JPS63125903A - Traction part for cable with optical connector - Google Patents

Abstract

PURPOSE:To treat and connect the excessive-length part of a cable in a narrow manhole or a manhole where cables are converged, or on a pole by arranging an optical fiber core protection sleeve composed of a detachable corrugated circular pipe for converting cable excessive length to core excessive length and treating the cable at a traction part. CONSTITUTION:The traction part is constituted by connecting a core protection sleeve 18 for absorbing cable excessive length, a core protection sleeve 23 for securing core connection excessive length, and a traction cap 28 to a plug 12 for cable connection which is fitted to a terminal of an optical cable 1 by screw clamping successively. The core protection sleeve 18 for cable excessive length absorption is structured by forming a screw part 20 at one end of the corrugated metallic circular pipe 19 and arranging a coupling nut 21 in the same shape with a coupling nut 14 and a rubber ring 22 at the other end. Consequently, the cable with the optical connector can be applied.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a traction section for laying a cable with an optical connector.

(Prior Art) In order to construct a subscriber communication system using optical cables, technology for laying and connecting optical cables equipped with multi-core optical fibers is essential. Conventionally, optical cables have been installed by attaching a towing part with a towing eye nut to the cable terminal and towing this.The optical cable is connected by cutting the towing part and then using a closure (a case that protects the connection part). The tensile strength body and sheath of the cable end are fastened to the closure using It is done by storing it.

In this method, optical fibers with very small diameters are connected using a connecting tool or a connecting device at a construction site, so the connection workability is poor and it takes a long time to connect. Furthermore, since fusion splicing, which is a semi-permanent connection, is used, there is a drawback that it is not possible to immediately respond to changes in the number of subscribers, isolation in the event of a failure, or connection replacement for emergency recovery. Therefore, in order to shorten connection work time and facilitate connection changes, the development of cables with optical connectors in which optical connector plugs are attached in advance to the optical fiber cores at the terminals of the optical cables is being developed.

With cables with optical connectors, fiber connection work at construction sites can be performed by simply mating optical connector plugs that have already been attached to optical fiber cores at factories or construction bases, and they can also be easily attached and detached. can.

In order to realize this cable with an optical connector, the installation traction part attached to the cable terminal must be able to protect the optical connector plug from external forces during installation, and also pass through the conduit for underground installation and the installation wheel for overhead installation. It is necessary that the diameter be as small as possible. Furthermore, it is necessary to match the length of the optical connector-equipped cable to the length of the installation route.

FIG. 4 shows the structure of a towing section of a conventional cable with an optical connector for subscriber wiring. The optical cable 1 has a structure in which a plurality of optical fiber cores 3 are arranged around a tensile strength member 2 made of stranded steel wires, and the outer sheath 4 covers the tensile strength member 2 . The optical fiber core 3 exposed from the cable terminal has a length that ensures the extra length necessary for connection, and an optical connector plug 5 is attached to the end of this core to protect the flexible connector. It is stored inside the tube 6. The strength member 2 at the cable end is connected to a traction strength member 8 via a strength member connection portion 7, and further to a traction member 10 having a traction eye nut 9. A connector protection plate 11 is arranged between the tensile strength member 8 passing through the center of the towing section and the connector protection tube 6 on the outer periphery.

Therefore, the traction tension during installation is carried directly by the cable's tensile strength body, and when passing through bends on the installation route,
The elastic deformation of the tensile strength member 8 and the connector protection tube 6 deforms the entire connector protection group so that it can be passed through.

After installation, the connector protection tube 6 of the towing section is removed, the tensile strength member connecting section 7 is cut off, and the cable's tensile strength body 2 and sheath 4 are secured to the closure assembled at the construction site to connect the cable to the outer sheath.

Next, connect the optical connector plugs that are attached to the optical fiber cores to be connected, and connect the fibers by storing this connection part and the extra length of the fiber core in the fiber processing sheet inside the closure. I do.

