JPS5838886B2 - Alternately twisted double armored submarine cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an alternating double armored submarine cable.

Conventionally, in order to prevent cables installed on the seabed from being damaged by movement due to waves and currents in rocky areas, or by damage caused by ship anchors, trawl nets, etc., an outer sheath, such as a steel wire sheath, has been applied to the outer periphery of the cable core. One or two layers of

In conventional armored submarine cables (hereinafter simply referred to as armored cables) that are wound in two layers in the same direction, the cables twist in one direction when tension is applied to the cables due to the up-and-down motion caused by the waves of the laying ship during installation or repair after installation. One of the causes of kink
They were one.

As a way to prevent this, a submarine cable with a two-layered sheath has been considered, which has an alternately twisted double sheath that is wound in opposite directions so that the torques of the inner and outer layers balance each other under tension.

When this alternately twisted double-armored cable is coiled in a fixed direction around a cable storage tank (hereinafter referred to as a tank), one cable is used each time it goes around the tank. While the gap between the wires becomes larger and the outer diameter of the outer sheath also becomes larger, in the outer layer, the outer wire becomes tighter, contrary to the above, and the gap between the wires and the outer diameter of the outer sheath become smaller.

For example, if an alternately twisted, double-armored submarine cable has an inner layer wound to the right (clockwise) and an outer layer wound to the left (counterclockwise), if it is stored in a tank right-handed, the diameter of the outer wire wound around the inner layer will increase. At the same time, the diameter of the outer wire wound on the outer layer becomes smaller and tightens.

In addition, when the inner layer is wound to the left and the outer layer is wound to the right, and the tank is stored in a left-handed manner, the same situation as above will occur. Burrs and abutments will occur.

Therefore, if a submarine cable with an alternately twisted double sheath is housed in a tank, undulations will occur in the submarine cable.

In order to reduce the undulations of submarine cables, it is possible to increase the winding diameter of the tank, but in this case, the amount of winding of the tank is limited, so submarine cables with alternately twisted double armor are relatively thin. There was a problem in that it was limited to various types of observation submarine cables that had short wire lengths and could be wound into drums, and it was difficult to make long submarine cables.

This invention was made in view of the actual situation,
In a submarine cable with an alternately twisted double sheath, a cushion layer made of gap-wound elastic rubber tape is provided between the inner layer and the outer layer of the sheath wire, and the sheath wires are held together by a button and a cushion layer. Relaxing notifications based on negotiations,
This was done to eliminate swells in submarine cables.

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings.
is the center internal conductor, 2 is the surrounding PE solid insulator, 3 is the central internal conductor,
is an outer conductor, 4 is a PE jacket, 5 is an inner layer exterior wire,
For example, tensile strength iron wires are twisted in a right-handed manner.

Reference numeral 6 indicates a cushion layer consisting of one to three gap-wound layers of rubber tape or the like provided thereon, and reference numeral 7 indicates an outer layer outer wire on the cushion layer 6, in which, for example, tensile strength iron wire is twisted in the direction in which the inner layer outer wire 5 is twisted. Twist in the opposite direction, that is, left-handed.

8 is the tape winding layer thereon, and 9 is the PE sheathing thereon.

In the alternately twisted double-armored submarine cable of the present invention having such a structure, when the coil is taken up in a tank in a right-handed manner, 1 the inner-layer armored wire 5 loosens, conversely the outer-layer armored wire 7 tightens, and the inner and outer layers are mutually connected. The outside diameter of the exterior changes due to the tightness of the exterior wire that occurs when the buttons are pressed.

However, in this invention, since the cushion layer 6 is provided, changes in the outer diameter due to loosening of the inner layer sheath wire 5 and tightening of the outer layer sheath wire 7 can be absorbed by the elasticity of the cushion layer 6, which occurs during coil winding. It is possible to prevent the generation of undulations in the submarine cable and wind the coil smoothly and uniformly.

Furthermore, after the submarine cable is laid, the cushion layer 6 has a restoring property, so that the strain received by the sheathing wire is restored and does not cause kink.

By the way, if the inner layer sheath wire 5 is wound to the left and the outer layer sheath wire 7 is wound to the right, they will be housed in the tank so that the inner layer sheath wire 5 is loosened and the outer layer sheath wire 7 is tightened. However, in this case as well, the cushion layer 6 has the effect of alleviating the undulations of the submarine cable.

(Normally, when coiling a cable in a tank, it is generally wound in a direction where the cable core is not tightened by the armored wire, not only for alternately twisted double-armored cables.

)Although the above embodiment shows a submarine cable in which a solid coaxial cable core is provided with an alternately twisted double sheath, the gist of this invention is related to an alternately twisted double sheath, so the invention is limited to a solid coaxial submarine cable. The present invention is also applicable to, for example, optical submarine cables that have an outer sheath 4 on the cable core without having to do so.

As explained above, the present invention provides an alternately twisted double armored submarine cable in which a jacket is directly applied to the cable core, in which a cushion layer made of a rubber material is provided between the layers of the alternately twisted double armored wires. Since it is a cable, it does not cause any undulations even when it is wound inside a tank, so it has the advantage that a long submarine cable suitable for tank storage can be easily manufactured.

Moreover, the cushion layer is made of elastic rubber tape wrapped in gaps, so the gap space is used for the outer layer.
It also has the effect of increasing the absorption effect against tightening and loosening of the inner layer.

[Brief explanation of the drawing]

The drawing is a perspective view of a submarine cable embodying the present invention. In the figure, 1 is an inner conductor, 2 is a PE solid insulator, 3 is an outer conductor, 4 is a PE jacket, 5 is an inner layer/exterior wire, 6 is a cushion layer, 7 is an outer layer/exterior wire, 8 is a tape wrapping layer, 9 indicates a PE jacket.

Claims (1)

[Claims] 1. In an alternately twisted double-armored submarine cable in which an outer sheath is applied to the cable core, a cushion layer is provided between the layers of the alternately twisted double-armored wires using a gap-wound tape made of elastic rubber material. An alternately twisted double-armored submarine cable.