DE1205601B - Electric cable - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

HOIb

German class: 21c-7/50

Number:
File number:
Registration date:
Display day:

H45435VIIId / 21c
April 11, 1962
November 25, 1965

The invention relates to metal-sheathed electrical cables for harsh operating conditions such as such as B. for overground laying or laying in mining operations above or below ground. In particular cables with an electrically sensitive core, such as coaxial cables, waveguide cables and the like, with normal construction are sensitive to shock, impact or pressure loads and must therefore be reinforced for rough operating conditions or, after installation, additionally, z. B. be protected by embedding in iron half-shells, reducing price and cable weight become undesirably high.

To increase the shock and impact resistance of such cables, it is known that the cable cores with a Sheath material with high mechanical strength, e.g. B. steel, to sheath, and it is also known such Corrugating or grooving cable sheaths to increase flexibility and transverse rigidity. Such cables must be excellent for the purpose on which the invention is based Corrosion protection are encased around the jacket material, which is very sensitive to corrosion To protect steel against rust and similar influences, and the one above the corrosion protection Outer sheath of the cable, usually an elastic plastic, must in turn also protect against mechanical Damage to be reinforced to protect the outer cable jacket from damage, that could allow moisture to penetrate. This way the cable regains its weight and price is very expensive and the flexibility that is available per se suffers due to the additional reinforcement such cables, so that laying in small radii of curvature, which is often required, is very difficult or even impossible.

The invention provides an electrical cable that can withstand shock, impact and pressure is largely insensitive, has good flexibility, is practically corrosion-resistant and lightweight.

Electrical cables with a double smooth or corrugated metal jacket are known per se. In one of these known cables is for thermal reasons to protect the cable core during A pressed aluminum jacket is applied to the jacket in two steps; the first to be pressed Coat has a thinner wall thickness than the second coat. This double coat becomes Although the protection of the cable core against mechanical stress is improved, the flexibility of the however, the finished cable is deteriorated; in addition, the double jacket makes the cable very heavy.

Electric cable

Applicant:

Hackethal wire and cable works

Corporation,

Langenhagen near Hanover, Stader Landstr. 1

Named as inventor:

Dr.-Ing. Rolf Wägele, Langenhagen near Hanover

In a known internal gas pressure cable with a double metal jacket are located between the inner and the outer metal jacket which extends in the longitudinal direction of the cable inner channels for the pressurized medium; the outer metal sheath takes over the mechanical one in this cable Protection of the cable core and is intended to keep the inner ducts open in the event of bends or Ensure transverse expansion of the cable core caused by the operating heat.

The invention relates to an electrical cable, the core of which is made of a thin metal sheath high mechanical strength and surrounded with this inner jacket in an outer metal jacket corrosion-resistant material is arranged. The invention consists in that on the cable core overlying corrugated inner jacket of one or more corrosion protection layers and a smooth one elastic coat, e.g. B. made of plastic, on which the corrugated outer metal jacket corrosion-resistant material rests on; according to a further idea of the invention, the corrugated outer metal jacket optionally also from a corrosion protection cover and / or a smooth one Coat made of elastic, abrasion-resistant material, e.g. B. made of polyethylene, be surrounded.

The invention is described using the drawing, for example, using a coaxial cable. It * 5 shows

A b b. 1 a step-wise stepped view and A b b. 2 shows a longitudinal section of one according to the invention established cable.

1 is the inner conductor, which is designed as a smooth tube of the coaxial cable chosen as an example, and 2 represents the inner conductor in the outer conductor 3 centering Kujiststoffhaltefendel. The

509 739/308

Outer conductor 3 is designed in a manner known per se as a corrugated metal tube and consists of a material of high mechanical strength, e.g. B. made of steel, which is on the inside for electrical reasons in a known manner with a plating of highly conductive material, z. B. made of copper, may be provided. Over this corrugated metal inner jacket 3 is a corrosion protection cover of known composition, which optionally consists of several layers 4 and 6, with the interposition of a separating film 5 overlying corrugated metal jacket 8 made of corrosion-resistant material, such as copper or aluminum, is applied. In order to obtain a smooth cable surface by filling the outer wave troughs of this corrosion-resistant metal jacket 8, this outer metal jacket can be provided with an outer jacket 10 made of elastic, abrasion-resistant material, e.g. B. made of polyethylene, be wrapped, optionally with the interposition of a soft plastic intermediate layer 9 for better filling of the wave troughs. With a suitable composition, this intermediate layer can also serve as a corrosion protection layer. Fungicidal and / or bactericidal additives can be incorporated into the layers 4, 6 and / or 7, which are sealed from the outside by the outer corrugated metal jacket 8, which make the cable immune to rot and, when laid in insect-infested areas, to insect damage .