Regarding the length of the cable, before laying the cable, pass a string through the underground conduit or overhead route to accurately measure the length of the cable, add measurement errors and cable manufacturing errors to this, and determine the length of the cable. The length of the cable is determined so that it is not shorter than the actual length of the installation route. In underground installations, the remaining cable after installation is disposed of by winding it into a coil or removing slack by winding it into a coil inside the manhole to which it is to be connected. In addition, when installing overhead cables, surplus cables are distributed and disposed of by removing slack at the edge of each utility pole, and the connection section is positioned at the edge of the utility pole to be connected, so that connection work can be performed from above the pole. ing.

In practice, the towing section of such a cable with an optical connector has the following drawbacks.

(11) Since the tensile strength body penetrates through the center of the traction part, it is possible to prevent the tensile strength body from becoming eccentric from the center of the connector protection tube and hitting the optical connector plug when passing through the bent part during installation. First, there remains the risk of damage to the optical connector plug.Furthermore, the storage space for the optical connector plug is limited, making it difficult to accommodate the increase in the number of optical cables.

(2) Prior to installation, it is necessary to accurately measure the installation route. This measuring work becomes difficult to carry out because it becomes enormous and diverse as the subscriber communication system expands.

Furthermore, in the case of underground installation, it is difficult to dispose of the excess cable after it has been laid by removing the coils inside the manhole, since it is difficult to secure the space necessary for removing the coils in narrow manholes or manholes in urban areas that are full of cables. It cannot be implemented.

In addition, in the case of overhead installation, excess cable is processed by removing slack at the edge of each utility pole, but if the slack cannot be removed, it is necessary to remove the coil at the edge of the utility pole.

Therefore, it is not possible to secure the necessary space to remove the coil from utility poles in urban areas where the cables are congested.

(Problems to be Solved by the Invention) The present invention enables connections to be made without having to measure the route at the installation site. The object of the present invention is to provide a towing section for a cable with an optical connector.

(Means for Solving the Problems) The present invention has a towing section that exposes an optical fiber core wire with an optical connector plug in front of a circular tube, and connects the optical cable with the tensile strength body of the optical cable held at the rear of the circular tube. a cable connection plug to be attached to the terminal of the optical fiber, an optical fiber protection sleeve consisting of a corrugated circular tube that accommodates the optical fiber core portion of the optical fiber core with the optical connector plug; It is constructed by accommodating the optical connector plug portion of the optical fiber core wire with a connector plug, and sequentially fastening screws to a traction cap having a traction end attached to one end of the circular tube.

The present invention differs from the conventional technology in that an optical fiber protection sleeve made of a removable corrugated circular tube is disposed in the traction section to convert excess cable length into excess cable length for disposal.

(Example) Figures 1 to 3 show examples of the present invention, in which Figure 1 is a perspective view when the traction section is assembled, Figure 2 is a sectional view when the traction section is assembled, and Figure 3 is a sectional view when the traction section is assembled. The figure is a perspective view of the towing section separated. In Figures 1 to 3, 1 is an optical cable, 2 is a tensile strength member of the optical cable, 3 is an optical fiber core, 4 is an outer jacket, 5 is an optical connector plug, 12 is a cable connection plug, and 13 is a metal circle. pipe, 14 is a coupling nut, 15 is a rubber ring, 16 is a tensile strength body retaining fitting, 17
18 is a cable protection sleeve for absorbing excess cable length, 19 is a corrugated metal circular tube, 20 is a threaded portion, 21 is a coupling nut, 22 is a rubber ring, and 23 is for securing extra cable connection length. Wire protection sleeve, 24 is a corrugated metal circular tube, 25 is a threaded portion, 26 is a coupling nut, 27 is a rubber ring, 28 is a towing cap, 29 is a metal circular tube, 3
0 is a threaded portion, 31 is a traction eye nut, and 32 is a traction end.

