JP2001086630A - Airtight connection of sheath pipe in additional optical- cable layering and fitting jig therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To connect a sheath pipe so as to be airtight without any interference with cable tensile auangement and an existing cable led to a closure. SOLUTION: At the opening ends of a pair of existing sheath pipes 2 protruded inside a hand hole 1, the existing sheath pipes 2 are branched into an air passage 4 and a cable passage 5, and a branching jig 6 divided into two portions vertically is fitted so as to be airtight respectively. A connecting sheath pipe 11 is croslinked between the two air passages and fitted so as to be airtight. An existing cable 3 is passed through the end of the cable passage 5 so as to be airtight, and the existing cable 3 is exposed outwards between the two cable passages 5, and the sheath pipe is connected so as to be airtight without any interference with cable tensile arrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for airtightly connecting an existing sheath pipe, in which a cable or the like is already laid and an optical fiber cable or the like is laid by a pneumatic feeding method, in a handhole. The present invention relates to a method for hermetically connecting a sheath tube in an additional optical cable laying method and a connection jig thereof.

[0002]

2. Description of the Related Art As the demand for information and communication has increased and the bandwidth has been broadened,
The construction of optical networks using optical fiber cables instead of metal cables is progressing on a global scale. When this optical fiber cable or the like is buried underground, it is generally laid in a protective tube called a sheath tube made of a polyethylene tube, a steel tube, or the like. However, civil engineering work for burying this sheath pipe in the ground is extremely expensive, so without newly burying the sheath pipe, the space inside the existing sheath pipe where metal cables and optical fiber cables are already laid, By utilizing the characteristics of the thin and lightweight optical fiber cable, a pneumatic feeding method for additionally laying has been developed. The outline is shown in FIG.

[0003] As shown in the figure, an additional optical fiber cable 53 wound around a drum 52 supported by a jack 51 installed on the ground is sent out by a pair of feeding caterpillars 54, and the end of an existing sheath tube 55. It is inserted through an annular seal portion (O-ring 58) into a pressure feed head 57 airtightly attached to one end of a branching jig 56 airtightly connected to the portion. The additional optical fiber cable 53 inserted into the pumping head 57 is connected to a compressor (not shown).
By the flow of the high-pressure air supplied into the pressure feeding head 57 and the feeding force of the feeding caterpillar 54, the pressure is fed in the axial direction and is laid in the existing sheath tube 55.

As shown in FIG. 5, the existing sheath pipe 55 is provided with hand holes 5 installed at intervals of about 250 m.
9 has been cut. This is because extra length is taken for the intermediate branch of the existing cable 61 and dropped into the closure in the handhole 59.

[0005]

In the above-mentioned conventional configuration,
Since the existing sheath tube 55 is cut for each hand hole 59, a long-distance pneumatic feeding method cannot be performed unless these are hermetically connected. However, since the existing cable 61 protrudes from the end of the existing sheath tube 55 for extra length or the like, it is not easy to airtightly connect the sheath tube including this cable treatment. However, if the pumping is repeatedly performed for each short distance section between the handholes 59, it is necessary to move and install the pumping device each time, and much labor and cost are required.
Since the merit of the pneumatic feeding method characterized by long cable laying cannot be used at all,
It was difficult to use the pneumatic feeding method.

Accordingly, the present invention has been devised to solve the above-mentioned problem, and an object of the present invention is to provide an additional optical cable without losing extra length or hindering an existing cable dropped to a closure. Another object of the present invention is to provide a method for hermetically connecting a sheath tube in an additional optical cable laying method capable of hermetically connecting the sheath tube, and a connection jig thereof.

[0007]

According to a first aspect of the present invention, there is provided an air conditioner, comprising: a pair of existing sheathing pipes projecting into a handhole; The jigs for branching that can be split into two upper and lower parts are hermetically attached to each other, and the connecting cable is wrapped between the two air passages for airtight attachment, and the existing cable is hermetically sealed from the cable passage end. This is an airtight connection method of a sheath tube in a method of laying an additional optical cable that is penetrated and taken out to the outside.

According to the above method, the existing cable is airtightly penetrated through the end of the cable passage and taken out to the outside. By air-tightly attaching the connecting sheath tube to the cable, the laying passage of the additional cable can be air-tightly connected to a long length, and the additional cable can be long and efficiently pneumatically fed.

