NO131741B

NO131741B -

Info

Publication number: NO131741B
Application number: NO741699A
Authority: NO
Inventors: N Y Akesson
Original assignee: Ericsson Telefon Ab L M
Priority date: 1973-05-10
Filing date: 1974-05-10
Publication date: 1975-04-07
Also published as: SE372994B; AR198762A1; NO131741C; DK129546B; AU6802474A; NL7405899A; DE2419843A1

Description

Skjermet elektrisk kabel. Shielded electrical cable.

Foreliggende oppfinnelse vedrorer en skjermet elektrisk kabel omfattende minst en isolert leder og en omkring denne anordnet metallskjerm. The present invention relates to a shielded electric cable comprising at least one insulated conductor and a metal shield arranged around it.

Kjente skjermede kabler kan, med hensyn til skjermens utforelse, Known shielded cables can, with respect to the design of the screen,

deles inn i to grupper. Den ene gruppen omfatter slike som er forsynt med trådskjermer, vanligvis bestående av i motspiraler rundt lederen (lederne) anordnede koppertråder. En slik skjerm er meget lett å koble fordi skjermtrådene ved enden av kabelen kan samles og vikles sammen til en mangetrådig leder. Tråd- are divided into two groups. One group includes those equipped with wire shields, usually consisting of copper wires arranged in counter spirals around the conductor(s). Such a shield is very easy to connect because the shield wires at the end of the cable can be collected and wound together to form a multi-stranded conductor. Thread-

skjermen har imidlertid den ulempe at den er kostbar å frem-stille. For å senke fremstillingsomkostningene har man i stadig storre grad gått over til metallbåndskjermer, ved hvilke skjermen however, the screen has the disadvantage that it is expensive to produce. In order to lower production costs, people have increasingly switched to metal strip screens, by which the screen

utgjores av et vanligvis meget tynt metallbånd som vikles rundt lederen eller legges i aksiell retning langs kabelen og boyes rundt denne slik at det helt omslutter kabelen. Disse metall-båndskjermene er imidlertid meget vanskelige å koble til forekommende koblingsanordninger. is made of a usually very thin metal band that is wrapped around the conductor or laid in an axial direction along the cable and bent around it so that it completely encloses the cable. However, these metal tape screens are very difficult to connect to existing connection devices.

Formålet med den foreliggende oppfinnelse er å tilveiebringe en skjermet kabel, hvis skjerm er like lett å koble som en tråd-skjerm og hvis fremstillingsomkostninger er av samme størrelses-orden som en metallbåndskjermet kabel. The purpose of the present invention is to provide a shielded cable, whose shield is as easy to connect as a wire shield and whose manufacturing costs are of the same order of magnitude as a metal tape shielded cable.

Dette oppnås ved at kabelen gis de i de etterfolgende patent-krav angitte, kjennetegn. This is achieved by giving the cable the characteristics specified in the following patent claims.

Oppfinnelsen skal nå beskrives nærmere i tilknytning til ved-lagte tegning, i hvilken The invention will now be described in more detail in connection with the attached drawing, in which

fig. 1 viser et parti av en kabel med en perforert metallbånd-skjerm ifolge oppfinnelsen, fig. 1 shows a part of a cable with a perforated metal tape shield according to the invention,

fig. 2 og 3 viser alternative utforels^sformer av perforeringen, og fig. 2 and 3 show alternative embodiments of the perforation, and

fig. 4 viser et korrugert skjermbånd i sideriss. fig. 4 shows a corrugated screen band in side view.

I fig. 1 betegner 1 en isolert leder omgitt av en metallbånd-skj erm 2, hvilken er forsynt med langsgående smale perforeringer eller slisser, hvorved skjermen er oppdelt i en antall smale bånd 3, hvilke bånd er bundet sammen av mellom båndene tverrgående broer 4. Kabelen er forsynt med et isolasjonssjikt 5 anordnet utenpå skjermen. In fig. 1 denotes 1 an insulated conductor surrounded by a metal strip screen 2, which is provided with longitudinal narrow perforations or slots, whereby the screen is divided into a number of narrow strips 3, which strips are tied together by transverse bridges 4 between the strips. provided with an insulation layer 5 arranged on the outside of the screen.

På grunn av perforeringen muliggjores en sammenrulling eller sammenvridning av skjermen slik at den danner en elektrisk leder som kan kobles til normale koblingsanordninger. Skjermens tyk-kelse og perforeringens utforelse er avhengig av skjermens funksjon i kabelen, I de tilfeller hvor den er beregnet på å anvendes som beskyttelses- eller null-ledere, må den nødvendig-vis tilpasses forekommende strømstyrker. Due to the perforation, a rolling or twisting of the screen is made possible so that it forms an electrical conductor which can be connected to normal connecting devices. The shield's thickness and the design of the perforations depend on the shield's function in the cable. In cases where it is intended to be used as protective or neutral conductors, it must necessarily be adapted to the currents occurring.

For forbedring av fleksibiliteten ved boying av kabelen kan skjermen være kruset i en retning vinkelrett på kabelens lengderetning, se fig. 4. To improve the flexibility when buoying the cable, the screen can be crimped in a direction perpendicular to the length of the cable, see fig. 4.

Claims

1. Shielded electric cable comprising at least one insulated conductor and a metal shield arranged around this, characterized in that the shield comprises a metal band, which is divided by means of mainly longitudinal narrow perforations into a number of narrow bands which are bound together by transverse bridges between the bands.

2. Shielded electric cable as stated in claim 1, characterized in that the perforations are extended in such a way that the transverse bridges form continuous sections perpendicular to the longitudinal direction of the band.

3. Shielded electric cable as stated in claim 1, characterized in that the perforation is extended in such a way that the transverse bridges form continuous sections that run diagonally across the band.

4. Shielded electric cable as stated in claim 2, characterized in that the perforations on both sides of the connected parts form an angle with each other.

5. Shielded electric cable as stated in claims 1-4, characterized in that the metal band which forms the shield is corrugated.