JPH02124505A - Optical fiber cord - Google Patents

Abstract

PURPOSE:To facilitate a terminal treatment by inserting optical fiber cores into a hollow pipe structure and coating the outer periphery of microsegments with a sinking tube. CONSTITUTION:A fine metallic pipe 2 is formed by butting the ends of a thin metallic sheet and plural pieces of the microsegments 3a to 3c are doubled and twisted on the outer peripheral surface of the metallic pipe to form the hollow pipe structure. The optical fiber cores 1a to 1d are inserted therein and the outer side of the hollow pipe structure is sunk 4 by the tube placed longitudinally along the outer side by the tape consisting of a stainless steel, etc. Laying operations at the time of easily forming a communication line by the optical fibers is facilitated in this way and the terminal treatment of the optical fiber cord in particularly is easily executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an optical fiber cord that is useful when directly buried underground or when providing emergency wiring.

[Summary of the invention]

The optical fiber cord of the present invention is made by butting thin metal plates to form a thin metal pipe, and twisting a plurality of micro segments on the outer circumferential surface of this metal pipe to form a hollow pipe structure. In addition to inserting the fiber core wire, the outside of this hollow pipe structure is
This is a sinking method using a tube vertically aligned with a tape made of stainless steel, etc., and it simplifies the installation work when forming a communication path using optical fibers, and is particularly useful for terminal processing of optical fiber cords. This is something that can be done easily.

[Conventional technology]

Communication channels using optical fibers are capable of transmitting extremely high density information and are used as communication lines in many information industry fields.

However, since optical fibers are fragile and easily damaged, it is usually necessary to protect them in some way to prevent direct stress from acting on them.

Figure 4 shows the optical fiber core PF in a small diameter SUS vibe S.
This figure shows an example of an optical fiber cord inserted into P. Although it is possible to use such an optical fiber code PC separately, as shown in Fig. 5(a) and (b), it is assembled together with a power supply or control line, and its outer periphery is covered with a sheath S and a tensile strength wire. By applying the exterior by the line W,
It may also be cabled. Note that CP indicates central tensile line force.

[Problem that the invention seeks to solve]

By the way, such cables are generally transported wrapped in a drum and pulled out at the work site, but when the curling caused by the drum winding was being corrected, the stainless steel pipe SP caved in and there was a problem inside. There is a problem with damaging certain optical fibers.

That is, as shown in FIG. 6(a), the optical fiber cord PC pulled out from the cable C still has some twisting, so when correcting this twisting, the stainless steel pipe part is removed as shown in the enlarged view. This often causes damage to the internal optical fibers.

Furthermore, the pipe SP of this optical fiber cord is shown in Figure 6 (
As shown in b), when pulling out the optical fiber core FE inside after cutting at point A, it is extremely difficult to prevent the optical fiber core wire FB from being damaged by the tool, resulting in extremely low work efficiency. There is a problem.

In addition, when manufacturing this optical fiber cord PC, the pipe SP part is manufactured by squeezing stainless steel tape into a cylindrical shape and welding the joints, but the flame during this welding There is a problem that the optical fiber core wire FB that is inserted inside is damaged.

[Means for solving problems]

The present invention was made to solve this problem, and as a structure for protecting optical fibers, fan-shaped microsegments are twisted onto a metal pipe made by abutting thin metal plates, or fan-shaped microsegments are directly formed. The pipes are placed vertically to form a hollow pipe structure, and this hollow pipe structure is sinked with a stainless steel tube.

[Effect]

The main member that protects the optical fiber is composed of multiple fan-shaped microsegments, which are fixed with stainless steel sinking tubes. It is possible to prevent the curling from occurring even at times, and also,
Since a hollow pipe structure is formed by the micro-segments, and the optical fiber core wire is inserted into the hollow pipe structure, the end treatment of the optical fiber cord can be easily performed.

[Example la Figures 1(a) and 1(b) show a perspective view and a cross-sectional view of the optical fiber cord of the present invention, including la, lb, lc,
ld is an optical 7-fiber core wire, 2 is a metal pipe constructed by butting together thin metal plate (SUS) tape, 3a, 3b,
3c is a microsegment (3c) with a sector-shaped cross section.
(sometimes more than a book).

Each of the micro segments 3a, 3b, and 3c has been slightly twisted by a collecting machine used in manufacturing electric wires.

4 indicates a sinking tube which is sinked by longitudinally placed stainless steel tape in order to maintain the hollow pipe structure formed by the plurality of microsegments 3a to 3b, and this sinking tube 4
The abutting ends of are burst-bonded by welding means.

Note that P is applied to the outer peripheral surface of the sinking tube 4 as necessary.
It is preferable to coat it with a synthetic resin such as VC to add weather resistance.

As described above, the optical fiber cord according to this embodiment first wraps the optical fiber cores 1a to 1d with a metal pipe 2 made of thin metal tape, and then uses the metal pipe 2 as a shell to connect a plurality of micro-optic fibers. segment)
Since the hollow pipe structure is constructed by twisting 3a to 3c, the center number is formed when twisting the micro segments, so it is possible to prevent the hollow structure from collapsing due to depression, and it is considerably It becomes possible to create a thin hollow pipe structure.

Moreover, since the metal pipe 2 merely maintains its cylindrical shape by butting, even when pulling out the optical fiber core from this optical fiber cord as described above, the sinking tube 4 must first be cut and removed. Then,
Manually expand and pull apart each microsegment.
The optical fiber core can be exposed by pushing and expanding the abutting portion of the metal pipe 2 inside the metal pipe 2, so when performing terminal processing of the optical fiber cord,
It has the characteristic that the optical fiber core wire will not be damaged by knives or tools.

