JPH0527703U - Optical fiber cable towing end structure - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a pulling end structure of an optical fiber cable in which the numbers of the optical fiber core and the connector can be easily identified and the workability is improved. [Structure] A pulling end structure in which a protection pipe 4 is attached to an end portion of an optical fiber cable having a plurality of optical fiber core wires 1 ... The core wires 1 ... Are divided into predetermined groups and inserted. A plurality of unit tubes are attached to the tube holders 25 ...
Holds 34 ...

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a pulling end structure used when pulling and laying an optical fiber cable.

[0002]

[Prior Art]

 In the past, in order to save labor in optical fiber cable connection work, a connector for connection was previously attached to the tip of the optical fiber core wire of the optical fiber cable at the factory, and a protective pipe was installed to protect the cable during storage and installation. They are shipped with the covered tow end formed, and the cable with the connector still attached is towed and laid in the pipeline, etc. at the site.

As shown in the simplified diagram of FIG. 9, the internal structure of the towing end is such that the connector mounting positions are dispersed in the longitudinal direction to prevent the connectors a ... Optical fiber cores f ... are held by a proper number of fiber holders d ... And connector holders e. Met.

[0004]

[Problems to be solved by the device]

 However, in an ultra-multifiber optical fiber cable with thousands of optical fiber cores, the number of connectors to be installed will increase from several hundreds to several thousands, so holding and connecting the connectors to the holder, etc. In this case, it becomes difficult to identify the numbers of the optical fiber core wire and the connector, and the workability becomes extremely poor.

Further, in the conventional pulling end structure of an optical fiber cable, when connecting each connector with a connection box or the like, the optical fiber core wire is entangled when the pulling end is disassembled and the connector is taken out. There was a problem of damaging the core wire and the connector.

Therefore, the present invention solves the conventional problems described above, and provides a pulling end structure for an optical fiber cable in which the numbers of the optical fiber core and the connector can be easily identified and the workability is improved. With the goal.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention has a pulling end structure in which a protective pipe is attached to an end portion of an optical fiber cable having a plurality of optical fiber core wires, and the pulling end structure includes a plurality of long and flexible fibers. The optical fiber core wires are inserted into the unit tube in predetermined groups, and the unit tubes are held in tube holders arranged in the protective pipe in the longitudinal direction at predetermined intervals. ..

[0008]

[Action]

 According to this unit tube, even in an ultra-multifiber optical fiber cable, the optical fiber core wires are divided into predetermined groups, so that the optical fiber core wires and the connector can be held or connected to the holder. The number can be easily identified.

Further, even if the pulling end is disassembled and the connector is taken out, the optical fiber core wire is held in the unit tube, so that it does not become disentangled and entangled. Moreover, when the unit tube is installed in the protective pipe, the interval between adjacent tube holders can be increased.

Further, even when a mechanical external force is applied during storage or installation of the optical fiber cable, the unit tube can more surely protect the optical fiber core wire.

[0011]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the drawings illustrating an embodiment.

1, FIG. 2 and FIG. 3 are half cross-sectional views showing the pulling end structure of the optical fiber cable according to the present invention divided into three parts. A protective pipe 4 is attached to an end portion of an optical fiber cable 2 having a plurality of optical fiber cores 1 ... When the cable 2 is pulled and laid in a conduit or the like, at the tip of the optical fiber cores 1 ... The attached connectors 3 for connection and the optical fiber cores 1 are protected.

The optical fiber cable 2 in the example shown in FIG. 1 has a core tension (optical fiber unit) in which an optical fiber tape core wire is housed in a grooved spacer (not shown) and covered with an outer cover (of a fiber unit). The figure illustrates an ultra-multicore unit-type optical fiber cable in which a plurality of members (tensile members) are arranged around the member.

Specifically, as shown in FIG. 1, the pulling end includes the base end of the pulling wire 5 passing through the center of the protection pipe 4 and the optical fiber cable 2 (exposed by peeling off the outer skin layer to expose it. The tip of the strength member 6 (cut to a predetermined length) is connected to the intermediate sleeve 7 via a connecting sleeve 8.

Reference numeral 9 denotes a spacer, which is attached by caulking or the like to a gripping metal fitting 10 attached to the distal end of the outer layer of the optical fiber cable 2 and is internally provided in the protective pipe 4 via O-rings 11, 11. Reference numeral 12 is a sealing tape, 13 is a washer, and 14 is a heat-shrinkable tube covering the end of the outer layer of the optical fiber cable 2.

