RU57508U1 - ELECTRIC COMMUNICATION CABLE (OPTIONS) - Google Patents

Abstract

An electric communication cable is proposed, including two conductive cores equipped with insulating sheaths and twisted into a pair, over which an electric screen is placed, a wire located under the screen and a moisture-proof sheath that is not spread on the screen, in which the insulation sheath of each core is made of at least from one layer of foamed polyethylene with a nominal thickness of "λ", calculated depending on the diameter "d" of cores according to the formula λ = d-0.05 for cores with a diameter of 0.03 mm to 0.65 mm (include ) and according to the formula λ = d for cores with a diameter of 0.65 mm to 1.0 mm.

Description

The utility model relates to the cable industry and can be used in the construction of communication and signaling cables.

It is a well-known telephone cable (CCI type), consisting of conductive cores made of soft copper wire, insulated with polyethylene, twisted in pairs between each other, and the total twisting of the pairs into the core. A belt insulation made of synthetic tapes, an aluminum-polyethylene screen with a metal surface inward with a tinned copper wire under the screen (screen wire), and a sheath made of polyethylene or polyvinyl chloride plastic are applied longitudinally or by winding in a spiral over the core.

A single element of an electric circuit in a known cable is two insulated conductive wires twisted in a pair. Such a telephone cable is designed to transmit analog signals in the range up to 4 kHz. (I.I. Grodnev et al. “Communication Lines”, from “Radio and Communication”, M., 1988).

The named cable type CCI is not designed to transmit digital high-frequency signals. In addition, its single element (twisted into a pair of cores), being separated from the core, does not provide requirements for the non-proliferation of combustion.

A telephone station cable (TSV type) is known, which differs from a cable type CCI in that the cores of a single element are insulated with polyvinyl chloride plastic (I. I. Grodnev et al. “Communication lines”, because of “Radio and communication”, M., 1988 g.).

Although this well-known telephone landline cable provides the requirements for non-proliferation of combustion, however, it, like the cable of the CCI type, is not intended for the transmission of digital high-frequency signals.

Known cables for transmitting digital high-frequency signals that are used in modern automatic telephone exchanges (EATS) and which contain conductive wires made of soft copper wire, insulated with solid polyethylene of individual colors, twisted into a pair, on which aluminum-lavsan tape is applied longitudinally or in a spiral with overlapping metal tape inward with tinned copper wire under the screen, while on top of the screen a lavsan ribbon is applied in a spiral with overlapping (“Cable products e. ”Volume 2. Cables, wires and communication cords. Part 2.“ Information and technical collection ”, M., OJSC“ VNIIKP ”).

However, these cables do not provide flame retardant requirements.

The prototype of the claimed utility model is a communication cable high-frequency station type KVSM, having modifications with one, two, four and eight pairs in the core. Moreover, a cable with more than one pair is produced by twisting single-pair cables into the core and applying a common protective sheath to the core (Journal of Communications Technologies, 2004, Mytishchi, Moscow Region, Utility Equipment, pp. 97-99) .

An electric single-pair communication cable of the KVSM type includes two conductive conductors with a diameter of 0.4 mm, equipped with insulating sheaths and twisted into a pair, on top of which there is a screen made of alumolavan with a metal layer inside with a screen wire under it. A moisture-proof polyvinyl chloride shell is applied over the screen, not

spreading combustion. Moreover, in this cable the insulating sheath has a normalized thickness equal to (0.425 ± 0.035) mm and provides a wave impedance of 120 ± 10 Ohms at a frequency of 1.024 MHz.

This well-known cable can only be used with the old known methods of installation using soldering when connecting the ends of the cores or screwing it in and cannot be used in modern connectors (connection unit) with knife connectors, as it has oversized structural dimensions.

The technical problem solved by the proposed utility model is the creation of an electric communication cable having the smallest possible size and providing the possibility of using it in modern communication equipment for transmitting digital high-frequency signals.

The technical problem is solved in that in the proposed utility model, which includes two conductive cores equipped with insulating shells and twisted into a pair, on top of which there is an electric screen, a wire located under the screen and a moisture-proof sheath that is not spreading on the screen, is new that the insulating shell of each core is made of foamed polyethylene or two-layer: of foamed polyethylene and a layer of solid polyethylene 0.05 mm thick or above ply: a layer of solid polyethylene 0.05 mm thick, a layer of foamed polyethylene located on top of it and located on top of the last layer of continuous polyethylene with a thickness of 0.05 mm, and the thickness of the insulation shell of foam polyethylene, or the total thickness of the two-layer insulation shell or total the thickness of the three-layer insulating shell, providing wave impedance in the range from

110 Ohms to 130 Ohms at frequencies of 1 MHz and more, and each equal to d-0.05 mm for conductive conductors with a diameter selected from the range: from 0.3 to 0.65 mm inclusively and diameter d for conductive conductors with diameter selected from the range: over 0.65 mm to 1.0 mm inclusive.

