WO1998042057A1

WO1998042057A1 - Recoverable article

Info

Publication number: WO1998042057A1
Application number: PCT/GB1998/000823
Authority: WO
Inventors: David Ions; Philip Roland Winfield; Josef Toerringer; George Gansbuehler; Sean Michael Lewington; Philip Costigan
Original assignee: Raychem Limited
Priority date: 1997-03-19
Filing date: 1998-03-18
Publication date: 1998-09-24
Also published as: AU6510498A; GB9705698D0

Abstract

A recoverable article (2) comprising an inner resilient tubular member (6, 4) that is held in a laterally expanded configuration by engagement with outer holdout means (8, 10), wherein the outer surface of the inner member (4) is provided with a plurality of cavities (14), wherein the holdout means occupies the cavities so as to provide the holdout engagement, and wherein means (16) is arranged to release the inner member from the holdout means substantially simultaneously around the periphery thereof progressively along its length, thereby to allow recovery of the tubular member towards its unexpanded configuration.

Description

RECOVERABLE ARTICLE

This invention relates to a recoverable article for, and method of, enclosing an elongate substrate. The substrate may comprise for example a cable, which may be an electrical power or telecommunications cable, and in particular a cable connection. The cable connection may comprise a joint, or splice, between two, or more, cables, or a termination of a cable, for example on to a terminating lug or bushing connected to electrical equipment such as switchgear or a transformer. The termination may comprise an adapter, for example an elbow.

The invention will be further particularly described with reference to an in-line joint between two electric power cables, but it is to be understood that this is by way of example only and not by way of limitation.

Joints between two power cables, whether either or both are polymeric or paper insulated cables, need to be enclosed within a protective arrangement that includes an electrically insulating layer. Heat shrink technology has been applied for this purpose for many years, with products available from Raychem and others. However, technologies that do not require heat are also employed. Push-on sleeves and elbows are available but unlike heat shrinkable products, these have severe range-taking limitations that necessitate a large inventory. Other so-called cold applied solutions require a tubular elastomeric sleeve to be radially expanded and mounted on a rigid holdout member, the internal diameter of which is larger than the maximum outer diameter of the cable joint to be enclosed. One example of the latter is the PST sleeve available from 3M, as exemplified in US-A-3515798. Such a sleeve has an inner holdout member that consists of a continuous narrow strip of tough flexible material in the form of a rigid closed helix having adjacent coils interconnected. The held out sleeve is mounted over the cable joint and the helical strip is then unwound, thus allowing the insulating stretched elastic cover to shrink down onto the joint. However, it is inconvenient having to unwind the holdout strip helically around the extended cable, especially if the work has to be done in the confined space of a trench or manhole. Another example of a cold applied arrangement is disclosed in US-A-3824331 (AMP), in which a resilient tubular cover is supported in a stretched condition by an easily removable external one piece support member, each end of the cover being rolled back over the outside of the support. The cover and support member are mounted on an internal sleeve in the form of a longitudinally slit tube held in a state of increased diameter by a dividing strip in the shape of an I-beam. When in position over the cable joint, removal of the dividing strip longitudinally from the slit allows the inner tube to be squeezed and then freely withdrawn from the cover. The cover ends are then unrolled onto the adjacent cable sections and the external support member is removed. It will be appreciated that such an arrangement requires an inner and an outer holdout member, each of which has to be removed. EP-B-0 530 952 (3M) discloses a cover assembly in which an elastomeric tube is held out in a stretched condition on an inner support core. The core is frangible such that application thereto of a force beyond that produced by the tube causes breakage of the core so as to allow contraction of the elastomeric tube onto the substrate. The fragments of the collapsed core remain within the tube and must therefore be as small as possible to facilitate accommodation therewithin.

