DE599735C - Cross-talk-free telecommunication cable made up of four or high-level groups - Google Patents

Description

Bur.

Ind.

ISSUED ON
7th JUU 1934

REICH PATENT OFFICE

PATENT LETTERING

CLASS 21 c GROUP 4oi

Patented in the German Empire on April 9, 1931

For the production of crosstalk-free telecommunication cables it has already been proposed that all twist, z. B. the four-wire of the cable, fundamentally different from each other close. However, this method can only be carried out with low-pair cables because it is not possible with cables with many wire pairs within the practically in question coming twist lengths a sufficient number of fundamentally different from each other Find helix lengths. In addition, this method is disadvantageous because the production of the Cable is very cumbersome due to the large number of twists that are fundamentally different from one another is. In addition, the operating capacities of the individual stranding elements are different because of their different twist lengths strongly from each other, so that in this way other disadvantages come about.

It has also already been suggested that within each group of four the same strand layer the twist lengths of the two double lines according to prior calculation or calculation

Alternate distances that can be determined and the twist lengths of the two Switch double lines of adjacent groups of four so that after the same distance the earlier swirl steps return. Four of them are not just in the same twisting position with the same twist system only a small distance apart, but they even lie stranding elements at a distance corresponding to the diameter of a stranding element with the same twist phases parallel to each other. The consequence of this are natural strong crosstalk couplings.

According to the invention, a crosstalk-free cable is obtained, even if only one a few fundamentally different nominal spindles, e.g. for the foursome, are used and arranges the four different twists in the individual layers next to one another, that never four of the same twist are adjacent, because different from the previous exercise each foursome along its length in sections with different Twists that have only slight deviations from the nominal twist, stranded and that appropriate the individual sections are the same or approximately the same length. The ' Stranding to the cable in such a way that the twist phases of the four of the same type or the same If possible, the nominal twist in the cable should never be adjacent to one another. So when the cable core is stranded, the Fours with the same nominal twist arranged so that they are not the same at the beginning of the cable Have a twist difference compared to the nominal twist. Then it is never possible that ζ. Β. Fours of the same nominal twist are coupled because of the section-wise Displacement of the twist of the same type of four never lie adjacent to the same twist phases.

In FIG. 1, a telecommunication cable constructed according to the invention is shown as an exemplary embodiment shown. The cable is made

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from the core quads, 6 quads in the first and 12 quads in the second layer. To build up the individual strand layers, three fundamentally different types of four or xenndraile have been used, with four of different types adjacent to each other. Were now. As it has been customary up to now, the fours of the same type each have exactly the same twist lengths over their entire length, so it would easily be possible that, for. B. a foursome α is coupled with the foursomes closest to it ο in the same position, or else a foursome b with the foursomes b closest to it . The same naturally also applies to the foursome c. According to the invention, such couplings are avoided in that, as FIG. 2 shows, each quad of the same type, i.e. each quad α, each quad b and ao each quad c has in sections slight deviations from its xenon twist, which, however, is not necessary is, in this case 2 to 5 ⁰ Z ₀ . So it would z. B- a quad α over a distance of z. B. 5 ° ^m its Xenndrall a _g , over the subsequent distance of 50 m a twist O ₁ equal to a ₀ -f- 2.5 ° / ₀ . The distance of 50 m that follows then has a twist a ₂ equal to a ₀ - 2.5 ° / ". This is then followed by a distance of 50 m with a twist a _s equal to ^a o + 5 °, Ό · This scheme is repeated continuously over the entire length of four. As already mentioned, the fours b and c are also produced in the same or a similar manner. The fours are then stranded to form the cable layer in such a way that the fours are approximately as shown schematically in FIG. 3, i.e. so that in fours of the same type, i.e. the same xenndrels, the same twist phases are never adjacent to one another. Naturally, such a twist scheme can be varied in any way without thereby deviating from the basic method of production that has hitherto been customary, namely that of using only a few xenndraile. The change in the twist in sections over the length of the individual fours can be achieved very easily by the manufacturer as a result of the only slight deviations from the Xenndrall. B. by using take-off disks, the diameter of which changes gradually by small amounts, or that mau equips the machine with suitable clutch gears that automatically change the take-off speed. In the same way, telecommunication cables can also be constructed, the stranding elements of which are not twisted continuously, but are manufactured using other stranding or interlacing processes. In multi-pair cables, in which a large number of stranding elements must be accommodated in the outer layers, it is not necessary that the twist phases of all fours are never adjacent to one another, but it is naturally sufficient that in-phase sections of two fours with the same nominal twist at every point of the cable are separated by a sufficient number of fours. For example, diametrically or approximately diametrically opposed fours in the same position can run in phase with one another without causing any disturbances. If it should be necessary, the individual swirl sections can be provided with a special identification in a known manner. For example, printing devices can be arranged that print characters on the outer insulating sleeve of the quad, or colored ribbons or cords can run into the stranding nipple during the stranding process; bundles of paper cords or wire can also be used.

Claims (2)

Patent claims: i. Xcross-talk-free telecommunication cable made up of four or higher order groups, in which groups in the stranded layer that are adjacent to one another have fundamentally different nominal bends, as a result characterized in that each foursome with different at certain, appropriately equal or approximately equal distances alternating twists, which have only very slight deviations from the nominal twist, is stranded, and that within the same If fours with the same nominal twist are closest to each other, if possible never have sections with the same Twist lengths are adjacent to one another. 2. Cross-talk-free telecommunication cable according to claim i, characterized in that the deviations in sections from the nominal twist amount to about 2 to 5 ° / ₀ . 1 sheet of drawings