, the improvement comprising, for each web, retarding means disposed along said web delivery path intermediate said spindle and said length of pipe operative to exert a retarding force on the web delivered to said length of pipe, and a splicing surface disposed along said web delivery path intermediate said spindle and said retarding means; said surface associated with said inner web being elongated in the direction of said path; and a web storage unit associated with said outer web comprising a web container for storing slack web and web drive means upstream along said web deliver path of said container selectively operative to supply web to said container at a rate which is faster than the rate which said web is applIed to said length of pipe.