RU51239U1 - CABLE ACCESS TO ACCESS CAMERA - Google Patents

Abstract

The utility model relates to fiber-optic technology and can be used in the construction and operation of fiber-optic communication lines using optical cables laid in the ground and in cable ducts from protective plastic pipes6, and is aimed at increasing strength, improving tightness, as well as ease of installation input. The specified technical result is achieved by the fact that the cable entry contains an additional nozzle made in the form of a piece of protective plastic pipe fixedly mounted and sealed on a collar of a collapsible fitting, a mechanical adapter sleeve with a remote internal stop is fixedly installed on the additional nozzle and inlet of the access chamber, and the adjacent to a collapsible fitting, a part of the outer sheath of the input optical cable, a collapsible fitting and a part of an additional sealing branch heat shrinkable tube.

Description

The invention relates to fiber-optic technology and can be used in the construction and operation of fiber-optic communication lines using optical cables laid in cable ducts from protective plastic pipes when connecting them to other types of cables.

At the ends of the construction lengths of the laid optical cables, access cameras (viewing devices) are installed for blowing the next construction length of the cable, laying optical connectors or junction boxes and storing cable stocks. The inlet nozzles of the access chambers are made in the form of pieces of plastic pipes that are mounted on the camera body so as to ensure the strength and tightness of their connection with the camera body. The connection of the inlet pipes of the access chamber with the protective plastic pipes of the cable duct is made using connecting straight or transitional mechanical or electric-welded couplings.

For laying cables in cable ducts from protective plastic pipes, as a rule, optical cables are used that have or without armor-coated synthetic fibers, and which are characterized by insignificant allowable tensile forces (1-2.5 kN) [Rules for the construction of fiber -optic lines of railway communication with laying cables in plastic pipelines. Approved By the order of the Ministry of Railways of the Russian Federation No. A-1062U of June 16, 1999, 114 pp.].

The process of introducing such cables into the access cameras does not cause special difficulties and ensures the tightness of the cable entry by installing plugs for optical cables, for example SIMPLEX JACKMOON, in the inlet pipes, and the strength is due to

mechanical characteristics of the assembled elements: a protective plastic pipe suitable for the chamber — a mechanical coupling — an inlet pipe and an access chamber housing. Thus, these elements play the role of an additional armored cable cover and provide the necessary cable tensile and crushing strength.

When switching from a cable laid in a protective plastic pipe to another type, for example, to a cable with round wire armor, with steel corrugated tapes, with synthetic armor cover from fiberglass rods or aramid fibers, problems arise with the strength and tightness of the cable entries of the listed cables into the access chamber . These problems are especially acute for cables armored with round wire armor and fiberglass rods. These cables are laid underground and absorb the tensile and crushing load mainly due to the mechanical properties of the armored cover. Available sources, existing instructions and installation rules for linear-cable communication facilities lack the fundamental possibility of reliable entry of armored cables, as well as structural solutions containing power elements connecting the armor of the cable to the inlet pipes of access cameras. Lack of proper attention to these problems leads, under possible mechanical stresses, to tearing armored cables out of the access chamber. The connection of the mechanical adapter sleeve of the inlet of the access chamber with the armored cable does not provide the necessary strength and tightness due to the mismatch between the actual cable diameters and the fixed values of the coupling diameters, as well as due to the absence of a rigid connection between the outer sheath of the cable and its armor cover.

These problems can be solved in two ways:

1. By connecting armored cables with cables laid in protective plastic pipes directly to

dead end optical coupler [Method for connecting optical cables laid in plastic underground pipelines. Patent RU 2 245 567 C1, IPC G 02 B / 36, 6/52; Coupler for optical cables laid in underground plastic pipes. Patent RU 36 902 U1, IPC G 02 B 6/52].

2. The proposed technical solution, in which the connection of the armored cover of the optical cable with the inlet of the access chamber ensures the strength and tightness of such a connection.

The design of the SIMPLEX JACKMOON bushing plug for optical cables is known (US Patent 4,842,364), [http://www.raychem-telecom.ru/index.php?id=9], which is installed in a protective plastic pipe with a maximum diameter of up to 63 mm or in the inlet pipe of the access chamber for sealing single cables. The bushing is installed in the cable duct. The plug has a collapsible design and is not intended for power fixing the cable during its possible longitudinal movement. The overall dimensions of the passage plugs in the cross section exceed the corresponding hole sizes in the protective plastic pipes and in the inlets to the access chambers, which implies the installation of the plugs only at the ends of the pipes or inlets, therefore it is made from the inside of the access chamber, which is extremely inconvenient, especially when using the camera sizes and installed in the pit. In addition, significant deviations in the shape of the openings of the inlet nozzles in the longitudinal and cross sections in existing access chambers, for example, KOT-2, Uponor, made by rotational molding, in most cases do not allow installing plugs through them, therefore, the tightness of the chamber is not ensured.