According to a second aspect of the present invention, there is provided an additional optical cable laying method in which the connecting sheath tube is formed of a highly flexible material such as fiber reinforced plastic, hard rubber or synthetic rubber, and connects the air passages by bending them. It is a method of airtight connection of the sheath tube in the above.

According to a third aspect of the present invention, there is provided a branch which has two openings for the sheath tube to which the sheath tube is connected in an airtight manner, has an opening for the cable through which the existing cable passes through in an airtight manner, and can be divided into upper and lower splits. FIG. 2 is a connecting jig for a sheath tube in an additional optical cable laying method, which has a jig for use and a connecting sheath tube which is bridged between openings for the sheath tubes of two branching jigs.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the present invention. In addition,
In the present embodiment, a case where the existing cable is a single cable will be described.

First, the construction of the sheath tube connecting jig in the additional optical cable laying method according to the present invention will be described.

As shown in the figure, a pair of existing sheath tubes 2 protrude from side walls of the handhole 1 facing each other. The tip of the existing sheath tube 2 is cut open.

An existing cable 3 is inserted into the existing sheath tube 2, and the existing cable 3 is generally exposed from the open end of the existing sheath tube 2 into the handhole 1, and the extra length is taken there. .

In the present invention, a branching jig 6 for branching the existing sheath tube 2 into an air passage 4 and a cable passage 5 is provided at the open end of each existing sheath tube 2.

The branching jig 6 is formed of a cylindrical body, and is substantially V-shaped or bifurcated from the base end side to the distal end side, which is airtightly connected and covers the open end of the existing sheath tube 2. Y
It is formed in a character shape. The branching jig 6 is configured to be vertically splittable along the axial direction.

An opening 7a for a sheath tube is formed on the base end side, and an annular sealing portion (O-ring 9) for sealing between the opening 7a for the sheath tube and the existing sheath tube 2 is formed inside the opening 7a. It is installed.

An opening 7b for a sheath tube for covering the end of a later-described connecting sheath tube 11 for airtight connection is formed on one end side located on an extension of the existing sheath tube 2,
An annular seal portion (O-ring 9) for sealing between the sheath tube opening 7b and the connection sheath tube 11 is mounted on the inside thereof.

At the other end of the branch, a cable opening 8 through which the existing cable 3 passes airtightly is formed. A seal portion (O-ring 12) for sealing between the cable opening 8 and the existing cable 3 is mounted inside the cable opening 8.

The above-mentioned O-rings 9 and 12 can also be vertically divided like the branching jig 6.

Each of the sheath tube openings 7a and 7b of the branching jig 6
An air passage 4 through which the compressed air for pumping the additional cable flows is formed between them, and a cable passage 5 in which the existing cable 3 is located between the sheath tube opening 7a and the cable opening 8 is formed. .

A connecting sheath tube 11 is bridged between the sheath tube openings 7b at the ends of the air passages 4 of the branching jig 6 attached to the ends of the two existing sheath tubes 2, respectively. I have.
Both ends of the connecting sheath tube 11 are O
The jigs 6 are respectively held by the rings 9 and connected to the branching jig 6.

The connecting sheath tube 11 is made of a pipe having substantially the same inner diameter as the existing sheath tube 3 and is made of fiber reinforced plastic (FR).
P), a material having high flexibility such as hard rubber or synthetic rubber. When the connecting sheath tube 11 is used in a straight shape as in the present embodiment, the material may be high-density polyethylene which is usually used as a sheath tube.

Thus, the one existing sheath tube 2, the air passage 4 of the branch jig 6, the connection sheath tube 11, the air passage 4 of the other branch jig 6, and the other existing sheath tube 2 are connected. It is airtightly connected, and the flow path of the compressed air is long and integrally formed.

Between the cable openings 8 at the ends of the respective cable passages 5 of the two branching jigs 6, the existing cable 3 is exposed to the outside so as to take extra length.

Next, a method for hermetically connecting a sheath tube in an additional optical cable laying method according to the present invention and its operation will be described.

First, the branching jig 6 including the O-rings 9 and 12 is divided into upper and lower parts, and one of the existing sheathing pipes having the lower part of the branching jig 6 projecting into the handhole 1 through the sheathing tube opening 7a. 2 and the existing cable 3 exposed in the handhole 1 is positioned in the cable opening 8. Then, the connecting sheath tube 11 is positioned in the sheath tube opening 7b,
The divided upper branching jigs 6 are joined and integrated.

