Fabrication of hoses or other elongated articles
Armouring tape (102) for wrapping around a hose (300) during its fabrication by a hose-wrapping machine (200; 400). The tape (102) is coiled into a roll (100) having a hollow core (109) from which the tape (102) is unwound to be wrapped onto the hose (300). The hose-wrapping machine (200; 400) rotatably mounts the roll (100) with the hose (300) passing through the roll core (109), the roll axis (108) being skewed to the hose axis (304) by the helix angle at which the tape (102) is to be wrapped onto and along the hose (300). The hose (300) is moved longitudinally through the longitudinally static roll (100) and at the same time, the roll (100) is rotated around the longitudinal axis (304) of the non-rotating hose (300). The armouring tape (102) unwinds from the inside (109) of the roll onto and along the hose (300) so as to wrap the hose (300) with a uniform helix of armouring tape (102). The use of a tape (102) containing an elastomer-embedded array of armouring cables (104) enables armouring wires and elastomer layers to be applied without a stabilising layer of fabric, and greatly simplifies setting-up of machinery for hose fabrication. The use of a tape roll (100) which can be unwound from its inside (109) enables hoses to be wrapped without having to orbit rolls that are very large and heavy.
This invention relates to the fabrication of hoses or other elongated articles, and relates more particularly but not exclusively to forms of armouring tapes and to wrapping machinery for sheathing or for armouring hoses or other elongated articles.
Hoses are flexible pipes, the larger sizes of which may be used for the bulk transfer of liquids and gases(e.g. between an oil production platform and a tanker) in a marine environment. Such large hoses are commonly armoured for increased strength against crushing and tensile loads, as well as to enhance their ability to withstand internal pressure. To certain extent, large electric cables for use underground or underwater can be considered as equivalent to hoses containing one or more insulated electric conductors, at least from considerations of the need for and methods of sheathing and armouring electric cables (e.g. consider electric cables that are cooled and/or insulated by internal fluid under pressure). Other elongated articles (e.g. umbilicals) may have similar properties and requirements that can be met by sheathing and armouring. In the following specification, for simplicity and brevity the term “hose” (or “hoses” in the plural) will be utilised as a collective designation for elongated articles including but not restricted to hoses and other flexible pipes, electric cables, umbilicals, and other elongated articles having analogous properties, for which sheathing and/or armouring is desirable or necessary; statements in the following specification should be construed accordingly.
In the current state of the art of hose manufacture, rubber-bonded hoses are armoured by first wrapping or extruding a layer of rubber around a hose core (assembly of inner layers), the rubber-coated core then being wrapped around with single-strand steel wires or multi-strand steel cables as the armouring material. Successive layers of rubber and armouring are extruded/wrapped around the part-fabricated hose to build up a completed hose. This rubber is initially unvulcanised, and each armouring wire or cable is individually wrapped onto the unvulcanised rubber under applied tension. If the unvulcanised rubber is not self-reinforced or otherwise constrained in some suitable manner, the armouring wire or cable will cut through the rubber to leave the armouring layer uneven and unstable, and consequently reduce the strength and stability of the armouring layer. Currently this problem is mitigated by infilling each layer of rubber with a woven fabric so as to inhibit the rubber from oozing around the armouring wire or cable as the wire or cable is being wrapped around the rubber layer.
Problems arise from the conventional hose armouring techniques, as follows:—
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- (1) the woven fabric (utilised as an infilling) will absorb gas during use of the finished hose, and is liable to initiate delamination and/or splitting of the multi-layered hose upon explosive decompression (i.e. upon rapid depressurisation of fluid contained within the bore of the hose);
- (2) the fabric adds to the cost of the finished hose in respect of the extra material and the additional manufacturing procedures required;
- (3) the set-up time for a wrapping machine that must rotate and wrap upwards of a hundred wires or cables is excessive, and given that setting-up usually interrupts production (because production cannot continue during setting-up), this procedure is counterproductive;
- (4) the armouring wires or cables must be laid with a packing density of less than 100%, and the wrapping of individual wires and cables inevitably results in bunching and the accumulation of gaps such that the final product is non-uniformly flexible and prone to “bird-caging” (a form of cable failure in which debonding and armour bulging occur);
- (5) conventional armour wrapping machines induce twisting of the armouring wires and cables as they are being wrapped;
- (6) alternate wrapping of rubber layers and wire/cable layers results in superficial bonding between these successive layers which will add to the problems outlined in paragraph (4) above;
- (7) conventional armour wrapping machines are planetary, i.e. rolls of wrapping wire/cable are carried in orbits around the hose being built up, and unwind from the outside of the rolls; this is tolerable for small rolls where inertia is minimal but becomes a serious problem with rolls whose diameters are four or five metres and which weigh many tonnes (as are required for larger hoses that must be manufactured without joints in the armouring wires, even in hoses of great length);
- (8) conventional armour wrapping machines are sufficiently large and expensive as to limit hose manufacturers to the purchase of a single such machine; this single-machine limitation requires that during its fabrication, a given hose must pass through the machine each time another layer of wires/cables is added (with resetting of the machine between each pass) whereas a hose would ideally pass only once along a multi-machine production line.
