APPARATUS FOR AND METHOD OF MANUFACTURING A HELICALLY WOUND TUBULAR STRUCTURE
An apparatus (50) for and method of manufacturing structures (116) includes coaxial rotating faceplates (74, 89, 97), capable of rotation at different angular speeds. A plurality of forming rollers (76) and diameter defining rollers (78) are mounted on the inner faceplate (74, 89), which, in operation, cause a strip material (80) to be plastically deformed into a helical winding which may be lain down in abutting or self-overlapping relationship to form said tubular structure (116). A plurality of support rollers are mounted in a circle on the inner faceplate (74, 89) at a distance from the axis exceeding that of the outermost forming roller and serve to support the stock of strip material.
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This application is a United States national phase application under 35 U.S.C. §371 of International Patent Application No. PCT/GB2010/050054 filed on Jan. 14, 2010, and claims the benefit of Great Britain Patent Application No. 0900721.2 filed on Jan. 16, 2009, both of which are herein incorporated in their entirety by reference. The International Application was published as International Publication No. WO 2010/082058 on Jul. 22, 2010.
FIELDThe present invention relates to a winding apparatus and a method of manufacturing structures and relates particularly to the manufacture of pipes and longitudinal structures formed by winding strips of material, such as metal, Kevlar, plastic, glass fibre, composites of such materials or strips formed from layers comprising one or more of said materials in a helical relationship. Other structures such as storage vessels, towers and support structures may also benefit from features described herein.
BACKGROUNDPresently it is known to manufacture tubular structures by winding pre-formed metal strip onto a rotating mandrel such that the strip is deposited onto the mandrel in a self-overlapping manner and is retained in place by mechanical deformation of an edge thereof such that it interlocks with an adjacent edge, thereby to retain the strip in place on the final structure. EP0335969 discloses an apparatus for forming a helically wound tubular structure formed from a flat strip of metal wound onto a mandrel. The flat strip is fed from one or other of a pair of supply spools mounted concentrically with the axis of the tubular structure to be made. A rotating winding head is used to wind the strip onto the mandrel and includes a plurality of powered forming rollers which impart an initial form to the cross section of the metal strip before it is passed to a final set of rollers that lay the strip onto the mandrel and then swage over an edge of the strip so that it becomes mechanically locked to the previous layer over which it is wound. This is a complex process. Also provided is a mechanism for ensuring the strip supply is maintained constant and this mechanism includes speed control of the forming rollers. The coaxial supply bobbins are fed from an external supply spool so as to maintain the supply thereof. A welding station is used to join one end of the strip material to another.
U.S. Pat. No. 4,738,008 discloses a winding apparatus for forming a non-rotating helix of metal strip having a rotating store of metal strip provided radially outward of a winding head and means for providing the store of material to the winding head which rotates at a different speed to the store of material. In this process it is necessary to stop the process when the strip material has been consumed and a fresh supply thereof is added before production can be recommenced. This can be a very lengthy process.
SUMMARY OF THE INVENTIONIt is an object of the present invention to provide an apparatus for and method of manufacturing tubular structures which reduces and possibly overcomes some of the problems associated with the prior art.
Accordingly, the present invention provides a winding apparatus comprising an inner faceplate rotatably mounted for rotation about a longitudinal axis X-X and having an output station thereon; an outer faceplate radially outward of said inner faceplate and being rotatably mounted for rotation about said longitudinal axis X-X; wherein said inner faceplate comprises a plurality of forming rollers for receiving a strip of material and supplying said strip to said output station and a plurality of inner support rollers for supporting said strip, said support rollers being arranged in a circle around the axis X-X at a distance from the axis exceeding that of the outermost forming roller, said inner and outer faceplates are substantially co-planar and said apparatus further includes a drive mechanism for driving each of said faceplates relative to each other about said longitudinal axis X-X.
Advantageously, this arrangement permits the outer and inner portions of the stock of material to be rotated at different speeds, facilitating the controlled consumption of stock at the forming station. Additionally, variation of angular speeds of different elements in the arrangement permits a reduction or even elimination of downtime for reloading of stock, by continuing consumption during the reloading. This allows for greater uniformity of the manufactured helical winding.
