JP2839752B2 - 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 a connector for connecting an optical fiber 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]

As described above, the strength of the cable main body of the optical fiber cable containing a metal tube has been enhanced, but in addition to this, the fastening of the cable main body to the fixing nut portion of the connector is required. Also, high strength is required for deformation such as tension, lateral pressure, and bending.

Further, the fiber cable with a metal tube has an important disadvantage 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 cable which strengthens the connection between a lightweight and high-strength fiber cable containing a metal tube and a connector.

[0011]

SUMMARY OF THE INVENTION The present invention provides an adapter (2) coupled to an apparatus; a metal tube coating (6) of an optical fiber cable (3, 6, 10) having a metal tube coating (6). Ferrule (12) that supports the tip of the optical fiber (10) outside of the tip of the metal adapter (2) and guides the tip to the optical fiber insertion hole of the metal adapter (2);
2) a spring member (14) for pushing the adapter (2) in a direction to penetrate; the bases (11, 15) supporting the ferrule (12) movably in the direction to penetrate and having one end fixed to the adapter (2). ); A swaging sleeve (8a / 8c / 8) extending in the direction through which the optical fiber (10) passes.
e), one end of which is fixed to the other end of the base (11, 15); and a fixed nut (8); one end of which is fixed to the fixed nut (8) and the other end of which is an optical fiber cable (3, 6, 6).
10) a cable adapter (7) fixed to at least the metal tube coating (6).

As a preferred example of the present invention, the fixing nut (8) is formed of a metal body in which the portion screwed to the base (11, 15) and the sleeve (8a) are integrally continuous or the fixing nut (8). Is an insulator portion (8b) screwed to the base (11, 15) and a metal sleeve (8c) fixed thereto.
It becomes. Symbols in parentheses indicate corresponding elements or items in the embodiment shown in the drawings and described later.

[0013]

According to this, in the optical fiber cable (3, 6, 10) having the metal tube coating (6), one end is fixed to the base (11, 15) and the other end is connected to the optical fiber cable (3, 6). , 10) are fixed to a cable adapter (7) fixed to at least a metal tube coating (6) by a fixing nut (8) fixed to a sleeve (8a / 8c / 8e) for caulking through which the optical fiber (10) passes. ), For example, by crimping a metal tube covering the optical fiber (10) with a crimping sleeve (8a / 8c / 8e) to increase the strength of the optical fiber (10) against deformation such as tension, lateral pressure, bending and the like. Can be achieved. Also, a swaging sleeve (8a / 8c / 8
The fixing nut 8 having e) can be used even when caulking a metal tube and when caulking is not required, so that it is convenient for parts management. Further, since the optical fiber (10) itself 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.

[0016]

FIG. 1 shows an embodiment of the present invention. This is the connector part 1 at one end (the other end is omitted) of the cable with metal tube.
2 shows a state where the connector adapter 2 is connected. The other end has the same configuration. Cable body is PV
A seamless pipe 4 coated with a resin 3, and near the both ends of the seamless pipe 4,
The flexible tube 6 coated with the resin 3 is fixed to one end of the flexible tube 6 with screws. In addition, the flexible pipe 6
The other end is fixed (screw-joined) to a fixing nut 8 of the connector section 1 (with a screw) via a flexible adapter 7.
The seamless tube 4 and the flexible tube 6 are made of an optical fiber 10 in which a bare fiber 9 is first coated with a thin resin coat.
Is covered 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 a fixing nut 8 is fitted therein.

The fixing nut 8 has a crimping sleeve 8a at its rear end and is integrated (the fixing nut 8 and the sleeve are made of a metal material), and the optical fiber 10 penetrates the sleeve 8a. FIG. 1 shows a state in which the swaging sleeve 8a is not used.

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. Generally, the connector adapter 2, the ferrule 12, and the connection nut 15 are made of metal in order to withstand repeated attachment and detachment of the connector. In the present invention, however, the ferrule 12, the connection nut 15, and the body 11 are made of an insulator (in this embodiment, an insulating material). (Polycarbonate having abrasion and high strength) to prevent current from flowing into equipment or devices.

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 4 and a flexible tube 6 is shown. However, the present invention is not limited to this, and a type in which a fixed nut portion of a tube end and a connector is fixed by a seamless tube. Alternatively, the present invention can be similarly applied to a type in which a fixing nut portion of a connector is fastened with a flexible tube via an adapter.

