GB2160676A - Flexible overhead electric conductor containing optical fibre - Google Patents
Flexible overhead electric conductor containing optical fibre Download PDFInfo
- Publication number
- GB2160676A GB2160676A GB08514947A GB8514947A GB2160676A GB 2160676 A GB2160676 A GB 2160676A GB 08514947 A GB08514947 A GB 08514947A GB 8514947 A GB8514947 A GB 8514947A GB 2160676 A GB2160676 A GB 2160676A
- Authority
- GB
- United Kingdom
- Prior art keywords
- optical fibre
- electric conductor
- overhead electric
- elongate
- tube
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000013307 optical fiber Substances 0.000 title claims abstract description 53
- 239000004020 conductor Substances 0.000 title claims abstract description 41
- 229920002545 silicone oil Polymers 0.000 claims abstract description 20
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 19
- 239000008119 colloidal silica Substances 0.000 claims abstract description 19
- 239000004944 Liquid Silicone Rubber Substances 0.000 claims abstract description 16
- 230000003287 optical effect Effects 0.000 claims abstract description 16
- 229920002379 silicone rubber Polymers 0.000 claims abstract description 16
- 239000000463 material Substances 0.000 claims abstract description 10
- 239000000725 suspension Substances 0.000 claims abstract description 7
- 230000006866 deterioration Effects 0.000 claims abstract description 6
- 229910052751 metal Inorganic materials 0.000 claims description 12
- 239000002184 metal Substances 0.000 claims description 12
- 229910001092 metal group alloy Inorganic materials 0.000 claims description 12
- 230000005540 biological transmission Effects 0.000 claims description 5
- 239000004697 Polyetherimide Substances 0.000 claims description 2
- 229920001601 polyetherimide Polymers 0.000 claims description 2
- 239000007787 solid Substances 0.000 claims description 2
- 230000009974 thixotropic effect Effects 0.000 abstract description 2
- 239000004411 aluminium Substances 0.000 description 7
- 229910052782 aluminium Inorganic materials 0.000 description 7
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 7
- 229910045601 alloy Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- 238000010276 construction Methods 0.000 description 3
- 229920004738 ULTEM® Polymers 0.000 description 1
- 229920004695 VICTREX™ PEEK Polymers 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
- G02B6/4401—Optical cables
- G02B6/4415—Cables for special applications
- G02B6/4416—Heterogeneous cables
- G02B6/4422—Heterogeneous cables of the overhead type
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B5/00—Non-insulated conductors or conductive bodies characterised by their form
- H01B5/08—Several wires or the like stranded in the form of a rope
- H01B5/10—Several wires or the like stranded in the form of a rope stranded around a space, insulating material, or dissimilar conducting material
- H01B5/108—Several wires or the like stranded in the form of a rope stranded around a space, insulating material, or dissimilar conducting material stranded around communication or control conductors
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Communication Cables (AREA)
Abstract
A flexible overhead electric conductor incorporating a least one optical fibre and/or optical bundle has throughout its length at least one elongate compartment in which an optical fibre element is loosely housed. The optical fibre element comprises a tube of polymeric material capable of withstanding indefinitely exposure to a temperature lying in the range 170 DEG C to 190 DEG C without deterioration of its mechanical properties to an undesirable extent, a separate optical fibre and/or optical bundle loosely housed in the bore of the tube and, filling the space between the optical fibre and/or optical bundle and the internal surface of the tube throughout the length of the optical fibre element, a liquid silicone rubber comprising a suspension of colloidal silica in a silicone oil, the proportion of colloidal silica to silicone oil lying in the range 1:3 to 1:10 parts by weight. The addition of colloidal silica to the silicone oil imparts thixotropic properties to the liquid silicone rubber. <IMAGE>
Description
SPECIFICATION
An improved flexible overhead electric conductor
This invention relates to flexible overhead electric conductors of the kind which comprise one or more than one layer of helically wound bare elongate elements of electrically conductive metal or metal alloy and which are adapted to be freely supported from spaced supports in long lengths.