According to a further aspect of the invention said inner faceplate includes a strip support at an outer diameter thereof and onto which, in operation, a supply of strip material may be wound.
According to a further aspect of the invention said apparatus further comprises a brake for preventing rotation of said outer faceplate as and when desired.
According to another aspect of the invention loading may be performed with minimal interruption or without interruption of the inner winding process, by which strip material taken from the inner portion of the stock is wound on to a central core or mandrel. This reduces downtime and may facilitate continuous supply of the strip material toward to the core, so that the final helical winding is uniform along the length of the manufactured pipe.
The present invention will now be more particularly described by way of example only with reference to the accompanying drawings in which:
Referring now to
Referring now more particularly to
Referring to the drawings in general but particularly to
In order to ensure an even feed of strip material from a supply thereof it may be desirable to provide a supply thereof in the form of an annular stock supply shown generally at 88.
Advantageously, the inner portion of the spool 80 is supported by means of inner support rollers 87 which are mounted on the inner faceplate 74, 89 positioned outside said forming station, being circumferentially spaced around longitudinal axis X-X. The inner support rollers 87 may be mounted on the back portion 89 of the inner faceplate 74, 77, 89 as in
By means of independent drive mechanisms respectively comprising motors 94 and 96 the outer faceplate 97 and the inner faceplate 74, 89, may be driven at different angular speeds.
Motors 94 and 96 are connected to and controlled by computer 140 shown in
Also shown in
Referring to the drawings in general, it will be appreciated that a tubular structure may be manufactured by causing the faceplate 74 to rotate. This action in turn will cause the strip material 80 to be drawn from the cassette, passed through forming rollers 76 and into diameter defining rollers 78 at which point the desired diameter is formed by appropriate positional control of rollers 78. As the strip exits the diameter defining rollers it is directed towards the core 54 and wrapped therearound in a self overlapping or abutting arrangement best appreciated with reference to
The various stages of the winding process and replenishment steps will now be more particularly described with reference to
As described earlier, the inner faceplate 74, 89 and the outer faceplate 97 of the stock support 90 may be rotated at different speeds.
The outer portion of the spool cooperates with and is held by adjustable strip brakes 95 located circumferentially on outer faceplate 74, 97, while the inner portion cooperates with rollers 87, as described previously. The inner faceplate 89 and the outer faceplate 97 and the corresponding drive mechanisms are connected to and controlled by the computer 140 (see
By varying the speeds of the inner and outer parts of the cassette it will be appreciated that material can be transferred from one portion of the spool to the other. If the whole spool rotates at the same speed, material consumed from the inner circumference of the inner portion is replaced by material from outer portion. If the speed of rotation of the outer portion is increased beyond that of the inner portion the inner portion will cease to strip off material from the outer portion and, as depletion of the inner portion continues, due to consumption of stock at the core, then the outer portion will peel off stock from the inner portion and a space will be created between the inner and outer portions. If the speed of rotation of the outer portion is decreased below that of the inner portion, the inner portion will peel material from the outer portion. It will be appreciated that controlling the relative speeds of the inner and outer portions effectively manages the transfer of material between the inner and outer portions of the spool, as well as the size of the space between the two portions.
A fully loaded stock support 90 is shown in
The following section describes a sequence of consumption and reloading processes with respect to
As consumption continues the transfer of material from the outer portion S2 to the inner portion S1 leads to the exhaustion of material on the outer annular faceplate as in
After the attachment step is complete clamping means 99 is released and the new feed stock may be wound from the external feed onto the supply stock 90, by rotation of the central inner faceplate 89 by means of the drive mechanism described previously. At this stage the outer faceplate 97 is still locked in a stationery position by bolt 75 and remains stationery until the loading is complete. The feed stock is introduced into the stock supply via the open clamping means 99.
When the feed stock has been completely wound onto the stock supply 90, the device is fully loaded. The supply 90 is then ready for renewed consumption from the inner circumference of the newly loaded stock, thereby returning to the beginning of the sequence, as depicted in
The arrangement may also include a sensor, such as an optical sensor, for monitoring the amount of material in one or either of the portions of the spool, connected to a computer and VDU, whereby the visual display indicates to the user the amount of stock available and the time available, calculated by the computer, before attachment of the new stock must be completed. This is not shown in the figures.
