DE1147281B - Core for telephone cables and high-frequency lines - Google Patents

Description

It is known to have high-quality cores for telephone cables with foam insulation, in particular made of foamed polyethylene. The required colored marking of the wires through Coloring the insulation causes considerable difficulties both in terms of the quality of the Isolation as well as in relation to the preparation of the coloring. When the plastic is colored a completely colored extrudate, but the color pigments interfere with the foaming and with the required color change the essential disadvantage arises that the quality of the insulation is not uniform and also eliminates the need to clean the screw press entails significant loss of time. In the case of completely dyed polyethylene, the colors have an effect different on the dielectric constant of the insulating material, since the colors have a high Have volume fraction of insulating material.

Also the well-known external marking in the form of a longitudinal or helical one colored stripe, which was also applied as a colored plastic film, prepares essential Difficulties, since it is necessary to use the foamed polyethylene for surface oxidation to make this color coding receptive. The spinning of plastic films also required a special effort, since these had to be welded and smoothed.

In the new wire, the disadvantages mentioned are eliminated by the fact that, according to the invention Insulating cover made of uncolored foamed insulating material, in particular polyethylene, consists of a thin-walled outer jacket made of full insulation, e.g. B. Vollpolyäthylen, which is in is colored in the desired identification color.

By using a natural-colored wire insulation, uniform electrical values are obtained, since the foaming process is not disturbed by any color pigments. Appropriately, the Application of the colored thin-walled casing in the same operation as the production of the Main insulation of the wire. For the colored envelope, additional known per se Screw presses are used that are interchangeable with the mouthpiece of the main screw press are connected to a color change without interrupting the extrusion process for labeling. A cleaning of the main screw press is thus at Color change not required.

Through the thin-walled outer sheath made of colored wire for telephone cables
and high frequency lines

Applicant:

Siemens-Schuckertwerke Aktiengesellschaft,

Berlin and Erlangen,
Erlangen, Werner-von-Siemens-Str. 50

Dipl.-Ing. Walter Hyprath, Neustadt near Coburg, has been named as the inventor

Solid polyethylene gives the insulation made of foamed polyethylene a better one mechanical hold. Further, a part of the inevitable pores opening outward becomes foamed in Insulating material closed. You can also expand the insulation from foamed Use insulating material after leaving the main screw press and the already thin colored one Stretch the envelope further and thus reduce the wall thickness. Dyed by the thin outer sheath are the dielectric values of the core insulation compared to a single-layer insulation changed only slightly.

In the drawing, a telephone wire according to the invention is shown in cross section. On the Copper conductor 1 is an insulating sleeve 2 made of natural-colored cell polyethylene, which with a thin-walled outer shell 3 made of colored solid polyethylene is surrounded.

Claims (2)

PATENT CLAIMS: 1. Wire for telephone cables and high-frequency lines with an Ioslierhülle made of foamed Iolierstoff, especially polyethylene, marked is characterized by an Iolierhülle made of uncolored foamed insulating material, for. B. polyethylene, on which a thin-walled outer jacket made of solid insulation, z. B. solid polyethylene, which is colored in the desired identification color. 2. A method for producing a wire according to claim 1, characterized in that the production of the colored marking 309 550/275 takes place in a known manner in one operation with the main insulation by additional screw presses, which are interchangeable, for. B. by moving or pivoting against each other with the mouthpiece of the main screw press in connection to a color change without interrupting the extrusion process
to take. for labeling Documents considered: German Auslegeschrift No. 1106382; Austrian Patent No. 189,249; Swiss patent specification No. 279074. 1 sheet of drawings