In the Complete Specification of our Patent
No: 1 598438 there is described and claimed a flexible overhead electric conductor or other flexible stranded body comprising at least one layer of helically wound bare elongate elements of metal or metal alloy, at least one elongate compartment within and extending throughout the length of the conductor and, loosely housed in the elongate compartment or at least one of the elongate compartments, at least one separate optical fibre and/or at least one optical bundle.
It is an object of the present invention to provide an improved flexible overhead electric conductor which includes at least one separate optical fibre and/or at least one optical bundle.
According to the invention, the improved flexible overhead electric conductor comprises at least one layer of helically wound bare elongate elements of metal or metal alloy, at least one elongate compartment within and extending throughout the length of the flexible conductor and, loosely housed in the elongate compartment or at least one of the elongate compartments, at least one optical fibre element, which optical fibre element comprises a tube of polymeric material capable of withstanding substantially indefinitely exposure to a temperature lying in the range 1 70 C to 1 90 C without deterioration of its mechanical properties to an undesirable extent, at least one separate optical fibre and /or at least one optical bundle loosely housed in the bore of the tube and, substantially filling the space between the optical fibre or fibres and/or the optical bundle or bundles and the internal surface of the tube throughout the length of the optical fibre element, a liquid silicone rubber comprising a suspension of colloidal silica in a silicone oil, the proportion of colloidal silica to silicone oil lying in the range 1:3 to 1:1Q parts by weight.
Preferably, the proportion of colloidal silica to silicone oil in the liquid silicone rubber is 1:3.5 parts by weight. Preferably, also, the preferred liquid silicone rubber is prepared by adding to 2 parts by weight of the liquid silicone rubber sold by Dow Corning under the trade name Liquid Silicone Rubber 9595A an additional 1 part by weight of silicone oil sold by Dow Corning under the trade name
Silicone Fluid 200/1000cs.
The addition of colloidal silica to the silicone oil imparts thixotropic properties to the liquid silicone rubber.
By virtue of the fact that the optical fibre element is housed loosely in the elongate compartment of the flexible conductor, limited relative movement between the optical fibre element and the flexible conductor can take place when the flexible conductor vibrates, oscillates or is otherwise flexed when it is being installed or is in service. The liquid silicone rubber substantially filling the space between the optical fibre or fibres and/or the optical bundle or bundles and the internal surface of the tube wall permits such limited relative movement and serves as a lubricant between the optical fibre or fibres and/or optical bundle or bundles, and between the tube wall and the optical fibre or fibres and /or optical bundle or bundles.
Especially suitable polymeric materials of which the tube of the optical fibre element may be made include polyetherimide sold under the trade name "Ultem" (RTM) and polyethersulphone sold under the trade name "Victrex (RTM) PES". Each of these polymeric materials has the advantage that it is capable of withstanding a temperature exceeding 220"C for a short period without softening to an undesirable extent.
In one preferred aspect of the invention, the elongate compartment in which the optical fibre element is housed loosely is within and extends throughout the length of a substantially circumferentially rigid central core and the or each layer of helically wound bare elongate elements of metal or metal alloy surrounds the central core. In one preferred embodiment of this aspect of the invention, the central core is a single extruded elongate member having a central bore which constitutes the elongate compartment.The single extruded elongate member initially may be of substantially U-shaped transverse cross-section, one or each of the limbs of the U being folded inwardly so that the gap between the free ends of the limbs is at least partially closed, the space between the limbs and the base of the U constituting the elongate compartment; alternatively, the central core may be formed from a tape of metal or metal alloy transversely folded to form a tube, the abutting longitudinally extending edges of the tape being welded or otherwise secured together.
Alternatively, the central core may be in the form of any one or more of the optional constructions described and illustrated in the
Complete Specification of our Patent No: 1598438.
In a further aspect of the present invention, the central core consists of two separately formed parts and comprises an inner solid elongate member of metal or metal alloy having i its outer surface at least one recess extending helically around the member and, surrounding the inner elongate member, a longitudinally applied, transversely folded tape of metal or metal alloy, which tape overlies the or each helically extending recess to form an elongate compartment. Preferably, the inner elongate member has in its outer surface three or four circumferentially spaced, helically extending recesses which, when surrounded by the transversely folded tape, constitute circumferentially spaced elongate compartments in at least one of which an optical fibre element is loosely housed.
