JP2001133668A - Spacer for optical fiber cable and optical fiber cable using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a high-tensile body from being damaged in terminal processing which exposes the high-tensile body in the end part of an optical fiber cable. SOLUTION: A notched part 15 is provided in the outer peripheral part of a solid layer 8 brought into contact with a high-tensile body 2. In the terminal processing of an optical fiber cable 7, a retaining and winding member 5 and a sheath 6 in the end part of the optical fiber cable 7 are removed first. A foamed layer 13 and a solid layer 14 are next removed with a cutter or the like, to expose the solid part 8. The notched part 15 is used to tear and removed the solid layer 8 by hand or a simple grip tool, and thus the high-tensile body 2 is exposed. Since a blade is not used to remove the solid layer 8, the high- tensile body 2 is prevented surely from being damaged by blades.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an optical fiber cable spacer having an optical fiber housing groove for housing an optical fiber core, and an optical fiber cable using the spacer.

[0002]

2. Description of the Related Art FIG. 2 is a sectional view showing an example of an optical fiber cable using an optical fiber cable spacer. In FIG. 2, an optical fiber cable spacer 1 is provided with an optical fiber housing groove forming body 3 centered on a tensile strength member 2. A groove 4 is formed.

[0003] An optical fiber core (not shown) is accommodated in the optical fiber accommodating groove 4, and a holding member 5 is provided outside the optical fiber accommodating groove forming body 3 accommodating the optical fiber core. Further, the outside is covered with a sheath 6 to form an optical fiber cable 7.

[0004]

In recent years, from the viewpoint of reducing the burden of laying optical fiber cables,
Lightening of the optical fiber cable 7 is required. In order to meet this demand, it is conceivable that the entire optical fiber housing groove forming body 3 is formed of a foam to reduce the weight of the optical fiber cable 7.

However, in this case, since the surface of the optical fiber housing groove forming body 3 which comes into contact with the strength member 2 becomes a concave and convex surface due to the foaming component of the foam, the strength member 2 and the optical fiber housing groove forming body are formed. Thus, there is a problem that the contact area between the tensile strength member 2 and the optical fiber housing groove forming body 3 is deteriorated, which causes inconvenience.

In order to avoid this problem, the innermost peripheral portion of the optical fiber housing groove forming member 3 as shown by the dotted line in FIG. It has been proposed that the solid layer 8 be made of With this configuration, the surface of the optical fiber housing groove forming body 3 that contacts the tensile strength member 2 is a flat surface with almost no irregularities, and the adhesion between the tensile strength body 2 and the optical fiber housing groove forming body 3 is improved. Can be enhanced.

When the optical fiber cable 7 is pulled by an optical fiber cable laying operation or the like, the terminal for exposing the tensile strength member 2 by removing the optical fiber housing groove forming body 3, the holding member 5, and the jacket 6 is removed. Processing needs to be performed. This terminal processing is performed, for example, first, as shown in FIG.
As shown in (2), the holding member 5 and the jacket 6 at the end of the optical fiber cable 7 are removed to expose the optical fiber housing groove forming body 3. Thereafter, as shown in FIG. 3 (b), a cut is made in a portion 3a to be removed indicated by a dotted line in FIG. 3 (b) of the optical fiber housing groove forming body 3 using a blade 10 such as a cutter. The part 3a to be removed is removed by using the cut. Thereby, the strength member 2 can be exposed.

However, as described above, if the solid layer 8 is provided at the innermost peripheral portion of the optical fiber housing groove forming body 3, the solid layer 8 is hard, and thus the solid layer 8 is attached to the solid layer 8 with the blade 10 at the time of the above-mentioned terminal treatment. Unless a cut is made to reach the strength member 2, it is difficult to remove the solid layer 8. For this reason, the operation | work which removes the solid layer 8 using the cutting tool 10 is always performed, and the cutting | disconnection as shown in FIG. There is a problem that the function of the tensile strength member 2 is deteriorated and disadvantageous.

