GB2283580A

GB2283580A - Multi-wire flexible power line with integrated optical waveguides

Info

Publication number: GB2283580A
Application number: GB9421895A
Authority: GB
Inventors: Peter Funken; Karl-Hans Heinen
Original assignee: Felten and Guilleaume Energietechnik AG
Current assignee: Felten and Guilleaume Energietechnik AG
Priority date: 1993-10-30
Filing date: 1994-10-31
Publication date: 1995-05-10
Anticipated expiration: 2014-10-31
Also published as: DE4337180A1; GB2283580B; GB9421895D0

Description

MULTI-WIRE FLEXIBLE POWER LINE WITH INTEGRATED OPTICAL WAVEGUIDES 2283580

The invention relates to a multi-wire flexible power line with integrated optical waveguides.

A multi-wire flexible power line, more particularly a trailing cable, with integrated optical waveguides is known from DE 38 10 714 Al, wherein the optical waveguides are arranged as an optical waveguide wire in an outer filling portion of the energy wires. For the purpose of protecting the optical waveguides, a heat-insulating coating is arranged over the plastics shell surrounding the said waveguides, the said coating comprising a plurality of layers of textile tape and/or fibrous webs made of a material which is heat-resistant up to at least 200 C and has low thermal conductivity, and the energy wire filling portion holding the optical waveguide wire is filled to over 50% of its volume with fillers made of jute threads or a similar material, for the purposes of mechanical protection, more particularly protection of the optical waveguide wire against compression.

An energy cable with integrated optical waveguides is also known from DE 40 27 538 Al, wherein an optical waveguide line in the filling portion region of the wires is provided with a metal cover as a means to prevent diffusion of moisture.

A power line is described in DE 32 24 597 Al, wherein optical wires are stranded into the wire filling portions.

Tension-proof members incorporated in strands with a long twist length are intended to ensure a high tensile strength of the line. The specification does not mention protection against compression of the optical wires.

2 When producing a multi-wire flexible power line of this type, in which an optical waveguide wire is arranged in one of the energy wire filling portions, there is the risk that the high pressures and temperatures arising when cross-linking the inner and outer shells, and possible tensile loads, will damage the optical waveguide wire. Cross-linking pressures of up to 25 bar are produced which, when an optical wire is formed in accordance with DE 3224597, will certainly lead to deformations and thus to damage of the optical waveguides inside the optical waveguide wire. A possible measure for reducing the cross-linking pressure would be a reduction of the cross-linking speed, which would, however, entail longer production times and hence higher manufacturing costs.

The power lines and hence the optical waveguide wires integrated in each case are also subjected to high mechanical loads during use, particularly when connecting large movable apparatus.

The object of the invention is therefore to increase the resistance to temperature and compression of an optical waveguide wire arranged in an energy wire filling portion of a multi-wire flexible power line.

According to the present invention, there is provided a multi-wire flexible power line with integrated optical waveguides which are arranged as an optical waveguide wire in one of the outer filling portions of the energy wires, the optical waveguide wire having a plastics shell arranged around the twisted or loosely bunched optical waveguides, and a heatinsulating coating, and the energy wire filling-portion chamber housing the optical waveguide wire is filled with a filler of jute threads of a similar material as protection against compression, characterised in that the optical waveguide wire is provided with a coating A 4 3 which is stable under compression and comprises steel or plastics wires.

Other, preferred, features of the invention will be apparent from the following description and the accompanying claims.

The optical waveguide wire is provided with a coating which is dimensionally stable and, more particularly, stable with regard to pressure. Braidings with a relatively short length of twist, wires applied in a coil formation Csupporting spirals") or individual annular members can be used as coatings which are stable under pressure. Wires or rings made of steel or plastics are provided as materials for the stable coating, so that deformations or damage to the optical waveguide wire, as a result of the cross-linking pressure arising when producing the power line, are avoided. Moreover, this measure acts as a mechanical protection for the optical waveguide wire against compression and crushing loads when the power line is in use.

The invention will now be described in detail with reference to the accompanying drawing, in which Figure 1 is a cross-sectional view of a power line in accordance with the present invention.

The power line has three energy wires 1, two partial protective conductor wires 2, an optical waveguide wire 3, fillers 4 made of jute threads inside the energy wire filling portion housing the optical waveguide wire 3, an inner shell 5 surrounding the twisted structure and an outer shell 6. The optical waveguide wire 3 comprises a number of optical waveguides 7 loosely bunched and coated with plastics, a plastics shell 8 surrounding the waveguides 7 and made of polyester (PBT) with an outer diameter of 3 mm, a heat-insulating coating 9 surrounding the shell 8 and made of a textile tape or spun filament yarn, and braiding 10 arranged over the said coating and made of galvanised round 4 steel wires of the dimensions (2 x 8 x 1) x 0. 31 mm., in accordance with DIN 2078, with high resistance to buckling, a nominal strength of 1770 N/mm 2 and a pitch of 45.

In a preferred embodiment, during production of the optical waveguide wire, fifteen aramide threads made of filament yarn with a linear density of 1210 dtex are applied, evenly distributed over the periphery and extending in the longitudinal direction, and in the following production step - which also has the advantage of securing the filament yarn threads - the metal braiding is applied. The plastics shell for the optical waveguide wire is thermally insulated from the metal wires by the layer of filament yarn, as the thermal conduction of aramide is low. The aramide threads provide good thermal protection for the duration of the thermal load during cross-linking.

Claims

Claims:

1. A multi-wire flexible power line with integrated optical waveguides which are arranged as an optical waveguide wire in one of the outer filling portions of the energy wires, the optical waveguide wire having a plastics shell arranged around the twisted or loosely bunched optical waveguides, and a heat-insui.ating coating, and the energy wire fillingportion chamber housing the optical waveguide wire is filled with a filler of jute threads of a similar material as protection against compression, characterised in that the optical waveguide wire is provided with a coating which is stable under compression and comprises steel or plastics wires.

2. A power line in accordance with claim 1, characterised in that the coating which is stable under compression, comprising braiding or a coil or annular members, is arranged on the heat-insulating coating.

3. A power line in accordance with claim 1 or 2, characterised in that the heat-insulating coating comprises a layer of substantially longitudinally extending filament yarn threads made of aramide.

4. A power line substantially as hereinbefore described with reference to Figure 1.