JPS5924612B2 - Pressure-resistant load-supporting tubular member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a load-supporting tubular member having pressure resistance.
In particular, it relates to pressure-resistant load-bearing tubular members used to support communication cables such as fiber optic cables.

When reinforcing a communication cable, it is necessary to maintain appropriate flexibility and avoid causing excessive strain on the communication cable.

In particular, in the case of communication cables that require durability in harsh environments, such as undersea cables, it is important to have appropriate flexibility, sufficient pressure resistance, and sufficient waterproofness. A reinforcing tubular member is required. Although such tubular members are necessary when using metal conductor cables, they are even more necessary when using fiber optic cables. Conventionally, as reinforcing members for communication cables,
A tubular member described in Japanese Patent No. 83 is known.

This tubular member has an inner layer formed by spirally winding a strip having a V-shaped cross section, and an outer layer formed by annularly disposing a large number of wire rods each having a round cross section. This conventional tubular member has a moderate degree of flexibility, but the outer layer consists of just adjacent wire rods with round cross sections, and the inner layer has the edge portions of the letter-shaped strips in contact with each other. Because of this structure, the pressure resistance and waterproofness of the tubular member are significantly reduced at the adjacent boundaries between the wire rods or strips in each layer.
On the other hand, the tubular member described in Utility Model Application Publication No. 276 of 1945 has thin strips spirally wound to form each layer. This results in a significant decrease in

Note that Patent No. 75560 discloses that a tubular member is formed by alternately arranging wire rods with a round cross section and wire rods with a constricted cross section of 1 type.
It is stated in the specification of the No.

The tubular member described in this patent specification is for a high-voltage power transmission line, and this hollow power transmission line is flexible because the wires with constricted cross sections touch each other beyond the round wires. Missing. In addition, in the case of such a structure, it is necessary to precisely finish the shape and dimensions of the wire rod with a constricted cross section.
Manufacturing costs will increase. In view of the above-mentioned shortcomings of the prior art, the present invention aims to provide a pressure-resistant load-supporting tubular member for reinforcing communication cables that can improve pressure resistance and waterproofness while maintaining appropriate flexibility. purpose.

The object is, according to the present invention, to provide a pressure-resistant load-bearing tubular member for use in supporting communication cables, such as optical fibers, comprising a first outer layer and a second outer layer concentric to each other.
each layer is formed around a central hole, and each layer is comprised of a plurality of wires with a round cross section and a plurality of wires with a constricted cross section; The constricted cross-section wires are arranged alternately with each other in each of the layers, and V1 in each layer, both sides of the constricted cross-section wire overlap both sides of the round cross-section wire, and the constricted cross-section wire in each layer The cross-section wires are spaced apart from each other and the cross-section of each constricted cross-section wire of the second inner layer is spaced apart from the first outer layer so as to form a pressure tube for supporting a cable within the central hole. The first outer layer wires and the second inner layer wires are brought into contact with each other by contacting the narrow cross section wires of the layer and the round cross section wires of the first outer layer. This is accomplished by means of pressure-resistant load-bearing tubular members that are in contact. That is, in the pressure-resistant load-supporting tubular member according to the present invention, both sides of the wire with a constricted cross section in each layer cover both sides of the wire with a round cross section, but the wires with a constricted cross section in each layer do not overlap with each other. The spacing allows the constricted cross-section wire in each layer to be displaced along the circumference of the round-section wire, providing flexibility.

Further, both sides of the wire with a constricted cross section in each layer are covered with both sides of the wire with a round cross section, so that the cross section of each constricted cross section of the wire in the second inner layer is the same as that of the first outer layer. The first and second layer wires are in contact with each other by contacting the constricted cross-section wires of the layer and the round cross-section wires of the first outer layer, so that the tubular The path of moisture between the wires from the outside of the member to the center hole is longer. Therefore, it is possible to prevent moisture from entering between the wires, and it is possible to improve the V1 waterproof property. In addition, the external pressure is evenly distributed to the constricted cross-section wires on both sides of the round-section wire in each layer, reducing the pressure acting on the round-section wire, thereby increasing pressure resistance.
In the pressure-resistant load supporting universal member according to the present invention, if a wire with a round cross section and a wire with a constricted cross section are twisted together, the pressure resistance strength can be further improved.

Further, the wires of the first outer layer and the wires of the second inner layer are arranged in a helical shape, and the helical direction of the wire of the first outer layer and the helical direction of the second inner layer are arranged. If they are turned in opposite directions, the pressure resistance will be further increased. below,
Embodiments of the present invention will be described with reference to the drawings. The figure shows a pressure-resistant load-bearing tubular member consisting of two wire layers.