Optionally, the reloading may occur without causing any interruption to the central process of winding material onto the core, as described later. As an alternative to the above arrangement, managing the depletion of stock from the individual portions S1 and S2, as indicated earlier, may also allow continuous consumption of stock from the rotating inner circumference of the inner portion S1, while stock is reloaded at the outer portion.
In this embodiment the drive mechanism for the outer portion S2 is modified. A plurality of drive rollers (not shown) impinge directly on the outer portion S2 and serve to both rotate the stock of material and to contain it. The drive 94, 91, described earlier is connected (connection not shown in the figures) to the driver rollers, rather than the outer annular faceplate 97 as described in previous embodiments. The inner circular faceplate continues to rotate and feed the post forming station 58, whereby the inner portion S1 is fed by the outer portion S2, as in
Additional features of this machine include feedback control from the computer to ensure the product diameter is maintained within desired limits and/or altered according to desired parameters. It will be appreciated that as one can control the degree of plastic deformation of the strip as it passes through the radius forming rollers 78 one can also control the final diameter of any tubular structure formed by this apparatus.
It will be appreciated that the described arrangement ensures an even supply of material. It also forms a complex interlocking profile in the material and winds the material onto a core at predetermined curvature, thereby providing a robust structure in the final windings as well as a suitable tensile compression.
It will also be appreciated that the apparatus may be used on strips of other materials such as Kevlar, plastic, glass fibre, composites of such materials or strips formed from layers comprising one or more of said materials. Indeed the machine lends itself particularly to use with some of these materials as it is able to pre-tension the strip as it is wound onto the final form of the tubular structure being formed. When used with composite materials having a portion of metal in the strip provided either as a layer or as part of any woven form thereof, said metal will act to maintain a degree of rigidity in the strip that will assist with the location thereof on the rollers and in maintaining a final curvature. Materials such as glass-fibre or Kevlar may be reinforced by a resin or other such material in the manner well known to those skilled in the art and, therefore, not described further herein. Clearly, any such materials may simply be wound into the desired shape without needing to be provided with a cross-sectional profile as described earlier herein.
Additionally, this arrangement advantageously provides a means of continuous or near continuous supply of winding material. Downtime for reloading of the apparatus with new stock is reduced, thereby also facilitating greater uniformity of the helical winding produced.
It will also be appreciated that the above described method and apparatus may be used to cover an already existing pipeline with an outer casing. In this arrangement the already existing pipeline forms a core and the machine simply rotates around the core and moves therealong so as to lay down the outer wrap of strip material onto the pipeline. Such an approach could be employed when one wishes to repair or strengthen an already existing pipeline.
Still further, it will be appreciated that if portion 86 (
Claims
1. A winding apparatus comprising; wherein said inner faceplate comprises a plurality of forming rollers for receiving a strip of material and supplying said strip to said output station and a plurality of inner support rollers for supporting said strip, said support rollers being arranged in a circle around said axis X-X at a distance from the axis X-X exceeding that of the outermost forming roller, said inner and outer faceplates are substantially co-planar and said apparatus further includes a drive mechanism for driving each of said faceplates relative to each other about said longitudinal axis X-X.
- an inner faceplate rotatably mounted for rotation about a longitudinal axis X-X and having an output station thereon;
- an outer faceplate radially outward of said inner faceplate and being rotatably mounted for rotation about said longitudinal axis X-X;
2. A winding apparatus as claimed in either of claim 1 wherein said apparatus includes a faceplate brake for preventing rotation of said outer faceplate as and when desired.
3. A winding apparatus as claimed in claim 2 wherein said faceplate brake comprises a friction brake.
4. A winding apparatus as claimed in claim 3 wherein said faceplate brake comprises a pin mounted on a non-rotatable portion of said apparatus and a recess in said outer faceplate for receiving said pin.
5. A winding apparatus as claimed in any one of claims 1 to 4 wherein said apparatus further includes a strip brake for preventing an outer diameter of any strip material wound onto said outer faceplate rotating relative to said outer faceplate.