In all cases, preferably the central core is of substantially circular transverse cross-section.
The improved flexible conductor of the present invention is especially suitable for use as an earth conductor of an overhead electric transmission line and, because it may be manufactured to have the same or approximately the same properties of sag and tension as those of conventional overhead conductors of substantially the same overall diameter, it provides the important advantage that the improved flexible conductor can be used to replace an earth conductor or other overhead electrical conductor of an existing overhead electric transmission system thereby to provide a communication means in the system.
Thus, the invention provides a relatively inexpensive communication link between stations, sub-stations and other locations along an electric transmission system.
Accordingly, the invention also includes an overhead electric transmission and distribution system which includes at least one improved overhead electric conductor incorporating an optical fibre element as hereinbefore described.
The invention further includes, for use in a flexible overhead electric conductor, an optical fibre element comprising a tube of a polymeric material capable of withstanding substantially indefinitely exposures to temperatures lying in the range 1 70 C to 1 90 C without deterioration of its mechanical properties to an undesirable extent, at least one separate optical fibre and/or at least one optical bundle loosely housed in the bore of the tube and, filling the space between the or each optical fibre and/or the or each optical bundle and the internal surface of the tube throughout the length of the optical fibre element, a liquid silicone rubber comprising a suspension of colloidal silica in a silicone oil, the proportions of colloidal silica to silicone oil lying in the range 1:3 to 1:10 parts by weight.
The invention is further illustrated by a description, by way of example, of three preferred forms of flexible overhead electric conductor incorporating an optical fibre element, with reference to the accompanying drawings, in which:
Figures 1 to 3 are transverse cross-sectional views of the three preferred forms of flexible overhead electric conductor.
The flexible overhead electrical conductor shown in Fig. 1 comprises a central core 1 constituted by a single extruded elongate aluminium member 2 of substantially U-shaped transverse cross-section, the gap between the free ends of the limbs of the U being closed to bound a space 4 constituting an elongate compartment. The central core 1 is surrounded by three layers 5 of helically wound round wires of aluminium-based alloy, the directions of lay of adjacent layers being of opposite hand. Loosely housed in the elongate compartment 4 is an optical fibre element 6.
The optical fibre element 6 comprises a tube 7 of polymeric material capable of withstanding substantially indefinitely exposure to a temperature lying in the range 1 70on to 1 90 C without deterioration of its mechanical properties to an undesirable extent, an optical fibre 8 loosely housed in the bore of the tube and, substantially filling the space between the optical fibre and the internal surface of the tube throughout the length of the optical fibre element, a liquid silicone rubber comprising a suspension of colloidal silica in a silicone oil, the proportion of colloidal silica to silicone oil being 1:3.5 parts by weight.
The flexible overhead electrical conductor shown in Fig. 2 comprises a central core 11 constituted by a transversely folded strip 1 2 of aluminium-based alloy, the abutting longitudinally extending edges of the strip being welded together to form a tube. The bore of the tube constitutes an elongate compartment 14. The central core 11 is surrounded by three layers 1 5 of helically wound round wires of aluminium-based alloy, the directions of lay of adjacent layers being of opposite hand.
Loosely housed in the elongate compartment 14 is an optical fibre element 1 6 which is of identical construction to the optical fibre element 6 of the overhead conductor shown in
Fig. 1 and which comprises a tube 1 7 of polymeric material capable of withstanding substantially indefinitely exposure to a temperature lying in the range 1 70 C to 1 90on without deterioration of its mechanical properties to an undesirable extent, an optical fibre 1 8 loosely housed in the bore of the tube and, substantially filling the space between the optical fibre and the internal surface of the tube throughout the length of the optical fibre element, a liquid silicone rubber 1 9 comprising a suspension of colloidal silica in a silicone oil, the proportion of colloidal silica to silicone oil being 1:3.5 parts by weight.