Each wire layer is constructed by alternately arranging wires 1 with a round cross section and wires 2 with a constricted cross section.
Although not particularly limited, each wire 1, 2 here consists of a twisted wire. The diameters of the round cross-section wires 1 in the two wire layers are approximately equal.

The cross-section of the wires 2 of constricted cross-section is suitably defined so that each wire layer forms a substantially complete cylinder when twisted together. In this case, as shown in the figure, the cross-sectional shapes of the wires 2 in the two wire layers are different. A central hole 3 is formed in the tubular member thus formed.

This central hole 3 extends over the entire length of the tubular member, into which a communication cable to be supported, such as an optical fiber cable (not shown), is inserted. To explain in more detail with reference to the drawings, both sides of the wire 2 with a constricted cross section in each wire layer cover both sides of the wire 1 with a round cross section. are spaced apart from each other, so that the constricted cross-section wire 2 in each wire layer is flexible enough to be able to be displaced along the circumferential surface of the round-section wire 1.

Further, both sides of the wire 2 with a constricted cross section in each wire layer cover both sides of the wire 1 with a round cross section, and the cross section of each constricted cross section wire 2 in the inner layer overlaps with the cross section of the wire 2 in the outer layer. wire 1 of the outer layer by contacting the wire 2 of constricted cross section and the wire 1 of round cross section of the outer layer.
, 2 and the inner layer wires 1, 2 are in contact with each other, the path of moisture between any wires from the outside of the tubular member to the central opening 3 is lengthened. Therefore, it is possible to prevent moisture from entering between the wires. Further, the external pressure is evenly distributed to the constricted cross-section wires 2, 2 on both sides of the round-section wire 1 in each wire layer, and the pressure acting on the round-section wire 1 is reduced, so that the pressure resistance of the tubular member is increased. The wire layer used to form the cylindrical tubular member preferably has a cylindrical cross-section as shown, but may have other cross-sectional shapes. Moreover, the wire groups of each layer can also be arranged in a spiral. In this case, each Wygo layer is arranged in a helical pattern with alternate left-handed and right-handed spirals. In this way, the pressure resistance of the tubular member is further improved, and the torsion of each wire layer can be offset. When one or more packaged optical fiber cables are accommodated in a tubular member and the optical fiber cables are supported by the tubular member, the optical fibers are accommodated in the tubular member with slack. You can do it like this.

That is, the optical fiber may be formed somewhat longer than the tubular member and accommodated within the tubular member. In this way, the optical fiber will not experience any strain within the tubular member. The number of wire layers is not limited to only two layers, and the outer wire layer may be formed with one or more coating layers of a water-resistant material.

That is, according to the present invention, various changes can be made to the above embodiments without departing from the scope of the claims.

[Brief explanation of the drawing]

The figure is a sectional view of a tubular member showing an embodiment of the present invention. 1... Wire with round cross section, 2... Wire with constricted cross section, 3... Center hole.

Claims (1)

Claims: 1. A pressure-resistant load-bearing tubular member used to support communication cables such as optical fibers, comprising a first outer layer and a second inner layer concentric with each other. , each layer is formed around a central hole 3, and each layer is made up of a plurality of wires 1 with a round cross section and a plurality of wires 2 with a constricted cross section. The wires 2 are arranged alternately in each layer, and in each layer, both sides of the wire 2 with the constricted cross section cover both sides of the wire 1 with the round cross section, and the constricted wires 2 in each layer The cross-section wires 2 are spaced apart from each other and the cross-section of each constricted cross-section wire 2 of the second inner layer is spaced apart from each other so as to form a pressure tube for supporting a cable in the central hole 3. The wires of the first outer layer and the wires of the second inner layer by contacting the wires 2 of the constricted cross section of the outer layer 1 and the wires 1 of the round cross section of the first outer layer. A pressure-resistant load-supporting tubular member characterized in that the wires are in contact with each other. 2. The pressure-resistant load-supporting tubular member according to claim 1, wherein the wires 1 and 2 are twisted wires. 3. In the pressure-resistant load-supporting tubular member according to claim 1 or 2, the wires of the first outer layer and the wires of the second inner layer are arranged in a helical shape. A pressure-resistant load-supporting tubular member, wherein the helical direction of the wire in the first outer layer and the helical direction of the wire in the second inner layer are opposite to each other.