JPS6233807B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for hoisting a cable with a support wire in which a cable sheath carries a messenger wire useful as a vertical main line in a high-rise building or the like.

Conventionally, when lifting a cable vertically, as shown in Figure 1, a drum 1 is installed on the ground side and a winch 2 is installed on the lifting side, and the cable 3 wound around the drum 1 is connected to the lifting rope on the winch side. 4 with a clamp 5, and the cable 3 is lifted up with a winch 2. 6 shows a fishing wheel with a lifting rope.

When installing a cable with a messenger wire, a method is used in which a lifting rope is fixed to the tip of the messenger wire of the cable body, and the cable is lifted without applying tension to the conductor.

In this case, if the cable body consists of multiple insulated wire cores twisted together and surrounded by a cable sheath, the entire cable will be twisted by the twisting of the insulated wire cores during lifting, and the support wire will also be twisted in a spiral. If this is left untreated, it may have a negative effect on the cable itself.

Conventional measures against twisting include a correction means that sequentially retwists the cable from the bottom after it is lifted and laid. This method is fine for lifting cables with a short length, but if the length of the cable is long, such as in a skyscraper, it is not possible to fully see the top and bottom, and it takes a lot of time.

SUMMARY OF THE INVENTION The present invention aims to solve the drawbacks of the prior art and to provide a lifting method that can prevent twisting of cables during lifting.

That is, the lifting method of the present invention surrounds a plurality of insulated wire cores that are twisted together with a cable sheath, and when lifting and laying a cable with a support wire in which a plurality of messenger wires are supported by this sheath, A plurality of grooved rollers are arranged at appropriate intervals, and the cable is suspended by passing each messenger wire through each grooved roller in sequence.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 2 shows a cable with support wire used in the present invention, which includes a plurality of insulated wire cores 10, 10, 10.
are twisted together, and a cable sheath 11 is applied thereon. At symmetrical positions on the cable sheath 11, projections 11a, 1 are provided along the longitudinal direction of the cable.
1a, and messenger wires 12, 12 are embedded and supported in each of these protrusions 11a, 11a.

The above cable is Messenger Wire 12,
The tip of 12 can be lifted with a lifting rope (not shown).

Figure 3 is a side view showing the lifting situation, Figure 4
The figure is a plan view of the same, and shows pairs of grooved rollers 13, 13, 1 at appropriate intervals in the cable lifting direction.
3, 13... are arranged facing each other, and the cable runs between the grooved rollers 13, 13, 13, 13... so that the supporting portions of the messenger wires 12, 12 are grounded to the respective grooved rollers. The cable is then lifted up and laid by guiding it from below to above.

14 is a fixed plate to which the shaft of the grooved roller 13 is pivotally mounted.

As described above, the present invention allows a plurality of messenger wires protruding from a cable sheath to pass through a plurality of grooved rollers installed in the lifting direction, so that rotation is suppressed and the cable itself is lifted. Can be installed without twisting.

Therefore, it has great industrial value, such as eliminating the waste of work conventionally required to correct twists after installation and greatly shortening the installation time.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing a conventional general cable lifting method, Fig. 2 is an explanatory cross-sectional diagram of a cable with support wire used in the present invention, and Fig. 3 is an example showing a lifting situation in the hoisting method of the present invention. The side view and FIG. 4 are its plan views. 10: Insulated wire core, 11: Cable sheath, 1
2: Messenger wire, 13: Grooved roller.

Claims (1)

[Claims] 1. When hoisting and laying a cable with support wires, in which a plurality of insulated wire cores twisted together are surrounded by a cable sheath and a plurality of messenger wires are supported by the sheath, a plurality of grooves are formed at appropriate intervals in the lifting direction. A method for lifting cables with support wires, characterized in that rollers with support wires are arranged, and the cable is lifted by passing each messenger wire through each of the grooved rollers in sequence.