JPS6345743Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a structure for taking out a ground wire from a cable connection part of a communication cable having a plastic jacket.

In general, communication cables, whether overhead cables or underground cables, are grounded at regular intervals primarily for security purposes.

The commonly used methods for grounding are connecting lead pipes at cable connections.
Alternatively, take out the ground wire from the metal insulation layer between the cable core and the outer sheath.
A common method is to connect this directly or indirectly to the earth.

By the way, when taking out the ground wire from the cable connection part in this way, the problem is the sealing performance (airtightness, watertightness, etc.) of the cable connection part.
For example, when connecting plastic-sheathed cables, in recent years, so-called heat-shrinkable sleeves that have heat-sealing properties are used to cover and seal the cable connections.
The ground wire must pass through the seam of this heat-shrinkable sleeve and be taken out to the outside. In this case, since the ground wire is considerably thinner than the cable, the contact area between the ground wire and the sleeve at the penetration part is also small, which causes the problem of reduced airtightness and watertightness of the cable connection part. be.

This idea was made taking the above points into consideration.The part of the ground wire that passes through the heat-shrinkable sleeve is made of a conductive metal rod with a larger diameter than the other part, and this metal A coating layer that is heat-sealable to the heat-shrinkable sleeve is provided on the surface of the rod, and an adhesive layer is further provided between the coating layer and the metal rod for bonding them together. An object of the present invention is to provide a ground wire lead-out structure that improves the sealing performance of a cable connection part.

This invention will be explained below based on an embodiment shown in the drawings.

In the figure, reference numerals 1 and 2 are cables that are connected to each other, and the core connection portion 3 of the cables 1 and 2 is hermetically sealed with a heat-shrinkable sleeve 4 that is heat-sealed to the outer jacket of the cables 1 and 2. has been done. A spacer 5 is set inside the sleeve 4 and has the function of ensuring the mechanical strength of the connection portion and determining the contracted shape of the sleeve 4. In the illustrated example, the spacer 5 has a cylindrical body 5a, and the diameter becomes smaller as it goes from the body 5a toward both ends.
A support portion 5 that is pressed into contact with the outer jacket portion of the cables 1 and 2
b, 5b, and an insertion hole 5c is formed in one support portion 5b.

Reference numeral 6 denotes a conductive metal rod for taking out the ground wire from the cable connection portion covered and sealed by the heat-shrinkable sleeve 4;
A ground wire 7 made of stranded wire or the like is connected to one end, and a lead wire 8, which is also a part of the ground wire, is connected to the other end. And this lead wire 8
is guided into the spacer 5 through the insertion hole 5c and connected to a bond wire 9 that keeps the cables 1 and 2 at the same potential. The metal rod 6 has a larger diameter than the ground wire 7 and is solid, and its surface (outer circumferential surface) is made of a plastic material that can be fused to the inner layer of the heat-shrinkable sleeve 4 (for example, the inner layer of the sleeve 4 is made of plastic material). A coating layer 10 made of polyethylene (such as uncrosslinked polyethylene) is provided. Furthermore, an adhesive layer 11 is provided between the coating layer 10 and the metal rod 6 for integrally adhering the coating layer 10 to the metal rod 6. This adhesive layer 11 is made of a hot-melt adhesive mainly composed of a copolymer of ethylene monovinyl acetate, which has good adhesion to both the metal rod 6 and the coating layer 10 and is also heat resistant. It is preferable to form. Both end portions of the metal rod 6, that is,
The connecting portion between the metal rod 6 and the ground wire 7 and the connecting portion between the metal rod 6 and the lead wire 8 are sealed with end coverings 12 and 13, respectively, which are made of, for example, heat-shrinkable tubes and fused together. has been done. In addition, as shown in FIG. 3, the ground wire 7 has a knotting material 7b made of solder plating or the like on the outer periphery of the stranded wire 7a so that it has sufficient airtightness. Outer cover 7
A cross-sectional structure with c is used. Note that the lead wire 8 also has a cross-sectional structure similar to that of the ground wire 7.

By the way, various construction methods (procedures) can be used to implement such a ground wire extraction structure together with the cable connection work, and one example will be briefly described here.

In advance, for example, at a factory or a cable connection site, as shown in FIG. 4, a ground wire 7 and a lead wire 8 are connected to both ends of a metal rod 6, which has a coating layer 10 on its surface via an adhesive layer 11. Furthermore, end coatings 12 and 13 are applied. Before heating and shrinking the heat-shrinkable sleeve 4 in the cable connection work, first connect the lead wire 8 to the bond wire 9 as shown in FIG. After positioning, the heat-shrinkable sleeve 4 may be heat-shrinked.

In this invention, since the metal rod 6 has a larger diameter than the ground wire 7, its surface area is sufficiently large.
is provided and is strongly heat-sealed to the inner layer of the heat-shrinkable sleeve 4, and the covering layer 10 is integrally bonded to the metal rod 6 by the adhesive layer 11, so that the ground wire extraction portion Sealing performance, that is, airtightness, watertightness, etc., is significantly improved compared to conventional products. Further, in the embodiment, the end coverings 12, 13, the ground wire 7, the lead wire 8, etc. also contribute to this airtightness and watertightness. That is, for example, the ground wire 7 is made solid by filling the gaps between the individual wires constituting the stranded wire 7a with a knotting material 7b, as shown in FIG. 3, and then covering it with a plastic jacket 7c. Since the cross-sectional structure is made of This results in a more reliable sealing structure overall.

As explained above, in this invention, the part of the ground wire that passes through the heat-shrinkable sleeve is formed with a conductive metal rod having a larger diameter than the other part, and the surface of this metal rod is attached to the heat-shrinkable sleeve. The structure includes a thermally adhesive coating layer and an adhesive layer between the coating layer and the metal rod to bond them together, which significantly improves the sealing performance of the cable connection. It has an excellent effect.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of this invention, Fig. 2 is an enlarged sectional view taken along the - line in Fig. 1, and Fig. 3 is an enlarged sectional view showing an embodiment of the invention.
The figure is an enlarged sectional view taken along the line - in FIG. 1, and FIG. 4 is a sectional view shown for explaining an example of the construction method. DESCRIPTION OF SYMBOLS 1, 2... Cable, 4... Heat-shrinkable sleeve, 6... Metal rod, 7... Earth wire, 8... Lead wire, 10... Covering layer, 11... Adhesive layer.

Claims (1)

[Scope of utility model registration request] In a ground wire take-out structure in which a ground wire is taken out from a cable connection part covered and sealed by a heat-shrinkable sleeve by passing through the heat-shrinkable sleeve, the ground wire 7 has a portion that passes through the heat-shrinkable sleeve 4. is formed of a conductive metal rod 6 having a larger diameter than other parts, and a coating layer 1 that is heat-sealable to the heat-shrinkable sleeve is formed on the surface of this metal rod.
0, and an adhesive layer 11 having adhesive properties to both the coating layer and the metal rod is provided between the coating layer and the metal rod. Ground wire extraction structure at cable connection part.