JP2839753B2 - Metal tube coated optical fiber equipment connector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber connector, and more particularly, to an optical fiber connector covered with a metal tube.

[0002]

2. Description of the Related Art In recent years, optical communication cables, which have been widely used, have been compared with conventional wire communication cables.
No electromagnetic noise, large transmission capacity per core,
It has the advantage of not causing a signal failure due to contact with a live wire such as a high-voltage power cable or a jumper cable between devices.

[0003] Commercially available optical fiber cables having these advantages can be broadly divided into two types. One is a polymer cable in which a core or a clad (consisting of quartz or plastic) is primarily coated with a thin resin coat, or a core wire or a core wire is secondarily coated with an organic polymer (for example, Japanese Patent Application Laid-Open No. 58-142308). Gazette, JP-A-60-2
No. 63104) and the other one is an organic polymer 2
This is a fiber cable with a metal tube using a metal tube instead of the next coating.

[0004] The polymer cable has the advantages of the optical communication cable described above sufficiently, but since the entire cable is made of a material having low mechanical strength such as quartz, plastic, resin, and organic polymer, tension and lateral pressure are applied. It shows only a very low resistance to deformations such as bending and the like. Therefore, Kevlar and relatively high-strength plastics (Teflon, FR
P, etc.) to improve the strength. Particularly, in the case of an overhead wire or the like, an extremely high tensile strength may be required, and a steel wire may be used instead of a high-strength plastic linear body. The essential parts for signal transmission are the core and cladding, but the need for such protective reinforcement results in a heavy cable.

A fiber cable with a metal tube has a high strength by enclosing an optical fiber and a core wire in a metal tube, and is as light as a wire communication cable. In addition, the handling is simple, and it has a remarkable advantage in the work of extending the communication cable.

[0006] The following three types of fiber cables with metal tubes are commercially available.

(1) A type in which a fixed end of a connector is fixed to a pipe end with a seamless pipe. (2) A type in which a fixed nut of a connector is fixed with an adapter using a flexible pipe. (3) A cable body is a seamless pipe. However, after fixing the seamless pipe and the flexible pipe through the adapter only near both ends, the other end of the flexible pipe is further fixed to the fixing nut part of the connector via the adapter. Tubed fiber cables are excellent at completely protecting optical fibers from the atmosphere and corrosive gases, but are not as flexible as flexible tubes. On the other hand, a flexible tube has poor sealing properties. Therefore, the type (3) (a combination of a seamless pipe and a flexible pipe) has recently become the mainstream, although it takes time and effort in production.

[0008]

However, a fiber cable with a metal tube has an important drawback in terms of insulation. In other words, the enclosed optical fiber or core wire is made of an insulating material, so even if it comes into contact with a live wire, no signal disturbance will occur, but the outer metal tube is a good conductor, and current will flow. Electric current flows to the device or device via the connector attached to the terminal. In some cases, the current may destroy equipment and devices. On the other hand, it is possible to obtain insulation by coating an insulating material such as an organic polymer on a metal tube, but there is a disadvantage in that the cable weight increases. Further, when a thin coating is formed, the coating is easily broken.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high-safety fiber cable with a light weight and high strength, which prevents a current from flowing into an apparatus or a device.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a metal adapter (2) to be connected to equipment; a metal tube coating (6) of an optical fiber cable (3, 6, 10) having a metal tube coating (6). A) a metal ferrule (12) that supports the tip of the optical fiber (10) located outside the tip of the metal adapter (2) and guides the tip to the optical fiber insertion hole of the metal adapter (2); A metal member (11, 15) supporting a metal ferrule (12) movably in the penetrating direction and having one end fixed to a metal adapter (2); and,
An insulator cable connector (16) having one end fixed to the other end of the metal base (11, 15) and the other end fixed to at least a metal tube coating of the optical fiber cable (3, 6, 10);
Is provided. Symbols in parentheses indicate corresponding elements or items in the embodiment shown in the drawings and described later.

[0011]

According to the invention of the present application, in an optical fiber cable (3, 6, 10) having a metal tube coating (6), one end is fixed to a base (11, 15) and the other end is connected to the optical fiber cable (3, 6). Since the cable connector (16) fixed to at least the metal tube coating of (6, 10) is used as an insulator, a high degree of insulation is obtained between the metal tube and equipment and devices connected thereto. For example, even if it comes into contact with an electric wire in another live state, the current does not flow into the device and the device and does not destroy the device and the device. Further, according to this, for example, a fixing nut or the like for fixing to the bases (11, 15) can be integrally formed with the cable connector (16), which is advantageous in terms of parts management. Furthermore, since the optical fiber (10) is covered with a metal tube, it is lightweight and has high strength.

Therefore, a highly safe optical fiber cable can be obtained.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0014]

FIG. 1 shows a fiber cable with a metal tube according to an embodiment of the present invention. This shows a state in which the connector adapter 2 is connected to the connector part 1 at one end (the other end is omitted) of the cable with a metal tube. The other end has the same configuration. The cable body is a seamless pipe 4 coated with a PV resin 3 and is fixed (screwed) to one end of a flexible pipe 6 also coated with the PV resin 3 via a relay adapter 5 near both ends thereof. Further, the other end of the flexible tube 6 is connected via an adapter 16 (with screws) to the body 1 of the connector 1 described later.
1 is screwed (joined).