With each of these arrangements, the holdout member is disposed internally of the sleeve that is to be applied to the substrate cable. Thus, the sleeve cannot conveniently have an internal coating, of gel, mastic or adhesive for example, applied thereto. This problem, is avoided by the recoverable sleeve assembly disclosed in US-A-4410009 (Sigmaform), in which an inner elastomeric tube is maintained in a radially-stretched condition by having an outer rigid tube surrounding and secured to the outer surface thereof The outer tube is a rigid thermosetting adhesive polyurethane whereby the outer tube is suff-ciently adhesive to hold the inner tube in its stretched condition but will peel from the inner tube upon impact of force. US-A-4070746 (Raychem) discloses a recoverable tubular article in which an elastomeric sleeve is retained in a radially expanded condition by an outer constraint that is bonded thereto. The restraint is sufficiently strong to retain the sleeve in its expanded form under ordinary conditions of storage, but is susceptible to attack by solvents that weaken the bond sufficiently to allow the elastomeric sleeve to peel away from the restraint and to recover towards its original state. US-A-4233731 (Raychem) discloses a dimensionally-recoverable article comprising a hollow resilient member which has been expanded to a dimensionally unstable configuration in which it is retained by a keeper positioned between and separating two parts of the hollow member away from the path of recovery thereof. The keeper is made from a material that weakens or changes its shape upon heating and/or chemical treatment, for example by being chemically degradable when subjected to a solvent. In one embodiment a single wedge of fusible material is interposed in the break in the circumference of a split tube of beryllium copper alloy. In another embodiment a tubular member made from an engineering plastics material has dovetailed protuberances on its outer surface between which strips of a polycarbonate are inserted to maintain the expanded configuration. EP-A0590469 (Kabelmetal) discloses a recoverable elastomeric tubular article that is held in its expanded state by thermoplastic bracing means in the form of a profile applied helically to the outer surface of the expanded tube.

It is an object of the present invention to provide a recoverable article and its method of manufacture, in which the article is held out in its expanded configuration by an advantageous external holdout means so as not to interfere with any inner layer, of gel, adhesive or mastic material for example, which may be applied internally thereof as a coating or which may be located around the substrate to be enclosed.

Thus, in accordance with one aspect of the present invention, there is provided a recoverable article comprising an inner resilient tubular member that is held out in a laterally expanded configuration by engagement with outer holdout means, wherein the outer surface of the inner member is provided with a plurality of cavities, wherein the holdout means occupies the cavities so as to provide the holdout engagement, and wherein means is arranged to release the inner member from the holdout means substantially simultaneously around the periphery thereof progressively along its length, thereby to allow recovery of the tubular member towards its unexpanded configuration.

Advantageously, the holdout means comprises a plurality of discrete portions for engaging respective ones of the cavities, and the release means interlinks all the discrete portions.

Preferably, the cavities comprise a plurality of channels that extend longitudinally of the article, preferably parallel to one another. Preferably the holdout means comprises a plurality of strips that engage respective ones of the channels either substantially at each point along the lengths of the channels, or alternatively each strip may comprise a plurality of longitudinally spaced-apart holdout members that substantially fill a cavity at discrete positions along its length, successive holdout members of each strip being linked together.

In a further embodiment the holdout may be formed by a layer extending around the entire circumference of the inner member and bonded thereto so as to extend over the top of the cavities. In its holdout configuration, the layer be deflected into the cavities, and may be flipped outwards, for example progressively from one end of the article to the other, so as to hinge to a configuration that allows recovery of the article.

The simultaneous release of the holdout means is advantageous in that entrapment of air beneath the article as it recovers on to a substrate is avoided, or at least minimised. The resilient member will engage the substrate substantially simultaneously at all points on a circumference thereof, and then progressively along its length. Although it is envisaged that a single article as described would be arranged to recover from one end to the other over a substrate, a single inner member may have two holdout means associated therewith. In such an embodiment, each holdout means may be arranged to recover from a point intermediate the length of the inner member towards respective ends thereof.

The release means may be formed integrally with the holdout means, and in one preferred embodiment the release means may comprise an annular member that engages the holdout means and which can be pulled longitudinally over the outer surface of the tubular member from one end to the other to effect said release. Alternatively, the release means may only be required to initiate release at one end of the article.

The holdout means may comprise at least two components engaging with each cavity, removal of one of the components being arranged to facilitate the removal of the other(s). In one embodiment, the holdout means may comprise a plurality of high modulus material strips engaging respective channels of the castellated outer surface of the inner member, each strip being encased within a lower modulus sheath that retains a lubricant. Release of the holdout may be effected by slitting the outer sheaths from one end to the other so that the lubricant facilitates the recovery force of the inner member urging the strips out of the channels. The slitting may be effected by an annular ring with inwardlyprojecting cutting surfaces for engaging respective holdout strips.

The outer surface of the inner member may be castellated with the valleys of the castellations providing the cavities, for example the longitudinal channels, thereof.