Further, an end cap 15 is attached to the base end of the protection pipe 4 to hold the optical fiber cable 2. Reference numeral 16 is a protective tape wound around and fixed to the end cap 15, the protective pipe 4, and the optical fiber cable 2.

Further, as shown in FIG. 3, a metal cap 17 is attached to the tip of the protective pipe 4 with an adhesive or the like, and the cap 17 and the protective pipe 4 are covered with a heat shrinkable tube 18.

In this cap 17, a male threaded sleeve 19 fixed to the tip of the traction line 5 is fixed by a nut 21 via a small O-ring 20, and at the tip of the sleeve 19, An eye nut 22 for towing is attached.

Further, as shown in FIGS. 1, 2 and 3, a plurality of connector holders 23, a fiber holder 24, and a tube holder 25 are arranged side by side in the protection pipe 4 in the longitudinal direction. .. Specifically, the connector holders 23, the fiber holders 24, and the tube holders 25 are attached to the traction line 5 at predetermined intervals.

The connector holder 23 is a soft plastic molded product. For example, as shown in FIG. 4, a cylindrical outer peripheral wall 26 having a predetermined thickness is provided and an insertion hole (through which the traction wire 5 is inserted) is formed in the center. A prism 28 having 27 is provided, and further, a plurality of plate-shaped holding walls 29 having a predetermined thickness are provided between the prism 28 and the outer peripheral wall 26 at predetermined intervals, and a plurality of connector accommodating chambers 30 are provided. Is formed. The connector accommodating chambers 30 ... Are open in both axial directions, and the width dimensions A of the connector accommodating chambers 30 are substantially equal.

The connector accommodating chamber 30 has a function of elastically holding and protecting the connector 3, and a part of the outer peripheral wall 26 is appropriately cut out, for example, the hatched portion Y is cut with a knife or scissors. It is constructed so that it can be cut open and used in the fiber guide housing 31 for guiding the optical fiber core wires 1.

Further, as illustrated in FIG. 5, the fiber holder 24 includes holding portions 32 ... In the shape of an arc groove, which guide the optical fiber core wires 1 ..., And insertion holes 33 through which the traction wires 5 are inserted. The protective pipe 4 made of plastic is formed of a metal material or a hard resin in order to prevent deformation of the protective pipe 4.

Further, as shown in FIG. 6, in the tube holder 25 made of a metal such as an aluminum alloy, a guide portion 35 of a U-shaped groove for holding a unit tube 34, which will be described later, is provided on the outer diameter side in the axial direction. An insertion hole 36 is formed in the center so that the traction line 5 is inserted therethrough.

Further, the long tubular unit tube 34 is made of plastic or the like and has flexibility (see FIG. 2), and the optical fiber cores 1 ... Are inserted and held in the unit tube 34. Is becoming A slit-like slit 37 is formed in the outer peripheral wall of the unit tube 34 in the longitudinal direction, so that the optical fiber cores 1 ...

Thus, as shown in FIG. 7, the plurality of optical fiber core wires 1 ... Exposed by peeling the outer layer of the optical fiber cable 2 are provided in predetermined groups--for example, 38 fiber units in the illustrated example. Each of them is divided into and inserted into the unit tube 34.

The length to the tip of the optical fiber core wires 1 to which the connectors 3 are attached is sequentially changed for each predetermined group. As a result, the connectors 3 ... At the tips of the all optical fiber cores 1 ... In each group are mounted on the same connector holder 23 (as shown in FIG. 4).

Further, as shown in FIG. 1, each fiber unit 38 ... Is held by a unit holder 39 attached to the strength member 6, and each fiber unit 38 ... , Is guided by the fiber guide 40.

Further, as shown in FIG. 1, FIG. 2 and FIG. 6, the unit tubes 34 ... In which the optical fiber cores 1 ... It is held by the guide portion 35 of the holder 25.

Then, as shown in FIGS. 2, 3 and 4, the connectors 3 are sequentially arranged in predetermined groups toward the tip of the protective pipe 4 in the connector accommodating chambers 30 of the connector holders 23. Portions of the outer peripheral wall 26 of the connector storage vacant chamber 30 other than the connector storage vacant chamber 30 that retains the elasticity 3 and retains the connectors 3 are cut out (as indicated by the diagonal line Y in FIG. 4) to form the fiber guide storage portion 31. The optical fiber core wires 1 of the other group, which are arranged to extend beyond the connector 3 to the tip, are held.

