EP0540796A1 - Conductive cable with high rate of filling - Google Patents

Abstract

Conductive cable with a high amount of filling and having a low volume variation as a function of the external hydrostatic pressure, intended for transmitting electrical power and video and/or remote-control signals, characterised in that it has a coaxial structure and in that it includes a core (10) providing the transmission of the video and/or remote-control signals, at least two coaxial conductive layers (14,20) each constituted by a plurality of small-diameter electrical conductors wrapped as plies and insulated from each other by an insulating covering (24) and a sheath (18) made from synthetic or natural fibres providing the tensile strength. <IMAGE>

Description

The present invention relates to a cable intended for transmitting both electrical power and video and / or remote control signals. This cable is more particularly intended to supply electrical energy and the remote control of an underwater vehicle to a system as described in the patent application filed on the same day as this application by the same owner and entitled : "Improvements to filo-guided underwater vehicles."

• possibilité de fonctionnement en immersion complète dans de l'eau de mer une température comprise par exemple entre 0 et 20° C ;
• possibilité d'enroulement sur un tambour de diamètre relativement faible (de l'ordre de 100 mm) et de supporter des séquences répétées d'enroulement/déroulement à vitesse élevée (de l'ordre de 5 m/seconde) ;
• utilisation continue à puissance élevée de l'ordre de 20 kw;
• possibilité de fonctionnement en immersion profonde (plusieurs centaines de mètres) avec de faibles variations de volume.

In such an application, the cable must meet a certain number of requirements:

• possibility of operating under complete immersion in sea water, a temperature for example between 0 and 20 ° C;
• possibility of winding on a drum of relatively small diameter (of the order of 100 mm) and of supporting repeated sequences of winding / unwinding at high speed (of the order of 5 m / second);
• continuous use at high power of the order of 20 kw;
• possibility of operation in deep immersion (several hundred meters) with small variations in volume.

• d'une part une section minimale afin de réduire la valeur des effets de traînée ainsi qu'on l'a mentionné dans la demande de brevet citée ci-dessus et ;
• d'autre part une section suffisante assurant une bonne résistance mécanique et un bon transfert d'énergie entre la source et le véhicule avec lequel il est lié, et des signaux de télécommande.

Furthermore, given the fact that, in this application, such a cable must have great flexibility, it must necessarily be of small diameter, that is to say of the order of 5 mm. So this cable should have optimized characteristics to achieve the best compromise between:

• on the one hand a minimum section in order to reduce the value of the drag effects as mentioned in the patent application cited above and;
• on the other hand a sufficient section ensuring good mechanical resistance and good energy transfer between the source and the vehicle with which it is linked, and remote control signals.

The present invention proposes to provide a cable meeting the requirements specified above.

To this end, the invention relates to a conductive cable with a high filling rate and having a small variation in volume as a function of the hydrostatic external pressure intended for the transmission of electrical energy and of video and / or remote control signals, characterized in that that it has a coaxial structure and in that it comprises a core ensuring the transmission of video and / or remote control signals and at least two coaxial conductive layers each consisting of a plurality of small diameter electrical conductors coated in the form of '' a covering and isolated from each other by an insulating sheath, preferably made of polytetrafluoroethylene (Teflon), the tensile strength being obtained by a sheath made of synthetic or natural fibers.

According to the invention, the transmission of the video and / or remote control signals can be carried out either using a mini coaxial cable or via one or more optical fibers of the multimode, single mode or other type.

Other characteristics and advantages of this invention will emerge from the description given below with reference to the appended drawing, the single figure of which is a view in axial section illustrating a non-limiting exemplary embodiment of the cable which is the subject of the invention more particularly intended for the application mentioned above.