In comparison to conventional hose armouring techniques, it would be preferable if:—
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- (1) the rubber or other elastomer was free of fabric;
- (2) the armouring wires or cables were evenly distributed;
- (3) the time required for setting-up (and hence the duration of production interruption) was significantly reduced;
- (4) an unvulcanised rubber or other polymer could be guaranteed to flow all around the armouring wires or cables, and for multi-strand cables, also be equally dispersed within the cables;
- (5) allow the use of alternative materials for armouring (e.g. carbon fibre, aramid, and the like, which may be in the form of cords, wires, fibres, or cables) using the same manufacturing equipment.
Achievement of these desiderata would ensure that the resultant hose has maximum strength and suffers minimum disruption while flexing, and would minimise the chances of delamination from explosive decompression while eliminating the potential for tearing that would be initiated by fatigue failure of the fabric.
According to a first aspect of the present invention there is provided a method of fabricating a hose (300) that is to be sheathed with at least one layer (102) of hose-sheathing material (104+106), the method being characterised by the step of providing a roll (100) of the hose-sheathing material (104+106) in the form of a tape (102), the roll (100) having a hollow core (109) whose diameter is greater than the external diameter of the hose (300), the tape (102) being withdrawable from the inside (109) of the roll (100), the method being further characterised by the additional steps of locating the roll (100) around the hose (300) such that the hose (300) passes through the core (109) of the roll (100), effecting relative rotation of the roll (100) and the hose to (300) unwind the tape (102) of hose-sheathing material (104+106) from the inside (109) of the roll (100) and onto the hose (300) while simultaneously effecting relative longitudinal translation of the hose (300) and the roll (100) so as helically to wrap the tape (102) of hose-sheathing material (104+106) onto and along the hose (300).
The roll is preferably mounted with its axis skewed relative to the longitudinal axis of the hose by a skew angle that is substantially equal to the helix angle at which the tape is helically wrapped onto and along the hose. The roll may be rotated about its own axis and/or about the longitudinal axis of the hose. Either the roll may be rotated about the longitudinal axis of the hose while maintaining the hose non-rotational about its longitudinal axis, or, alternatively, the hose may be rotated about its longitudinal axis while maintaining the roll non-rotational about the longitudinal axis of the hose. Either the hose may be longitudinally translated while maintaining the roll longitudinally static, or, alternatively, the roll may be longitudinally translated while maintaining the hose longitudinally static.
The tape of hose-sheathing material used in the first aspect of the invention may comprise an array of mutually parallel armouring wires or cables extending along the length of the tape, the array of armouring wires or cables being embedded in polymer.
According to a second aspect of the present invention there is provided a hose-wrapping machine (200; 400) for helically wrapping a tape (102) of hose-sheathing material (104+106) onto a hose (300), the hose-wrapping machine (200; 400) comprising roll-mounting means (414+416+418) for rotatably mounting a roll (100) of the tape (102) around the hose (300) with the hose (300) passing through a hollow core (109) of the roll (100), tape handling means (402, 404) for withdrawing the tape (102) from the inside (109) of the roll (100) and for wrapping the tape (102) onto the hose (300), and relative movement means (420+422) for effecting relative rotation of the roll (100) and the hose (300) and simultaneously effecting relative longitudinal translation the hose (300) and the roll (100) so as helically to wrap the tape (102) of hose-sheathing material (104+106) onto and along the hose (300).
