JPH0531605Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an optical fiber cable, particularly a two-core cable whose core wires can be easily extracted.

(Prior Art) As shown in FIG. 2, an optical fiber core 1 has an inner coating 3 made of silicon, acrylate, or the like to strengthen the fiber on the optical fiber 2, and a protective coating to facilitate handling. An outer coating 4 made of nylon or an ultraviolet curing resin such as urethane acrylate, epoxy acrylate, or silicone acrylate is applied as a layer, and a buffer layer 5 made of silicone resin or the like is provided between the inner coating 3 and the outer coating 4 to withstand lateral pressure. Structures with a built-in structure are widely used.

In the case of a two-core cable, conventionally, as shown in Figure 2, two optical fiber cores 1 as described above are twisted or arranged in parallel, and then directly and commonly coated with nylon, urethane acrylate, epoxy acrylate, or silicone. A structure having a protective coating 6 made of an ultraviolet curing resin such as acrylate is used.

(Problem to be solved by the invention) It is possible to connect each optical fiber core to another single optical fiber by protruding from the terminal of the above-mentioned two-core optical fiber cable, or to fold back the protruding two-core optical fiber. In some cases, connection work such as connecting to a loop is performed using a cable, but when performing the above-mentioned lead-out of the core wire, the outer sheath 4 and the protective sheath 6 of the optical fiber are made of almost the same resin, so the protective Covering 6
When stripping off, the outer coating 4 of the optical fiber sticks to the protective coating and is stripped off at the same time.

Optical fiber cores are originally small pores, so when the reinforcing outer coating 4 is stripped off, they become thinner and harder to handle, become weaker against bending and tension, and easily break, and are also less resistant to impact. Because it was weak, it was necessary to reinforcing the entire optical fiber by reinforcing it by extrapolating a reinforcing tube over the cored optical fiber, which had been exposed and had no outer coating, and to proceed with the connection work, etc. at home.

(Means for Solving the Problems) The present invention has been made to solve the problems as described above. Young's modulus
Optical fiber twin-core cable with a structure provided with a fragile intermediate layer 7 made of silicone resin or ultraviolet curable resin such as urethane acrylate, epoxy acrylate, silicone acrylate, butadiene acrylate, etc. with a breaking elongation of 0.5 Kg/mm ² or less and 50% or less of elongation at break. The main points are as follows.

(Function) By making the cable structured as above,
When the protective coating is stripped using a jacket stripper or the like, the fragile intermediate layer is torn to pieces, so that only the protective coating is removed and the outer coating of the optical fiber is not stripped.

(Embodiment) Fig. 1 is a cross-sectional view of an embodiment of the optical fiber twin-core cable according to the present invention. 1 consists of an optical fiber 2 made of quartz glass, an inner coating 3 made of modified silicon, a buffer layer 5 made of silicone resin, and an outer coating 4 made of nylon. After twisting, Young's modulus is 0.5Kg/mm ²
In the following, a fragile intermediate layer 7 is provided by coating with a silicone resin having an elongation at break of 50% or less, and a protective coating 6 made of nylon is applied thereon. When this cable was stripped using a jacket stripper, the protective coating 6 could be easily stripped off without stripping the outer coating 4 of the optical fiber.

(Effect of the invention) According to this invention, the opening coating 4 made of nylon resin or ultraviolet curing resin is placed on the optical fiber 2.
Two optical fiber cores 1 having a Young's modulus is 0.5Kg/ ^mm2 or less between
Since it is configured to provide a fragile intermediate layer 7 made of silicone resin or ultraviolet curing resin with an elongation at break of 50% or less, when a part of the protective coating 6 is pulled out and removed using a jacket stripper or the like, The fragile intermediate layer 7 made of silicone resin or ultraviolet curing resin having a Young's modulus of 0.5 Kg/mm ² or less and an elongation at break of 50% or less is broken into pieces, and only a portion of the protective coating 6 is pulled out and removed. Therefore, it is possible to easily take out the optical fiber with the outer coating 4 still attached, which makes it easier to connect the optical fiber after the fact, and in addition, there is no need to cover it with a reinforcing tube as in the past. There is no.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of a two-core optical fiber cable according to the present invention, and FIG. 2 is a cross-sectional view of a conventional example of a two-core optical fiber cable. DESCRIPTION OF SYMBOLS 1... Optical fiber core wire, 4... Outer coating of optical fiber, 6... Protective coating, 7... Fragile intermediate layer.

Claims (1)

[Scope of utility model registration request] Two optical fiber cores 1 having an outer coating 4 made of nylon resin or ultraviolet curing resin on the optical fiber 2 are twisted together or arranged in parallel, and the outside of these fibers is commonly coated with nylon or ultraviolet curable resin. A protective coating 6 made of ultraviolet curable resin is provided, and between the external coating and the protective coating there is a brittle resin made of silicone resin or ultraviolet curable resin having a Young's modulus of 0.5 Kg/mm ² or less and an elongation at break of 50% or less. An optical fiber twin-core cable characterized in that an intermediate layer 7 is provided.