The flexible overhead electric conductor shown in Fig. 3 has a central core 21 consisting of two separately formed parts comprising an inner extruded elongate member 23 of aluminium having in its outer surface four circumferentially spaced, helically extending recesses 24 and, surrounding the inner elongate member, a longitudinally applied transversely folded tape 22 of aluminium, which tape overlies the helically extending recesses to form circumferentially spaced elongate compartments. Loosely housed in each of the elongate compartments 24 is an optical fibre element 26 which is of the same construction as the optical fibre elements 6 and 1 6 of the overhead conductors shown in Figs.
1 and 2. The central core 21 is surrounded by three layers 25 of helically wound round wires of aluminium-based alloy, the directions of lay of adjacent layers being of opposite hand.
Claims (14)
1. A flexible overhead electric conductor comprising at least one layer of helically wound bare elongate elements of metal or metal alloy, at least one elongate compartment within and extending throughout the length of the flexible conductor and, loosely housed in the elongate compartment or at least one of the elongate compartments, at least one optical fibre element, which optical fibre element comprises a tube of polymeric material capable of withstanding substantially indefinitely exposure to a temperature lying in the range 1 70 C to 1 90 C without deterioration of its mechanical properties to an undesirable extent, at least one separate optical fibre and/or at least one optical bundle loosely housed in the bore of the tube and, substantially filling the space between the optical fibre or fibres and/or the optical bundle or bundles and the internal surface of the tube throughout the length of the optical fibre element, a liquid silicone rubber comprising a suspension of colloidal silica in a silicone oil, the proportion of colloidal silica to silicone oil lying in the range 1:3 to 1:10 parts by weight.
2. A flexible overhead electrical conductor as claimed in Claim 1, wherein the proportion of colloidal silica to silicone oil in the liquid silicone rubber is 1:3.5 parts by weight.
3. A flexible overhead electric conductor as claimed in Claim 1 or 2, wherein the polymeric material of the tube of the optical fibre element is made of polyether imide or polyethersulphone.
4. A flexible overhead electric conductor as claimed in any one of the preceding
Claims, wherein the elongate compartment in which the optical fibre element is housed loosely is within and extends throughout the length of a substantially circumferentially rigid central core and the or each layer of helically wound bare elongate elements of metal or metal alloy surrounds the central core.
5. A flexible overhead electric conductor as claimed in Claim 4, wherein the central core is a single extruded elongate member having a central bore which constitutes the elongate compartment.
6. A flexible overhead electric conductor as claimed in Claim 5, wherein the single extruded elongate member initially is of substantially U-shaped transverse cross-section, one or each of the limbs of the U being folded inwardly so that the gap between the free ends of the limbs is at least partially closed, the space between the limbs and the base of the U constituting the elongate compartment.
7. A flexible overhead electric conductor as claimed in Claim 4, wherein the central core is formed from a tape of metal or metal alloy transversely folded to form a tube, the abutting longitudinally extending edges of the tape being welded or otherwise secured together.
8. A flexible overhead electric conductor as claimed in Claim 4, wherein the central core consists of two separately formed parts and comprises an inner solid elongate member of metal or metal alloy having in its outer surface at least one recess extending helically around the member and, surrounding the inner elongate member, a longitudinally applied, transversely folded tape of metal or metal alloy, which tape overlies the or each helically extending recess to form an elongate compartment.
9. A flexible overhead electric conductor as claimed in Claim 8, wherein the inner elongate member has in its outer surface three or four circumferentially spaced, helically extending recesses which, when surrounded by the transversely folded tape, constitute circumferentially spaced elongate compartments in at least one of which an optical fibre element is loosely housed.
1 0. A flexible overhead electrical conductor as claimed in any one of Claims 4 to 9, wherein the central core is of substantially circular transverse cross-section.
11. A flexible overhead electric conductor substantially as hereinbefore described with reference to and as shown in Fig. 1, 2 or 3 of the accompanying drawing.
12. An overhead electric transmission and distribution system which includes at least one flexible overhead electric conductor as claimed in any one of the preceding Claims.