The relative movement means is preferably such that during operation of the hose-wrapping machine, the hose moves longitudinally but does not rotate about its longitudinal axis, while the roll of hose-sheathing tape rotates about the axis of the hose but remains longitudinally static. The roll-mounting means may be such that the roll is rotatably mounted for rotation about its own axis, and is preferably such that the axis of the roll is skewed relative to the longitudinal axis of the hose by substantially the helix angle with which the hose-sheathing tape is intended to be wrapped on the hose, and the roll is mounted for simultaneous rotation both about the axis of the roll and about the longitudinal axis of the hose being wrapped. According to a third aspect of the present invention there is provided a tape of hose-sheathing material, the tape comprising an array of mutually parallel armouring wires or cables extending along the length of the tape, the array of armouring wires or cables being embedded in a polymer.
According to a fourth aspect of the present invention there is provided a method of manufacturing the tape of hose-sheathing material, the method comprising the steps of providing a coating die having a substantially straight row of apertures along a first side thereof and a substantially parallel-sided slit along a second side thereof opposite said first side, the number of said apertures being equal to the number of wires or cables to be incorporated into the tape, the apertures being individually dimensioned to be a close sliding fit around a respective wire or cable, said slit being dimensioned to correspond to the intended cross-section of the tape (after any necessary allowance for dimensional changes in the newly fabricated tape), the method further comprising the additional steps of threading a respective wire or cable in through each of said apertures and out through the opposite slit to a take-up means, and pumping a polymer into the die to coat the wires or cables while simultaneously operating the take-up means to take up the newly fabricated tape.
According to a fifth aspect of the present invention there is provided a roll of hose-sheathing material in the form of a tape, wherein the tape can be unwound from the inside of the roll. The tape is preferably a tape according to the third aspect of the present invention, and/or a tape manufactured by the method according to the fourth aspect of the present invention.
Embodiments of the invention will now be described by way of example, with reference to the accompanying drawings wherein:
Referring first to
While the cables 104 preferably each have an open multi-strand form for maximisation of the elastomer/steel bonding area, and preferably also are stranded from a relatively large number of relatively small diameter wires for greater tape strength per unit of cross-sectional area (with consequent reductions in weight and cost for a tape-sheathed hose of given performance), the cables 104 can each be substituted by single-strand steel wire. As an alternative to steel, the cables 104 can be formed of a suitable non-steel material, e.g. carbon-fibre, aramid, and the like, that may be in the form of cords, wires, fibres, or cables. The tape-forming coating die 110 will have dimensions, plus aperture sizes & numbers, to suit the size and composition of the tape to be formed thereby, a separate die being provided for each such variation.
Turning now to
As viewed in
During wrapping of the tape 102 onto the hose core 302, the tension under which the tape 102 is wrapped is sensed and controlled by a co-operating pair of pinch rollers 202 (
In the particular situation where the hose 300 is to have a finished outside diameter of a nominal fourteen inches (approximately three hundred and fifty-six millimetres), the tape 102 may have one hundred and twenty-two cables 104 at 95% packing density, each cable 104 having a diameter of 6.5 millimetres. The tape 102 will have a width of four hundred and eighty millimetres and the helix angle will be in the range forty (angular) degrees to seventy (angular) degrees. The roll 100 holding sufficient of this form of the tape 102 to wrap a fourteen-inch hose having an overall length of five hundred metres will weigh about twenty-six tonnes.
For a hose of similar length but having a nominal outside diameter of three inches (about seventy-six millimetres) and using reinforcing cables having individual diameters of about three millimetres, the tape will have a width of one hundred and eighty millimetres and the roll will weigh about eight tonnes.
These high roll weights indicate the utility of the invention in enabling the avoidance of immense technical difficulties in moving such massive rolls in a planetary orbit around a hose core for the purpose of wrapping the hose with the tape contained in the roll. The tape itself greatly simplifies the problems of wrapping a hose in a large number of armouring wires or reinforcing cables by enabling simple wrapping onto to hoses without having to apply a large number of individual reinforcing cables under tension hence precluding the need for fabric reinforcements, and the tape also avoids the problems of ensuring good bonding between the wires or cables and the rubber or other elastomer since they are mutually bonded under pressure within the coating die 110 rather than within the sheathing of the hose.
