JPS5821206A - Optical fiber cable - Google Patents

Abstract

PURPOSE:To obtain an optical fiber cable of a long life against breakage easily by containing optical fiber cores in the grooves provided on the outside circumference of a rubber-like elastic body of a long size and providing allowances for elongation to the optical fiber cores despite elongation of the rubber-like elastic body. CONSTITUTION:Plural lines of spiral grooves 2 are provided on the outside circumference of a long sized elastic body 1 of a circular section which is rubber or the like having, for example, >=200% elongation in such a way that the depth and width of the grooves remain smaller than the outside diameter of optical fiber cores 3 at the max. elongation generated in an optical fiber cable. After the cores are inserted into said grooves 2, the tapes 4 laminated with metallic tapes 4A and thin plastic layers 4B on the outside thereof are coated thereon and further the outside circumference of the tapes 4 are extrusion coated with plastic tapes 5 to melt stick said tapes to the layers 4B, whereby a cable sheath 6 is provided. Even when the long sized rubber-like elastic body elongates, there are allowances in the extension of the cores 3 and the cores restore the original state when tension is released. Thus the optical fiber cable of a long life is obtained.

Description

[Detailed description of the invention] This publication relates to the Hikari 7 Eye Pacer.

When forming an optical 7-ipa cable, the optical fiber O
The transmission characteristics shall not be further impaired during manufacturing, installation work, or use, and the optical 7I d
It is important that the material does not break.

Hikari 7 Aipah is weak against stretching, so conventionally Hikari 7 Aipah Shin! In order to prevent tension from being applied to the Hikari 7-Ipa (the outer circumference of the Hikari 7-Ipa is provided with a protective covering such as glass or glue), the 1-Hikari 7-Ipa core wire is wrapped around the outer periphery of a long tensile strength body and fixed. The extra length was accommodated in the PL or the safety ∆ig.

However, forming an optical fiber coupler so that it does not stretch with a long tensile strength member requires the use of a high tensile strength member, which increases the cable diameter, increases the cable weight, and costs. It has the disadvantage of poor flexibility.

t, long O-retention film)
Inserting it with extra length has the disadvantage of being technically very difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical fiber cable that does not adversely affect the optical fiber core even when stretched, and can easily provide an extra length O to the optical fiber core.

The optical fiber cable of the present invention includes a rubber-like elastic elongated body provided with a spiral groove on the outer periphery, and a core having an optical fiber core wire accommodated in the spiral groove of the shim-like elastic body.
and the rubber-like elastic elongated body! When the rubber-like elastic elongated body stretches when the I force is applied, a moan occurs as the rubber-like elastic elongated body stretches, and the optical fiber core 7 can also elongate accordingly. This is to prevent negative effects such as elongation due to tension or lateral pressure from reaching the fiber core.

Hereinafter, embodiments of the present invention v4 will be explained in detail with reference to the drawings. Figs. 1 and 2 show the @1 embodiment of the optical fiber cassor according to the present invention.

As shown in the figure, the optical fiber cable of this embodiment has a rubber-like elastic elongated body 1 having a circular cross section and made of, for example, rubber or elastomer having an elongation rate of 200 or more. This f
A plurality of threads 0** grooves 2 are provided on the outer periphery of the rubber-like elastic long body 1, and a core fiber core 3 is inserted into each of these spiral grooves 2.
is accommodated.

The depth and width of each spiral groove are selected so that the depth and width of each spiral groove do not exceed the outer pole of the optical fiber core 3 even when the optical fiber cable is stretched to its maximum extent. Rubber-like elastic elongated body lO
On the outer periphery, a metal-plastic laminate 14 consisting of a metal tape 4 and a thin plastic layer 4B laminated on the outer periphery is covered vertically so as not to tighten the rubber-like elastic elongated body 1. A plastic sheath 5 is extruded and coated on its outer periphery, and the plastic sheath 5 is fused to the plastic thin layer 4B to provide a hollow cable sheath 6.

In such an optical fiber cable, when tension is applied to the rubber-like elastic elongate body 1 and the rubber-like elastic elongate body 1 is stretched, the rubber-like elastic elongate body 1 becomes thinner and the elastic length s' becomes thinner. The radius from the center of the ulnar body 1 to the bottom of the spiral groove 30 is small, and as the radius decreases, the optical fiber core 3 also has room to stretch, and the optical fiber core 3 can be saved from tension. . When the tension applied to the rubber-like elastic elongate body 1 is removed, the rubber-like elastic elongate body 1 is restored to its original length, and the optical fiber core II3 is also locally moved within the space of the groove 2. It can be restored to its original state without being subjected to severe lateral pressure.

In addition, if it is necessary to increase the strength of the cable sheath in the structure as described above, a layer of tensile strength member such as polyamide fiber can be provided around the outer periphery of the electrostatic sheath 5, and furthermore, plasti or tasheath can be applied to the outer periphery. Bye.