Particularly, from the viewpoint of reducing the weight of the optical fiber cable 7, a fiber bundle (reinforcement fiber bundle) formed by bundling a plurality of fibers.
When the tensile strength member 2 is formed by the above, there is a possibility that the cutting tool 10 cuts a number of fibers of the tensile strength body 2 and causes a significant decrease in reliability of the tensile strength body. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to maintain good adhesion between a tensile strength member and an optical fiber housing groove forming member, and at the time of terminal processing of an optical fiber cable. It is an object of the present invention to provide an optical fiber cable spacer capable of preventing the strength member from being damaged and an optical fiber cable using the same.

[0011]

Means for Solving the Problems In order to achieve the above object, the present invention has the following structure to solve the above problems. That is, the optical fiber cable spacer according to the first invention is an optical fiber cable spacer in which the optical fiber housing groove forming body is provided in close contact with the tensile strength member around the tensile strength member. The surface of the fiber housing groove forming body that is in close contact with the tensile strength member is formed of a solid body, and the above-described problem is solved by a structure in which a cut portion for tearing the solid layer is provided on an outer peripheral portion of the solid layer made of the solid body. It is a means to solve.

According to a second aspect of the present invention, there is provided an optical fiber cable spacer having the structure of the first aspect, wherein at least one pair of notches facing each other via a tensile member is provided on the outer periphery of the solid layer. It is characterized by having.

A third aspect of the present invention provides an optical fiber cable spacer having the configuration of the first or second aspect, wherein the cut portion is formed by a groove extending in the longitudinal direction.

An optical fiber cable spacer according to a fourth aspect of the present invention includes the structure of the first, second, or third aspect of the present invention,
The optical fiber housing groove forming body is characterized in that it has a foaming region formed by a foam.

According to a fifth aspect of the present invention, there is provided an optical fiber cable spacer having the structure of the first, second, third or fourth aspect, wherein the tensile strength member is constituted by a fiber bundle formed by bundling a plurality of fibers. It is characterized by having.

An optical fiber cable according to a sixth aspect of the present invention is characterized by including the optical fiber cable spacer according to the first, second, third, fourth, or fifth aspect of the present invention.

In the invention having the above structure, a solid layer having a surface in close contact with the tensile strength member is formed in the optical fiber housing groove forming body of the optical fiber cable spacer, and a cut portion is formed on the outer periphery of the solid layer. It is formed in advance. For this reason, when performing terminal processing of optical fiber cables,
By simply tearing the solid layer using the above-mentioned cut portion with a hand or a simple gripping tool, the solid layer can be easily removed and the strength member can be exposed without using a blade.

As described above, since the solid layer can be removed without using a blade, the problem that the strength member is damaged by the blade at the time of terminal processing of the optical fiber cable does not occur, and the above-mentioned problem is solved. Can be.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1A is a sectional view showing an optical fiber cable using an optical fiber cable spacer which is characteristic in this embodiment. In the description of this embodiment, the same components as those of the optical fiber cable shown in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In this embodiment, an optical fiber housing groove forming body 3 is provided around a strength member 2 made of a fiber bundle to constitute an optical fiber cable spacer 1. The optical fiber housing groove forming body 3 includes a solid layer 8 (for example, a thermosetting polyolefin solid layer), a foam layer 13 (for example, a polyolefin foam layer having a foaming ratio of 30%), and a solid layer. The layer 14 (for example, a polyolefin solid layer) has a multilayer structure in which layers are sequentially stacked, and a plurality of optical fiber housing grooves 4 (eight in the example shown in FIG. 1) are formed in the outermost solid layer 14. ing.

In the outer peripheral portion of the solid layer 8 in contact with the tensile strength member 2, the cut portion 15 most characteristic in this embodiment is provided.
Are formed. As shown in FIG. 1B, the cuts 15 are formed by grooves extending in the longitudinal direction, and the two cuts 15 are formed so as to face each other with the tensile strength member 2 interposed therebetween. . This notch 1
Numeral 5 is for tearing the solid layer 8 as shown in FIG. 1 (c), and the groove width and depth of the cutout 15 are appropriately set to a size capable of easily tearing the solid layer 8. For example, when the thickness of the solid layer 8 made of a thermosetting polyolefin material is 1.2 mm, the depth of the cut 15 is set to 0.8 mm.

After the optical fiber core wire is housed in the optical fiber housing groove 4, a holding member 5 is formed outside the optical fiber housing groove forming body 3, and a jacket 6 is further provided outside the holding member 5. The optical fiber cable 7 is configured.

