JPH028505Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) The present invention relates to a cable with a branch installed inside the shaft of a building.

(Prior Art) A so-called shaft cable installed on the shaft of a building is a branched cable having a plurality of branch cables for distributing power to each floor of the building. The branches of such branched cables include T-branches and Y-branches, the insulation of which is constructed by tape wrapping or plastic molding.

Among the cables with both branches, the Y-branch cable is often used because it can be wound into a drum even though it has a plurality of branches, and is advantageous in terms of transportation to the installation site. This Y-branched cable includes a tape-wound insulated Y-branch and a prefabricated Y-branch.

The tape-wrapped insulation Y-branch will be explained below with reference to FIG. In this figure, the split trunk cable 2 is cut to a length corresponding to the floor height of the building where the branched cable is to be installed or an integral multiple thereof.
The conductors 1 and 21 are inserted into one through hole of the conductor connection tube 22 having two through holes, and the branch cable 23
The conductor is inserted into the other through hole, and the conductor connecting tube 22
By compressing the above, a cable with branches having branches at intervals of the floor height or an integral multiple thereof is constructed. An insulating layer 24 is formed on the connecting portion by wrapping with tape, and a waterproof layer 25 is formed on the outer periphery of the insulating layer 24 by wrapping with tape.
Although not shown, an internal semiconductor layer is formed at the conductor connection portion, and an external semiconducting layer is formed at the outer periphery of the insulating layer 24.

In addition to the tape-wrapped insulated Y-branches described above, prefabricated Y-branches have also been used.

The outline of the prefabricated Y branch will be explained below with reference to FIG. In this figure, the conductor connection fitting 31 is formed integrally with two mutually parallel first and second connection rods 32 each having a compression connection part 32a at the tip thereof, and is perpendicular to them. An intermediate member 33 connects the base ends thereof, and a compression connecting portion 34 at the tip protrudes from the center of the intermediate member on the side opposite to the first and second connecting rods 32 and parallel to them.
A and a third connecting rod 34 having a substantially Y-shaped configuration. In addition, the conductor connection fitting 3
1, except for the compression connection parts 32a and 33a at the tips of the first and second connection rods 32 and the third connection rod 33,
The insulating layer 31a is covered with a mold.

The branched cable is constructed as follows using the conductor connection fittings 31 described above. That is, the split trunk cables 35 and 36 cut into lengths corresponding to the floor height of the building where the branched cable is to be installed or an integral multiple thereof are connected to the first and second connecting rods 3.
2 and the third connecting rod 34 through the compression connecting portions 32a and 34a, and the branch cable 37 is connected to the other of the first and second connecting rods 32 at the required intervals. A branched cable with branches is configured. In addition, at the connection part between either one of the first and second connecting rods and the split trunk cable 35, and the connection part between the third connecting rod 34 and the split trunk cable cable 36, there is a split trunk cable. 3
Spacers 38 and 39 are provided to engage with the ends of each of the split trunk cables 35 and 36 for matching the outer diameters of the split trunk cables 5 and 36 with the outer diameter of the insulating layer 31a,
These spacers 38, 39 and the insulating layer 31a
An inner shielding layer 40, 4 is provided between the opposite ends of the
1 is provided. Further, each of the connection parts is covered with external connection tubes 42 and 43, and the insulating layer 31
the terminals of a and the external connection tube 4 facing them;
2 and 43, each of the external connection tubes 42 and 43
The other terminals and the split trunk cables 35 and 36 inserted therein are wrapped with tape. Incidentally, a similar process is applied to the connection portion between the other of the first and second connection rods 32 and the branch cable 37.

The branched cable having the above configuration is used in the following manner. That is, a cable with a branch is suspended within the shaft of a building by appropriate means, and the branch cable 37 is drawn into the floor of the building corresponding to the branch cable.

(Problems to be Solved by the Invention) In the conventional cable with a branch having the above structure, since the tape-wound insulation Y branch having the above structure employs tape-wound insulation, there is a drawback that voids are likely to occur in the insulating layer. In particular, tape winding is difficult at the crotch portion of the Y branch, and most dielectric breakdowns occur in this portion. Furthermore, if an external force is applied during drum winding or wire stretching, there is a risk that a tear may occur from the Y-shaped crotch portion.

In addition, the prefabricated Y branch has no risk of dielectric breakdown or mechanical breakdown due to the voids in the Y-shaped crotch part, but the external connection tubes 41, 42, sleeve covers, spacers 27, 28, etc. are separated by conductor size. Must be prepared. Furthermore, there is a drawback that the branch connection portion is very large and heavy, and the price is also high.

This invention was made based on the above circumstances,
It is an object of the present invention to provide a branched cable that eliminates the above-mentioned conventional drawbacks.

[Structure of the invention] (Means for solving the problem) The branch cable of the invention connects the main cable conductor and the branch cable conductor to form a Y branch using a conductor connection tube, and covers the entire branch connection part. A fixing metal fitting comprising a molded insulator, having a clamp fixed to the main cable at one end, and a sleeve rotatable about an axis perpendicular to the clamp axis through which the branch cable is inserted at the other end. Accordingly, the distance between the trunk cable and the branch cable is fixed.