Referring now to FIGS. 6 to 12, these show a second embodiment 400 of hose-wrapping machine in accordance with an aspect of the invention. The hose-wrapping machine 400 as shown in
Referring particularly to
Since this roll 100 has the coiled tape 102 withdrawn from the roll 100 by unwinding the innermost layer of the coiled material, the roll 100 cannot be supported by a conventional hub mounting (suitable for conventional peripheral withdrawal only). Instead the roll 100 is externally clamped by the roll mounting system 408 (
The front wheel 424, the backing wheel 408, and their respective drive systems are each mounted on a common turntable 432 (
For the hose-wrapping machine 400 as shown in
Whichever option is selected for relative rotation of hose and machine in the
A further alternative for hose-wrapping operation consists of modifying the machine 400 as described above and as illustrated in
As well as wrapping cable-reinforced armouring tape 100 (as described with reference to
While certain modifications and variations have been described above, the invention is not restricted thereto, and other modifications and variations can be adopted without departing from the scope of the invention as defined in the appended claims.
Claims
1-26. (canceled)
11. A hose-wrapping machine (200; 400) for helically wrapping a tape (102) of hose-sheathing material (104+106) onto a hose (300), the hose-wrapping machine (200; 400) comprising roll-mounting means (414+416+418) for rotatably mounting a roll (100) of the tape (102) around the hose (300) with the hose (300) passing through a hollow core (109) of the roll (100) and for wrapping the tape (102) onto the hose (300), and relative movement means (420+422) for effecting relative rotation of the roll (100) and the hose (300) and simultaneously effective relative longitudinal translation the hose (300) and the roll (100) so as helically to wrap the tape (102) of hose-sheathing material (104+106) onto and along the hose (300).
12. A hose-wrapping machine (200, 400) as claimed in claim 11, characterized in that the roll-mounting means (414+416+418) mounts the roll (100) such that the axis (108) of the roll (100) is skewed relative to the longitudinal axis (304) of the hose (300) by substantially the helix angle with which the hose-sheathing tape (102) is intended to be wrapped on the hose (300).
13. A hose-wrapping machine (200; 400) as claimed in claim 11, characterised in that the roll-mounting means (414+416+418) rotatably mounts the roll (100) for rotation about the longitudinal axis (304) of the hose (300).
14. A hose-wrapping machine (200; 400) as claimed in claim 11, characterised in that the roll-mounting means (414+416+418) rotatably mounts the roll (100) for rotation about its own axis (108).
15. A hose wrapping machine (200; 400) as claimed in claim 11, characterised in that the roll (100) is mounted for simultaneous rotation both about the axis (108) of the roll (100) and about the longitudinal axis (304) of the hose (300) being wrapped.
16. A hose wrapping machine (200; 400) as claimed in claim 11, characterised in that the roll-mounting means (414+416+418) rotatably mounts the roll (100) whilst simultaneously maintaining the hose (300) non-rotational about its longitudinal axis.
17. A hose wrapping machine (200; 400) as claimed in claim 11, characterised in that the hose (300) rotates about its longitudinal axis (304) whilst the roll (100) is simultaneously maintained non-rotational.
18. A hose-wrapping machine (200; 400) as claimed in claim 11, characterised in that the relative movement means is such that during operation of the hose-wrapping machine (200; 400), the hose (300) moves longitudinally while the roll (100) of hose-sheathing tape (102) remains longitudinally static.
19. A hose-wrapping machine (200; 400) as claimed in claim 11, characterised in that the relative movement means is such that during operation of the hose-wrapping machine (200; 400), the roll (100) of hose-sheathing tape (102) moves longitudinally while the hose (300) remains longitudinally static.
20. A hose-wrapping machine (200; 400) as claimed in claim 11, characterised in that the tape (102) of hose-sheathing material (104+106) comprises an array of mutually parallel armouring wires or cables (104) extending along the length of the tape (102), the array of armouring wires or cables (104) being embedded in an elastomer (106).
Type: Application
Filed: Jul 1, 2005
Publication Date: Nov 3, 2005
Inventors: Keith Dixon-Roche (Kent), Luc Julien Bourgeois (Desselgem)
Application Number: 11/173,323