The implementation of the insulating sheath of foamed polyethylene provides a wave impedance of the cable at frequencies of 1 MHz and higher, which is in the range from 110 to 130 Ohms, because due to air bubbles, this material has a lower dielectric constant and, as a result, the working electric capacity decreases.

The use of a cable with a two-layer insulating sheath is advisable in conditions of high humidity.

The use of a cable with a three-layer insulating sheath is advisable in conditions where it is necessary to ensure adhesion of the insulation to the conductive core, for example, when there is pulling out the wires from the connection node (connector).

It is advisable when laying the cable in the ground, so that it additionally contains a layer of water-blocking material superimposed on the said moisture-proof sheath, armor made of metal wires and a moisture-proof hose.

To enable the cable to be suspended on poles and communication supports with gripper-type clamps, it is advisable that the single-pair cable additionally contains another protective sheath located on top of the moisture-proof sheath with a cable placed inside it, parallel to a pair of current-carrying conductors.

The technical problem is also solved by the fact that the proposed electrical communication cable, comprising at least two electric single-pair cables made according to claim 1 in a protective sheath.

This design of the cable simplifies the technology of laying several identical single-pair cables that perform the same functions.

Preferably, to ensure compact design, at least two of these single-pair electric cables are twisted together into a core placed in the said protective sheath made of a moisture-proof material that does not spread combustion.

To lay the cable directly into the ground, it is advisable that the multi-pair cable additionally contains a layer of water-blocking material superimposed on the protective sheath, armor made of metal wires and a moisture-proof hose.

To suspend the cable on poles and supports with gripper-type clamps, it is advisable that the multi-pair cable additionally contains another protective sheath located on top of the moisture-proof sheath with a cable placed in it parallel to the core.

To suspend the cable on poles and supports with spiral clamps of a twisting type, it is advisable that the multi-pair cable additionally contains a cable and at least two of these single-pair electrical cables twisted around it into the core, while the core is placed in the said protective sheath.

In the future, the proposed utility model of the communication cable is illustrated by specific examples and the accompanying drawings, in which:

figure 1 depicts a cross section of the proposed single-pair communication cable with a single-layer insulating sheath;

figure 2 - the same as in figure 1, but with a two-layer insulating sheath;

figure 3 - the same as in figure 1, but with a three-layer insulating sheath;

4 is a cross section of the proposed multi-pair electrical communication cable;

5 is a cross section of an armored electric communication cable;

6 is a cross section of a single-pair or multi-pair electrical communication cable with a cable integrated in the protective sheath;

7 is a cross section of a multi-pair electrical communication cable with a cable integrated in the core.

A single-pair communication cable 1 (Fig. 1) consists of two tinned copper conductive conductors 2, each of which is equipped with a single-layer insulating sheath 3 made of foamed polyethylene with a nominal thickness equal to d-0.05 mm for conductive conductors with a diameter selected from the range from 0.3 to 0.65 mm inclusive and equal to the diameter d for conductive cores with a diameter selected from a range of more than 0.65 mm to 1.0 mm inclusive. The insulating conductors 2 are twisted together in a pair, on top of which an electric screen 4 is laid with metal inward with a screen wire under the screen 5. A moisture-proof sheath 6 is applied to the screen 4, which does not spread combustion and is made of plastic, the nominal thickness provides wave resistance in the range from 110 up to 130 ohms at frequencies of 1 MHz or more.

Figure 2 shows an embodiment of the proposed single-pair electric communication cable 7 having a structure similar to the cable construction described above, but it has a double-layer insulation sheath

and consists of an inner layer 8 of foamed polyethylene and an outer layer 9 in the form of a thin film of continuous polyethylene having a thickness not exceeding 0.05 mm, and the total thickness of layers 8 and 9 is equal to the thickness of the shell.