(Function) In the branched cable of the present invention having the above configuration, the distance between the trunk cable and the branch cable is fixed as described above, and the trunk cable and the branch cable are made almost parallel to each other by rotation of the sleeve. If this is done, winding onto the drum can be done easily and reliably.

(Embodiment) FIG. 1 is a partially cutaway front view of an embodiment of the present invention, FIG. 2A is a partially enlarged front view, and FIG. 2B is a side view thereof. In Fig. 1, the conductor 2 is exposed at the branch attachment part on the main cable 1, and the branch cable 3 with the conductor 4 exposed at its terminal is arranged so that the main cable 1 and the branch cable 3 form a Y-shape. The exposed conductor 2 and the conductor 4 are compressed and connected by a conductor connecting tube 5. The conductor connecting tube 5 has a conventional C-shaped cross section with an axial gap that is closed during compression.

Insulation is applied to the above conductor connection portion in the following manner. First, a semiconductive tape is wound around the conductors 2 and 4 and the conductor connection tube 5 to form the internal semiconductive layer 6. Next, a mold made of, for example, a silicone rubber mixture, which can be cured at a temperature that does not have a thermal effect on the cross-linked polyethylene that is the insulator of the main cable 1 and the branch cable 3, i.e., at room temperature or slightly higher than that, is molded. As a result, the molded insulator 7 is formed to cover the conductor connection portion, the main cable 1, and the portion of the branch cable 3 near the conductor connection portion, in other words, the entire branch connection portion. Furthermore, an external semiconductive layer 8 is formed on the outer periphery of the molded insulator 7 by applying a semiconductive paint and winding a semiconductive tape. A tin-plated annealed copper wire 9 is wound around the outer circumferential surface of this external semiconducting layer, thereby electrically connecting the shielding layers of the trunk cable 1 and between the shielding layers of the trunk cable 1 and the shielding layers of the branch cable 3. It is set to connect. Furthermore, a protective layer 10 is formed around the outer periphery by winding an adhesive vinyl tape.

In the branch connection section having the above configuration, the trunk cable 1 and the branch cable 3 are fixed by a fixing fitting 11 whose details are shown in FIGS. 2A and 2B. The fixing fitting 11 includes a plate-shaped main part 11c, a cylindrical clamp 11a with a two-part structure that is provided at one end of the plate-shaped main part 11c and is engaged and fixed to the main cable 1, and a cylindrical clamp 11a of a two-part structure that is provided at one end of the main part 11c and fixed to the main cable 1. The sleeve 11b is rotatably provided about an axis perpendicular to the axis, and has a sleeve 11b through which the branch cable 3 is inserted.
It is assumed that the branch cable 3 is inserted into the sleeve 11b of the fixture 11 before being connected to the main cable 1. After the construction of the branch connection part is completed, the fixture 11 is fixed to the main cable by the clamp 11a, and the distance between the main cable 1 and the branch cable 3 is fixed.

As shown above, trunk cable 1 and branch cable 3
If the distance between the main cable 1 and the branch cable 3 is fixed, and the main cable 1 and the branch cable 3 are made substantially parallel by rotating the sleeve 11b, winding around the drum can be easily and reliably performed. Furthermore, even when pulling each branch cable 3 to a desired floor after suspending and supporting the main cable 1, the sleeve 11b into which the branch cable is inserted is rotatable, so that no excessive force is applied to the branch cable 3. It is possible to provide the necessary flexure without any bending.

[Effect of the invention] As is clear from the above, the branched cable of the present invention has a main part, a clamp provided at one end of the main part and fixed to the main line, and a clamp provided at the other end of the main part. Since the spacing between the branch cable and the main cable is fixed by the fixing fitting, which includes a sleeve that is rotatable around an axis perpendicular to the clamp axis and allows the branch cable to pass through, the distance between the branch cable and the main cable is fixed. Installation can be done easily and reliably.
Furthermore, since the trunk cable and the branch cable are fixed as described above, there is no possibility that the cable will be torn from the Y-shaped crotch part due to the action of an external force.

Furthermore, since it has a molded insulator instead of a tape-wound insulation Y-branch, the crotch portion does not become a weak point in terms of insulation.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view of an embodiment of the present invention, Fig. 2A is a partially enlarged front view, Fig. 2B is a side view, and Fig. 3 is a conventional Y-branch. FIG. 4 is a partially cutaway front view of another example of a conventional Y branch. 1... Trunk cable, 2, 4... Conductor, 3...
Branch cable, 5... Conductor connection tube, 6... Internal semiconductive layer, 7... Molded insulator, 8... External semiconductive layer, 9... Tin plated annealed copper wire, 10... Protective layer, 1
1...Fixing metal fittings, 11a...Clamp, 11b...
...Sleeve, 11c...Main part.

Claims (1)

[Scope of utility model registration request] A main cable conductor and a branch cable conductor are connected to form a Y branch using a conductor connection tube, a molded insulator is formed by covering the entire branch connection part, a clamp is provided at one end to be fixed to the main cable, and the other end is provided with a clamp to be fixed to the main cable. A branching device characterized in that the distance between the trunk cable and the branch cable is fixed by a fixing fitting having an end through which the branch cable is inserted and a sleeve that is rotatable about an axis perpendicular to the clamp axis. cable.