JPS60156017A - Optical fiber cable connecting part - Google Patents

Abstract

PURPOSE:To prevent breakdown of terminal station devices even in case of the falling of a thunderbolt by connecting mechanically metallic tension members in an optical cable connecting part to insulate electrically them. CONSTITUTION:In the optical fiber cable connecting part, metallic tension members, namely, copper twisted wires 4 and 6 are connected mechanically by a sleeve 5. Since the sleeve 5 is formed with an electrically insulating material and a stop part 12 provided in the sleeve 5 prevent copper twisted wires 4 and 6 from being brought into contact with each other, copper twisted wires 4 and 6 are isolated electrically. Therefore, even if an induced voltage is generated in wires 4 and 6 in accordance with rise of the earth potential due to the falling of a thunderbolt, this current is intercepted by the sleeve 5, and breakdown of terminal station devices is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber cable connection section that interrupts the flow of current during lightning strikes by connecting metallic tension members in an insulated state.

Optical fiber cables have recently been used as cables in areas affected by lightning, and are said to be the best cables. One reason for this is that unlike conventional copper cables, optical core cables do not use metals, but instead are composed of optical fibers whose main component is inorganic quartz and the outer sheath, which is made of organic materials. It is. However, when the cable becomes long, the tension in the cable becomes excessive (due to friction with the inside of the conduit or the inner wall of the trough), and the cable sheath shows a phenomenon of stretching when cut.
Installation may be extremely difficult or impossible. For this reason, a method is often used in which a metallic tension member made of stranded steel wire or the like is coated with polyethylene or the like is inserted into the center of the optical fiber cable to increase the tensile strength and then the cable is stretched and laid.

When connecting optical fiber cables equipped with such metal tension members, it goes without saying that the optical fibers are connected to each other and the cable sheaths are connected to each other.
It is also important to interconnect the metallic tension members. In this case, conventionally, expanded metal tension members are inserted into metal sleeves and connected by crimping, soldering, or the like. However, since metal tension members are not insulators, if they are used in damaged areas, an induced voltage will occur in the steel stranded wires as the ground potential increases due to lightning strikes, and this current will flow backwards and destroy the terminal equipment. It is expected that

As described above, in conventional optical fiber cables equipped with one metal tension member, there was a risk that current would flow through the metal tension member during lightning strikes and destroy the terminal equipment.

An object of the present invention is to provide an optical fiber cable connecting section in which metallic tension members are connected in an insulated state, thereby protecting terminal equipment in the event of a lightning strike or the like. The structure of the present invention that achieves this object includes the following steps in a connection section for interconnecting optical fiber cables each having a metallic tension member:
A tension member sleeve inserted to connect the metal tension members to each other is formed of an electrically insulating material, and a stop portion is provided at the center of the interior of the tension member to prevent the social attribute tension members from coming into contact with each other. It is characterized by being formed.

EMBODIMENT OF THE INVENTION Hereinafter, the optical fiber connection part of this invention will be explained in detail based on an Example.

An embodiment of the present invention is shown in FIGS. 1 and 2.

As shown in the figure, the optical fiber cable 1.7 to be connected in the present invention has a plurality of (two in this embodiment) a metal tension member made of stranded steel wires 4.6 coated with polyethylene, etc. ) are arranged, and these are covered with a jacket. The ends of the optical fiber cables 1.degree. 7 to be connected are faced to each other, and the jacket, polyethylene, etc. are removed from them, and the optical fibers 2 and the steel strands 4, 6 are exposed.

The ends of the optical fibers 2 are butted against each other and connected at a connecting portion 3. The ends of the steel strands j, 6°, are inserted into the tension member sleeve 5 facing each other.

The tension member sleeve 5 has a cylindrical shape, and its inner diameter is slightly larger than the outer diameter of the steel strands 4 and 16. Further, a stop tp part 12 is formed in the center of the interior of the tension member sleeve 5 to close the insertion hole, and the steel stranded wire 4 is connected to this stop tp part 12.
, 6 are prevented from coming into contact with each other. Moreover,
This tension member sleep 5 is made of an electrically insulating material such as thermosetting resin. The gap between the insertion hole of the tension member sleep 5 and the steel stranded wires 4 and 6 is filled with adhesive 11 to achieve a connection strength sufficient to withstand the tensile force after installation. Oka, 8 in the figure is optical fiber 2, steel stranded wire 4,
This is a protective case that protects the exposed parts of 6.

