US2210663A

US2210663A - High-frequency cable

Info

Publication number: US2210663A
Application number: US55421A
Authority: US
Inventors: Hahnemann Walter Max
Original assignee: Standard Elektrik Lorenz AG
Current assignee: Alcatel Lucent Deutschland AG; C Lorenz AG
Priority date: 1934-12-22
Filing date: 1935-12-20
Publication date: 1940-08-06
Anticipated expiration: 1957-08-06

Description

Filed Dec. 20, 1935 Patented Aug. v6, 1940 UNITED STATES PATENT OFFICE HIGH-FREQUENCY CABLE Walter Max Hahnemann,

Berlin-Marienfelde,

Germany, assignor to G. Lorenz Aktiengesellschaft, Berlin-Tempelhof, Germany, a company I Claims.

It is well known that the transmission over cables of electrical energy for communication purposes may be carried out by means of high frequency alternating currents. The cables used 5 to such end are either so-called concentric cables, i. e., cables having coaxial conductors, or are of the type in which the conductors are parallel with each other, that is, arranged aside one another. Equally, constructions of such cables are known which mainly aim at requiring the least possible expenditure in insulating material in order that the mutulal capacity of the conductors and hence losses within the cable shall be as low as possible.

The invention likewise proceeds from this consideration. It relates to two-core cables and makes use of flat or strap-shaped conductors, that is, conductors which are not of a circular or similar cross-sectional area.

In this way it is possible owing to the skin-effeet to employ cables of a two-core type, that is,

not of the concentric type, without the resistance becoming too great. With cable cores circular in cross-section the current distribution over the cross-sectional area is only appropriate if the cable is a concentric one, that is to say, is not appropriate in the two-core case.

The conductors or cores in cables as provided by the invention are so arranged with respect to each other as to ensure that the mutual capacity is as low as possible.

Some embodiments of the invention are described hereafter with reference to the accompanying drawing in which--- I v Fig. 1 in a cross-section through the conductor arrangement illustrates the simplest embodiment. Fig. 2 is a diagram relating to the mode of action of the novel arrangement. Figs. 3 and 3a are views of the two conductors of a device according to Fig. 1. Fig. 4 is a somewhat diagrammatic perspective view of a device consisting of the two conductors represented in Figs. 3 and 3a.

Fig. 5 is a representation similar to Fig. 4 and illustrates the completed state of the device shown there. Fig. 6 is a sectional view of a further development of the device represented in Fig. 5. Fig. 7 shows a section on the line 1-1 of Fig. 6. Fig. 8 is a sectional view illustrating a modification of the arrangement represented in Figs. 6 and -'7.. Fig. 9 is a sectional diagrammatic view of a multiple cable formed of a plurality of cross-shaped conductors.

The arrangement according to Fig. 1 consists of two fiat or strap-shaped conductors I, 2 whichconstitute the two-core arrangement, one

of them being a'return conductor. These two conductors are arranged to intersect lengthwise at right angles, so that the arrangement formed in this way is cross-shaped'in cross-section.

By this fundamental arrangement, with the 5 least possible resistance the 'most favorable current distribution and the least possible capacity between the conductors is attained owing to the skin efiect.

Such cross-shape of a two-core arrangement 10 has the advantage that the cross-sectional area is utilized in a particularly advantageous manner, since the skin efiect causes the high frequency currents to flow only on the surface facing the field. Due to the cross-shape also the 1 current distribution is very advantageous. It can be ascertained in this regard that the current distribution which occurs in the arrangement shown in Fig. 1, in consequence of the field displacement that will arrive is about of the form of curve represented inFig. 2 and is so with respect to both sides of the conductor surface,

Arrangements according to Fig. 1 may be accomplished in the manner appearing from Figs; 3 to 5. The strap-shaped conductor I here has slots I. The strap-shaped conductor 2 is made in two parts 8, 9. These are provided with tongues b, 0 adapted to be inserted in the slots 1, so that the parts I, 8, 9 can be assembled in the manner obvious from Figs. 4 or 5. The tongues 11, c are 0 then fixed to each other, as by riveting or spot welding, or in any other suitable manner. The mutual insulation of the conductors I, 2 may be effected by means of pieces I2 inserted in the slots 1, as indicated in Figs. 4 and 5.

In order to secure the conductors I, 2 in their mutual position, they are preferably provided with notches Ill in their edges and securing means of .an insulating material are. disposed in these notches.

Such notches are shown in Figs. 40 5 to 8.

The securing means may consist in rings II, as shown in Figs. 5 to 7, or in a string II' coiled round the conductors I, 2 as illustrated in Fig. 8.

As represented in Figs. 6 to 8, the securing 45 means may serve also for supporting a cable sheathing I3 which may be a metal screening active against outer fields'and may be wound around the rings I I, as shown on the left in Fig. 6, or coiled on the string II". 50

Cables of the novel construction may be combined to form a multiple cable, in such a manner for instance, that onto a cable having a metal sheathing or screening I3, as bef re described, other cables of this or a similar construction are u ,ments thus combine the advantage of concentric cables. that is, of having no outer field; with the advantage of two-core cables, which consists in doing away with induction from without, and,

' as regards the current distribution, are superior to the customary arrangements of high frequency cables.

What is claimed is:

1. A high frequency cable having strap sh'aped conductors intersecting lengthwise at right angles wherein the conductors are slotted and one of them is made in two parts assembled in the slots of the other conductor. 1

2. A cable in accordance with claim 1 wherein insulating rings are arranged on the conductors for securing them in their mutual position.

3. A high frequency cable according to claim 1 wherein insulating means is positioned around said conductors for securing them in their mutual I position.

4. A high frequency cable according to claim 1 wherein an insulating string is coiled around said conductors for securing them in their mutual position.

'5. A high frequency cable according to claim 1 wherein insulating means'is positioned around said conductors for securing them in their mutual position and a metal sheathing. encircles said conductors and is supportedpbyssaid insulating means.

WALTER MAX HAHNEMANN.