Generally, the adapter 16 is composed of a fixing nut for fixing the body 11 and an adapter (flexible adapter) for fixing the flexible tube 6, and is constituted by fixing (screw-joining) the fixing nut and the adapter (flexible adapter). However, the adapter 16 of the present invention has a fixed nut and an adapter (flexible adapter) integrally formed.

[0016] Seamless pipe 4 and flexible pipe 6
Is a cable in which an optical fiber core wire 10 in which a bare fiber 9 is primarily coated with a thin resin coat is secondarily coated with a metal tube. The flexible tube 6 has a property of maintaining straightness in the longitudinal direction.

The connector 1 has a cylindrical body 11. The body 11 has a ferrule 12 inserted at the front and a collar 13 inserted at the rear. The tip of the ferrule 12 protrudes from the body 11. A coil spring 14 is inserted between the ferrule 12 and the collar 13. The inner periphery of the body 11 and the ferrule 12 are spline-connected, and the annular stopper 1
The ferrule 12 is positioned by 1a. A connection nut 15 is provided on an outer periphery of the body 11, and an annular stopper 15 a is provided on an inner periphery of the connection nut 15. When the connection nut 15 is advanced with respect to the body 11, the stopper 15a
1b, and moves forward integrally with the body 11.
A screw 11c is cut on the outer periphery near the rear end of the body 11, and one end of the adapter 16 fits into the screw 11c.

A screw 2a is cut on the outer periphery of the connector adapter 2, and the connection nut 15 is fitted to the stopper 2b provided on the connector adapter 2 until the tip of the body 11 contacts the stopper 2b. As a result, the tip of the ferrule 12 becomes 1-2 to maintain the center line of the optical fiber.
It is inserted into the inner periphery of the connector adapter 2 with an accuracy of about μ.

Therefore, the points that are always in contact with the connector adapter 2 are the ferrule 12, the connection nut 15, and the body 11. Of course, various shapes of the connector itself are conceivable, and there is a possibility that another contact point may occur. However, these three contact points cannot be easily avoided.

In the present invention, the connector adapter 2, ferrule 12, and connection nut 15 are made of metal to withstand repeated attachment and detachment of the connector.
The adapter 16 interposed between the flexible tube 6 and the flexible tube 6 is made of an insulating material (polyethylene in this embodiment) to prevent current from flowing into the device or device.

The insulator is a qualitative expression meaning a substance having a large electric resistance. The insulator defined in the present invention is an insulator having the following characteristics.

Volume resistivity (relative humidity 50%, 23 ° C.)
> 10 ¹³ Ωcm Withstand voltage (short-time method, thickness 3.17 mm)> 100 kV /
cm The material is ceramic, resin or a mixture thereof. On the other hand, these insulators require mechanical strength. For example, the internal tensile strength of the mechanical strength is 150
kgf / cm ² or more is desirable.

In the present embodiment, a fiber cable with a metal tube of a combined type of a seamless tube and a flexible tube has been described. However, the present invention is not limited to this, and a seamless tube and a fixed nut of a connector and a fixing nut portion of a connector are used. The present invention can be similarly applied to a type in which a fixing nut portion of a connector is fastened by a tube via an adapter.

In this embodiment, the adapter 16 is made of an insulating material. Alternatively, although not shown, a grounding point may be provided in a metal tube portion near the insulating material.

[0025]

As described above, according to the present invention, a high degree of insulation can be obtained between the metal tube and the equipment and devices connected to the metal tube. It does not flow into equipment and devices and destroy equipment and devices. According to this, for example, the base (11,
Since a fixing nut or the like for fixing to the cable connector (15) can be integrally formed with the cable connector (16), it is advantageous in terms of component management. Furthermore, since the optical fiber (10) is covered with a metal tube, it is lightweight and has high strength. Therefore, a highly safe optical fiber cable can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

[Explanation of symbols]

1: Connector part 2: Connector adapter (metal adapter) 2a: Screw 2b: Stopper 3: PV resin 4: Seamless pipe 5: Relay adapter 6: Flexible pipe (metal pipe coating) 9: Bare fiber 10: Optical fiber core ( (Optical fiber) (3, 6, 10: Optical fiber cable) 11: Body 11a: Annular stopper 11b: Key 11c: Screw 12: Ferrule (metal ferrule) 13: Collar 14: Coil spring (spring member) 15: Connection nut ( 11 and 15: metal base) 15a: stopper 16: adapter (insulated cable connector)

Claims (1)

(57) [Claims] An optical fiber cable having a metal tube coating supports an end of an optical fiber which is located outside the end of the metal tube coating, and inserts this end into an optical fiber of the metal adapter. A metal ferrule that guides the hole into the hole; a spring member that presses the metal ferrule in a direction that penetrates the metal adapter; a metal base that movably supports the metal ferrule in the direction that penetrates the metal ferrule and has one end fixed to the metal adapter; A metal tube-coated optical fiber device connector comprising: an insulator cable connector fixed to the other end of the metal base, and the other end fixed to at least the metal tube coating of the optical fiber cable.