FIG. 2 shows the swaging sleeve 8 shown in FIG.
This shows a state where a is used. This is the case where the end of the tube and the fixing nut of the connector 1 are fastened by the seamless tube 4.
Sleeve 8a for caulking integrally formed with fixed nut 8
Crimps the seamless pipe 4, thereby increasing the strength against deformation such as tension, lateral pressure, bending, etc. in fastening the optical fiber 10 and the fixing nut 8 of the connector.

The fixing nut portion shown in FIGS. 1 and 2 is a fixing nut 8 integrally formed with a sleeve 8a. However, in FIG. 3, the fixing nut 8b and a metal caulking fitting 8c are separately formed. In other words, the configuration is such that the stability of the optical fiber 10 is increased by caulking the metal tube 4 with the caulking metal 8c by screwing the caulking metal 8c to the fixing nut 8b. In FIGS. 1 and 2, the ferrule 12, the connection nut 15 and the body 11 are made of an insulating material. Instead, only the fixing nut 8b is made of an insulating material (plastic), and a current flows into a device or device. This is to prevent that. It is not preferable in terms of strength to form the caulking fitting 8c also with an insulator. Here, the thickness of the narrow portion of the caulking fitting 8c is 0.4 mm with respect to the thickness of the metal tube 4 of 0.2 mm.

FIG. 4 shows a fixing nut 8d made of an insulating material.
In this configuration, a metal caulking collar 8e is fitted into the metal tube 4 and the metal tube 4 is caulked with the caulking collar 8e.
The thickness of the caulking collar 8e is 0.4 mm. According to this, the insulation of the fixing nut can be made larger than that shown in FIG.

[0027]

As described above, according to the present invention, 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 optically connected. A fixing nut (8) fixed to a cable adapter (7) fixed to at least a metal tube coating (6) of the fiber cable (3, 6, 10) is a crimping sleeve through which the optical fiber (10) passes. (8a / 8c / 8e), for example, by caulking a metal tube covering the optical fiber (10) with a crimping sleeve (8a / 8c / 8e) to pull, side-pressure, bend, etc. the optical fiber (10). The high strength against deformation can be achieved. Further, the fixing nut 8 having the sleeve (8a / 8c / 8e) for caulking can be used even when caulking a metal tube and when caulking is not required, which is convenient for parts management. Further, an optical fiber (1
0) Since it 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.

FIG. 2 is a cross-sectional view showing a state in which a sleeve 8a of the fixing nut 8 shown in FIG. 1 is used.

FIG. 3 is a cross-sectional view showing another example of the fixing nut 8 shown in FIG.

4 is a sectional view showing another example of the fixing nut 8 shown in FIG.

[Explanation of symbols]

1: Connector part 2: Connector adapter (adapter) 2a: Screw 2b: Stopper 3: PV resin 4: Seamless pipe 5: Relay adapter 6: Flexible pipe (metal pipe coating) 7: Flexible adapter (cable adapter) 8: Fixing nut 8a: sleeve (sleeve for swaging) 8b: fixing nut (insulating part) 8c: swaging metal fitting (sleeve, metal sleeve) 8d: fixing nut 8e: swaging collar (sleeve) 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 13: Collar 14: Coil spring (spring member) 15: Connection nut (11, 15) : Base) 15a: Stopper

Claims (3)

(57) [Claims] An adapter coupled to a device; an optical fiber cable having a metal tube coating, which supports an optical fiber end outside the metal tube coating end, and inserts the optical fiber insertion hole of the metal adapter into the optical fiber insertion hole. A spring member that presses the ferrule in a direction that penetrates the adapter; a base body that movably supports the ferrule in the direction that penetrates and has one end fixed to the adapter; a caulking extending in the direction through which the optical fiber penetrates Comprising a fixing nut having one end fixed to the other end of the base; and a cable adapter having one end fixed to the fixing nut and the other end fixed to at least a metal tube coating of the optical fiber cable. Tube-coated optical fiber equipment connector. 2. The metal tube-coated optical fiber device connector according to claim 1, wherein said fixing nut is a metal body in which a portion screwed to a base and a sleeve are integrally continuous. 3. The metal tube-coated optical fiber device connector according to claim 1, wherein the fixing nut comprises an insulator portion screwed to the base and a metal sleeve fixed to the insulator portion.