FIGS. 3 and 4 show a second embodiment of the optical fiber cable according to the present invention. The optical fiber cable of the 0-strand embodiment has a tensile strength member 7 made of glass fiber reinforced plastic or the like. A plurality of optical fiber cable units 8 are wound, and a pressing layer 9 is provided on the outer periphery of the optical fiber cable unit 8.
At its outer circumference! There are nine structures in which there are 10 plastic plates and sieves 10 (for example, last plates, etc.). Optical fiber cable: LJLy) As shown in Figure 4, the fiber optic cable has an elastic long body l with a shell-shaped cross section, and a plurality of spirals 1p12 are provided on its outer periphery, and inside these spiral grooves 2. Each light 7 Aiva heart! Is is accommodated. At each helical mzo entrance, in order to prevent the optical fiber core 3 from escaping from the groove 2, a fiber escape prevention member 11 is integrally formed and protrudes from one side wall of the l1iI. Such a shape O:/mu-shaped elastic elongated body 1 can be formed by spiral extrusion in which extrusion is performed while rotating a die.

The same effects as in the first embodiment can be obtained even with such an optical 7-eye scanner. In this case as well, if it is necessary to increase the strength of the cable sheath, a layer of fiber material (for example, I-reared fibers) is installed on the outer periphery of the plastic sheath 100, and a plastic sheath is further placed on the outer periphery of the snow. In addition, in the case of the optical fiber cable shown in FIG. 1, the elastic elastic elongated body l having a structure as shown in FIG. 4 may be used.

In addition, in the case of the optical fiber cable shown in FIG. 3, the optical fiber cable unit 8 is such that, as shown in FIG. It is also possible to use a structure in which a core wire escape prevention member 11 called a motherboard is provided on the outer periphery of the elastic long body 10. With such a structure, the rubber-like elastic elongated bodies 1 do not come into direct contact with each other, and the rubber-like elastic bodies 1 can be expanded and contracted smoothly.

The two formations of the core wire escape prevention member 11, such as ΔEve, are, for example, f9, etc. It can be formed by extrusion.

Example 1 A rubber-like elastic body made of vulcanized rubber with an outer diameter of 44 Wφ and an elongation characteristic of 300 was coated with a width of 15 sIIm and a depth of 1.5 mm.
wxO#AtII! 4 grooves were provided with grooves T 200 wx in width and width. A cored optical fiber was accommodated in each spiral groove. The fiber cores of each party are made by coating a glass fiber with an outer diameter of 115μ and φ with a primary coat of silicone rubber and a buffer layer of silicone rubber with an outer diameter of α4 and a round or rubber-like elasticity. A 0.75 mm thick OAl 4-/V ethylene sheath is applied around the outer circumference of the body so that the inner pole is 4@■φ and the outer diameter is 6 mm. Ale, 20 of ryamide fibers are twisted and covered, and the outer circumference K is 1. ! ■Thick full
An optical fiber cable with an outer diameter of 11 mm was constructed by covering it with an ethylene sheath.

Although the optical fiber cable was stretched by 411 degrees, no breakage of the optical fiber was observed.

Example 6 outer poles with a lunate sheath configured as described above
The four-core optical fiber cables are twisted in 6 biased sets on the circumference of a tensile member with an outer diameter of 6 mm, and a pressing layer of non-woven fabric is applied to the outer periphery to make the outer diameter 19 mm. An optical fiber cable with an outer diameter of 21.5 φ was constructed by applying an aluminum-polyethicine lanate sheath with an outer circumference K of 1.2 wx thickness.

The tension member is made of glass fiber-reinforced plastic with an outer diameter of 1 m1, twisted with one wire, and a wire sheathed around the outer periphery to give an outer diameter of 6 mm.

Although this optical fiber cable was given a 4-degree elongation, no breakage of the optical fiber was observed.

As explained above, in the optical fiber casing according to the present invention, since the optical fiber core wire is housed in the spiral groove on the outer periphery of the rubber-like elastic body, the rubber-like elastic body stretches under tension and becomes thinner, so that the optical fiber cassette becomes light at the nine edge. It is possible to provide the fiber core with an elongation margin, and it is possible to protect the optical fiber core from tension.

Therefore, according to the present invention, it is possible to provide a fiber cable with excellent breaking life. Furthermore, according to the present invention, extra length for protecting the optical fiber core from tension can be provided by simply inserting the optical fiber core into the spiral groove of the rubber-like elastic elongated body. It is. Therefore,
According to the present invention, it is possible to easily manufacture a multiplication fiber cable with excellent breaking life.

[Brief explanation of drawings]

gi is a cross-sectional view of the optical fiber cable 4) according to the first embodiment of the present invention, [Figure 2 is a perspective view of the rubber-like elastic elongated body used in the present invention, and Figure 3 is a cross-sectional view of the optical fiber cable according to the present invention. FIG. 4 is a cross-sectional view of the fiber cable unit used in this embodiment, and FIG. 5 is a cross-sectional view of another example of the optical fiber cable unit used in this embodiment. FIG. 1--Shim-like elastic elongated body, 2--Spiral groove, 3--Optical fiber core wire, 4--Lasted wire, 5--Gutsuti, Kushiisu, 6--Shim-shaped elastic sheath, 7--Tensile member, 5 -jtya4.4 Cape #zx, ), 9
... Pressure winding layer, 10-Plasti, Kushisu, 11.
- Core wire escape prevention member. Agent Patent Attorney Hideshi Matsumoto

Claims (1)

[Claims] An optical fiber cable characterized in that one optical fiber core III is accommodated in a spiral groove provided on the outer periphery of a rubber-like elastic elongated body.