• une âme centrale 10, destinée à assurer la transmission des signaux vidéo et/ou de télécommande et constituée par un mini câble coaxial ou par une ou plusieurs fibres optiques du type multimode, monomode ou autre. Cette âme centrale 10 est munie d'une gaine protectrice 12 ;
• une gaine 18 assurant la tenue en traction. Cette gaine 18 peut être réalisée à l'aide d'un faisceau de mèches de fibres synthétiques assemblées en long, par exemple des fibres aramides ;
• une première couche conductrice 14 constituée par un nappage ou guipage d'une pluralité de fils conducteurs de faible section, par exemple en cuivre, protégé par un enroulement d'un ruban 16 par exemple en polytétrafluoréthylène (Téflon) ;
• une seconde couche conductrice 20 constituée comme la première couche 14 par un guipage d'une pluralité de fils conducteurs de faible diamètre, protégé par un ruban de "Téflon" 22, cette seconde couche conductrice étant isolée de la première par une gaine 24 de préférence en "Téflon" et ;
• une gaine extérieure 26 destinée à assurer l'étanchéité transversale.

As can be seen in the drawing, the cable according to the invention has a coaxial structure and it essentially comprises:

• a central core 10, intended to ensure the transmission of video and / or remote control signals and constituted by a mini coaxial cable or by one or more optical fibers of the multimode, monomode or other type. This central core 10 is provided with a protective sheath 12;
• a sheath 18 ensuring the tensile strength. This sheath 18 can be produced using a bundle of wicks of synthetic fibers assembled lengthwise, for example aramid fibers;
• a first conductive layer 14 consisting of a covering or covering of a plurality of conductive wires of small section, for example made of copper, protected by a winding of a ribbon 16 for example made of polytetrafluoroethylene (Teflon);
• a second conductive layer 20 formed like the first layer 14 by covering a plurality of conductive wires of small diameter, protected by a "Teflon" tape 22, this second conductive layer being isolated from the first by a sheath 24 preferably in "Teflon"and;
• an outer sheath 26 intended to ensure transverse sealing.

For the application specified above, the cable can also be provided with an outer buoyancy sheath 28 ensuring slightly negative buoyancy.

By way of example, it may be indicated that a cable according to the invention having a diameter on an outer sheath 26 of the order of 5 mm makes it possible to transfer electrical energy of 20 Kw at a voltage of 4000 volts with a yield equal to or greater than 0.7 under the conditions of use mentioned above, that is to say in deep immersion, of the order of 300 m, and under a length of 1000 to 1300 m, with a excellent tensile strength, of the order of 500 daN, and a small variation in volume as a function of the hydrostatic external pressure. This cable also has the advantage of being non-magnetic.

It remains to be understood that this invention is not limited to the embodiment described below, but that it encompasses all variants thereof. It is also not limited to the specific application example mentioned above.

Claims (6)

Conductive cable with a high filling rate and having a small variation in volume as a function of the hydrostatic external pressure intended for the transmission of electrical energy and of video and / or remote control signals, characterized in that it is of coaxial structure and in what it comprises a core (10) ensuring the transmission of video and / or remote control signals, at least two coaxial conductive layers (14,20) each consisting of a plurality of small diameter electrical conductors covered with covering and insulated from each other by an insulating coating (24) and a sheath of synthetic or natural fibers (18) ensuring the tensile strength. Conductive cable according to claim 1, characterized in that the core ensuring the transmission of the video and / or remote control signals (10) consists of one or more optical fibers of the single-mode, multimode or other type. Conductive cable according to claim 1, characterized in that the core ensuring the transmission of the video and / or remote control signals (10) is a mini coaxial cable. Cable according to any one of the preceding claims, characterized in that the sheath (18) ensuring the tensile strength is constituted by a bundle along strands of synthetic fibers, in particular aramid fibers. Cable according to any one of the preceding claims, characterized in that it also comprises an external transverse sealing and / or buoyancy sheath (26-28). Cable according to any one of the preceding claims, characterized in that it is applied to a self-propelled, self-propelled underwater vehicle to which it transmits the electrical energy necessary for its operation as well as the remote control signals.

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