Of course, the application of the structure according to the invention is not applicable to cables with high sensitivity Souls limited, but is always used appropriately when cables against unusually rough operational influences are to be protected.

According to a further idea of the invention, the transverse stability and flexibility of the new Cable further increased by the fact that the corrugation of the metal inner jacket 3 and the metal Outer jacket 8 are carried out with different wave inclination and wave depth by the outer Metal jacket 8 with a smaller pitch and greater wave depth, preferably with half the pitch and double the corrugation depth than the inner metal jacket 3 is designed, the corrugation of the two Metal jackets can run in the same direction or opposite to one another.

The high flexibility of the new cable, which is in itself very resistant, and the almost absolute protection the cable core against kinking when the cable is bent by a very small bending radius - that The new cable can be bent by a radius of 50 cm with small cable diameters without damage the cable core possible - is achieved in that the outer corrugated metal jacket 8 on the smooth surface of the elastic inner jacket 7 can slide, whereby the individual corrugations (ribs) of the metal jacket 8 can move in the axial direction of the cable when bending the cable and nevertheless the smooth inner sheath and thus the cable core in places that are close to one another Support evenly around the circumference so that it is practically impossible for the cable core to buckle is. The corrugation can be annular or helical. The new cable is manufactured expediently such that the inner metal jacket consists of a smooth thin metal band around the cable core Shaped around a small distance from this as a slotted tube, preferably by means of argon arc welding Longitudinally welded and then by helical corrugation of the resulting Smooth tube is brought to rest on the cable core. After applying the anti-corrosion layer and the smooth elastic inner jacket is then made of the outer metal jacket a smooth thin metal band around this elastic inner jacket with a small distance from it Shaped around as a slotted tube, preferably longitudinally welded by means of argon arc welding and then firmly resting on it by means of helical corrugation of the smooth tube that has been created in this way curled onto the elastic inner jacket, whereupon, optionally with the interposition of the soft plastic intermediate layer, the smooth abrasion

ao solid outer jacket on the corrugated metal jacket is applied. This production can be carried out continuously in one continuous operation during construction the corresponding work route can be made, which makes the manufacture of the cable cheaper.

* 5 In the case of the one described as an exemplary embodiment Design of the cable according to the invention as a coaxial cable has the inner corrugated metal sheath 3 zero potential when the cable is in operation. It is therefore possible, after another thought, the Invention, the outer metal corrugated jacket 8 and the inner metal corrugated jacket 3 in addition Command impulses or streams for the transmission of control or switching commands or speech impulses to be used for the transmission of commands or for the transmission of power. the The same use is for the construction of the new cable as a waveguide or for a different core structure possible, since the inner metal corrugated jacket always has zero potential during operation or at least on this potential can be laid. The inner metal corrugated jacket 3 should then consist of an electrically highly conductive material, e.g. B. made of hard copper.

Claims (9)

Patent claims: 1.Electric cable, the core of which is covered by a thin metal sheath of high mechanical strength, such as B. steel, surrounded and with this inner jacket in an outer metal jacket corrosion-resistant material, such as. B. copper, is arranged, characterized in that that the corrugated inner sheath (3) resting on the cable core (1,2) is of one or several corrosion protection layers (4,6) and a smooth elastic jacket (7), for. B. off Plastic, is surrounded on which the corrugated outer metal jacket (8) made of corrosion-resistant Material rests. 2. Electrical cable according to claim 1, characterized in that the outer corrugated Metal jacket (8) of a corrosion protection cover (9) and a smooth jacket made of elastic, abrasion-resistant material, ζ. Β polyethylene that is surrounded. 3. Electrical cable according to claim 1 and 2, characterized in that the corrosion protection each of the outer wave troughs of the corrugated metal jacket completely fills. 4. Electrical cable according to claim 1, characterized in that when using two or more anti-corrosion layers over the inner corrugated metal jacket each Layers are separated by intermediate foils. 5. Electrical cable according to claim 1 to 4, characterized in that the outer metal jacket narrower and deeper than the corrugated inner metal jacket. 6. Electrical cable according to claim 5, characterized in that the outer metal jacket is corrugated with half the pitch and twice the corrugation depth of the inner metal jacket. 7. Electrical cable according to claim 1 to 4, characterized in that the two metal sheaths are helically corrugated. 8. Electrical cable according to claim 1 or the following, characterized in that the inner corrosion protection cover lying under the outer corrugated metal jacket and / or fungicidal and / or bactericidal additives are added to the inner plastic jacket. 9. Electrical cable according to claim 1 or the following, characterized in that the inner and outer corrugated metal jacket for the transmission of additional speech or command impulses or is used for power transmission. Considered publications:
German Patent Nos. 974572, 973 485;
German interpretative document No. 1031 391. 1 sheet of drawings 509 739/308 11.65 © Bundesdruckerei Berlin