Thereafter, another branching jig 6 is attached to the other existing sheath tube 2 protruding into the handhole 1 in the same manner as described above. Thereby, the pair of existing sheath tubes 2 are connected by the two branching jigs 6 and the connection sheath tube 11.

At this time, O is not used in the sheath tube openings 7a and 7b.
The existing sheath tube 2 and the connecting sheath tube 11 are hermetically attached to each other by the ring 9, and the existing cable 3 is airtightly penetrated by the O-ring 12 in the cable opening 8.

As described above, the existing sheath tube 2 is branched into the air passage 4 and the cable passage 5 by the branching jig 6, and the existing cable 3 is passed through the cable passage 5 and penetrates the cable opening 8. Since the cable 3 is exposed inside the handhole 1, there is no problem with the extra length of the cable 3 or the existing cable 3 dropped to the closure.

The existing cable 3 is airtightly penetrated through the cable opening 8 by an O-ring 12, and the existing sheath tube 2, the branching jig 6 and the connection sheath tube 11 are air-tightly connected to each other. Therefore, the installation path of the additional cable can be air-tightly connected to a long length. Therefore, even if high-pressure air flows through the inside of the sheath tube, there is no leakage, and long and efficient air pressure feeding of the additional cable becomes possible.

FIGS. 2 and 3 show another embodiment of the present invention.

As shown, in the handhole 1,
The axes of the two existing sheath tubes 2 may be shifted (see FIG. 2) or may intersect (see FIG. 3). In this case,
The connecting sheath tube 11 formed of a material having high flexibility is curved and connected between the sheath tube openings 7b of the branching jigs 6.

The other parts are the same as those shown in FIG.

By the way, in the above embodiment, the case where the existing cable 3 is a single cable has been described, but the present invention is not limited to this. When there are a plurality of existing cables 3, the numerical aperture of the cable opening 8 may be increased in accordance with the number of existing cables.

[0037]

As described above, according to the present invention, the existing cable is hermetically pierced through the cable opening, so that the sheath tube can be airtightly sealed without any extra length or obstruction to the existing cable dropped to the closure. Can be easily connected, and the installation path of the additional cable can be air-tightly connected to a long length. Therefore, even if high-pressure air flows through the inside of the sheath tube, no leakage occurs, and long and efficient air pressure feeding of the additional cable becomes possible, and an excellent effect of reducing labor and cost can be achieved.

Further, by bending the connecting sheath tube, it is possible to adapt to the axial deviation or intersection of the existing sheath tube.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of a method for hermetically connecting a sheath tube and a connecting jig in an additional optical cable laying method according to the present invention.

FIG. 2 is an explanatory view showing another embodiment of a method for hermetically connecting a sheath tube and a connecting jig in an additional optical cable laying method according to the present invention.

FIG. 3 is an explanatory view showing still another embodiment of a method for hermetically connecting a sheath tube and a connection jig in an additional optical cable laying method according to the present invention.

FIG. 4 is an explanatory view showing a pneumatic feeding method.

FIG. 5 is a sectional view showing the inside of a conventional handhole.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hand hole 2 Existing sheath pipe 3 Existing cable 4 Air passage 5 Cable passage 6 Branching jig 7 Sheath tube opening 8 Cable opening 11 Connection sheath tube

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Masatoshi Kumagai 5-9-15-1 Hidaka-cho, Hitachi City, Ibaraki Prefecture F-term within Hitachi Cable Engineering Co., Ltd. 5G369 AA19 BA04 BA06 DC09 DD02 EA01

Claims (3)

[Claims] At the open ends of a pair of existing sheath tubes protruding into a handhole, branching jigs which can divide the existing sheath tubes into an air passage and a cable passage and can be divided into upper and lower splits are airtightly provided. A sheath tube in an additional optical cable laying method, wherein the sheath tube is connected between two air passages, and the existing sheath cable is air-tightly penetrated from the end of the cable passage and taken out to the outside. Airtight connection method. 2. The additional optical cable laying method according to claim 1, wherein the connecting sheath tube is formed of a highly flexible material such as fiber reinforced plastic, hard rubber, or synthetic rubber, and connects the air passage by bending. Method for hermetic connection of the sheath tube. 3. A branching jig having two openings for a sheath tube to which the sheath tube is connected in an airtight manner, having an opening for a cable through which an existing cable passes airtightly, and dividing the cable into upper and lower splits. A connecting pipe for a sheath tube in an additional optical cable laying method, comprising: a connecting sheath pipe which is bridged between openings of the sheath pipes of two branching jigs.