JP2006030909A - Optical fiber cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber cable which has optical fibers prevented from being damaged by oviposition of cicadas while holding tearability and is capable of holding airtightness when stored in a closure. <P>SOLUTION: Since cover members 21 are provided on parts of notches 20 for sheath tearing, a section of an optical fiber cable 10A has an approximately rectangular shape. Therefore, airtightness between a seal part of the closure and the optical fiber cable 10A can be held, and coated optical fibers 11 are prevented from being damaged by piercing of ovipositors of cicadas at the time of oviposition of cicadas because a sheath 13 in parts of notches 20 is as thick as in the other parts. Since notches 20 are provided in the same manner as conventional methods, tearability is held. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical fiber cable, for example, an optical fiber cable that can be used for an aerial collective drop cable or the like temporarily installed between utility poles immediately before the optical fiber is drawn into a subscriber's house.

Conventionally, as an optical fiber cable used for, for example, an aerial collective drop cable or the like, the one shown in FIG. 6 is known (see, for example, Patent Document 1).
In the optical fiber cable 100 shown in FIG. 6, two tension members 102 are provided on both sides of the optical fiber core 101 at the center, and the optical fiber core 101 and the tension member 102 are collectively covered with the jacket. 103. The outer cover 103 is generally rectangular, and a V-notch 104 having a V-shaped cross section extending in the longitudinal direction of the optical fiber cable 100 is provided at the center of the upper and lower surfaces. The optical fiber core wire 101 can be easily taken out by tearing.

By the way, when the optical fiber cable 100 as described above is used in an aerial manner, there is a case where a spear pierces the egg-laying tube from the shape of the V-notch 104 to lay eggs on the optical fiber cable 100. In this case, since the jacket 103 is the thinnest at the bottom of the V notch 104, it has been confirmed that an accident has occurred in which the laying tube reaches the optical fiber core wire 101 and is damaged. For this reason, as shown in FIG. 6, in order to protect the optical fiber core wire 101, for example, a protective member 105 such as a pipe is provided.
JP 2002-90591 A (FIG. 1)

  On the other hand, when the optical fiber cable 100 having the V-notch 104 as described above is housed in a closure and buried in the ground, a space is created between the seal portion of the closure and the V-notch 104 and the airtightness is lowered. There was an inconvenience.

  The present invention has been made in view of the above-described problems, and its purpose is to prevent damage to the optical fiber due to spawning of spiders while maintaining tearability and to maintain airtightness when stored in a closure. An object of the present invention is to provide an optical fiber cable that can be used.

  In order to achieve the above-described object, an optical fiber cable according to the present invention covers an optical fiber core wire and a tension member in a substantially rectangular shape with an outer cover, and on an outer surface facing the outer cover in a longitudinal direction. An optical fiber cable in which a notch for cutting a jacket is formed, and a lid member having a shape filling the notch is provided outside the notch.

  In the optical fiber cable configured as described above, the cover member is provided at the notch portion for cutting the jacket, so that the cross-sectional shape of the optical fiber cable is substantially rectangular. For this reason, it is possible to maintain the airtightness between the sealing portion of the closure and the optical fiber cable, and for the spawning of the cocoon, the outer cover of the notch portion is as thick as the other portions. Can be prevented from penetrating and damaging the optical fiber core wire. Moreover, since the notch is provided in the same manner as in the prior art, the tearability can be maintained.

  Moreover, the optical fiber cable according to the present invention is characterized in that the outer surface of the lid member protrudes more outward than the outer surface of the other part of the jacket.

  In the optical fiber cable configured in this way, the outer surface of the lid member protrudes outward from the outer surface of the other part of the jacket, so that when an external force is applied from the outside, the notch and the lid member Thus, the airtightness between the sealing portion of the closure can be maintained. Further, when the optical fiber cable is cut from the notch, the lid member can be easily removed to the outside.

  The optical fiber cable according to the present invention is characterized in that a cross-sectional shape of the notch is V-shaped.

  In the optical fiber cable configured as described above, it is possible to easily tear the jacket from the V-shaped notch and take out the optical fiber core wire.

  The optical fiber cable according to the present invention is characterized in that a cross-sectional shape of the notch is a trapezoidal shape that spreads toward the outside of the jacket.

  In the optical fiber cable configured as described above, since the jacket can be easily torn from the trapezoidal notch, the optical fiber cable is particularly suitable when a plurality of optical fiber cores are aligned and wide.

  According to the present invention, since the notch portion is provided with the lid member, the cross-sectional shape of the optical fiber cable is substantially rectangular. For this reason, it is possible to maintain the airtightness between the sealing portion of the closure and the optical fiber cable, and for the spawning of the cocoon, the outer cover of the notch portion is as thick as the other portions. Can be prevented from penetrating and damaging the optical fiber core wire.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of an optical fiber cable according to the present invention, and FIG. 2 is a sectional view of a die used for manufacturing the optical fiber cable according to the present invention.

  As shown in FIG. 1, an optical fiber cable 10 </ b> A according to an embodiment of the present invention covers an optical fiber core wire 11 and a tension member 12 in a substantially rectangular shape with a jacket 13 at the center. The outer surface 13a, 13b is formed with a notch 20 for tearing the jacket along the longitudinal direction. A lid member 21 having a shape filling the notch 20 is provided outside the notch 20.