The holdout means may be applied in a flowable form, such as sand or other granular material, and held in place by a wrapping of polymeric or other suitable material. The flowable material may be a hardenable, or curable, material, such as plaster of paris, cement, a curable epoxy resin system or other thermoset. which may or may not require a wrapping.

In general, however, whether or not the holdout means is flowable, it may be desirable to enclose the article of the invention within an outer sheath to enhance retention of the holdout means during storage and transport.

The holdout means may comprise foam, preferably high density foam, which may be formed in strips to fit channels in the outer surface of the inner member for example, or which may be foamed in situ to fill the expanded cavities.

The holdout means may be formed, especially when of strip configuration, of material that exhibits good resistance to compression in the transverse direction, whilst exhibiting more flexibility, or brittleness, in the longitudinal direction of the inner member, thereby to facilitate controlled removal thereof, and thus controlled recovery of the inner member. Cardboard has been found to be a suitable material, for example a material comprising composite layers of Kraft board approximately 0.9mm thick. Wooden laths, fibre board or plasterboard are also suitable materials. In the latter case, a board comprising a layer of plaster 9mm thick laminated between layers of cardboard giving an overall thickness of about 10mm has been found suitable. Such holdout means are comparatively cheap and are also bio-degradable. It is also envisaged, however, that the holdout means of the article of the invention may be polymeric, preferably bio-degradable, and preferably when in strip form has a high modulus.

The holdout means may be extruded on to the outer surface of the inner tubular member.

Advantageously, the cavities, for example the longitudinal channels, in the outer surface of the inner member are re-entrant so as to enhance retention of the holdout means.

It will be appreciated that the shaping of the cavities has to be such as to ensure that the inner member is retained in its expanded configuration under expected conditions of storage and transport to its place of application and then to be released without the need for undue force, preferably manually, when the article is to be applied to a substrate. The shaping of the interface between the inner member and the holdout means will thus depend on factors such as (i) the material of the inner tubular member and of the holdout means, in particular the relative hardness, and (ii) the force within the expanded tubular member tending to cause it to recover, which will itself depend on the material, the expansion ratio of the member, and its thickness. Thus, for example a thickwalled inner member made of highly expanded, relatively high modulus material would require a relatively greater amount of mechanical interlocking by the holdout means due to its relatively high recovery forces.

The inner member is preferably made from polymeric, preferably elastomeric material.

One or both ends of the inner tubular member may advantageously have a bevelled (especially chamfered) internal surface. This can help to prevent the end of the tubular member digging into a substrate (e.g. a cable) around which it is recovered.

The inner member may form part of an enclosure for an electric cable splice, termination, or the like, and may be formed from electrically conductive material, for example for forming electrical continuity across, and/or electrical screening of, the joint. The inner tubular member may have one, or more, further layers on its inner surface, which may be co-extruded therewith. For example, an electrically insulating layer and/or an electrically stress grading polymeric layer may be co-extruded internally with the inner member. Such an additional layer may have different mechanical properties from the inner member, for example by being more resilient so as to enhance conformity with the substrate, for example a cable splice. There may also be an innermost electrically conductive layer, for example extending along only part of the length of the other layer(s), to provide a Faraday cage. An inner layer of gel, mastic or adhesive may be provided to enhance conformability and sealing, for example to exclude air and/or moisture, with the substrate. It is also envisaged that such a sealant layer may be applied separately to the substrate.

In accordance with another aspect of the present invention, there is provided a substrate, for example a cable joint, termination or elbow, enclosed by a recovered article in accordance with the said one aspect of the present invention.

In accordance with a further aspect of the present invention, there is provided a method of manufacturing an article in accordance with said first aspect, and a method of enclosing an elongate substrate with an article in accordance with said first aspect, in which the holdout means is peeled away from the inner member from one end to the other.

Embodiments of a recoverable article, each in accordance with the present invention, will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is an isometric view of one embodiment of article in a partially recovered configuration; Figure 2 is an isometric view of a second embodiment;

Figures 3 to 6 show part of four alternative holdout means; Figure 7 is an isometric view of a third embodiment of the article;

Figures 8 and 9 are partial end views of further embodiments of recoverable article; Figure 10 shows a release member for use with the embodiments of Figures 8 and 9; Figure 11 is a partial end view of a modified holdout means; Figure 12 is an isometric view of a further embodiment of the article;

Figure 13 is an end view of the article of Figure 12; and

Figure 14 is an isometric view of a recovered article forming part of an in-line power cable splice