A known design of a dead end sleeve for an optical cable with sealed fittings for input and output optical

cables ... [Patent RU 2 174 250, IPC G 02 B / 40, H 02 G 15/04], which is the closest analogue and in which the ends of optical cables with armored covers after their cutting are sealed in special collapsible fittings, which are then inserted in the nozzle of the headband, and securely fastened and sealed in it by heat-shrinkable tubes (TUT) over the outer sheath of the cable and the fingers of the headband. The sealing of optical cables in the fittings, including between the steel wires of the armor, is performed using special sealing tapes, crushed when the armor wires are pinched between the conical surfaces of the inner sleeve and the outer cone of the nozzle when the nozzle rod is screwed onto it. This design ensures the tightness of the input armored cable and the strength of its termination at the level of up to 80% of the permissible tensile force of the cable. However, the use of such fittings is possible only after changing the design of the known access chambers and equipping them with inlet nozzles of the required sizes, which will lead to the inability to enter protective plastic pipes. In addition, the assembly and installation of such fittings is also extremely inconvenient when using a small camera installed in the pit because of the need to carry out work on fixing the fittings inside the access chamber and sealing the input of the HER inside the pit.

The essential features of the claimed utility model are: the presence of an access camera with inlet nozzles, a collapsible fitting with an armored assembly, sealed on an optical cable made with round-armored armor, or corrugated steel tapes, or with synthetic armored cover made of fiberglass rods or aramid fibers, an additional nozzle made in the form of a piece of a protective plastic pipe, fixedly mounted and sealed on a collar of a collapsible fitting, for additional patrol side and inlet

the access chamber is fixedly mounted with a mechanical adapter sleeve with a remote internal stop, and the part of the outer sheath of the input optical cable adjacent to the collapsible fitting, the collapsible fitting and part of the additional pipe are sealed with a heat-shrinkable tube.

These essential features of the utility model allow to obtain a technical result, which consists in ensuring the strength and tightness of the cable entry of the armored cable into an existing or new access chamber, as well as in the convenience of its installation.

The salient features of the utility model from the closest analogue are: an additional pipe made in the form of a piece of a protective plastic pipe that is fixedly mounted and sealed on a collapsible fitting rod; a mechanical adapter sleeve with a remote internal stop is fixedly mounted on an additional pipe and an inlet pipe of the access camera the part of the outer sheath of the input optical cable adjacent to the collapsible fitting, the collapsible fitting and a part of an additional cable the tube is sealed by a heat-shrinkable tube.

In the proposed utility model, an increase in strength and tightness is achieved through the use of a mechanical adapter sleeve with a remote internal stop, a collapsible fitting, a sealant, and a heat-shrinkable tube. Thus, the well-known design of a mechanical adapter sleeve, for example, Plasson, designed to connect the ends of protective plastic pipelines of various fixed diameters (25 mm, 32 mm, 40 mm, 63 mm) [http://www.plasson.com/index.html LineT Series 7110], ensures the tightness of the connection of protective plastic pipelines at a pressure of up to 16 Bar, as well as mechanical

tensile strength commensurate with the strength of the connected pipelines. Removing the internal stop in the sleeve provides ease of assembly of the cable entry and does not affect the mechanical tensile strength of the sleeve.

The known design of the cable entry - the closest analogue ensures the tightness of the input armored cable and the strength of its termination at a level of not less than 80% of the allowable tensile force of the cable. A patent holder - a manufacturer of couplings with such inputs (Svyazstroydetal CJSC) serially produces sets for inputting armored cables, which include collapsible fittings for fastening and sealing cables with round-wire armor, with corrugated steel tapes, with synthetic armored cover from fiberglass rods or aramid fibers. All of them are interchangeable on landing surfaces and are used in the proposed technical solution.

The use of an additional nozzle made in the form of a piece of a protective plastic pipe fixed (without a gap) installed and sealed on a collar of a collapsible fitting allows using the mechanical adapter sleeve to firmly and hermetically connect the inlet of the access chamber and the collapsible fitting.