In the optical fiber cable 10A shown in FIG. 1, the notch 20 has a V-shaped cross section. A V-shaped lid member 21 is provided so as to cover the V-shape, and one end portion of the lid member 21 is integrally continuous with the outer cover 13. Therefore, an L-shaped slit 22 is formed between the lid member 21 and the notch 20.
Further, the outer surface 21 a of the lid member 21 protrudes outward from the outer surface 13 a of the other part of the outer cover 13. That is, for example, if the height from the optical fiber core wire 11 to the outer side surface 21a of the lid member 21 is L1, and the height from the optical fiber core wire 11 to the outer side surface 13a of the jacket 13 is L2, then L1> L2. It has become.

  Next, a method for manufacturing the above-described optical fiber cable 10A will be described. FIG. 2 shows a cross section of a die 30 that can be used when manufacturing the above-described optical fiber cable 10A. A substantially rectangular hole 31 corresponding to the outer shape of the optical fiber cable 10 is provided in the center of the die 30, and an L-shaped slit is formed corresponding to the slit 22 between the lid member 21 and the notch 20. A portion 32 is provided protruding from the hole 31. In addition, in order to form the jacket 13 so that the outer surface 21a of the lid member 21 protrudes outside the outer surface 13a of the jacket 13, the hole 31a on the side corresponding to the lid member 21 projects outward. Is formed.

  Accordingly, the optical fiber core wire 11 and the tension member 12 are supplied so as to pass through a predetermined position of the hole 31 of the die 30, and the molten resin is supplied from the extrusion molding device to the hole 31 of the die 30 so that the optical fiber is supplied. The core wire 11 and the tension member 12 are integrally formed, and the lid member 21 is also formed at the same time. At this time, since the resin is not supplied to the portion corresponding to the slit forming portion 32, the slit 22 is formed.

  As described above, according to the optical fiber cable 10A described above, since the cover member 21 is provided in the notch 20 portion for cutting the jacket, the cross-sectional shape of the optical fiber cable 10A is substantially rectangular. For this reason, since the cover member 21 exists between the seal portion and the optical fiber cable 10A when stored in the closure, the airtightness can be maintained. Moreover, since the outer cover 13 of the notch 20 part is thick as well as other parts for spawning of the pupa, it is possible to prevent the optical fiber core wire 11 from being damaged by penetrating the egg-laying tube. Moreover, since the notch 20 is provided in the same manner as in the prior art, it is possible to maintain the tearability.

  Moreover, since the outer side surface 21a of the lid member 21 protrudes outward from the outer side surface 13a of the outer cover 13 of other portions, a slit between the notch 20 and the lid member 21 when an external force is applied from the outside. 22 can be maintained to maintain airtightness with the sealing portion of the closure. Further, when the optical fiber cable 10A is torn from the notch 20, the lid member 21 can be easily removed to the outside.

The optical fiber cable 10A of the present invention is not limited to the above-described embodiment, and appropriate modifications, improvements, and the like are possible.
For example, in the above-described embodiment, the case where the arrangement of the slits 22 forming the lid member 21 is point-symmetrically provided with respect to the optical fiber core wire 11 that is the center of the optical fiber cable 10B has been described. As shown, it can also be provided vertically symmetrically. In addition, the same code | symbol is attached | subjected to the site | part which is common in optical fiber cable 10A mentioned above in FIG. 1, and the overlapping description is abbreviate | omitted.

  In the above-described embodiment, the V-shaped cross section of the notch 20 is exemplified. However, in this optical fiber cable 10C, as shown in FIG. The notch 23 may be provided. That is, the slit 24 is provided as shown in FIG. 4 and the lid member 25 is formed in a trapezoidal shape, but the outer side surface 25a of the lid member 25 is outside the outer side surface 13a of the other part of the outer cover 13 (L1> L2 ) Is the same. This case is particularly suitable for a case where the optical fiber core wire 11 having a large number of cores (for example, four cores) is widely disposed laterally.

  1, 3, and 4, only the so-called drop cable main body has been described. However, as shown in FIG. 5, a cable support line 16 in which a tension member 14 is covered with a jacket 15 is provided integrally. The same can be applied to the case where it is used.

It is sectional drawing which shows embodiment which concerns on the optical fiber cable of this invention. It is sectional drawing of the die | dye used for manufacture of the optical fiber cable which concerns on this invention. It is sectional drawing which shows the modification which changed arrangement | positioning of a slit. It is sectional drawing which shows the modification of the shape of a cover member. It is sectional drawing which shows the case where a cable support line is provided. It is sectional drawing which shows the conventional optical fiber cable.

Explanation of symbols

10A, 10B, 10C, 10D Optical fiber cable 11 Optical fiber core wire 12 Tension member 13 Outer surface 13a, 13b Outer surface of outer cover 20 Notch 21, 25 Lid member 21a, 25a Outer surface of lid member

Claims (4)

An optical fiber cable in which an optical fiber core wire and a tension member are collectively covered in a substantially rectangular shape with a jacket, and notches for cutting the jacket are formed along the longitudinal direction on opposite outer surfaces of the jacket. And
An optical fiber cable, wherein a lid member having a shape filling the notch is provided outside the notch.   2. The optical fiber cable according to claim 1, wherein an outer surface of the lid member protrudes outward from an outer surface of another portion of the outer jacket.   The optical fiber cable according to claim 1 or 2, wherein a cross-sectional shape of the notch is V-shaped.   3. The optical fiber cable according to claim 1, wherein a cross-sectional shape of the notch is a trapezoidal shape that extends toward an outer side of the jacket.

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