JPS6216406B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanical connection structure between connected cables in an optical cable connection section having a tension member at the center.

Figure 1a is a perspective view of a conventional optical cable connection section installed underground, and Figure 1b is a
It is a cross-sectional view at A′, where 1 is an optical cable, 2
is an optical fiber core wire, 3 is a connection part of the optical fiber core wire, 4 is a bobbin for processing the extra length of the optical fiber core wire,
5 is a tension member, and 6 is a fixing part of the tension member, which has a structure in which the tension members from both connected cables are sandwiched between two metal plates having semicircular grooves on the inner surface and tightened with screws. There is. Reference numeral 7 denotes a cylindrical internal metal fitting for fixing the cable sheath, which is installed after making a cut in the cable sheath 1a to facilitate insertion. Numerals 8 and 8' are external fittings which, when tightened with screws 9, sandwich and fix the cable sheath 1a between them and the internal fitting 7. Reference numeral 10 denotes a connecting rod for mechanically connecting both cable jacket fixing parts. Numeral 11 is a screw for fixing the connecting rod 10 to an external metal fitting 8' for fixing the cable sheath. 12 is a connection case for maintaining airtightness.

FIG. 2a is a conceptual diagram of the connection part of an optical cable used in conventional overhead wiring, and FIG. 2b is an enlarged perspective view of the vicinity of the cable jacket fixing part in FIG. 2a.
FIG. 2c is an enlarged perspective view of the vicinity of the tension member in FIG. 15a is a metal frame for mechanically connecting both cables; 15a is a cable sheath fixing rod forming a part thereof; 15b is an auxiliary fitting; 15c is a tension member fixing rod; 16 is a cable sheath fixing rod. The internal fitting is inserted inside the cable jacket after making a cut in the cable jacket. 17 is a screw for tightening the cable jacket fixing fitting; 18 is an auxiliary fitting for clamping and fixing the tension member 5; and 19 is a tightening screw. 20 is a non-sealing type cover.

As mentioned above, conventional connections employ a structure in which the cable jacket is clamped between the inner and outer metal fittings to prevent mechanical force from acting on the optical fiber core. was. In addition, a part for fixing the tension member was provided separately. As a result, the work is complicated and inefficient, and the structure of the connection part is complicated and large.

In order to solve these problems, the present invention is a connecting body that mechanically holds connected cables together, in which a tension member and a part of the cable jacket are fastened and fixed together to one cable gripping part. be. This will be explained below with reference to the drawings.

FIG. 3a is a perspective view of an embodiment of the mechanical connection structure of the connecting portion of the underground optical cable of the present invention;
Figure b is a sectional view taken along the line A-A' in Figure 3a, where 1b is a part of the cable jacket, which is produced by removing 1/2 to 1/3 of the outer periphery of the cable jacket. 21
An intermediate metal fitting is used for tightening the tension member 5 and the cable sheath 1b and for a spacer, and has a hole through which a tightening bolt 24 passes, and a connecting rod 10 is fixed to the side surface. Reference numeral 22 denotes a tension member holding fitting, and a semicircular groove matching the outer diameter of the tension member 5 is provided on the inside. Reference numeral 23 denotes a cable jacket holding fitting, which has a female thread that matches the tightening bolt 24. Therefore, as shown in FIG.
The lower surface of the intermediate metal fitting 21 and the cable jacket holding fitting 23
After sandwiching the cable sheath 1b between them, by tightening the tightening bolt, the tension member and the cable sheath can be fixed at the same time in a compact manner with good workability.

In addition, in the structure of the present invention, since only a part of the cable jacket is gripped and fixed, the tensile strength as a cable connection part is slightly lower than the conventional structure in which the entire circumference of the cable jacket is gripped. Since the tensile strength of the optical cable is originally designed to be shared by the tension member, there is no problem at all.

In the structure of the present invention, the percentage of the cable sheath of the entire circumference that is gripped varies depending on the cable structure, but the expansion and contraction force of the cable sheath due to temperature changes in the environment where the cable connection part is installed is suppressed. It is sufficient if it is possible to do so, and about 1/2 to 1/3 of the entire circumference is sufficient.

FIG. 4 shows an embodiment of the connection part of an overhead wiring optical cable according to the present invention, in which a female thread is cut in the metal frame 15 for connecting the mechanical strength of the cable, and an intermediate metal fitting 21 and a tension member holder are attached as in the underground optical cable connection part. Tension member 5 and cable jacket 1b are fixed using hardware 22 and tightening bolts 24.

As explained above, the mechanical connection structure of the optical cable connection part of the present invention allows the tension member and the cable sheath to be fixed at the same time in one place, which reduces the size of the mechanical connection part between the connected cables and reduces the work required. This has the advantage of contributing to economical and efficient optical cable connections.

In addition, with the recent increase in the number of optical fibers in optical cables, the space for accommodating optical fiber connections within the optical cable connection section has become insufficient, but the present invention can increase the space for accommodating optical fiber connections.
It has the advantage of being applicable to multi-core optical cable connections.

[Brief explanation of the drawing]

Figure 1a is a perspective view of a conventional underground optical cable connection, Figure 1b is a sectional view taken along line A-A' in Figure 1a, and Figure 2a is a conceptual diagram of a conventional optical cable connection for overhead wiring. , Fig. 2b is an enlarged perspective view of the vicinity of the sheath fixing part in Fig. 2a, Fig. 2c is an enlarged perspective view of the vicinity of the tension member in Fig. 2a, and Fig. 3a is an enlarged perspective view of the vicinity of the tension member in Fig. 2a. A perspective view of an embodiment of the mechanical connection structure of the optical cable connection part, FIG. 3b is the same as A- in FIG. 3a.
A cross-sectional view at A', and FIG. 4 is a perspective view of another embodiment of the mechanical connection structure of the optical cable connecting portion for overhead wiring according to the present invention. DESCRIPTION OF SYMBOLS 1... Optical cable, 1a, 1b... Cable jacket, 2... Optical fiber core wire, 3... Optical fiber core wire connection section, 4... Connection surplus length processing bobbin, 5... Tension member, 6... ...Tension member fixing part, 7...Internal metal fitting, 8, 8'...External metal fitting, 9
...Screw, 10...Connecting rod, 11...Screw, 12
... Connection case, 13 ... Optical fiber core wire connection accommodating section, 14 ... Suspension wire, 15 ... Metal frame, 15a
... Cable jacket fixing rod, 15b ... Auxiliary metal fittings,
15c...Tension member fixing rod, 16,1
6'...Internal metal fitting, 17...Screw, 18...Auxiliary metal fitting, 19...Screw, 20...Cover, 21...
Intermediate hardware, 22...Tension member presser metal fitting,
23... Cable jacket holding fitting, 24... Tightening bolt.

Claims (1)

[Claims] 1. At the connection part of an optical cable that connects two optical cables having a tension member at the center via a connector that mechanically connects each other, a plate-shaped tension holding metal fitting and the upper surface of an approximately rectangular parallelepiped intermediate metal fitting are connected. The tension member of the optical cable to be connected is held between them, and the remaining portion of the cable jacket of the optical cable to be connected, after a part of the outer periphery of the cable jacket of the optical cable to be connected is removed, is placed between the lower surface of the intermediate hardware and the plate-shaped cable jacket holding fitting. A mechanical connection part of an optical cable, characterized in that a cable gripping part is attached to the connecting body, and the tension member holding part, the intermediate metal part, and the cable jacket holding part are fastened together with a tightening bolt. Connected structure.