The use of heat-sealed TUT tubes with an adhesive layer, for example MWTM or XCSM manufactured by Rayhem (Tuso Electronics) [http://www.raychem-telecom.ru/index.php?id=15] allows for tightness and additional mechanical protection, protection from corrosion and insulation of metal elements of the cable entry.

The use of the proposed cable entry makes it unnecessary to install a sealing cable entry, for example, SIMPLEX JACKMOON, into the opening of the inlet pipe inside the access chamber housing.

The location of the proposed cable entry outside the access camera provides ease of installation due to the exclusion of work performed in cramped conditions inside the camera.

Using the proposed cable entry provides the fundamental possibility of a durable and tight entry of armored cables into the access chamber.

Figure 1 presents a General view of the cable entry into the access chamber, as an option, for a cable armored with round wire armor or fiberglass rods.

Figure 1 shows: an access chamber 1 with an inlet pipe 2, a mechanical adapter sleeve 3 with a remote internal stop, a collapsible fitting 4, an additional pipe 5, an optical cable 6, an optical cable with armor protection 7 removed, an armor ground wire of an optical cable 8, heat shrinkable tube 9, sealant 10.

The device operates as follows. Previously, outside the pit, they cut the armored cable 6, remove the outer shell and cut the armor at the desired distance from the end of the inlet pipes 2. This creates a reserve of optical cable with removed armor protection 7, which is then placed in the access chamber 1. On a standard sleeve 3 mechanically remove the internal stop restricting the movement of the additional pipe 5. A sealant 10 is applied to the cylindrical part of the fitting 4 and an additional pipe 5 is pushed onto it, and a mechanical adapter ft 3 and fix it. A heat-shrinkable tube 9, a plastic cap and a threaded part of the outer cone of the fitting 4 are sequentially pushed onto the cable 6. optical cable, fasten it and an additional pipe 5 with a nut (not marked

numbered elements are part of a collapsible fitting 4). The nozzle 4 is assembled according to the manufacturer's recommendations (Svyazstroydetal CJSC), and the cable is sealed with the armor removed 7 in the nozzle 4, including between the armor elements, which is performed using special sealing strips 10, crushed when the armor elements are pinched between the conical the surfaces of the inner sleeve and the outer cone of the fitting 4 when screwing on the shaft of the fitting. An earth cable for the armor of the optical cable 8 is connected to the fitting, which, together with the cable with the removed armor protection 7, is inserted into the access chamber housing 1 through the inlet pipe 2. The part of the outer sheath of the input optical cable 6 adjacent to the collapsible fitting and the part of the collapsible fitting protruding from the coupling 3 4 with an additional pipe 5 push the heat-shrinkable tube 9 and produce its shrinkage. Lower the assembled cable entry into the pit and push the mechanical adapter sleeve 3 onto the inlet pipe 2, and then fix it.

An example of the implementation of the claimed utility model can be a cable entry into the access chamber 1, for example, into the optical pipe chamber KOT-2 manufactured by 000 Tvertrubplast, having inlet pipes 2 made in the form of pieces of plastic pipes with dimensions of 40 mm / 33 mm. The cable entry consists of a mechanical adapter (F 40 mm / F 25 mm) coupling 3 - Plasson Cat. No. 71100254, collapsible fitting 4 from set No. 4, used for inputting armored cables, manufactured by Svyazstroydetal CJSC (Moscow), additional branch pipe 5 - a piece of protective plastic pipe of standard size F 25 mm / F 21 mm, ground wire of the armor of the optical cable 8 - GLP, piece of heat-shrinkable tube TUT 9 - MWTM - 35/12 - 1000, sealant 10 - 2900R. At the same time, the diameter of the input optical cable without armor is 7 to 14 mm.

Claims (1)

A cable entry into the access chamber with inlet pipes, comprising a collapsible fitting with an armored assembly, sealed on an optical cable made with round-armored armor or steel corrugated tapes, or with a synthetic armored cover made of fiberglass rods or aramid fibers, characterized in that it contains an additional nozzle made in the form of a piece of a protective plastic pipe, fixedly mounted and sealed on a collar of a collapsible fitting, to an additional pipe and inlet the access chamber pipe is fixedly mounted with a mechanical adapter sleeve, and the part of the outer sheath of the input optical cable adjacent to the collapsible fitting, the collapsible fitting and part of the additional pipe are sealed with a heat-shrinkable tube.