The article 2 of Figure 1 comprises a tubular electrically conductive elastomeric inner member 4 that has a castellated outer surface. An innermost thick-walled right-cylindrical tube 6 of electrical stress grading material is co-extruded on the interior of the resilient member 4. After the component 4, 6 has been extruded, it is radially expanded, by a factor of two, on a mandrel, and whilst being held in the expanded configuration, a holdout arrangement 8 is applied thereto. The holdout 8 consists of twelve strips 10 that push-fit into respective ones of expanded channels 14, which lie between the lands of the castellated surface of the tube 4, and which extend parallel to each other and to the axis of the tube 4 from one end to the other thereof. At one end, and preferably at each end, all the strips 10 are joined together by an annular ring 16, preferably integrally therewith, which lies longitudinally beyond the end of the tube 4. Additionally or alternatively, the ring 16 may extend radially outwards from the tube 4. For illustration purposes only, the castellated inner member 4 is shown cutaway at one end, exposing the innermost stress grading layer 6.

By gripping the ring 16 and pulling it evenly over the outer surface of the article 2, the strips 10 are progressively released from the channels 14 of the castellations and the article 2 recovers evenly around its circumference from one end to the other on to a substrate (not shown).

As shown in Figure 1 , the holdout strips 10 are solid continuous members of substantially rectilinear section. The article 20 of Figure 2 differs from that of Figure 1 in that holdout strips 22 are formed from discrete substantially rectangular blocks 24 that are longitudinally spaced apart along the castellation channels 14, the blocks 24 within any one channel 14 being secured together by a fibre 26. At one end, and preferably at each end (not shown), all the strips 22 are secured to a cylindrical ring, or collar, 28 that is gripped and pulled back over the article 20 in order to secure the progressive simultaneous recovery thereof. Figures 3 and 4 show alternative holdout strips 30, 40 respectively, formed by extrusion of sheet material. As a further alternative, the holdout strip may comprise an elastomeric backing strip with high modulus blocks secured thereto.

The further modification of holdout strip 50 of Figure 5 shows a flexible transversely slotted strip having a hole 52 extending longitudinally therealong through which may be threaded a fibre or string for effecting its release from the inner resilient member.

Figure 6 shows a further holdout block 60, or alternatively a section of a continuous holdout strip, that is in two parts. The inner part 62 has a pair of sidewalls 64, that engage the sides of the channels of the inner resilient member, and that are interconnected by a hinge portion 66. The other part of the block 60, or continuous strip, forms a cap 68 that fits over the upper parts of the sidewalls 64 to prevent any movement of the hinge. In order to release the holdout, the cap or caps 68 of all the holdout strips around the inner member are removed simultaneously and progressively longitudinally of the article. Removal of the cap 68 allows the associated part 62 to rotate about its hinge portion 66 such that the recovery force of the resilient inner member tends to eject the blocks 60 from the channels and thus to permit recovery of the article.

Figure 1 1 shows a segment of an end view of an article with a holdout strip 60 as shown in Figure 6 in place.

The article 70 of Figure 7 has a still further modified holdout and release arrangement. In this embodiment, the twelve holdout strips 72 are of inverted-V configuration, and are initially retained within the channels of the castellated outer surface of the inner resilient member 74 by an enveloping polymeric tubular sheath 76 that fits along the entire length of the article 70. Sliding removal of the tube 76 along the article, in conjunction with the shaping of the strips 72 and the action of recovery forces, causes the strips 72 to be released and ejected from the channels as the V-shape tends to open out, allowing the article 74 to recover. Figure 8 shows an end view of a segment of a further embodiment of the recoverable article in which a channel 80 between adjacent lands 82 of the outer surface of a resilient inner member is filled by a two-part elongate holdout strip 84. A central support part 86 of the strip 84 is of general-H shape with the narrow intermediate bridging portion forming a hinge. The other part of the holdout strip 84 consists of a pair of side strips 88 that act to provide a lower friction interface with the central part 86 than the part 86 would have with the sides of the lands 82.