As shown in FIGS. 2, 3 and 5, the holding portions 32 of the fiber holders 24 ... Hold the optical fiber cores 1 ... It is wound to prevent the core wires 1 ... from coming off.

Then, the eye nut 22 is pulled in the direction of the arrow to lay the optical fiber cable 2 (see FIG. 1) in the conduit or the like, and then this pulling end is disassembled to install the optical fiber core wires 1 ... The taken out unit tubes 34 and the connectors 3 are taken out and connected to a mating connector 3 shown by a virtual line in FIG. 8 in a connection box such as a closure (not shown). At this time, the clip 41 keeps the connectors 3 and 3 connected.

However, according to the unit tube 34, even in the optical fiber cable 2 having an extremely large number of fibers, the optical fiber core wires 1 ... Are divided into predetermined groups, so that the connector 3 ... It is possible to easily identify the numbers of the optical fiber core wires 1 ... And the connectors 3 ... When connecting to the other side.

Further, since the optical fiber cores 1 ... Are held in the unit tube 34, the optical fiber cores 1 ... Do not freely disintegrate and become entangled when the drawing end is disassembled.

Further, even if a mechanical external force is applied during storage or installation of the optical fiber cable 2, the unit tube 34 can more reliably protect the optical fiber core wires 1. Moreover, when the unit tube 34 is incorporated in the protective pipe 4, the interval between the adjacent tube holders 25 can be lengthened, and the number of tube holders 25 ... Can be reduced.

It should be noted that the present invention is not limited to the above-described embodiments, and design changes can be freely made without departing from the gist of the present invention.

For example, the number and width dimension A of the connector accommodating chambers 30 of the connector holder 23 of FIG. 4 can be freely increased and decreased, and the connector accommodating chambers 30 can be formed in various directions other than those shown in the drawing. is there. Further, the shape and material of the tube holder 25 in FIG. 6 can be changed, and the number of guide portions 35 can be increased or decreased. In the case of the optical fiber cable 2 having a slot structure, it may be inserted into each tube 34 for each slot.

[0037]

[Effect of the device]

 Since the present invention is constructed as described above, it has the following great effects.

Even in the super-multi-fiber optical fiber cable 2 in which the number of the optical fiber core wires 1 reaches several thousand, the numbers of the optical fiber core wires 1 ... It is easy to do and workability is greatly improved.

Further, when the pulling end is dismantled, the optical fiber core wires 1 ... Do not disperse arbitrarily, so that the optical fiber core wires 1 ...

Further, when the unit tube 34 is incorporated in the protective pipe 4, the interval between the adjacent tube holders 25, 25 can be increased, the number of tube holders 25 ... Can be reduced, and the weight and cost can be reduced. .. Moreover, even if a mechanical external force is applied during storage or laying of the optical fiber cable 2, the unit tube 34 can protect the optical fiber core wires 1 more reliably.

[Brief description of drawings]

FIG. 1 is a half sectional view showing a base end portion of an embodiment of the present invention.

FIG. 2 is a half cross-sectional view showing the intermediate portion.

FIG. 3 is a half cross-sectional view showing the tip portion.

FIG. 4 is a plan view of a connector holder.

FIG. 5 is a plan view of a fiber holder.

FIG. 6 is a plan view of a tube holder.

FIG. 7 is a simplified view of an end portion of an optical fiber cable.

FIG. 8 is a perspective view of a connector.

FIG. 9 is a simplified view showing an internal structure of a tow end of a conventional example.

[Explanation of symbols]

 1 Optical fiber core wire 2 Optical fiber cable 4 Protective pipe 25 Tube holder 34 Unit tube

Claims (1)

[Scope of utility model registration request] 1. A pulling end structure in which a protective pipe is attached to an end portion of an optical fiber cable having a plurality of optical fiber core wires, and the optical fiber core is connected to a plurality of long and flexible unit tubes. A pulling end structure for an optical fiber cable, characterized in that wires are divided into predetermined groups and inserted, and the unit tubes are held by a plurality of tube holders arranged in parallel in the protection pipe in the longitudinal direction at predetermined intervals. ..