JPS5830706A - Closed type device for preventing movement of optical fiber core - Google Patents

Abstract

PURPOSE:To prevent the movement of an optical fiber core and to hold airtightness, by providing tapers having the same inclination in a movement preventing member and a backup member. CONSTITUTION:Coatings of terminal parts of optical fiber cores 1 are removed completely to expose parts of strands 6, and clean faces are butted to each other and are heated by discharge and are connected to each other by melt-sticking. A melt-stuck connection point 7, strands 6, and coating layers are covered with a split mold having tapers in both sides, and a hardening resin, a thermoplastic resin, rubber, or the like is molded in the mold to form a conical movement preventing member 5 having tapers in both sides as one body. Conical metallic parts 8 are brought closely into contact with both sides of the member 5, and the member 5 is inserted into a taper hole 4 of backup members 2, and members 2 are brought closely into contact with each other. The diameter of holes 10 of rubber parts 9 is slightly smaller than the outside diameter of cores 1. Metallic sleeves 14 are fixed to members 2 to tighten O ring parts 12 of rubber parts 9 by press rings 13, thus, a device is assembled.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber cable movement prevention device in a sealed termination cable lead-out section of a submarine optical cable that requires water-resistant sealing.

FIG. 1 shows the sealed core lead-out portion of a conventional submarine optical cable. The figure (3) is a sectional view, and the figure (a) is a view of figure (a) viewed from the direction of the arrow.

As shown in the figure, a part having a hole (4) with a through hole (C) somewhat larger than the outer diameter of the optical fiber core at one end of the optical fiber core (1) near the center of the bottom. (2
) ° through the through hole (3) at the bottom, then insert the hole (4)
The movement of the optical fiber core (11), which constitutes the hardenable resin part (5) 1 by filling and hardening a curable resin around the optical fiber core (1) contained within the It mainly depends on the adhesion between the nylon resin, which is the core wire coating material, and the hardening resin.However, in order to increase reliability, holes (
4) It was necessary to make the terminal long, which was a disadvantage in that the termination part could not be made smaller.

Furthermore, the properties of curable resins vary depending on the formulation and curing conditions, and they have drawbacks such as difficulty in drawing the optical fibers straight through, and their properties vary depending on the skill level of the operator. Ta.

As for the optical fiber core structure, a structure with buffered waste is currently being considered. When a submarine optical cable is cut, the optical fiber core comes into direct contact with high-pressure seawater. In the cushioning debris structure currently under consideration, there is no adhesive between the silicone rubber used for the buffer layer and the nylon secondary coating material.
Complete airtightness cannot be ensured because high-pressure seawater enters the interface between the two. In this case, even if movement of the core wire can be prevented, the original role of ensuring airtightness is not fulfilled.

In order to ensure complete airtightness, the coating is removed from the optical fiber core and that part is molded with curable resin, but the coating must be removed midway through the optical fiber core, which can lead to breakage of the optical fiber. The disadvantage is that the probability is very high.

In order to eliminate the drawbacks of the conventional art, the present invention provides a connection point in which the strands of the coated optical fibers are fused in the center, and the connection points are connected to the strands of the strands and the optical fibers on the left and right sides of the strands. A movement prevention member made of a hardening resin or the like having a symmetrical conical shape with a taper that descends left and right at the center is provided,
a back amplifier member outside the connection point through which the optical fiber core is inserted symmetrically with respect to a plane passing through the connection point;
Tapered metal parts, rubber parts, presser rings and 1
A plastic bag nand type metal sleeve is disposed, a hole is provided in the center of the bank-up member into which half of the movement prevention member can be inserted closely, the movement prevention member is inserted, and the tip of the movement prevention member in the hole is inserted. disposing the tapered metal part;
The backup member is provided with a cylindrical recess on the outside of the hole, and the rubber part has an O-ring part on the connection point side and a nozzle part on the outside, while the cap nut-shaped metal sleeve has a cylindrical recess on the connection point side. A cylindrical groove into which the nozzle part is inserted is provided at the center of the groove, and an annular groove into which the presser ring is inserted on the outer periphery of the groove, and the O-ring part of the rubber component and the presser ring are placed in the recess of the backup member.

