GB2196170A

GB2196170A - Electric or optic cable

Info

Publication number: GB2196170A
Application number: GB08719956A
Authority: GB
Inventors: William James Ian Johnston
Original assignee: General Electric Co PLC
Current assignee: General Electric Co PLC
Priority date: 1986-10-08
Filing date: 1987-08-24
Publication date: 1988-04-20
Also published as: GB8719956D0; GB8624171D0

Abstract

A cable, especially for a signal distribution system, comprises a pair of elongate strips 1,2 bonded together face to face with a plurality of filamentary conductors 3,4 extending along and sandwiched between them. Such a cable being of strip form can be located under a floor covering without forming a pronounced ridge, and one of the strips conveniently has a self adhesive outer surface 5 so that the cable can be readily attached to a surface. The conductors may be electrical or optical. One elongate strip may be made of hard plastics and the other of soft. The surface of one strip may be grooved to receive the conductors. <IMAGE>

Description

SPECIFICATION Signal distribution systems and cables therefor This invention relates to signal distribution systems and to cables for use therein.

It would be advantageous to provide a system for feeding electrical signals to various parts of a building, for example for the remote control of apparatus, or for the passage of information from equipment located in one area to a display or monitoring device in another area. In the case of new buildings the installation of cables for achieving this presents no great problem, but in existing buildings this can give rise to difficulties.

An object of the present invention is to provide a form of cable which simplifies the installation of such a system: According to the invention a cable comprises a pair of elongate strips bonded together face to face with a plurality of filametary conductors extending along and sanwiched between them.

Preferably one of the strips has a self-adhesive outer surface. Such a cable can be simply attached to a surface, for example to a wall or floor, and, being of strip form, can be located under a carpet without forming a pronounced and unsightly ridge.

The self-adhesive surface is preferably covered by a backing trip which can be peeled away immediately prior to the installation of the cable to permit the cable to be attached to a supporting surface.

The cable may contain two pairs of conductors, conveniently electrical conductors in the form of thin wires. In use, one pair may be arranged to carry signals in digital form, for example computer data, or control signals, and the other pair may be arranged to carry analogue e.g. voice signals, although both pairs may carry digital signals or analogue signals depending upon the required use.

The wires of each pair are preferably twisted together, and the two pairs spaced apart a distance sufficient to avoid any significant cross-talk between them, preferably at least 1cm. However the cable can incorporate more than two pairs of wires, and may alternatively or additionally incorporate one or more light conductors in the form of optical fibres for conveying light signals.

Preferably the strips enclosing the filamentary conductors are formed of flexible plastics materials, the strip which is designed to be outermost in use conveniently being of a relatively tough, hard plastic to protect the conductors from damage, the underlying strip being of a softer, and possibly a more resilient, plastic.

The tougher plastic strip may have grooves formed at appropriate positions in its inner surface in which the conductors are wholly or partially accommodated, the grooves serving to maintain the required spacing of the conductors.

Cables in accordance with the invention may be used, for example, to carry signals for controlling the operation of electrical appliances such as cookers or washing machines from a remote position, e.g. from control means located in another part of the building. Such control means may be in the form of a manual control panel or a suitably programmed microprocessor, and may, in some cases, be activated from outside the building, for example by a radio or telephone link. Other activities may similarly be controlled from a remote position. In addition, signals from appliances or other equipment may be fed through the cables to an indicator or display device.

One form of cable in accordance with the invention will now be described by way of example with reference to the accompanying schematic non-scale drawing.

The cable comprises two flat strips 1, 2 of flexible plastics materials bonded together in any convenient manner with two pairs of individually insulated wires 3, 4 sandwiched between them. The two pairs of wires 3, 4 are spaced apart, the wires of each pair being twisted together as shown. The outer face of one of the strips (e.g the strip 2 of the drawing) carries an adhesive coating 5 covered by a backing strip 6 which is arranged to be peeled away from the coating 5 to enable the strip assembly 1, 2 containing the wires 3, 4 to be attached to a supporting surface, such as a wall or floor. As the cable is of strip form it can readily be accommodated beneath a carpet.

Accordingly the cable is suitable for installation in an existing building for conveying electrical signals to different parts of the building.

Such a cable can, for example, be used to distribute both analogue, e.g. voice, and digital, e.g. computer data or control, signals, aroundsthe building, and is especially suitable for use in domestic premises, although it can also be used to advantage in other forms of building.

The twisting of the individual pairs of wires, and the separation of the pairs, limits the possibility of cross-talk of analogue to digital and vice versa.

However the cable may be used to carry only digital or only anologue signals, depending upon the use to which it is to be put.

Also, instead of circular-sectioned wires as shown, the cable may contain flattened conductors, for example conducting ribbons, to convey the electrical signals, and the word filamentary is intended to include conductors of this form.

Moreover in some cases the cable could incorporate more than two pairs of electrical conductors, and possibiy one or more optical fibres for carrying light signals.

The strip 1 is conveniently formed of a relatively tough hard plastic, this serving to protect the wires, and also any optical fibres that may be provided, from damage. The possibil ity of damage may be further reduced by providing grooves in the inner surface of the strip 1 for accommodating the wires and/or optical fibres. The grooves will also serve to hold the wires and/or fibres in position and thus maintain a required spacing between them.

Although a cable in accordance with the invention is particularly suitable for fixing to a floor or wall, it will be appreciated that where a duct is available the cable can be accommodated within the duct.

Claims

1. A signal distributing cable comprising a pair of elongate strips bonded together face to face with a plurality of filamentary conductors extending along and sandwiched between them.

2. A cable according to Claim 1 wherein one of the strips has a self-adhesive outer surface for securing the cable to a supporting surface.

3. A cable according to Claim 2 wherein the self-adhesive surface is covered by a backing strip which can be peeled away immediately prior to the installation of the cable to permit the cable to be attached to a supporting surface.

4. A cable according to any preceding Claim wherein at least one of said filamentary conductors is an electrical conductor.

5. A cable according to Claim 4 incorporating at least one pair of said electrical conductors in the form of thin wires twisted together.

6. A cable according to any preceding Claim wherein at least one of said filamentary conductors is an optical fibre.

7. A cable according to any precedin.g Claim wherein the strips enclosing the filamentary conductors are formed of flexible plastics material.

8. A cable according to Claim 7 wherein one of the strips has an adhesive surface for securing the cable to a supporting surface, wherein the other strip is formed of a relatively tough hard plastics material and the strip having the adhesive surface is of a relatively softer plastics material.

9. A cable according to Claim 8 wherein said other strip has grooves formed in its inner surface in which the filamentary conductors are wholly or partially accommodated.

10. A signal distributing cable substantially as shown in and as hereinbefore described with reference to the accompanying drawing.

11. A signal distribution system incorporating at least one cable according to any preceding Claim.

12. A signal distribution system according to Claim 11 installed in a building and incorporating a plurality of said cables for distributing both analogue and digital signals around the building.

13. A signal distribution system according to Claim 12 wherein at least one of said cables is arranged to carry control signals for controlling the operation of electrical equipment located within the building from control means located in another part of the building.

14. A signal distribution system according to Claim 13 wherein at least one of said cables is arranged to carry signals from said equipment to an indicator or display device.

15. A signal distribution system according to Claim 13 or 14 wherein the control means comprises a manual control panel or a microprocessor.

16. A signal distribution system according to Claim 15 wherein the control means comprises a microprocessor which is designed to be activated from outside the building through a telephone or radio link.