The optical fiber cable spacer and the optical fiber cable shown in this embodiment are constructed as described above. The terminal processing of the optical fiber cable shown in this embodiment will be briefly described.

First, the holding member 5 and the jacket 6 at the end of the optical fiber cable 7 are removed by an appropriate length. Then, a cut is made in the foam layer 13 and the solid layer 14 of the optical fiber housing groove forming body 3 using the blade 10 and the foam layer 13 and the solid layer 14 are removed by using the cut, and FIG. 2), the outer surface of the solid layer 8 is exposed.

Next, as shown in FIG. 1 (c), the solid layer 8 is torn off using the cutout portion 15 with a hand or a simple gripping tool, and the tensile strength member 2 is exposed.

According to this embodiment, since the cutout 15 for tearing is provided on the outer peripheral portion of the solid layer 8 of the optical fiber housing groove forming body 3, the blade 10 is used at the time of terminal processing of the optical fiber cable 7. Instead, the strength layer 2 can be exposed by tearing and removing the solid layer 8 using the cutout 15 with a hand or a simple gripping tool.
As described above, since the blade 10 is not used when the solid layer 8 is removed, it is possible to prevent the above-described problem, that is, the problem that the strength member 2 is damaged by the blade 10 when the solid layer 8 is removed. Can be.

In particular, in this embodiment, the strength member 2 is constituted by a fiber bundle to reduce the weight of the optical fiber cable 7. Solid layer 8 using cutter 10 as in the prior art
Is removed, the blade 10 cuts the fibers of the tensile strength member 2, causing a problem that the reliability of the tensile strength member 2 is greatly reduced. However, in this embodiment, as described above, Since the solid layer 8 can be removed without using the blade 10, the fibers of the tensile strength member 2 are not cut, and a decrease in the reliability of the tensile strength member 2 can be reliably suppressed. is there.

Further, in this embodiment, since the two cut portions 15 are formed to face each other with the tensile strength member 2 therebetween, the solid layer 8 can be easily torn without applying a strong force. .

Further, in this embodiment, since the surface of the optical fiber housing groove forming body 3 that contacts the tensile strength member 2 is formed of a solid body, the strength member 2 and the optical fiber housing groove forming body 3 are brought into close contact with each other. It is possible to improve the adhesion between the strength member 2 and the optical fiber storage groove forming member 3.

Furthermore, in this embodiment, since the optical fiber housing groove 4 is formed in the solid layer 14, the following effects can be obtained. For example, when the inner peripheral surface of the optical fiber housing groove 4, that is, the surface in contact with the optical fiber core wire is formed of a foam, the inner peripheral surface is formed as a surface having irregularities due to the foaming component of the foam. However, there is a concern that the optical fiber core wire may be bent due to the unevenness, and a problem that the conduction loss of the optical fiber core may increase. In contrast, in this embodiment, the solid layer 14
Since the optical fiber housing groove 4 is formed on the inner surface, the inner peripheral surface of the optical fiber housing groove 4 is formed as a flat surface having almost no irregularities made of a solid body, thereby causing the inner peripheral surface to have irregularities. The problem of an increase in the conduction loss of the optical fiber can be prevented.

Note that the present invention is not limited to the above-described embodiment, but can adopt various embodiments. For example, in the above-described embodiment, a pair of cut portions 15 facing each other with the tensile strength member 2 interposed therebetween is formed in the outer peripheral portion of the solid layer 8. Two or more pairs of notches 15 that face each other may be formed. In this case, the solid layer 8 can be further easily torn. Further, it is not necessary to provide the pair of cuts 15 as shown in the above embodiment, and an appropriate number of cuts 15 may be formed at desired positions on the outer periphery of the solid layer 8.

Further, in the above embodiment, the cut 15 is formed linearly in the outer periphery of the solid layer 8 along the longitudinal direction. For example, the cut 15 is spirally formed in the outer periphery of the solid layer 8. It may be formed in a shape. In this case, since the solid layer 8 can be easily torn and removed by providing only one cut portion 15, the number of cut portions 15 may be one.

Further, in the above-described embodiment, the cut portion 15 is formed by a groove. However, the cut portion 15 may be, for example, a dotted cut portion 15 in which a large number of concave portions are arranged at intervals.

