JP3282400B2 - High tensile strength optical fiber cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high tensile strength optical fiber cable having an increased allowable installation tension.

[0002]

2. Description of the Related Art FIG. 2A is an external perspective view of a slot type optical fiber cable on which the present invention is based.
(B) is a sectional view taken along line AA.

[0003] The slot type optical fiber cable is provided with a tubular slot plastic portion 3 for accommodating an optical fiber core wire 2 on the outer periphery of a central tensile strength member 1. A sheath 5 is provided.

In this slot type optical fiber cable, a center tensile member 1 and a slot plastic part 3 are tightly integrated.

Apart from this, it has a structure substantially similar to that of the slot type optical fiber cable shown in FIG. 2, and the center tensile member and the slot plastic portion are not integrated, and can be slid by a lubricant. Structures have been proposed but have not yet been put to practical use.

[0006]

However, in the above-mentioned slot type optical fiber cable, when the tension is applied to the central tensile member 1 in the longitudinal direction, the elongation caused by the tension becomes the elongation of the entire cable. A tension exceeding the allowable elongation strain of the optical fiber core wire 2 could not be applied.

In the latter structure, since the center tensile strength member and the slot plastic portion slide after the cable is laid and drawn, the slot plastic portion vibrates or slips in the longitudinal direction at the cable terminal portion, so that the cable does not slide. It becomes stable, and there is concern about troubles such as disconnection of the optical fiber core wire at the cable connection part.

It is an object of the present invention to solve the above-mentioned problems and to provide a high tensile strength optical fiber cable having a large allowable installation tension.

[0009]

Means for Solving the Problems The present invention to achieve the above object, the slot type optical fiber cable provided with a slot plastic portion for accommodating the optical fiber to the outer circumference of the central strength member, the central strength member Add the outer circumference of
Cover with metal tape formed to a thickness that can be tightened.
When a tensile force is applied to the tensile member in the longitudinal direction, the central tensile strength is reduced.
The force member is made to slide in the longitudinal direction in the metal tape, and the metal tape is bonded to the slot plastic portion with an adhesive.

[0010]

[0011]

[0012]

[0013]

According to the above construction, since the center tensile member can move in the longitudinal direction in the metal tape, the elongation of the center tensile member does not become equal to the elongation of the entire cable. The tension in the elastic region of the center tensile member becomes equal. For this reason, the incidence of disconnection accidents during laying and wire drawing is reduced, and the efficiency of laying and wire drawing work is improved.

After the cable has been laid and extended, the metal tape covering the central tensile strength member is swaged, so that the slot plastic portion can be fixed to the central tensile strength member, thereby improving the stability at the cable end portion. Can be done.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1A is an external perspective view of an embodiment of a high tensile strength optical fiber cable according to the present invention, and FIG.
Is a sectional view taken along the line BB. Note that the same members as those shown in FIG. 2 are denoted by the same reference numerals.

Reference numeral 1 denotes a central tensile member, which is a plurality of members (7 in the figure).
Books, but not limited to). A stainless laminated tape 6 is wound around the outer periphery of the center tensile member 1 such that the adhesive surface is exposed on the outer periphery.
The stainless laminating tape 6 has an adhesive applied to one side, and has a thickness that can be caulked at the tip 6a, for example. An annular slot plastic portion 7 is formed on the outer periphery of the stainless steel laminated tape 6, and the slot plastic portion 7 and the stainless laminated tape 6 are bonded with an adhesive. That is, the stainless laminated tape 6 and the slot plastic portion 7 are tightly integrated.

A plurality (although not limited to four in the figure) along the longitudinal direction of the outer periphery of the slot plastic portion 7
Are formed. Each groove 8
The optical fiber cores 2 are respectively disposed in the inside, and the presser winding 4 and the LA
A P (aluminum laminated polyethylene) sheath 5 is provided.

Next, the operation of the embodiment will be described.

In the high-tensile-strength optical fiber cable of the present embodiment, a tension in the longitudinal direction is applied to the central tensile strength member 1 at the time of laying, extending, or after laying. As a result, strain is applied to the central tensile member 1, but since the central tensile member 1 can slide in the longitudinal direction while being covered with the stainless steel laminated tape 6, almost no stretch is applied to other portions. Therefore, (allowable tension of the cable) = (tension in the elastic region of the center tensile member 1) can be satisfied.

The high tensile strength type optical fiber cable of this embodiment is a cable having a high tensile strength and a circular cross section. Therefore, when used for an aerial cable, it has a small air resistance coefficient and is very effective. No erection is required.

Further, in the high tensile strength optical fiber cable of the present embodiment, after the cable is laid and extended, a stainless steel laminated tape covering the central tensile strength member is swaged at the cable end portion, so that the slot plastic portion is added to the central tensile strength member. Can be fixed, and the stability at the cable terminal can be improved. As shown in FIG. 3, when the cable is installed, it is preferable that the entire high-tensile-strength optical fiber cable 9 of the present invention is protected by a line guard 10 and attached to a suspended metal object 11 as shown in FIG. 3. .

In this embodiment, a stainless steel laminated tape coated with an adhesive on one side is used as the metal tape. However, the present invention is not limited to this, and the metal tape can be crimped and the adhesive is applied. Other types of metal tape, such as aluminum, may be used. In this case, an adhesive is required so that the metal tape and the slot plastic portion adhere to each other. Also, the case where the groove of the slot plastic portion is linear has been described, but may be spiral. Furthermore, the case where the stainless laminated tape is wound around the outer periphery of the center tensile member has been described, but the central tensile member may be covered by longitudinally attaching.

[0024]

In summary, according to the present invention, the following excellent effects are exhibited.

[0025] Even if the central tensile strength member is stretched, the central tensile strength member slides in the metal tape, so that the other portion is hardly subjected to the stretch strain, so that the tension is reduced to the tension in the elastic region of the central tensile strength member. Can be added.

[Brief description of the drawings]

FIG. 1A is an external perspective view of an embodiment of a high tensile strength optical fiber cable according to the present invention, and FIG.
It is a line sectional view.

FIG. 2A is an external perspective view of a slot type optical fiber cable on which the present invention is based, and FIG.
FIG. 3 is a sectional view taken along line A.

FIG. 3 is a partial front view showing a column fixing portion of the high tensile strength optical fiber cable of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Central tensile strength body 2 Optical fiber core wire 4 Holding winding 5 Sheath (LAP sheath) 6 Metal tape (stainless steel laminated tape) 7 Slot plastic part

Claims (1)

(57) [Claims] 1. A slot type optical fiber cable provided with a slot plastic portion for accommodating an optical fiber core wire on an outer periphery of a central tensile strength member, wherein the outer periphery of the central tensile strength member is formed so as to be crimped. Cover with metal tape
When a longitudinal tension is applied to the center tensile member,
The center tensile member slides longitudinally in the metal tape.
High tensile strength type optical fiber cable and the metal tape, characterized in that the adhesively bonded to the slot the plastic part with Unisuru.