GB2204409A

GB2204409A - Cable identification device

Info

Publication number: GB2204409A
Application number: GB08708912A
Authority: GB
Inventors: Richard Weatherley
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-04-14
Filing date: 1987-04-14
Publication date: 1988-11-09
Anticipated expiration: 2007-04-14
Also published as: GB8708912D0; GB2204409B

Abstract

A cable identification system or use in identifying a particular cable amongst a bundle of visually identical cables comprises a transmitter (7) to which one end of the cable is connected to receive a square wave signal from the transmitter, and a cable identification device (1) sensitive to the test signal. The cable identification device (1) emits an audio signal when a probe (2) associated with the device (1) is in the general vicinity of the radiating cable, the amplitude of which increases as the probe is moved nearer to the cable. A second, visual, signal provided by a dot bar indicator (5) operates when the probe (2) is relatively close to the cable and assumes a unique configuration (e.g. all dots lit) when the probe (2) is in immediate juxtaposition to the cable. Preferably, the system includes a hand set (9) which can be connected to the identified cable to establish a voice link between the user of the cable identification device and the position of the transmitter (7). <IMAGE>

Description

CABLE IDENTIFICATION DEVICE This invention relates to a cable identification device, and in the preferred embodiment provides a device capable of uniquely identifying a cable of interest amongst a bundle of individual cables.

During the installation, modification, and repair of electric cable systems it is frequently necessary to identify a particular cable at two spaced apart points along a length of the cable. The two points may be the opposite ends of the cable, or any other two points along the length of the cable.

In order to locate a particular cable of interest amongst a bundle of visually identical cables it is known to apply a signal to one of the cables, and to identify the cable carrying the signal by means of a suitable device sensitive to the signal. Existing systems of this type do, however, suffer from the disadavantage that they are not capable of uniquely identifying the cable of interest amongst a bundle of visually identical cables without piercing the insullation of at least one of the cables to obtain direct electrical contact with the conducting core of the cable. This is clearly unsatisfactory.

According to one aspect of the present invention a cable identification device comprises a receiver sensitive to a test signal radiated by a cable, and operative to produce a first signal which indicates that a probe associated with the receiver is in the general vicinity of the cable, and a second signal, separate from the first signal, which varies with the distance that the probe is from the cable and achieves a recognizable form indicating that the probe is in immediate juxtapostion to the cable.

With the preferred embodiment of the invention the first signal is produced when the probe is a significant distance from the cable (perhaps as much as 1500 mm) and increases in intensity as the probe is moved nearer the cable of interest. In this way, the identification device can be readily scanned across a large mass of cable in order to locate in general terms the position of the cable of interest. In the preferred embodiment of the invention the first signal is an audio signal the amplitude of which increases as the probe is moved nearer to the cable radiating the test signal.

The second signal is of a nature which is separate and distinct from the first signal, and is of a character which varies with the distance that the probe is from the cable. The second signal achieves a form which is recognizable as indicating when the probe is in immediate juxtaposition to the cable - i.e.

touching or very nearly touching the cable. The second signal is preferably a visual signal, and in the preferred embodiment comprises a LED dot bar indicator of which progressively more dots light up as the probe moves progressively nearer the radiating cable, and of which all the dots light up only when the probe is in immediate juxtaposition to the cable. In the alternative the second signal may comprise a dot bar indicator of which a lit dot moves, e.g. from left to right, as the probe moves progressively nearer the radiating cable, the lit dot acheiving its extreme (right) position only when the probe is in immediate juxtaposition to the cable.

In use, therefore, the probe is moved across the mass of cables which includes the cable radiating the test signal until the first, audio, signal is heard. The probe is then moved to maximise the amplitude of the audio signal, and the operator watches the dot bar indicator until some of the dots are seen to light up or a single dot moves to the right. The operator then moves the probe to light progressively more of the dots, or further dots to the right, and when touching the outside of the cable radiating the test signal will see all the dots lit, or the far right dot lit. The cable radiating the test signal is accordingly uniquely identified without piercing the insullation of the cable.

The preferred embodiment of cable identification device is preferably part of a cable identification system comprising the cable identification device, a transmitter, and a telephone type hand-set.

The transmitter generates the test signal and the cable to be identified is connected to the output of the transmitter. When the cable had been identified by use of the cable identification device the remote hand-set may be connected to the identified cable and to a suitable return wire leading to the transmitter, and this action of connecting the remote hand-set to the identified cable and the return line triggers a transmitter to discontinue emitting the test signal and to connect the identified cable and the return line to a hand-set connected to the transmitter thereby establishing a voice link between the remote end of the identified cable and the transmitter.