Figure 3 shows another embodiment of the proposed single-pair electrical communication cable 10 having a design similar to that of the cable shown in figure 1, but it has an insulating sheath made of three layers and consists of an inner layer 11 in the form of a thin film of solid polyethylene with a thickness not exceeding 0.05 mm, the intermediate layer 12 of foamed polyethylene and the outer layer 13 in the form of a thin film of continuous polyethylene with a thickness not exceeding 0.05 mm, while the total thickness of all layers 11, 12 and 13 is equal and the thickness of the shell.

Figure 4 shows an electric communication cable 14, which consists of at least two single-pair cables 1 or cables 7 or cables 10, twisted together in a core, covered with a protective sheath 15 made of plastic.

To ensure the possibility of laying the cable directly into the ground, an armored cable 16 is made, shown in Fig.5. A single-pair cable 1 or cable 7, or cable 10, or cable 14 serves as the core for this cable. A layer 17 of release material, armor of round wires 18 and a moisture-proof hose 19 are applied over the core. Round wires 18 are layered in the form of a braid.

For the suspension on the supports of communication lines and fences, electric cables 20 (Fig. 6) with a built-in cable 21 and cables 22 (Fig. 7) with a built-in cable 23 are manufactured.

Cable 20 includes a single-pair cable 1 or cable 7, or cable 10, or the core of cable 14, formed from twisted together two single-pair cables 1 or cables 7, or cables 10 and a protective sheath 24, inside of which is placed a cable 21 located parallel to a pair of conductive lived or core.

Cable 22 includes a cable 23 with a polymer layer 25 and single-pair cables 1 or cables 7 or cables 10 twisted around it into the core and cables 10 and a common protective sheath 26 laid on top of the core.

Cable manufacturing technology according to the claimed utility model includes the following operations.

Conducting cores 2 are made of copper wire "wire rod" as a rule, with a diameter of 8 mm by drawing. Depending on the diameter of the finished conductive core, the following operations can be used: coarse and medium drawing or coarse, medium, fine drawing.

Conducting cores 2 can be tinned copper, un tinned copper, single-wire and multi-wire.

Single wire tinned wires are annealed to provide softness. Annealing is not required to obtain tinned veins. Tinning is done in a hot way, as a result of which the core becomes soft.

For stranded cores, the same technology is used to produce wire in the required amount, which is then twisted in the required combination on cigar, frame or lamp machines.

The insulation on the conductors 2 is applied by extrusion. When applying a single-layer insulation 3 of foamed polyethylene, one extruder is installed in the line, into which granules of polyethylene are loaded,

having a blowing agent. When applying double-layer insulation 8 and 9, two extruders are installed in the line, in one of which granules of ordinary polyethylene are loaded, in the other - granules of polyethylene containing a blowing agent. The extruders squeeze the mass into one forming head consecutively in distance, as a result of which concentric layers of different materials are formed on the conductive core 2 linearly moving through the head; inner 8 of foamed polyethylene and outer 9 of solid polyethylene. When applying a three-layer insulation 11, 12 and 13, three extruders are installed in the line, in two of which granules of ordinary polyethylene are loaded, in one - granules of polyethylene containing a blowing agent. The extruders squeeze the mass into one forming head consecutively over the distance, as a result of which concentric layers of different materials are formed on the conductive core 2 linearly moving through the head: the inner 11 is made of continuous polyethylene, the intermediate 12 is made of foamed polyethylene and the outer 13 is made of continuous polyethylene. Twisting of insulated conductive conductors 2 in a pair is usually carried out on twisting machines of frame twisting.

Screen 4 can be made in the following options:

- from alumolavsan tape;

- from alumina polyethylene tape;

- from aluminum-polyvinyl chloride tape;

- from a copper lavsan tape;

- from a copper-polyethylene tape;

- from copper-polyvinyl chloride tape;

- in the form of a braid from soft copper or tinned copper wires;

- in the form of a winding made of soft copper or tinned copper wires.

The use of screens 4 made of non-laminated metal tapes is unacceptable, since the technological integrity of the screen 4 is violated. Screening tapes can be applied in the form of spiral windings on special winding machines or devices combined with torsion machines, or longitudinally using special devices built into the extrusion line.

Screen 4 in the form of a braid is superimposed on braiding machines, and in the form of a winding - on special winding machines. In order to increase the density of the braid or winding, individual wires are collected in skeins (bundles of several wires laid in parallel) on reed machines.

Screen wire 5 in combination with a copper screen is made in the form of a soft copper wire, in combination with an aluminum screen - in the form of a tinned copper wire, it can be laid in a straight and zigzag shape, previously curved (corrugated) on a special device. In some cases, the screen wire is made flexible multi-wire. The technology for producing screen wire is the same as the technology for manufacturing a conductive core.