The nozzle part and the presser ring of the rubber part are inserted into the cylindrical groove and the annular groove of the cap nut-shaped metal sleeve, and the cap nut-shaped metal sleeve is interlocked and fixed to the backup member. The purpose of this is to shorten the member for preventing movement of the optical fiber and improve airtightness.

The present invention will be explained based on the drawings.

FIG. 2 shows a sectional view of an example of the sealed optical fiber cable movement prevention device of the present invention.

In the figure, (1) is a cored optical fiber, (6) is a bare optical fiber from which the coating layer has been completely removed from the cored optical fiber;
(7) is a fusion splice between optical fiber wires; (2) is a bank amplifier member having a penetrating taper hole (4);
(5) is tapered on both sides, contains a fusion splice, an uncoated strand, a coated core, and is molded from curable resin, thermoplastic resin, or rubber. Prevention member, (8) is a tapered metal part,
(9) has a nozzle part 11 having a through hole 10 somewhat narrower than the outer diameter of the optical fiber core in the center including the main body part, and a ring-shaped collar 03 on the inside and around the periphery. Rubber parts, α3) is a holding ring that holds the O-ring part,
(14) indicates a metal strip 17-.

Next, the assembly order of the sealed optical fiber core movement prevention device of the present invention will be explained. There is a metal strip on each of the two optical fiber cores (1)! J-7" Q4), presser ring 03). Pass through the optical fiber core through hole (1,0
1 is somewhat smaller than the outer diameter of the optical fiber, so a hypodermic needle-like wire passing jig γ) having an inner diameter somewhat thicker than the outer diameter of the optical fiber is inserted into the hole of the rubber part in advance. After passing the optical fiber (1) through the hole of the wire threading jig (1) and pulling out the wire threading jig (IT), the optical fiber coated wire (1) and the rubber part ( Pass the nozzle side of 9) toward the side opposite to the end of the optical fiber core wire (1). Further, a backup cutting member (cutting member) and a tapered metal part (8) are passed through the optical fiber core wire (1). Completely remove the coating on the end of the optical fiber (1) to expose the strand (6), cut the end of the strand (6) to expose a clean surface, and connect the clean surfaces together. They are brought together and fused and spliced by electrical discharge heating. Next, the fusion splice point (7), the optical fiber bare wire (6) without a coating layer on both sides, and a tapered split mold on both sides including the coating layer are covered, and a hardening resin or heat is applied. A plastic resin or rubber is molded in the mold to form a cone-shaped movement prevention member (5) integrally tapered on both sides. Place the conical metal parts (8) on both sides of the movement prevention member (5), and then insert them into the tapered holes (4) of the backup member (2) and make the IT pick-up members (2) stick together to form a 6° rubber part ( Since the hole (10) in 9) is somewhat smaller than the outer diameter of the optical fiber core (1), the rubber part (
9) is difficult to move, but the grease improves lubricity and allows it to move.

Next, the presser ring (0-I of the rubber part (9) at 1311)
The sealed optical fiber movement prevention device of the present invention is assembled by tightening the ring portion α2 by fixing the cap nut-shaped metal sleeve a (a) to the backup member (2).

When the sealed optical fiber fiber movement prevention device of the present invention is submerged on the seabed and water pressure is applied to either side, watertightness is achieved between the O-ring part 02) located around the rubber part (9) and the optical fiber. It is held by a nozzle section around the core wire. Moisture that has entered the interface between the buffer layer and the secondary coating can be removed if the coating is completely removed near the connection point and that area is sealed and integrated with the optical fiber core using a curable resin, thermoplastic resin, or rubber. This part completely prevents intrusion further. In addition, movement of the optical fiber core wire is also prevented because the movement prevention member (5) has tapers on both sides, and the backup member (2) into which the movement prevention member (5) is inserted also has a taper with the same slope. When the movement prevention member (5) moves to the low pressure side, the taper acts as a stopper, thereby preventing movement to the low pressure side.

