JPS6315806B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cable installation method, and is particularly suitable when the cable is installed under high tension, such as when the cable is long or when the installation route is bent. It is related to.

Cables such as communication cables and power cables are installed in underground conduits, utility poles, and the like. in this case,
A longer cable length is advantageous in terms of reducing the number of cable connection points, but if the cable length is long, the friction applied to the cable during installation will increase, and a large tensile force will be applied to the cable. There is a risk of damage to the cable. In order to solve this problem, the applicant installs a drum around which the cable to be laid is wound at the middle point of the laying section, pulls out the cable from this drum and lays it from this middle point to one end of the laying section, and then , the remaining cables are pulled out from the drum and accumulated in a figure-eight shape at an intermediate point, and finally the cables are drawn out from this figure-eight-shaped cable accumulation and laid from the intermediate point to the other end of the laying section. (Special application 1982)
-Refer to No. 179867). However, even with this method, if the installation section is extremely long and the distance from the intermediate point to both ends of the installation section is long, the tensile force of the cable will still be large enough to damage the cable.
Incidentally, even if the length of one cable is short, if the installation route is bent, the cable tensile force will increase and the same problem will occur.

An object of the present invention is to provide a method for laying a cable without increasing the tensile force on the cable even when the cable length is long or the laying route is bent.

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an example in which a cable 1 is laid in an underground conduit 10. Although the cable is laid in a part of the length up to the end, the same method can be applied to the case where the cable is laid in the entire length from one end (first point) to the other end. In FIG. 1, reference numerals 12A to 12F indicate manholes, and 10A to 10F indicate conduit portions that communicate between the manholes.

First, the drum 14 around which the long cable 1 to be laid is wound is installed near the manhole 12A located at the middle point (first point) of the laying section. drum 14
is rotatably supported by a drum support stand 16. Next, from manhole 12A to manhole 12
Pass the cable lead wire 18 through the conduit portions 10A and 10B up to C and connect the cable 1 to the rear end.
Connect the tip (pulling end) 1a of the In this state, the cable 1 is pulled out from the drum 14 by pulling the lead wire 18 with a pulling machine (not shown), and the cable 1 is pulled out from the drum 14.
The cables 1 are laid between the manhole 12A as a point and the manhole 12C as a second point, and near the manhole 12C the cables 1 are accumulated in a figure 8 shape with the tension end 1a facing down as shown in FIG. 3A. At this second point, the figure-of-eight accumulation section 20 is located in the manhole 1.
The storage capacity is equivalent to the remaining cable installation length up to 2F.

Next, this figure-of-eight storage section 20 is connected to the tension end 1a of the cable 1, as shown in FIGS. 1 and 3B.
Turn over the lead wire 18 connected to the tension end 1a from the manhole 12C to the manhole 12E.
The cable is pulled out from the figure-of-eight storage part 20' by a pulling machine (not shown), and is pulled out from the second point, manhole 12C, to the third point, manhole 1.
2E, and in this case, as in the second point, a figure 8-shaped accumulation section 21 is formed near the manhole 12E, and this accumulation section is turned over again as shown by the reference numeral 21'. Finally, the lead wire 18 is connected in the same manner from this turned-over figure-of-eight storage section 21'.
Cable 1 is pulled out, and cable 1 is similarly laid to the fourth point, manhole 12F.

In addition, the left half of the cable laying section is covered by the patent application filed in 1982.
- Drum 14 as disclosed in No. 179867.
Unwind the remaining cable 1 from above to form a figure-8-shaped accumulation section, and from this figure-8-shaped accumulation section, lay the cable in small increments while forming a figure-8-shaped accumulation section in the same manner as described above. .

FIG. 2 shows an example in which the cable 1 is installed on utility poles 22A, 22B, 22C, . . . . In this example, cable 1 is cable wire 2, which is stretched between telephone poles.
The example is substantially the same as that of FIG. 1, except that the cable 1 is laid through a plurality of metal wheels 26 suspended from the wire wheels 26. That is, the cable 1 in the drum 14 near the utility pole 22A, which is the first point, is pulled out by taking the lead wire 18 with a pulling machine (not shown), and laid between the utility poles 22A and 22B, which is the second point. A figure 8-shaped accumulation section 20 is formed below the utility pole 22B, and then this accumulation section 20 is turned over as shown by 20', and the cable is similarly pulled out from this second point to form the figure-8 accumulation section 20. Repeating this process, the cables are laid on subsequent utility poles in sequence.

According to these methods, the cable 1 is sequentially laid from the first point to the final point while repeating accumulation and withdrawal little by little, so the tensile force on the cable can be small and the cable will not be damaged. Further, since the cables are accumulated in a figure 8 shape at each point and then turned over before being pulled out, no twist is applied to the cable 1, and the cable can be laid smoothly.

In the above embodiments, the case where the laying route is a straight line has been described, but the same can be applied to the case where the laying route is bent in the middle.

According to the present invention, as described above, the cable is laid by dividing it into one to several points from the first point of the laying section and repeating the accumulation and withdrawal in small steps, so that the length of laying each time is short. As a result, the tensile force of the cable can be significantly reduced. Therefore, it is particularly effective when the cable length is extremely long or when the installation route is curved. Further, since the cables are accumulated in a figure 8 shape and then turned over and pulled out one after another, the cables can be laid smoothly without twisting at each point.

[Brief explanation of the drawing]

FIG. 1 is a sectional view illustrating an example in which the method of the present invention is used to install a cable in an underground conduit;
Figure 2 is a side view illustrating an example in which the method of the present invention is used to lay cables on utility poles, and Figures 3A and B show cables accumulated in a figure-eight shape as part of the process of the present invention. FIG. 2 is a perspective view showing a state in which it is turned over; 1... Cable, 1a... Tensile end, 10... Underground conduit, 12A to 12F... Manhole, 14
... Drum, 20, 20', 21, 21'... Figure-of-eight storage section, 22A to 22C... Utility pole.

Claims (1)

[Scope of Claims] 1. A cable accumulation section for laying a cable is installed at a first point of a laying section where a cable is to be laid, the cable is pulled out from this cable accumulation section, and the cable is pulled to a pulling end at a second point of the laying section. at the second point, turn the figure-eight cable storage section over so that the pulling end is upward, and then pull the cable out of the figure-eight cable storage section to A cable installation method characterized by laying a cable section beyond two points. 2. The cable laying method according to claim 1, wherein the cable storage section at the first point is a drum. 3. The cable laying method according to claim 1, wherein the cable accumulation section at the first point is a figure-eight accumulation section in which the cables are accumulated with the tension end facing upward.