The optical fiber cable connection section of the present invention having the above-mentioned configuration mechanically connects metallic tension members, that is, steel stranded wires 4 and 6, with a tension member sleep 5. Moreover, this tension member sleeve 5 is formed of an electrically insulating material, and the stopper portion 12 provided on this tension member sleeve 5 prevents the steel strands 4 and 6 from coming into contact with each other.
Therefore, the steel strands 4 and 6 are electrically disconnected. Therefore, even if an induced voltage is generated in the steel *1114.6 due to the rise in earth potential due to falling hoe, this current is blocked by the tension member sleep 5 of the present invention, preventing destruction of the terminal equipment. can be prevented. Similarly, the tension member sleep 5 is not limited to that of the above embodiment, but may be of any structure as long as it can connect the stranded steel wires 4 and 6 in an electrically insulated state. Further, as a means for mechanically isolating, it is not limited to the adhesive used in the above embodiments, and screwing, peeling, or the like may also be used. In addition, the metal tension member may be a stranded steel wire without the polyethylene coating, or may be a steel wire.
Non-metallic materials such as FRP wires can be used.

As explained above in detail based on the embodiments, the optical fiber cable connection part of the present invention mechanically connects the metal tension members, but since they are electrically insulated, even in the event of a lightning strike, the end It is possible to prevent damage to the device.

[Brief explanation of the drawing]

1 and 2 relate to an embodiment of the optical fiber pull connection section of the present invention, FIG. 1 is an overall sectional view thereof, and FIG. 2 is a partial sectional view of the main part thereof. In the drawing, 1.7 is the optical fiber of the optical fiber cable 2, 3 is the connection part, 4.6 is the steel stranded wire, 5 is the tension member sleeve, 11 is the adhesive, and 12 is the stopper part. Patent Applicant Sumitomo Electric Industries, Ltd. Nippon Telegraph and Telephone Public Corporation Agent Patent Attorney Mitsuishi Shibu (and 1 other person) Procedural Amendment February 27, 1985 To the Commissioner of the Japan Patent Office 1 Indication of Case Patent Application No. 68 of 1988 No. 3. Relationship with the case of the person making the amendment Patent applicant Postal code: 541 5-15-4 Kitahama, Higashi-ku, Osaka-shi, Osaka Prefecture Agent postal code: 107 Japan Shortwave Broadcasting Center, 9-15 Akasaka-chome, Minato-ku, Tokyo Vol. 3, each column of “Claims” and “Detailed Explanation of Part 1” of the specification to be amended? , Contents of the amendment (1) The statement in the "Claims" column of the specification is amended as per the amended claims attached in the appendix. (2) "The tension member sleeve" written on page 3, line 16 of the specification is corrected to "the entire or part of the tension member sleeve." (3) In the fifth line of page 6 of the specification, after "...anything is acceptable", "In other words, in the above embodiment, the entire tension member sleeve 5 is made of an insulating material. Although the case has been described, it is not necessary that the entire tension member sleeve 5 is made of an insulating material, and only the inner surface of the tension member sleeve 5 that may come into contact with the steel strands 4.6 is made of an insulating material. Insert the sentence "You may do so." 8. List of Attached Documents 1, Amended Patent Claims 1 Reverse Amended Claims In a connection section for interconnecting optical fiber cables provided with metal tensile members, for interconnecting said metal tensile members. The entire tension member sleeve inserted into the tension member sleeve is made of an electrically insulating material, and a stop portion is formed in the center of the interior of the tension member sleeve to prevent the metal tension members from coming into contact with each other. Fiber optic cable connection.

Claims (1)

[Claims] Optical fibers with metal tension members/(at the connection point for interconnecting cables, a tension member sleeve inserted to interconnect the metal tension members is formed of an electrically insulating material and the tension member is An optical core ino (cable connection part) characterized in that a stop TP part is formed in the center of the inside of the member sleeve to prevent the metal tension members from coming into contact with each other.