Since the movement prevention member (5) is symmetrical in the axial direction of the optical fiber, it has the effect of preventing movement of the optical fiber even if pressure is applied from either side. However, the airtightness is maintained, and the movement prevention portion of the optical fiber core can be concentrated in one place, which has the effect of shortening the length. Furthermore, if an attempt is made to remove the coating in the middle of the optical fiber, the probability of breakage of the optical fiber becomes very high. In the sealed optical fiber cable movement prevention device according to the present invention, the part from which the coating is removed for fusion splicing the optical fiber cables is coated with a hardening resin to obtain airtightness.
Since it is useful for forming the ξ movement prevention member, the number of steps does not increase.

There may be a gap between the metal part (8) and the rubber member (9) at normal pressure, but when pressure is applied from the nozzle side of the rubber member, the rubber member easily deforms and this gap occurs. Since the space is filled, this space is not left at atmospheric pressure, and even if high pressure water enters the optical fiber core, there is no possibility of damaging the coating in this space.

If extra length processing sections are provided on both sides of the sealed optical fiber cable movement prevention device of the present invention, they can also be used as connecting sections.

In the sealed optical fiber core movement prevention device of the present invention, as described above, the movement prevention member provided at the center has a taper that goes down from the top to both sides, and the bank up member also has a taper with the same slope. Therefore, movement of the optical fiber core wire can be prevented against force 1 from any of the 4. Since the rubber members with nozzles are arranged on both sides with the backup member in between, airtightness can be maintained in both directions.

Since the movement prevention member is molded with a curable resin by removing the coating of the optical fiber core, it is possible to prevent water from entering between the buffer layer and the secondary coating interface.

Since the movement preventing member is provided at the connecting portion, there is no difficulty in removing the coating in the middle of the optical fiber core wire.

- If used together with an extra length processing section, it can be applied to the connection section of an optical cable with an airtight dam.

[Brief explanation of the drawing]

Fig. 1 shows a conventional sealed optical fiber movement prevention device, (3) is a sectional view, Fig. CB1 is a view seen from the direction of the turning arrow, and Fig. 2 shows a sealed optical fiber movement prevention device according to the present invention. 1: Optical fiber core wire 2: Banokanop member 3: Core wire through hole 4: Hole 5: Movement prevention member 6: Optical fiber wire
7: Fusion splicing point 8: Tapered metal part 9: Rubber part 10: Optical fiber core through hole 11: Nozzle part 12: O-ring part
13: Holder ring 14: Cap nut-shaped metal sleeve Patent applicant: Isao Abe, patent attorney representing Nippon Telegraph and Telephone Public Corporation

Claims (1)

[Claims] A connection point is provided in the center by which strands of coated optical fibers are fused together, and the strands and the left and right optical fibers have tapers that descend to the left and right around the connection point. A movement prevention member made of a hardening resin 4 or the like having a conical shape is provided, and a backup member and a tapered metal are provided on the outside of the connection point through which the optical fiber core wire is inserted symmetrically with respect to a plane passing through the connection point. A part, a rubber part, a presser ring, and a bag nand type metal sleeve are arranged, a hole is provided in the center of the backup member into which half of the movement prevention member can be inserted closely, the movement prevention member is inserted, and the movement prevention member is inserted into the hole. The tapered metal part is disposed at the tip of the movement prevention member, the puncture-up member is provided with a cylindrical recess outside the hole, and the rubber part is provided with an OIJ on the connection point side.
a cylindrical groove portion into which the nozzle portion is inserted into the center of the connecting point side of the bag-nant-type metal sleeve, and the retainer ring is inserted into the outer periphery of the groove portion; An annular groove is provided, and the pushing part of the rubber part 00 and the presser ring are inserted into the recess of the backup member, and the nozzle part and the presser ring of the rubber part are inserted into the cylindrical groove and the annular groove of the cap nut type metal sleeve. , a sealed type optical fiber core movement prevention device comprising the bag nand type metal sleeve intertwined and fixed with the backup member;