As shown in Figures 1 to 3, the towing section is connected to the optical cable 1.
A cable protection sleeve 18 for absorbing excess cable length, a cable protection sleeve 23 for securing excess cable connection length, and a towing cap 28 are sequentially screw-fastened to the cable connection plug 12 attached to the terminal of the cable. The cable connection plug 12 has a structure in which a coupling nut 14 and a rubber ring 15 are arranged at the front part of a metal circular tube 13, and a tensile strength body retaining fitting 16 having a cylindrical part with a tensile strength body insertion hole formed at the rear part. The tensile strength member 2 of the optical cable is placed therein, and an optical fiber core ``&'i3'' with a plurality of optical connector plugs is passed through the inside thereof.

Next, the structure of the cable protection sleeve 18 for absorbing excess cable length is such that a threaded portion 20 that fits into the force/knob ring nut 14 of the cable connection plug is formed at one end of the corrugated metal circular tube 19, and a cup is formed at the other end. A coupling nut 21 having the same shape as the ring nut 14 and a rubber ring 22 are arranged. Next, the structure of the cable protection sleeve 23 for securing extra cable connection length is as follows.
This is basically the same as the corrugated metal circular tube 24, with a threaded portion 25 formed at one end, and a coupling nut 26 and a rubber ring 27 arranged at the other end. Next, the structure of the towing camp includes a towing part 32 having a threaded part 3o formed at one end of the metal circular tube 29 and a towing eye nut 31 at the other end.
is attached.

To attach the cable connection plug 12, first remove the outer sheath 4 etc. from the terminal of the optical cable 1, and then attach the optical fiber core 3.
expose. Next, the tensile strength member 2 at the cable end is secured to the tensile strength member retaining fitting 16.

This fastening is carried out by filling the insertion hole of the cylindrical part of the fastening fitting with adhesive, inserting the tensile strength member, and then curling the cylindrical part from the outside. As a result, the tensile strength member 2 is firmly fixed to the retaining fitting 16 by adhesion and tightening. Next, the cable sheath 4 is gripped and fixed by the sheath gripping fitting 17. Next, an optical connector plug 5 is attached to the end of the optical fiber core 3. Finally, after passing the optical fiber core 3 with an optical connector plug through the inside of the metal circular tube 13,
The rear end and the front end of the jacket gripping fitting 17 are fitted together with the tensile strength member retaining fitting 16 sandwiched therebetween, thereby completing the assembly of the cable connection plug.

To assemble a towing section using this cable connection plug 12, first, the optical fiber core 3 with the optical connector plug exposed from the cable connection plug is passed through the inside of the cable protection sleeve 18 for absorbing excess cable length. After that, the coupling nut 14 of the cable connection plug is fitted to the threaded portion 20 with the rubber ring 15 interposed therebetween. At this time, the rubber ring is compressed and deformed to seal the gap between the fitting parts and prevent water from seeping through the fitting parts.

Next, the core wire 3 with the optical connector plug exposed from the core wire protection sleeve 18 for absorbing excess cable length is passed through the core wire protection sleeve 23 for absorbing excess cable length, and then the coupling nut 21 is inserted into the threaded portion 25. are fitted with the rubber ring 22 sandwiched between them. Finally, after storing the end portion of the core wire 3 including the optical connector plug 5 inside the towing cap 28, the coupling nut 26 is fitted into the threaded portion 30 with the rubber ring 27 sandwiched between them, and the towing cap 28 is towed. Complete the assembly of the parts.

