US2009854A - Transmission line - Google Patents

Description

July 30, 1935. A. MEISSNER TRANSMISSION LINE Filed Oct. 29, 1931 INVENTOR ALEXANDER MEI SNER ATTORNEY Patented July 30, 1935 PATENT OFFICE TRANSMISSION LINE Alexander Meissner, Berlin, to Allgemeine Elektricitats rich Karl Ufer, Berlin,

of Germany Germany, assignor Gesellschaft, Fried- Germany, a corporation Application October 29, 1931, Serial No. 571,800 In Germany October 30, 1930 3 Claims.

This invention relates to a line or conductor for high-potential and high-frequency purposes more in particular this invention is concerned with a novel mode of construction of lines in which the chief aim is to diminish the corona losses or to act upon the capacity of the line. The invention more particularly is characterized by the feature that two systems are provided which are inter-enveloping, the enveloped system taking care of the conduction of the current, whereas the enveloping system governs the capacity of the line and the field distribution about the current-carrying conductor. The enveloping system in this scheme is in electrical conductive relationship at one or more places with the current conductor or conductors. The currentcarrying conductor may be enveloped in the present arrangement either throughout its entire length or only at certain endangered points by the enveloping system. In the case of highpotential air-lines it is often suflicient, for instance, if the line is surrounded by the sheath only in the vicinity of the insulators.

In order to insure light and inexpensive construction it is advisable to give the enveloping sheath a discontinuous or broken-up structure. For instance, a wire helix or else a reticular form of construction could be used consisting, say, of two or more oppositely running wire helices. The identical effect is attainable also by that several annular hollow cylinders are provided.

In the accompanying drawing a number of embodiments are illustrated by Way of example in which the enveloping system has a helical form, Fig. 1 showing a system in which the currentcarrying wire is positioned concentrically in relation to the sheath or envelope, Fig. 2 a system in which the sheath or shell bears upon the current-carrying wire, Fig. 3 a system in which two current-carrying conductors support the enveloping shell, and Fig. 4 a system in which two current carrying conductors support an enveloping shell of wire network or gauze. Figures 1 2 3 and 4 are end views of Figures 1, 2, 3 and 4 re spectively.

Referring to Fig. 1, the current-carrying conductor is denoted by a; it is positioned centrally inside the elastic wire helix b whose turns have an intervening distance being from 3 to 10 times larger than the diameter of the wire. The helix b is in conductive relationship with the central wire a at one or more points. As a result the outer field of the entire system will be governed only by the field of the helix. The potential stress, for instance, of the air in the neighborhood of the conductor system therefore corresponds to the field prevailing at the helix b. The new line in this direction behaves therefore as a massive (solid) or hollow conductor having the same diameter as the helix 0. Also the capacity of the 5 conductor system towards the outside depends only upon the sheathing shell.

If the helix b surrounding the conductor a is wholly or partly made of magnetic material, the inductance of the line is raised whereby partial 10 pupinization desirable for many purposes is attained in a very simple manner.

It is not necessary that the line or conductor a should be disposed in the center of the helix b; in fact, as shown in Fig. 2, the latter could also 15 be suspended above the line a. Incidentally there results approximately the same relief of field of the current-carrying conductor.

The advantage residing in this novel system is that for high-potential lines, in order to avoid 20 corona losses it is no longer necessary to have recourse to larger conductor diameters than what is required from the viewpoint of current load or density. Hence, it is thus feasible to avoid the use of hollow cables for high-potential work.

Another field of practical use of the invention is in radio frequency technics, for it will be seen that the novel line may be used both for aerial purposes as well as up-leads or down-leads (or what is known as energy-transfer lines), say, for short-wave and broadcast work. The antenna most suitably consists of a system of the kind shown in Fig. 3. At the two lateral currentcarrying wires (1 and e is suspended and secured the spiral f. In order to insure more uniform conductive bearing of the lateral wires upon the spiral the sheathing or envelope towards both outsides is so enlarged that the contour forms a parabola. The capacity of the arrangement corresponds to the diameter 0 of the spiral. In 40 this way, by the aid of simple and cheap means, it is possible to replace the cage antenna and energy-leads heretofore used in radio frequency work. The system shown in Fig. 3 is useful also as an energy feed line for beam radiators and receivers. By the surrounding or enveloping system I supported by the two wires d and e, the entrance of an outer field is perfectly precluded. The dissymmetric fields of the conductors d and e are changed by the spiral or helix into a uniform central field, i. e., into a field such as would be exhibited by a conducting tube enveloping the conductors and having the same diameter as the spiral.

The weight of the whole system is so low that itcan be easily suspended from poles or masts.

At the points where the insulators of the inner conductor are attached, it would in this case be advantageous to provide screening means to afford protection against external actions, such as rain, etc., at the line system. i

It will be understood that the invention is -not confined to air-lines and radio frequency lines-or arrangements, indeed, that it may also be employed in connection with the building of cables and transformers.

It may also be mentioned that the novel'forrn safeguard any live lines or conductors nov matter of what kind against mechanicalzand electrical damage. The same furthermore represents an excellent arrangement for therlrainingof excesspotentials of a line if the enveloping system is grounded. 4

I'claim:

1..A transmission line for. the transfer fenergy at high frequency, comprising twolateral current carrying.wiressuspended andsecured to but located within a spiral shaped conductor,- the turns of said spiral shaped conductor being enlarged at each end of said transmission line so that the outer line of said turns form a parabola to insure uniform conductor bearing of the lateral current carrying wires and the inside of said spiral shaped conductor turns.

12.;A transmission line for the transfer of energy at high frequency,- comprising at least two lateral current carrying Wires suspended and se- ,-cured to but located within an envelope of wire gauze. forming a'helical shaped conductor, said "helical shaped conductor enlarged at each end of construction hereinbefore disclosed is; suited to of said transmission; line so that the contour of said envelope forms a parabola to insure uniform .conductor bearing of the lateral current carrying Wires and the inside of said envelope.

v3..-A transmission line for the transfer of en- 1 ergyat high frequency, comprising at least two lateral current carrying wires suspended and secured to but located within a spiral shaped conductor of magnetic material, saidspiral, enlarged ,at each end ,ofsaid transmission line,

ALEXANDER MEISSNER.

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