The plastic moisture-proof sheath 6 of single-pair cables 1, cables 7 and cables 10, multi-pair cables 14, respectively, can be made of both polyvinyl chloride plastic compound and halogen-free compound by extrusion. The twisting of the core of multi-pair cables 14 is made of single-pair cables 1 or cables 7, or cables 10 on a flashlight type machine.

For armored cable 16, a single-pair cable 1 or cable 7, or cable 10, or multi-pair cable 14 is taken, on which a tape of water-blocking material 17 is applied by winding in a spiral on a winding machine.

Also, a tape of water blocking material may be allowed under armor 18 for reservation operations. The application of the armor 18 can be carried out in the form of a braid with galvanized steel wires or similar materials on a braid machine or in a braid on an armor machine.

Moisture-proof sheath 19 is applied, as a rule, from polyethylene on an extrusion line.

The cable 21 is usually bought ready-made, twisted from metal wires, glass fibers or strong synthetic threads. The polymer insulation 25 of the cable 23 can be made of any polymer material by extrusion.

The protective sheath 24 and 26 is preferably made of polyethylene by extrusion, however, other polymers can be used instead of polyethylene. In this case, for the cable 20 shown in Fig.6, the sheath is superimposed on the core and the cable at the same time. In the core of the cable 22 shown in FIG. 7, the cable 23 is laid in the core for twisting operations, the cable arriving longitudinally, and single-pair cables are twisted around it.

Below is table 1, which shows the calculated values of wave impedances depending on the diameter of the conductive wires.

Table 1 Diameters d of conductive wires, mm The calculated values of the wave resistance. Ohm, at nominal insulation shell thicknesses single layer of foamed polyethylene two layer three layer 0.3 122.95 120.0 118.59 0.64 122.76 120,99 120.47 1,0 127.16 126.38 126.08

The permissible limits of wave impedance are 110-130 Ohms. The calculation of wave impedances was carried out according to the well-known method described in the book by I. I. Grodnev, S. M. Vernik “Communication Lines”, because of “Radio and Communication”, M., 1988, and in the book by B. M. Tareev “Physics of dielectric materials”, from “Energy”, M., 1973

Claims (8)

1. A single-pair electrical communication cable, including two conductive cores, equipped with insulating sheaths and twisted into a pair, on top of which an electric screen is placed, a wire located under the screen and a moisture-proof sheath that is not spreading on the screen, characterized in that the insulating sheath of each of the wires made of foamed polyethylene or two-layer: of foamed polyethylene and a layer of continuous polyethylene 0.05 mm thick located on top of it or three-layer: layer of continuous polyethylene polyethylene 0.05 mm thick, a layer of foam polyethylene located on top of it and located on top of the last layer of solid polyethylene 0.05 mm thick, and the thickness of the insulation shell of foam polyethylene or the total thickness of the two-layer insulation shell, or the total thickness of the three-layer insulation shell wave resistance in the range from 110 Ohms to 130 Ohms at frequencies of 1 MHz or more, each of them is equal to d-0.05 for conductive conductors with a diameter selected from the range from 0.03 to 0.65 mm inclusive and diameter d for conductive conductors with a diameter selected from the range: over 0.65 mm to 1.0 mm inclusive, where d is the diameter of the conductive core. 2. The cable according to claim 1, characterized in that it further comprises a layer of water-blocking material superimposed on the said moisture-proof sheath, armor made of metal wires and a moisture-proof hose. 3. The cable according to claim 1, characterized in that it further comprises a protective sheath located on top of the moisture-proof sheath, and a cable placed therein parallel to a pair of conductive cores. 4. An electric communication cable containing at least two single-pair cables according to claim 1, enclosed in a protective sheath. 5. The cable according to claim 4, characterized in that at least two of the aforementioned electric single-pair cables are twisted together into a core placed in the said protective sheath made of a moisture-proof material that does not spread combustion. 6. The cable according to claim 5, characterized in that it further comprises a layer of water-blocking material superimposed on the said moisture-proof sheath, armor made of metal wires and a moisture-proof hose. 7. The cable according to claim 5, characterized in that it further comprises a protective sheath located on top of the moisture-proof sheath and a cable placed therein parallel to the core. 8. The cable according to claim 4, characterized in that it further comprises a cable and at least two of the aforementioned single-pair electric cables twisted around it into the core, the core being housed in said protective sheath.