The cable connection plug and towing section described above are assembled at a factory or construction base. An optical cable with a towing section will be delivered to the construction site. Laying is carried out by towing the towing eye nut 31 at the tip of the towing section. In order to make the connection after installation, a closure having a structure in which threaded portions that fit into the coupling nuts 14 and 21 are formed on both end faces of an existing closure is used. First, the towing camp 28 and the sleeve 23 for securing extra cable length are unfastened and removed from the towing section. Next, the core wire 3 with the optical connector plug exposed from the core wire protection sleeve 18 for absorbing excess cable length connected to the cable connection plug 12 is passed through the threaded part on the end face of the closure and drawn into the closure. Extra length absorption core wire protection sleeve 1
Fit the compling nut 21 of No. 8 into the threaded portion on the end face of the closure. Similar processing is performed for the towing portion of the cable with an optical connector to be connected. Next, the optical connector plugs to be connected are connected to each other within the closure, and the connecting portion and the extra length of the core wire to be connected are stored in a core wire treatment sheet within the closure to complete the connection. If the extra length of the cable that has been laid cannot be removed by removing the cable, attach the cable protection sleeve 18 to the cable connection plug 12 for absorbing the excess cable length.
Release the screw fastening and remove it, and convert the cable surplus length to core wire surplus length. In this case, cable connection plug 1
Fit the coupling nut 14 of No. 2 into the threaded portion on the end face of the closure, and connect the connection portion between the optical connector plugs, the connecting extra length core wire, and the core wire converted from the cable surplus length to the core wire length inside the closure. Connection is made by storing it in a wire treatment sheet.

The length of the cable protection sleeve 18 for absorbing excess cable length varies depending on the installation conditions such as the length of the installation route.
As an example, a case will be described in which a 60-fiber optical cable commonly used for overhead wiring is installed at a length of approximately 250 m, which is considered to be the longest cable.

First, the length of the installation route is calculated from the equipment record drawing. Facility record drawings usually record the distances between utility poles, and the distances between utility poles are added up along the installation route. The distance between utility poles is 50 m, and the error in this distance is ±0.5 m. If the added installation route length is 250m, ±2.
There will be an error of 5m. To avoid cable length being too short after installation, take the maximum error on the positive side (250
+2.5)m, plus ±0 error during cable manufacturing.
．． If it is 5m, add this error (250+3)
m. The actual installation route length is (250-2,5) m when the maximum error on the negative side is taken. Therefore, the maximum remaining length of the cable after installation will be 5°5m. This excess cable length can be partially absorbed by removing slack in the cable at each utility pole. The absorption amount for each utility pole is approximately 0.5m, and the total absorption capacity is approximately 2.5m. Therefore, when the maximum cable length after installation is 5.5m, excluding the approximately 2.5m that can be absorbed by removing slack, approximately 3.
An extra cable length of m is left. Therefore, if the length of the sleeve for absorbing the excess cable length at the dam is set to a total of 3 m at both ends, even when the maximum excess cable length occurs,
The cable surplus length can be converted into a core wire surplus length and stored in the closure, and the position of the connection part can be set at a predetermined position on the utility pole to be connected. Note that the sleeve for absorbing the excess cable length may be divided into parts. The length of the sleeve for securing extra length for connecting the core wires is approximately the same as the length of the conventional bracing part, which is approximately 1 m.

According to the above-mentioned configuration of the tie-down part, the tensile strength body of the optical cable is held in place by the retaining metal fitting provided at the rear of the hold-down part, and the pulling tension during installation is based on the metal circular tube of the towing camp and the core protection sleeve. It is attached to the outer periphery of the corrugated metal circular tube and the metal circular tube of the cable connection plug. Compared to conventional dams, the tensile strength body does not penetrate inside, so
You can take up a large storage space for the optical connector plug,
A large number of optical connector plugs can be stored at high density. In addition, since the optical connector plug is housed inside the highly rigid circular metal tube, there is no risk of the optical connector plug being damaged by external force during installation. In addition, since the core wire protection sleeve uses a corrugated metal circular tube that has high mechanical strength and flexibility, it protects the core wire from external forces during installation and allows it to easily pass through bends. .

Furthermore, when connecting after installation, the cable protection sleeve, which is a component of the dam, can be easily removed by releasing the screws, allowing excess cable length to be converted to excess cable length and disposed of within the closure. It is possible.

Therefore, there is no need to actually accurately measure the route at the installation site prior to installation, as is the case in the past, and it is sufficient to read the length of the installation route from the equipment record drawing. Also, conventionally,
It can also be applied over manholes and pillars where narrow manhole cables are crowded, where it is difficult to apply cables with optical connectors.