Also, the patent application No. 63-223492 previously proposed by the present applicant
As seen in the invention of No. 1, the feature is that terminal processing is facilitated.

[Embodiment 2] FIGS. 2(a) and 2(b) show a perspective view and a cross-sectional view of an optical fiber cord showing another embodiment of the present invention.
As in the case of FIG. 1, 1a-1d are optical fiber cores.

5a and 5b have semi-cylindrical cross sections, and their end surfaces (
As shown in FIG. 2(b), the joint surface) is two microsegments cut at an angle of θ = 300 to 55° from the radial direction, 6 is this microsegment) 5
This is a sinking tube that is sinked around the outer periphery of a and 5b.

In the case of this embodiment, the metal pipe 2 included in the optical fiber cord shown in FIG.
Since the butt joint surfaces of the metal pipe 2 are shaped to have an angle θ, when the micro segments are twisted together or when an external force is applied, the wedge effect prevents these end faces from shifting from each other, and the metal pipe 2 Even if microsegments 5a and 5b are omitted, the twisting of microsegments 5a and 5b is strengthened.

[Embodiment 3] FIGS. 3(a), (b), and (C) show still another embodiment of the present invention, which is an optical fiber cord in which the metal pipe 2 is omitted as in FIG. 2. An example is shown.

In this embodiment, microsegments 7a and 7b protect the optical fibers 1a to ld.

7c and 7d are similar to the embodiment shown in FIG. 1 in that the cross section is fan-shaped, but each microsegment)
is characterized by the fact that it is not twisted.

That is, in the optical fiber cord of this embodiment, each of the micro segments 7a to 7d is assembled into a hollow shape by a vertical alignment method with respect to the optical fiber cores 1a to 1d (usually slightly twisted). It is something that

The vertical alignment method is a manufacturing process in which a cylinder is formed so as to wrap the optical fiber while running microsegment materials from all sides on the optical fiber that is running on the production line, and is fixed with a sinking tube 8. As a result, there is almost no misalignment of the end faces of each micro segment, and a hollow pipe structure can be achieved.

In addition, each micro segment divided into four,
As shown in the cross section of FIG. 3(C), it can also be formed at unequal division angles.

i.e. upper and lower microsegments) 7a.

If the dividing angle 01 of the left and right micro-segmented doors b and 7d is set to be θ2 minus OI with respect to the dividing angle θ2 of 7c, strong proof strength can be exhibited even when an external force is applied from a specific direction.

As mentioned above, the characteristics of the optical fiber cord of the present invention have been shown through the three examples, and in all cases, it has the characteristic that it is hard to get bent by winding on a drum etc.
As seen in the optical fiber cord and its connection method (Japanese Patent Application No. 63223492) previously filed by the present applicant, there is an advantage that terminal processing is simplified.

〔Effect of the invention〕

As explained below-1-, the optical fiber code of the present invention is
Since the pipe structure that protects the optical fiber core is mainly composed of fan-shaped micro segments, it is possible to prevent the pipe structure from being damaged by drum winding, etc. There is an advantage that the optical fiber core wire can be easily exposed and the securing operation can be performed.

In addition, by providing a small diameter butt pipe on the inner circumferential side of the micro segment, twisting becomes easier.
By angling the joint surfaces of the microsegments, a wedge effect can be exerted, and the pipe structure can be made resistant to external pressure (not immersed).

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are perspective views and sectional views showing one embodiment of the optical fiber cord of the present invention, and FIGS. 2(a) and (b) are perspective views showing another embodiment of the present invention. Diagram and sectional view, Figure 3 (a
), (b), and (c) are perspective views and cross-sectional views showing still other embodiments of the present invention, and cross-sectional views when the dividing angle is changed; FIG. 4 is a cross-sectional view of a conventional optical fiber cord; Figure 5(a)
, (b) are cross-sectional views of a cable using a conventional optical fiber cord, and FIGS. 6(a) and 6(b) are explanatory diagrams of the terminal processing of the conventional optical fiber cable. In the figure, 1a to ld are optical fiber cores, 2 is a butt pipe, 3a to 3c, 5a to 5b, 7a to 7C are micro segments, and 4, 6.8 are sinking tubes. b Figure 30″≦0≦55゜Figure a

Claims (3)

[Claims] (1) A hollow pipe structure is created by twisting a plurality of fan-shaped micro segments on the outer peripheral surface of a small diameter metal pipe made by butting thin metal plates, and an optical fiber is inserted inside the hollow pipe structure. While inserting the core wire,
An optical fiber cord characterized in that the outer periphery of the micro segment is covered with a sinking tube. (2) A hollow pipe structure is created by twisting two or more microsegments that have a cross-sectional shape such that when fan-shaped cross sections are joined into a cylindrical shape, the angle of the joint surface is inclined by θ from the radial direction of the cylinder. An optical fiber cord is characterized in that the outer periphery of this hollow pipe structure is covered with a sinking tube, and an optical fiber core wire is inserted into the inner periphery of the sinking tube. (3) A hollow pipe structure is formed by vertically aligning three or more microsegments with fan-shaped cross sections, and the outer periphery of the hollow pipe structure is covered with a sinking tube, and an optical fiber core is attached to the inner periphery of the hollow pipe structure. An optical fiber cord characterized by having a wire inserted through it.