Removal of the holdout 84 is achieved by means of the trigger ring 100 of Figure 10. The ring 100 is formed from a rigid plastics material and has an annular portion 102 that is large enough to pass around the outside of the article of Figure 8, and a set of twelve tapering fingers 104 that are axially directed and set on a circle of radius such that when the ring 100 is positioned axially at one end of the article of Figure 8, the fingers 104 engage with respective ones of the apertures formed between the central support parts 86 and the bottom of the associated channels 80. Thus, as the ring 102 is moved along the length of the recoverable article, the central support parts 86 are triggered so as to be pulled out of the channels, allowing the article to recover. The side strips 88 may be removed separately, or may be left in place provided they do not interfere with the recovery of the article and the subsequent reduction in the transverse dimension of the channels 80.

Figure 9 shows a modification of the article of Figure 8, in that the central support part 90 is of general hollow rectangular shape with external corners radiussed, and side strips 92 are wedge-shaped to conform to the correspondingly-shaped side walls of the channel of the castellated inner member, and to enhance retention of the holdout part 90 therein.

The trigger ring 100 of Figure 10 will be arranged to engage beneath the central part 90, and the radiussing of its inner corners will assist in its ejection.

In a further embodiment, the reduction in friction achieved by employing side pieces of a holdout, such as the side strips 88 or 92, may alternatively be achieved by spray coating the sides of the channels of the inner member or the holdout part 84,90 with a low friction material, or by applying a grease thereto. In the last mentioned embodiments of the invention, a retaining sheath, for example the sheath 76 of Figure 7, may be needed to retain the holdout strips in position until their release is required. In such instances, the ring 100 of Figure 10 may not be required.

Figures 12 and 13 show another embodiment of recoverable article, in which an inner resilient member 120 has a longitudinally castellated outer surface, each of the twelve channels of the castellation being filled with a holdout strip 122. Each strip 122 consists of a generally hollow rectangular outer portion 124, that has a collapsible or weakened inner wall 126, which is held out by an internal rigid tube 128 along its length. As the twelve tubes 128 are simultaneously withdrawn longitudinally, radial recovery of the expanded article 120 tends to result in a reduction in its circumference so that lateral forces are exerted on the side walls of the holdout portions 124. These forces cause the weakened inner walls 126 to fold inwardly, and the portions 124 are ejected from the castellation channels thus allowing the member 120 to recover towards in unexpanded diameter, being restricted from achieving full recovery by conforming engagement with the substrate (not shown).

Figure 14 shows an article 140, which may be in accordance with any one of the preceding embodiments, in its recovered condition on an in-line electric power cable splice. The article 140 consists of a castellated electrically conductive resilient member 142 and an innermost layer 144 of polymeric electrically insulating material. Each cable has an outer polymeric jacket 146, folded back earth screen wires 148, and primary dielectric 150. Prior to the recovery of the article 140, the region around the connector of the cable conductors (not shown) has been enclosed within a layer 152 of stress controlling material, that has been compressed into conformity with the underlying components by the recovery of the article 140, thereby excluding air from the splice region. Although not shown, it will be understood that an outer protective jacket is to be applied to the splice as shown in Figure 14 so as to encompass the article 140 and to seal on to each cable jacket 146. Electrical continuity across the joint, via the conductive layer 142, between the cable wires 148 will also be made. Advantageously, the outer protection jacket is as disclosed in British Patent Application No.9626364.5, the entire contents of which are included herein by this reference.

Claims

1. A recoverable article comprising an inner resilient tubular member that is held out in a laterally expanded configuration by engagement with outer holdout means, wherein the outer surface of the inner member is provided with a plurality of cavities, wherein the holdout means occupies the cavities so as to provide the holdout engagement, and wherein means is arranged to release the inner member from the holdout means substantially simultaneously around the periphery thereof progressively along its length, thereby to allow recovery of the tubular member towards its unexpanded configuration.

2. An article according to claim 1, wherein the holdout means comprises a plurality of discrete portions for engaging respective ones of the cavities, and the release means interlinks all the discrete portions.

3. An article according to claim 1 or claim 2, wherein the cavities comprise a plurality of channels that extend longitudinally of the article, preferably parallel to one another.

4. An article according to claim 3, wherein the channels extend substantially parallel to the longitudinal axis of the inner tubular member.

5. An article according to claim 3, wherein the channels extend substantially helically along and around the longitudinal axis of the inner tubular member.

6. An article according to any one of claims 2 to 4, wherein the holdout means comprises a plurality of strips that engage respective ones of the cavities.

7. An article according to claim 6, wherein the strips substantially fill the cavities substantially at each point along their lengths.

8. An article according to claim 6 or claim 7, wherein each strip comprises one portion that is removable from the cavity and a further portion or portions that assist in the removal of said one portion.