The invention will be better understood from the following description of å preferred embodiment thereof, given by way of example only, reference being had to the accompanying drawing wherein the single figure schematically illustrates a preferred embodiment of the invention.

Referring to the drawing there is illustrated a cable identification device 1 comprising a probe 2 and a hand-held battery powered receiver 3. The probe 2 forms and aerial capable of receiving a radiated test signal emitted from a cable 4. When the probe 2 is brought within the general vicinity of the cable 4 an audio tone is produced by the receiver, the intensity of which increases as the probe is moved nearer to the radiating cable. Preferably, the audio tone is first produced when the probe is approximately 1500 mm from the cable. As the probe 2 is moved closer to the cable the dots of a LED dot bar indicator 5 are progressively lit until, when the probe 2 is touching the insullation of the cable, all the dots are lit, or the far right segment lit.The system is arranged such that all the dots are lit, or the far right segment is lit, only when the probe 2 is resting or very nearly resting against the insullation of the radiating cable, and accordingly the visual signal provided by the dot bar indicator uniquely identifies the radiating cable even though that cable may be part of a bundle of closely packed visually identical cables.

The test signal is preferably a square-wave signal 6 produced by a transmitter 7 to which one end of the cable 4 is connected. A square-wave is preferred since it produces a better response in the receiving circuit of the receiver 3, and in turn generates a audio tone which is particularly adapted to the purpose of the invention. The transmitter 7 preferably has connected to it a hand-set 8 which, in association with a remote handset 9 can be used to establish a voice link between the transmitter and the remote point of cable detection.

For this purpose, a return conductor connected between the transmitter and the remote hand-set 9 is required.

The return conductor may be in the form of a cable provided for that purpose, or may be constituted by a previously identified cable of the cable bundle which contains the cable 4. In use, an operator working at the remote end of the cable 4 uses the device 1 to lcoate that cable 4 which is connected to the output of the transmitter 7. He then connects the remote hand-set 9 between the identified cable and the return conductor.

This action triggers the transmitter to interrupt emission of the test signal, and to establish a voice link between the local hand-set 8 and the remote hand-set 9. This serves both to provide absolute confirmation that the correct cable 4 has been located and provides a means of communication between a person operating the transmitter, and the person identifying the cables at a point remote from the transmitter. It will be appreciated, however, that the use of the remote hand-set is not essential to the invention.

Whilst in the preferred embodiment of the invention the first signal is in the form of an audio signal and the second signal is in the form of a light signal provided by the dot bar indicator, other arrangements are possible provided that the second signal attains a recognizable form only when the probe is in immediate juxtaposition to the cable. The recognizable form could, for example, be constituted by full scale deflection of a meter needle, or by any other suitable means.

Claims

1. A cable identification device comprising a receiver sensitive to a test signal radiated by a cable, and operative to produce a first signal which indicates that a probe associated with the receiver is in the general vicinity of the cable, and a second signal, separate from the first signal, which varies with the distance that the probe is from the cable and achieves a recognizable form indicating that the probe is in immediate juxtaposition to the cable.

2. A cable identification device according to claim 1 wherein the first signal is a audio signal the intensity of which increases as the probe is moved nearer to the radiating cable.

3. A cable identification device according to claim 1 or claim 2 wherein the second signal is a visual signal.

4. A cable identification device according to claim 3 wherein the visual signal is provided by a set of dot indicators progressively more of which are energized as the probe is moved nearer to the radiating cable, and all of which are energized when the probe is in immediate juxtaposition to the cable in order to provide said recognizable form of signal.

5. A cable identification device according to claim 3 wherein said second signal is provided by a set of dot indicators only one of which is energized at any one time, the position of the energized dot being indicative of the position of the probe relative to the cable, and the energization of a particular dot being indicative that the probe is in immediate juxtaposition to the radiating cable, in order to provide said recognizable form of signal.

6. A cable identification device according to claim 4 or claim 5 wherein the set of dot indicators is an LED bar indicator.

7. A cable identification system comprising the cable identification device of any preceding claim and a transmitter for generating said test signal, wherein said test signal is a square-wave signal.

8. A cable identification system according to claim 7 including a telephone hand set associated with the transmitter and a telephone hand set associated with the cable identification device whereby after a particular cable has been identified using the cable identification device a voice link may be established between the transmitter and the cable identification device using the hand sets.

9. A cable identification system according to claim 8 wherein connection of the hand set to the identified cable at the position of the cable identification device automatically interrupts generation of the test signal and establishes said voice link.

10. A cable identification device substantially as hereinbefore described with reference to the accompanying drawing.

11. A cable identification system substantially as hereinbefore described with reference to the accompanying drawing.