6. A winding apparatus as claimed in claim 5 wherein said strip brake comprises a plurality of friction brakes mounted for radial movement on said outer faceplate and including a friction surface for engagement with an outer diameter of any strip material wound onto said outer faceplate.
7. An apparatus as clamed in any one of claims 1 to 6 wherein said apparatus further includes a pair of feed rollers mounted on an outer diameter of said outer faceplate for receiving a supply of strip material to said apparatus and for guiding said strip towards said inner faceplate.
8. An apparatus as claimed in any one of claims 1 to 7 wherein said apparatus further includes a strip clamping and cutting station.
9. An apparatus as claimed in any one of claims 1 to 8 wherein said inner faceplate further includes a central bore for receiving a supply of core material onto which strip supplied to said apparatus may be wound.
10. An apparatus as claimed in claim 9 wherein said apparatus further includes a core supply mechanism for supplying a continuous or semi-continuous supply of core material to said apparatus.
11. An apparatus as claimed in claim 10 further comprising a servo mechanism for positioning the core supply mechanism relative to the inner faceplate.
12. An apparatus as claimed in claims 1 to 11 further comprising roller wheels mounted on the outer circumference of the outer faceplate, each roller wheel comprising a friction surface for engaging directly with the outer surface of the stock of material, and a drive mechanism for rotating said roller wheels.
13. An apparatus as claimed in any one of claims 1 to 12 further comprising a monitoring means for monitoring the amount of strip material present in said apparatus.
14. A method for supplying a strip of material, in an apparatus comprising an inner faceplate with support rollers arranged in circle around its axis and an outer faceplate, the faceplates being rotatable at independent variable speeds about a common axis, the method comprising the steps of:
- loading a stock of strip material onto said faceplates by winding said strip material onto the support rollers,
- consuming stock of said strip material from the inner circumference of the stock between adjacent support rollers, by rotating said inner faceplate, and
- replenishing the stock of said strip material at the inner faceplate from the outer faceplate.
15. A method as claimed in claim 14 further comprising the step of stopping the rotation of the outer faceplate.
16. A method as claimed in claim 15 wherein the rotation stopping step comprises friction braking
17. A method as claimed in claim 16 wherein the rotation stopping step comprises inserting a pin movably mounted on a fixed portion of said apparatus into a recess on said outer faceplate.
18. A method as claimed in any one of claims 14 to 17 further comprising the step of preventing rotation of the outer portion of said wound stock relative to the outer faceplate by clamping the outer circumference of said wound stock by strip brakes mounted on the outer faceplate.
19. A method as claimed in any one of claims 14 to 18 further comprising a clamping step wherein the free end of said wound stock is selectively clamped to the outer faceplate
20. A method as claimed in any one of claims 14 to 19 further comprising the step of reloading a new stock of strip material into the apparatus
21. A method as claimed in claim 20 wherein the reloading step comprises the steps of
- stopping rotation of the outer faceplate,
- unclamping the free end of the remaining stock on the outer faceplate
- attaching the free end of the stock to be replaced to the free end of the replacement stock
- winding the replacement stock by rotating the inner faceplate.
22. A method as claimed in claim 21 wherein the stopping step further comprises stopping rotation of the inner faceplate.
23. A method as claimed in claim 21 wherein, by continued rotation of the inner faceplate, consumption from the inner circumference of the stock is continuous.
24. A method as claimed in claim 14, further comprising the step of reloading a new stock of strip material into the apparatus, said outer faceplate further comprising outer support wheels positioned around its outer circumference, the reloading comprising the steps of
- stopping rotation of the outer faceplate,
- attaching the free end of the stock to be replaced to the free end of the replacement stock
- winding the replacement stock by rotating the outer support wheels
25. A method as in any one of claims 14 to 24 further comprising the step of transferring stock of strip material between the inner and outer faceplates by varying their respective speeds.
26. A computer program product comprising a readable medium for storing instructions for implementing the method of claims 14 to 25.
Type: Application
Filed: Jan 14, 2010
Publication Date: Nov 17, 2011
Applicant: ITI SCOTLAND LIMITED (GLASGOW)
Inventor: Richard Martin Curtis (Essex)
Application Number: 13/144,843
International Classification: B21B 1/08 (20060101); B21C 37/06 (20060101);