9. An article according to claim 6, wherein each strip comprises a plurality of longitudinally spaced-apart holdout members that substantially fill a cavity at discrete positions along its length, successive holdout members of each strip being linked together.

10. An article according to any one of the preceding claims, wherein the holdout means is sufficiently rigid so as to be retained in the cavities by initial relaxation of the inner tubular member.

11. An article according to any one of the preceding claims, wherein the release means is arranged so as mechanically to release the inner member from the holdout means.

12. An article according to any one of the preceding claims, wherein the release means is integral with the holdout means.

13. An article according to any one of the preceding claims, wherein the release means comprises an annular member that engages the holdout means and which can be pulled longitudinally over the outer surface of the tubular member from one end to the other to effect said release.

14. An article according to any one of the preceding claims, wherein the holdout means, at least at one end forms an aperture with the inner tubular member, and wherein the release means is arranged to engage the aperture for effecting the release of the inner member.

15. An article according to claim 14, wherein the release means comprises an annular ring of diameter greater than the outer diameter on the holdout means so as to be able to pass thereover, and has a plurality of longitudinally-directed projections for engaging with respective ones of the apertures.

16. An article according to any one of the preceding claims, wherein the holdout means comprises at least two components engaging with each cavity, removal of one of the components being arranged to facilitate the removal of the other(s).

17. An article according to any one of the preceding claims, wherein the inner member comprises a tubular member with an outer surface comprising longitudinally-extending ribs that define the holdout cavities therebetween.

18. An article according to claim 17, wherein the ribs are integral with the inner member.

19. An article according to claim 17 or claim 18, wherein at least two, and preferably all, of the ribs of the resilient inner member are reinforced with a relatively rigid material.

20. An article according to claim 19, wherein the reinforcing material is located internally of the ribs.

21. An article according to any one of the preceding claims, wherein the holdout means comprises: (a) a particulate material; or (b) a cured material; or (c) high density foam material; or (d) compacted fibrous material; said material being retained in place by an enveloping cover, if required.

22. An article according to any one of the preceding claims, wherein the holdout means comprises form-stable, preferably bio-degradable, material.

23. An article according to claim 22, wherein the holdout material is polymeric.

24. An article according to any one of the preceding claims, wherein the inner tubular member is electrically conductive.

25. An article according to any one of the preceding claims, wherein the inner tubular member is made from polymeric, preferably elastomeric, material.

26. An article according to any one of the preceding claims, comprising an additional, radially inner, resilient tubular arrangement on which the inner tubular member is mounted, preferably integrally therewith.

27. An article according to claim 26, wherein the additional tubular arrangement comprises at least one tubular member that is more resilient than the inner resilient tubular member.

28. An article according to claim 26 or claim 27, wherein the additional tubular arrangement comprises an electrically insulating tubular member and/or an electrically stress-controlling tubular member.

29. An article according to any one of claims 26 to 28, wherein the additional tubular arrangement is made from polymeric material.

30. An article according to any one of claims 26 to 29, comprising an innermost electrically conductive layer radially inwards of the additional tubular arrangement, and preferably located only in a longitudinally central region of the article so as to provide a Faraday cage.

31. An article according to any one of the preceding claims, of substantially right-cylindrical configuration.

32. An article according to any one of the preceding claims, wherein the inner member is of castellated configuration.

33. A recoverable tubular article comprising:

(a) an inner resilient cylindrical tubular member of electrically-conductive polymeric material having an outer surface that comprises a plurality of longitudinally-extending ribs that define channels therebetween, the ribs extending substantially parallel to the axis of the member;

(b) an additional, radially inner, tubular member of electrically-insulating polymeric material bonded to the inner conductive member; (c) a relatively rigid outer holdout means that comprises a plurality of strips that extend along respective ones of the channels of the inner member thereby to hold out the inner member in a radially-expanded configuration;

(d) release means comprising an annular member that is integral with the plurality of holdout strips at one end of the article, and which is arranged to be pulled over the outer surface of the inner tubular member so as to release the inner member from the holdout means substantially simultaneously around the periphery thereof progressively along its length, thereby to allow recovery of the inner tubular member to, or towards, its unexpanded configuration.

34. A recoverable article substantially as hereinbefore described with reference to the accompanying drawings.

35. An electrical component, including an electric cable splice, termination or elbow, enclosed by a recovered article in accordance with any one of the preceding claims.