Further, in the above embodiment, the optical fiber housing groove forming body 3 has a layer structure as shown in FIG. 1B, but the optical fiber housing groove forming body 3 is in contact with the strength member 2. The surface to be formed may be constituted by a solid body and provided with a solid layer made of the solid body, and is not limited to the structure shown in FIG. For example, in the above embodiment, the foamed layer 13 which is a foamed area is formed in the optical fiber housing groove forming body 3, but the foamed area may not be provided. However, since the optical fiber housing groove forming body 3 has the foaming region, the weight reduction of the spacer 1 and the optical fiber cable 7 can be promoted.

Further, in the example shown in FIG. 1A, eight optical fiber storage grooves 4 are formed in the optical fiber storage groove forming body 3, but the number of formed optical fiber storage grooves 4 is limited. The number is not limited, and an appropriate number can be adopted. Further, in the above-described embodiment, the tensile strength member 2 is configured by a fiber bundle, but the tensile strength member 2 may be configured by a material other than a fiber bundle such as a steel wire.

[0037]

According to the present invention, the optical fiber housing groove forming body has a solid layer in contact with the tensile strength member, and a cut portion for tearing the solid layer is formed on the outer periphery of the solid layer. Therefore, when performing the terminal treatment of the optical fiber cable, the solid layer can be easily torn and removed by using the cut portion with a hand or a simple gripping tool without using a blade. As described above, since the solid layer can be removed without using a blade, the strength member is not damaged by the blade when the solid layer is removed, and a decrease in reliability due to damage to the strength member is prevented. Can be avoided.

According to the present invention, as described above, damage to the tensile strength member can be suppressed, and the surface of the optical fiber storage groove forming body that contacts the tensile strength member is formed of a solid body, and the optical fiber storing groove forming member is formed. Since the adhesion between the body and the strength member is improved, it is possible to provide an optical fiber cable spacer and an optical fiber cable having excellent strength member strength.

Further, according to the present invention, as described above, since the solid layer can be easily removed, the time required for terminal processing of the optical fiber cable can be reduced.

In the case where one or more pairs of cut portions facing each other are provided on the outer peripheral portion of the solid layer with a tensile member interposed therebetween, the solid layer is wound up from the tensile member by the pair of cut portions. Therefore, the solid layer can be more easily removed.

In the case where the cut portion is formed by a groove extending in the longitudinal direction, the solid layer can be smoothly torn, and the working efficiency of the terminal treatment can be further improved.

When the optical fiber housing groove forming body has a foamed region, the weight of the optical fiber cable spacer and the optical fiber cable using the same can be reduced.

In the case where the strength member is constituted by a fiber bundle, as described above, a blade is not used for removing the solid layer, so that the fiber of the strength member is cut by the blade when the solid layer is removed. It is very effective because there is no fear of serious problems that may occur.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an example of an optical fiber cable using a spacer by a cross-sectional view.

FIG. 3 is an explanatory diagram showing a conventional problem.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spacer 2 Strength member 3 Optical fiber storage groove forming body 4 Optical fiber storage groove 7 Optical fiber cable 8 Solid layer 15 Notch

Claims (6)

[Claims] 1. A spacer for an optical fiber cable in which an optical fiber housing groove forming body is provided in close contact with the strength member with the strength member as a center. A spacer for an optical fiber cable, wherein a surface to be adhered is formed of a solid body, and a cut portion for tearing the solid layer is provided on an outer peripheral portion of the solid layer made of the solid body. 2. The optical fiber cable spacer according to claim 1, wherein at least one pair of cuts facing each other via a tensile member is provided on an outer peripheral portion of the solid layer. 3. The cutout portion is formed by a groove extending in a longitudinal direction.
An optical fiber cable spacer as described in the above. 4. The spacer for an optical fiber cable according to claim 1, wherein the optical fiber storage groove forming body has a foamed region formed by a foam. 5. The tensile strength member is formed of a fiber bundle formed by bundling a plurality of fibers.
5. The spacer for an optical fiber cable according to claim 2, 3 or 4. 6. An optical fiber cable comprising the spacer for an optical fiber cable according to claim 1, 2 or 3, or 4 or 5.