1 3. For use in a flexible overhead electric conductor, an optical fibre element comprising a tube of a polymeric material capable of withstanding substantially indefinitely exposures to temperatures lying in the range 1 70 C to 1 90 C without deterioraton of its mechanical properties to an undesirable extent, at least one separate optical fibre and/or at least one optical bundle loosely housed in the bore of the tube and, filling the space between the or each optical fibre and/or the or each optical bundle and the internal surface of the tube throughout the length of the optical fibre element, a liquid silicone rubber comprising a suspension of colloidal silica in a silicone oil, the proportion of colloidal silica to silicone oil lying in the range 1:3 to 1:10 parts by weight.
14. An optical fibre element as claimed in
Claim 13, wherein the proportion of colloidal silica to silicone oil in the liquid silicone rubber is 1:3.5 parts by weight.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB848415168A GB8415168D0 (en) | 1984-06-14 | 1984-06-14 | Flexible elongate body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8514947D0 GB8514947D0 (en) | 1985-07-17 |
| GB2160676A true GB2160676A (en) | 1985-12-24 |
Family
ID=10562419
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB848415168A Pending GB8415168D0 (en) | 1984-06-14 | 1984-06-14 | Flexible elongate body |
| GB08514947A Withdrawn GB2160676A (en) | 1984-06-14 | 1985-06-13 | Flexible overhead electric conductor containing optical fibre |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB848415168A Pending GB8415168D0 (en) | 1984-06-14 | 1984-06-14 | Flexible elongate body |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1267008A (en) |
| GB (2) | GB8415168D0 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0458607A1 (en) * | 1990-05-22 | 1991-11-27 | BICC Public Limited Company | Overhead electric & optical transmission systems |
| GB2307565A (en) * | 1995-11-27 | 1997-05-28 | Samsung Electronics Co Ltd | Optical fibre composite overhead ground cable |
| EP1054276A1 (en) * | 1999-05-20 | 2000-11-22 | Lucent Technologies Inc. | Article comprising a fiber bundle, and method of making the article |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2046471A (en) * | 1979-03-22 | 1980-11-12 | Telephone Cables Ltd | Tube containing optic fibre(s) and thixotropic fluid |
| GB2064163A (en) * | 1979-11-28 | 1981-06-10 | Ass Elect Ind | Electro-Optical Cable |
-
1984
- 1984-06-14 GB GB848415168A patent/GB8415168D0/en active Pending
-
1985
- 1985-06-13 GB GB08514947A patent/GB2160676A/en not_active Withdrawn
- 1985-06-13 CA CA000483847A patent/CA1267008A/en not_active Expired
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2046471A (en) * | 1979-03-22 | 1980-11-12 | Telephone Cables Ltd | Tube containing optic fibre(s) and thixotropic fluid |
| GB2064163A (en) * | 1979-11-28 | 1981-06-10 | Ass Elect Ind | Electro-Optical Cable |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0458607A1 (en) * | 1990-05-22 | 1991-11-27 | BICC Public Limited Company | Overhead electric & optical transmission systems |
| GB2307565A (en) * | 1995-11-27 | 1997-05-28 | Samsung Electronics Co Ltd | Optical fibre composite overhead ground cable |
| FR2741724A1 (en) * | 1995-11-27 | 1997-05-30 | Samsung Electronics Co Ltd | COMPOSITE AERIAL WIRE STRUCTURE OF OPTICAL FIBERS USING A LOOSE TUBE, AND METHOD FOR MANUFACTURING THE SAME |
| GB2307565B (en) * | 1995-11-27 | 1998-01-21 | Samsung Electronics Co Ltd | Optical fibre composite overhead ground cable |
| EP1054276A1 (en) * | 1999-05-20 | 2000-11-22 | Lucent Technologies Inc. | Article comprising a fiber bundle, and method of making the article |
| US6397636B1 (en) | 1999-05-20 | 2002-06-04 | Lucent Technologies Inc. | Method of applying a precursor to an assembled fiber bundle and fusing the bundle together |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8415168D0 (en) | 1984-07-18 |
| GB8514947D0 (en) | 1985-07-17 |
| CA1267008A (en) | 1990-03-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |