JPH04215604A - Optical cable terminal and optical cable connection - Google Patents

Abstract

PURPOSE:To easily handle the surplus length of an optical fiber and easily draw out the optical fiber from a surplus length handling unit. CONSTITUTION:The outer peripheral surface of an optical fiber drawn out from the end part of an optical cable 1 with a surplus length is covered with a shape-memory tube 16 spirally shape-memorized.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical cable terminal section and an optical cable connection section.

0002

[Prior art] In order to improve the workability of connections on site,
As shown in FIG. 4, an optical cable has been proposed in which a connector 3 is attached in advance to each optical fiber 2 led out from the terminal of a cable 1. In addition, 4 is optical cable 1
This is a sheath retaining part provided at the end of the cable sheath 5.

[0003] In such an optical cable with a connector,
In order to protect each connector 3 and each optical fiber 2 during drum winding, storage, and installation, a flexible protective tube 6 is placed at the tip of the cable sheath 5 in a liquid-tight manner to cover each optical fiber 2 with a connector, as shown in the figure. installed. The flexible protection tube 6
The outer diameter of the tube is set to a size that allows it to pass through the pipe. Inside the flexible protective cylinder 6, reinforcing disks 7 are arranged intermittently in the longitudinal direction in order to maintain the ironing strength. A pulling eye 8 is attached to the tip of the flexible protection tube 6. A connector accommodating disk 9 is further provided inside the flexible protection tube 6, and the connector accommodating disk 9 has a connector accommodating hole 1.
0 is provided for each. The connectors 3 are inserted and housed in the connector housing holes 10, respectively. The positions of the connectors 3 are shifted in the longitudinal direction so that the outer diameter of the flexible protection tube 6 does not increase due to overlapping positions.

[0004] In this case, the optical fibers 2 within the flexible protection tube 6 may have the same protrusion length from the cable sheath 5. In such a case, the optical fiber 2 attached to the connector 3 on the side closer to the cable sheath 5 has an extra length, so the extra length is processed. Conventionally, the surplus length of the optical fiber 2 has been processed by storing the surplus length of the cut optical fiber 2 in a sheet or in a tray.

[0005] After the optical cable terminal part having the structure shown in FIG. 4 is installed in a conduit, the optical fibers 2 of each cable 1 are connected with a connector 3 in a manhole or the like to form a fiber connection part 11. It is housed in a closure 1 as shown in FIG. 5, and becomes an optical cable connection section 13. Note that the closure sleeve is omitted in this figure, and the end plate 14 that closes both ends of the closure sleeve is shown. At this time, an extra length is generated in the optical fiber 2, so it is necessary to process the extra length. Conventionally, when processing the extra length of the optical fiber 2, the extra length of the optical fiber 2 that has been looped is processed as shown in FIGS.
This has been done by storing it in a sheet 15 shown in FIG. 1 or in a tray (not shown).

[0006]

However, such conventional optical cable terminal sections and optical cable connection sections have a problem in that processing the excess length of the optical fiber 2 requires considerable effort and time. Furthermore, in the conventional method, the optical fiber 2 which has been looped in order to process the excess length is stored in a sheet 15, a tray, etc., so there is a problem in that it takes time and effort to pull out the optical fiber 2 when necessary.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical cable terminal section and an optical cable connection section that can easily process the excess length of an optical fiber and easily draw out the optical fiber from the excess length processing section. It's about doing.

[0008]

[Means for Solving the Problems] The structure of the present invention for achieving the above object will be explained as follows.

[0009] In the optical cable terminal portion according to claim 1, the outer periphery of the optical fiber led out with an extra length from the end portion of the optical cable is coated with a shape memory tube having a spiral shape memory. It is characterized by

[0010] In the optical cable connection section according to claim 2, a shape memory tube having a spiral shape is formed around the outer periphery of the optical fiber led out with an extra length from the ends of both optical cables to be connected. The optical cables are covered with each other, and the tip ends of both optical cables are connected to each other.

[0011]

In the structure of claim 1, a straightened shape memory tube is placed over the outer periphery of the optical fiber, and then the shape memory tube is heated. In this way, the shape memory tube assumes a previously memorized helical shape, and accordingly, the internal optical fiber also assumes a helical shape. In the present invention, when this state is reached, processing of the extra length of the optical fiber is completed. In such a spiral extra length processing section, since the shape memory tube also serves as a protector, there is no need to store it in a sheet, a tray, or the like.

[0012] In the structure of claim 2, since the helical extra length processing portion is formed by covering the outer periphery of both optical fibers to be connected with a shape memory tube having a helical shape memory, In this state, processing of the extra length of the optical fiber is completed, and processing of the extra length becomes easy. Further, in this helical extra length processing section, the required optical fiber length is supplied by extending the helical portion. The helical extra length processing section does not need to be accommodated in a seat, tray, or the like.

[0013]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIGS. 1 and 2 show an example of the optical cable terminal section of this embodiment. In this embodiment, the outer periphery of the optical fiber 2 led out from the end of the optical cable 1 with an extra length is covered with a shape memory tube 16, which has been memorized in a spiral shape in advance, in a straightly extended state. As the shape memory tube 16, a shape memory alloy tube such as a Ni-Ti alloy or a shape memory plastic tube is used, for example.

A connector 3 is connected to the tip of the optical fiber 2 led out from the tip of the shape memory tube 16, and the connector 3 and the shape memory tube 16 and the shape memory tube 16 and the optical cable core 17 are connected to each other using a fixture 18. , 19. In this state, the shape memory tube 16 is heated to, for example, about 40° C. to form a helical shape with a preliminarily memorized pitch. For example, the inner diameter of the spiral in this case is set to 60 mmφ, which is greater than the allowable bending radius of the optical fiber 2. Accordingly, the optical fiber 2 inside the spiral shape memory tube 16
It also has a spiral shape. In this way, the spiral extra length processing section 10 is formed.

The spiral extra length processing section 20 is housed in the flexible protection tube 6, and the connector 3 is inserted into the connector accommodation hole 10 of the connector accommodation disk 9 provided in the flexible protection tube 6. to fit in. At this time, the spiral extra length processing section 20 is expanded or contracted depending on the position of the connector housing disk 9 in the longitudinal direction of the flexible protection tube 6.

[0017] In this way, the optical cable terminal part as shown in FIG. 2 is completed. Spiral extra length processing section 2 inside flexible protection tube 6
0, since the shape memory tube 16 itself also serves as a protector for the optical fiber 2, there is no need to store it in a sheet or tray.

FIG. 3 shows an example of the optical cable connection section 13 formed using the optical cable terminal section shown in FIG. In the optical cable connection section 13, the connectors 3 at the tips of both helical extra length processing sections 20 are connected to each other within the closure 12 to form a fiber connection section 11,
The fiber connection section 11 is supported by a connection section support 21 .

[0019] Since the shape memory tube 16 itself also serves as a protector for the optical fiber 2, the spiral extra length processing part 20 in the closure 12 of the optical cable connection part 13 can be stored in a sheet, a tray, etc. There's no need.

[0020]The fiber connection section 11 is connected to the optical fiber 2.
They may be fused and connected to each other.

[0021]

[Effects of the Invention] As explained above, according to the optical cable terminal section and the optical cable connection section according to the present invention, the following effects can be obtained.

[0022] In the optical cable terminal section and optical cable connection section according to claims 1 and 2, the optical fiber led out from the terminal section of the optical cable with an extra length is wrapped in a shape memory tube whose shape has been memorized in a spiral shape in advance. Since the helical extra length processing section is formed by coating and forming the shape memory tube into a spiral shape, there is no need to store it in a sheet, tray, etc. again. This helical extra length processing section can be formed into a spiral shape simply by covering it with an optical fiber shape memory tube and heating it, so when looping an optical fiber as in the conventional method, the optical fiber bounces due to its elasticity and the loop breaks. This makes it easier to process excess length. In addition, in this helical extra length processing section, the shape memory tube maintains the spiral shape, so when the looped portion of the optical fiber is taken out from a sheet etc. as in the conventional case, the looped shape is broken and becomes straight. This makes handling easier. Moreover, when tension is applied to this helical extra length processing section, the helical pitch increases and expands, and conversely, it is also possible to reduce the helical pitch to a small spiral pitch, and the extra length can be processed according to the position from the fiber connection section, etc. This has the advantage that optical fibers can be freely supplied from the department.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a state of an embodiment of an optical cable terminal section according to the present invention before a protection tube is attached.

FIG. 2 is a longitudinal cross-sectional view of an embodiment of an optical cable terminal section according to the present invention.

FIG. 3 is a longitudinal cross-sectional view of an embodiment of the optical cable connection part according to the present invention.

FIG. 4 is a vertical cross-sectional view of a conventional optical cable terminal section.

FIG. 5 is a perspective view of a conventional optical cable connection section with a closure sleeve omitted.

FIG. 6 is a front view of a conventional extra length processing section.

[Explanation of symbols]

1 Optical cable 2 Optical fiber 3 Connector 4 Sheath retaining part 5
Cable sheath 6 Flexible protection tube 8 Pulling eye 9
Connector housing disk 10 Connector housing hole 11 Fiber connection section 12 Closure 13 Optical cable connection section 14
End plate 15 Sheet 16 Shape memory tube 17
Optical cable cores 18, 19 Fixture 20 Spiral extra length processing section 21
Connection support

Claims (2)

[Claims] 1. An optical cable terminal section, characterized in that the outer periphery of an optical fiber led out with an extra length from the end of the optical cable is coated with a shape memory tube having a spiral shape memory. 2. A shape memory tube having a spiral shape is placed over the outer periphery of each optical fiber led out with extra length from the ends of both optical cables to be connected, and the shape memory tube of both optical cables is An optical cable connection part characterized in that the tip parts are connected to each other.