DE2053075C3 - Process for the production of a spacer for coaxial high-frequency cables made of insulating material - Google Patents

Description

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The invention relates to a method which is used for producing an insulating material Spacer to be used for coaxial radio frequency cables. The spacer consists of a continuous one that rests on the inner conductor of the cable and surrounds it in a spiral shape Strips with web-shaped protruding radially outward at intervals from the stripe Support elements on which the outer conductor of the cable rests.

Spacers for coaxial high-frequency cables should, for electrical reasons, if possible be poor in material. This requirement is limited by the mechanical strength of the spacer. You should be tensile, because it must fit closely to the inner conductor and accordingly under tensile load is applied. All thermoplastics are particularly suitable as the material for this spacer Polyethylene and polytetrafluoroethylene. Because of the required low-material structure difficulties arise in the manufacture of such spacers, since their structure is quite complicated and so continuous production using conventional injection molding machines is not possible.

Such a spacer goes for example from German Offenlegungsschrift 1 465 637 coaxial high-frequency cables, bcj which the Stiitzclementc are designed in "T" shape. Here the support elements should be carved out of an injection-molded and cut-to-size tape, which is undoubtedly only possible with considerable machine effort.

The invention is based on the object of specifying a method by means of which a low-material and tensile strength spacer for coaxial high-frequency cables can be produced economically.

This object is achieved with the method of the type described at the outset according to the invention solved that, as a first step, a part of the spacer is made in an injection molding machine which consists of a strip section with at least one support element and in which both ends of the strip section running in the same direction in the sense of an area enlargement are sold that as a second step, the finished part of the spacer in the mold of the injection molding machine is relocated and that as a third step, before the cooling of the already finished part, another the same part is injected onto the first, this process being repeated continuously.

A spacer built according to the method of the invention is almost continuous Can be produced in the desired length. Welding occurs through the injection of the new part both parts, so that the connection points of the individual parts of the spacer are able to withstand all tensile and bending loads.

An embodiment of the invention is explained with reference to the drawing. In

F i g. 1 shows views of differently constructed spacers;

F i g. 2 and 3 show views of the spacer according to FIG. 1 in the direction of arrow A, and in

Fig.4 is schematically an apparatus for Implementation of the method according to the invention reproduced.

1 with the continuous strip of a spacer for coaxial high-frequency cables is referred to. The structure of these cables is otherwise arbitrary. So the two conductors can be used as smooth tubes be designed, but corrugated tubes or a solid conductor can also be used as the inner conductor will. On the continuous strip 1, which rests on the inner conductor of the cable should, the support elements 2, 3 and 4 are attached, which form a part with the strip. These support elements can have the most varied of shapes according to FIG. 1 and, for example, as simpler Finger 2, as "T" 3 or as "T" 4 with a rounded head.

At the end of a spraying process, with which part of the spacer is completed has been, the ends of the strip 1 of such a part in the sense of an area increase, for example according to FIG. 2 beveled or according to FIG. 3 graded. The part of the spacer to be connected has a correspondingly opposite slope or gradation. Of course the area enlargement can also be carried out in any other expedient manner.

To produce the spacer is in an injection molding machine 5, in the storage container 6, for example Filled with polyethylene and in the first

Process step in the tool 7, a part of the spacer is made. After completion this part is shifted so far in the second process step in the tool 7 that in the third process step can be another part of 5.

the same can be injected. In this way, an almost endless strand of 8 ckr spacers produce which, emerging from the injection molding machine, are wound onto a drum 9

1 sheet of drawings

Claims (3)

Patent claims: 1. Process for the manufacture of an insulating material existing spacer for coaxial high-frequency cables, which consist of a continuous, on the inner conductor of the cable, with strips surrounding it in a helical manner bar-shaped support elements protruding radially outward at intervals from the strip, "on which the outer conductor of the cable rests, is constructed, characterized in that that as a first step a part of the spacer is manufactured in an injection molding machine (5) which consists of a strip section (1) with at least one support element (2,3,4) exists and in which both ends of the strip section (1) in the sense of an area enlargement running in the same direction, are sold that the finished part of the second step Spacer in the tool of the injection molding machine (5) is relocated and that as a third In the second step, before the already finished part cools down, another identical part is molded onto the first this process is repeated continuously. 2. worship according to claim 1, characterized in that the ends of the strip sections (1) are stepped. 3. The method according to claim 1, characterized in that that the ends of the strip sections (1) are beveled.