RU2543510C2 - Shielded symmetrical four-pair cable - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: in symmetrical four-pair cable containing conductors in polymer insulation, shielded pairs, a drain conductor, a common sheath from foil and braiding and an external polymer cover, one of the pairs is chosen as a central one and is put into a metal polymer sheath with metal to the outer side with longitudinal overlapping of edges throughout the cable length and a metal band with overlapping of edges throughout the cable length, and around this sheath there placed are the rest three pairs of the same diameter, each of which is placed in the metal polymer sheath with metal to the outer side with overlapping of edges throughout the cable length and separated from each other with metal polymer tubular elements with metal to the outer side, which do not exceed as to the size of diameter of each pair; the drain conductor is located at one of the metal polymer tubular elements.

EFFECT: invention allows reducing mutual influences between pairs and simplifying access to each conductor.

1 dwg

Description

The invention relates to the field of electrical engineering and can be used in the construction of shielded symmetrical communication cables on public networks and structured cable systems located in strong electromagnetic fields and for operation in a wide frequency range up to 700 MHz.

A known design of a symmetric shielded four-pair cable containing copper conductors in polymer insulation twisted into a common core, each pair twisted with a step different from the steps of other pairs in the common screen and the polymer outer sheath (S / UTP) (in the book Structured cable systems, authors: A.B.Semenov, S.K. Strizhakov, I.R.Suncheley, DMK publishing house, M., 2002, p. 109, fig. 3.4 and 3.5).

Design disadvantage: significant mutual influence between pairs in the range above 100 MHz at a length of 100 meters.

Also known is the design of a shielded symmetric four-pair cable containing polymeric insulated conductors, each pair is placed on the aluminum-polymer foil screen with the foil facing out, and all shielded pairs are placed on the common foil and braid screen and the outer polymer sheath (S / STP) (Ibid., p. 109, fig. 3.4 and 3.5).

The disadvantage of this design with a sufficiently high shielding effect is the difficult access to the cores of various cable pairs.

The closest in technical essence is the design described in the brochure of Teldor 2006, www.teldor.com, teldor.russia@yahoo.com., P. 10 figure and p. 20 description.

Category 7 S / STP cable (600 MHz) contains eight copper conductors, each insulated with polyolefin, each pair wrapped in polyester aluminum foil with foil facing out with a coating density of 100%. All four pairs are twisted around a tinned copper drainage conductor with a diameter of 0.51 mm and placed in a common foil and braid shield and an external polymer shell.

The disadvantage of this design: difficult access to the veins of each pair with a high shielding ability and a small mutual influence between the pairs.

The task to which this technical solution is aimed is to create such a design of a shielded symmetrical four-pair cable that not only improves the shielding capabilities of the cable and reduces mutual influences between pairs, but also facilitates access to each core of each cable pair without damaging the screen.

To solve this problem, one of the pairs is selected central and placed in the metal-polymer module with the foil outward with longitudinal overlapping of the edges along the entire length of the cable, and around the module are the other three pairs, separated from each other by tubular metal-polymer elements with the foil outward, not exceeding the size of each diameter pairs, each pair is also placed in a metal-polymer screen with overlapping edges along the entire length of the cable with the foil outward, a common screen of foil and braid and shnyaya polymer shell.

Figure 1 shows the design of a shielded symmetrical four-pair cable. It contains cores in polymer insulation - 1 central pair - 2 in a metal-polymer screen - 3 metal outward with longitudinal overlapping of the edges - 4 along the entire cable length, a metal tape 5 is laid over the metal-polymer tape with overlapping edges along the entire cable length, the other three pairs are 8, 11, 14 with the same copper conductors 7 in a metal-polymer tape 9, 10, 15 each with overlapping edges along the entire length of the cable with metal outward each, separated by metal-polymer tubular elements - 6, 12, 16 metal outward over the entire length of the cable, drainage conductor 13, a common screen of metal tape 17 and braid - 18 and the outer polymer shell - 19.

In this design, due to the special arrangement of the screens, easy access to the copper cores of each pair is provided with an equal increase in the shielding efficiency of each pair and a decrease in the effect between pairs in the frequency range up to 700 MHz and higher over a length of 100 meters.

Claims (1)

A shielded symmetrical four-pair cable containing polymeric insulated conductors, shielded pairs, a drain conductor, a common foil and braid screen and an external polymer sheath, characterized in that one of the pairs is selected central and placed in the metal-polymer screen with the metal outward with longitudinal overlapping of the edges throughout the length of the cable and a metal tape with overlapping edges along the entire length of the cable, and around this screen are three other pairs of the same diameter, each placed in a metal-polymer screen out to the outside with overlapping edges along the entire length of the cable and separated from each other by metal-polymer tubular elements with metal to the outside, not exceeding the diameter of each pair, a drain wire is placed at one of the metal-polymer tubular elements.