(Effects of the Invention) As explained above, the fin section of the optical connector-equipped cable of the present invention is provided with a cable connecting plug for retaining a tensile strength member attached to the cable terminal, and a cable connecting plug for retaining the tensile strength member attached to the cable end, and a core of the optical fiber core wire equipped with the optical connector plug. A fiber protection sleeve for storing the wire portion and a towing cap for storing the optical connector plug portion of the optical fiber core with an optical connector plug are sequentially screwed together. can store optical connector plugs in a high density.
This has the advantage that there is no risk of damage to the optical connector plug due to external force. Furthermore, by simply removing the core wire protection sleeve from the dam by releasing the screws, the excess cable length generated after installation can be converted to excess core length, making it possible to dispose of the excess length within the closure. Therefore, there is no need to physically measure the cable installation route, and the cable with an optical connector can be applied to routes including narrow manholes, manholes and pillars where cables are crowded. This advantage becomes more effective as the subscriber communication system expands.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of an assembled towing unit according to an embodiment of the present invention, Fig. 2 is a sectional view of an assembled towing unit of an embodiment of the present invention, and Fig. 3 is an assembled perspective view of a towing unit according to an embodiment of the present invention. FIG. 4 is a perspective view when the traction section of the embodiment is separated, and FIG. 4 is a sectional view of the traction section of a conventional cable with an optical connector for subscriber wiring. 1-Optical cable 2-Strength member 3...-Optical fiber core 4-Sheath 5-Optical connector plug 6-Connector protection tube 7-Tensile member connection portion 8-Tension member for traction 9--
Towing eye nut 10--Towing part II--Connector protection plate 12--Cable connection plug 13-Metal circular tube 14-Coupling nut 15--Rubber ring 16--Tension member retaining fitting 17-・Sheath gripping fitting 18-・Core protection sleeve for absorbing excess cable length 19-・
- Corrugated metal circular tube 20 - Threaded portion 21... - Coupling nut 22... Rubber ring 23 - Core wire protection sleeve 24 for ensuring extra length for core wire connection.
- Corrugated metal circular pipe 25 - Threaded part 26 - Coupling nut 27 - Rubber ring 28 - Towing cab 2
9-- Metal circular tube 30...- Threaded part 31-
Towing eye nut 32--- Towing end

Claims (1)

[Claims] 1. Arranging a plurality of optical fibers around a tensile strength member,
Targeting an optical cable with a sheath, the towing part is used to install a cable with an optical connector, in which an optical connector plug is attached to the optical fiber core exposed from the end of the optical cable. A cable connection plug that exposes the optical fiber coated wire with the connector plug and attaches it to the terminal of the optical cable with the tensile strength member of the optical cable held at the rear of the circular tube, and the optical fiber core of the optical fiber coated wire with the optical connector plug. an optical fiber core protective sleeve consisting of a corrugated circular tube for housing a wire portion; an optical connector plug portion of the optical fiber core with an optical connector plug is housed inside the circular tube; and one end of the circular tube. 1. A towing part of a cable with an optical connector, characterized in that the towing cap is attached with a towing end, and the towing cap is sequentially fastened with screws. 2. In the towing section of a cable with an optical connector as set forth in claim 1, the cable connection plug has a coupling nut disposed at the front part of the circular tube and a tensile strength body retaining fitting at the rear part, and the optical cable The optical fiber core protective sleeve has a structure in which a tensile strength body is held back, and the optical fiber core protection sleeve has a threaded portion that fits into the coupling nut of the cable connection plug at one end of the corrugated circular tube, and a threaded portion that fits into the coupling nut of the cable connection plug at the other end. The towing cap has a structure in which a coupling nut having the same shape as the coupling nut of the plug is arranged, and the towing cap has a threaded part formed at one end of the circular tube to fit into the coupling nut of the optical fiber core protection sleeve, and the other end A towing section of a cable with an optical connector, characterized in that a towing end having a cable towing eye nut is attached to the towing part of the cable.