JPS6043605B2 - Submarine cable and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cable sheath with a high coefficient of friction for submarine cables, and in particular to a cable used for connecting a heavy armored cable and a lightweight protective cable when laying a submarine cable. Regarding the jacket structure.

Submarine cables are laid in and retrieved from the ocean or other water by a straight cable engine mounted on a cable ship.

During the laying of submarine cables, a straight cable engine must apply braking force to the cables so that the cable payout speed can be stably maintained at a predetermined value so that the cables can be laid smoothly into the submarine cable system. . This means that uncontrolled payout can result in twisted or knotted cables, insufficient cable to complete a particular link, or strained cables that are virtually impossible to retrieve for repair with current cable recovery equipment. This may occur. Many submarine cables have a sheath made of plastic material, which is attached to the cable by an extrusion process and thus has a generally smooth outer surface. Therefore, the degree of adhesion between the tires of a straight cable engine and the cable sheathing is not very high and slippage may occur, with the result that the necessary braking force is not applied to the cable. When laying submarine cables, armored, heavy-duty cables are laid in shallow waters to avoid wear and damage, and lightweight protective cables are laid outside the shallow waters in deep waters. In this case, conventionally, an armored cable with a gradually decreasing wall thickness is placed between the armored heavy cable and the lightweight protection cable as a connection cable, and the frictional engagement of the exterior of the connection cable is used to straighten the cable. A cable engine was used to sequentially lay connection cables and lightweight protection cables on the seabed. The object of the present invention is to provide a submarine cable that can be laid on both deep and shallow seabeds using a straight cable engine, and that can be used as a connecting cable in place of the conventional expensive connecting cable with a thick exterior. This is what we intend to provide.

According to the present invention, the cable is used for connecting a heavy armored cable and a lightweight protective cable, exhibits high adhesion between a straight cable engine and a vehicle with tires, and can be laid at a stable speed. In a submarine cable capable of applying a large braking force from an engine, the submarine cable has a longitudinally roughened plastic sheath with 2 to 10 (7) grooves per inch of cable length on the surface of the sheath. Diagonal grooves with a precision pitch are machined to increase the coefficient of friction in the length direction of the submarine cable, so that the submarine cable can be supported without slipping with the straight cable engine. A submarine cable is provided which is characterized by a two-fold improvement in maximum tension compared to non-grooved cables.

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawing is a schematic and exploded view of the device that cuts diagonal grooves on the surface of the plastic sheath of a submarine cable, and the cable itself is omitted from the center of the device for clarity. There is. The inventors have discovered that the adhesion between the straight cable engine and the submarine cable increases the coefficient of friction when the cable surface is coated in a controlled manner, i.e. relative to a cable sheath that is not roughened. , and can be improved by roughening the surface by a method that makes it uniform along the length of the cable. One such surface roughening method is to cut diagonal grooves with a precision pitch into the cable sheath, and the diagonal grooves are, for example, 0.020 inch deep and 0.0 inch wide.
It is approximately 50 inches long and has five grooves per inch of cable length. Other dimensions can also be used, for example in the following ranges: Depth: 0.
Width: 0.010" to 0.025" Width: 0.030" to 0.060" Number of grooves per inch of cable: 2 to 10 The cross section of the grooves may be, for example, U-shaped or V-shaped, and depending on the length of the cable. It is better to arrange the grooves in pairs of two or three than to arrange them at equal intervals.

And these numbers are currently manufactured 0.0990
inch cable, 1.47 inch cable, and 1.
It can be applied to submarine cables such as 7-inch cables. Then, a submarine cable with a roughened plastic sheath made by press forming diagonal grooves at a precision pitch with 2 to 10 grooves per inch of cable length is used as a connecting cable, and a straight line is used. As a result of laying armored heavy cables and lightweight protective cables in both shallow and deep sea areas using a cable engine, stable and successful installation was achieved. In order to provide diagonal grooves with such precision pitches, a groove cutting device as shown in the accompanying drawings can be used. The device also comprises a servo-controlled cable positioning section 1, a stator 2 with a through hole 3 into which a submarine cable 4 is loosely fitted, a groove cutting head 5, an eccentricity and servo control head 6. The positioning part 1 has a hole 7 through which the ungrooved cable 4 is extended into the device, and which adjusts the relative position of the cable 4 with respect to the stator 2 and the cutting head 5. Means are provided, the adjustment of which takes place in response to a control signal generated by a head 6, through which a grooved cable 9 emerges from the device through a through hole 8. Although the cutting head 5 is shown as having three cutting tools 10, thereby providing a diagonal groove with three starting points, other arrangements are possible;
The cutting head 5 is then rotated around the cable as a belt-driven roller. The control head 6 includes an eccentricity sensing circuit comprising two sets of opposing electrodes placed at right angles to the cable to be grooved and detecting the capacitive imbalance signal with the cable conductor grounded. An eccentric signal is detected and input into a bridge circuit, the output signal of which has a magnitude depending on the degree of imbalance and its current polarity depending on the direction of imbalance.
The phase discriminator converts the above bridge output signal into a unidirectional signal whose magnitude corresponds to the magnitude of the input and whose polarity corresponds to the position of the bridge output signal with respect to the oscillator output voltage. It is used to control the position of the cable 4, which is not located, with respect to the stator 2 and the cutting head 5 through the corresponding movement of the cable positioner 1.
Other methods of providing a grooved or roughened cable sheath surface include, for example, applying the sheath to the cable while it is extruded and still hot and soft, or after heating the sheath by an auxiliary heating device. is passed through or between a suitable grooved or patterned rotary die device arranged along the length of the transition of the cable to form diagonal grooves or otherwise a uniform pattern of grooves and ridges. and raised elements are imprinted onto the surface of the sheath, such as those provided around the periphery of vehicle tires, thereby increasing the friction that occurs between the cable sheath and the tire of the straight cable engine. Another method is to form a roughened surface over the entire surface of the cable sheath by shot blasting. The maximum tension that a grooved cable thus formed can hold without slipping in a straight cable engine is improved by a factor of two compared to a cable without grooves.

BRIEF DESCRIPTION OF THE DRAWINGS The figure is an exploded perspective view showing a precision pitch diagonal groove cutting device according to the present invention. DESCRIPTION OF SYMBOLS 1... Cable positioning part, 2... Stator, 3... Hole, 4... Submarine cable, 5... Groove cutting head, 6... Eccentricity and servo control head, 7, 8... Hole, 9
... Grooved cable, 10... Cutting tool.

Claims (1)

[Claims] 1. It is used for connecting heavy armored cables and lightweight protective cables, exhibits high adhesion between cars with straight cable engine tires, and can be laid at a stable speed, and also has a large braking force from the cable engine. In a submarine cable capable of being provided with a longitudinally roughened plastic sheath, the sheath surface has a precision pitch diagonal groove with 2 to 10 grooves per inch of cable length. Pressing the groove and measuring only the increase in the coefficient of friction in the length direction of the submarine cable,
As a result, the maximum tension that the submarine cable can support without causing slippage with the linear engine is improved to twice that of a non-grooved cable.