JPH01149009A - Spacer for optical cable and production thereof - Google Patents

Abstract

PURPOSE:To improve control of bending directions by alternately providing low side wall parts and high side wall parts to the side walls of a groove for housing an optical cable. CONSTITUTION:This spacer has the low side wall parts 2 and the high side wall parts 3 alternately on the side walls of the groove contg. a tensile body 1 in the bottom part. The spacer can be curved without exerting undue external pressures to the optical tape fiber and single fibers housed in the groove even if the spacer is curved along the side wall parts of the groove. The degradation in the transverse bending strength of the groove for housing the optical cable is thereby lessened and the control in the bending direction is improved over the entire part. The ease of bending is improved as well.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical cable spacer and a manufacturing method thereof, and particularly to an optical cable spacer and a manufacturing method thereof that are applied to cables in which the direction of bending of an SPP cable needs to be controlled. It is related to.

[Conventional technology]

Conventionally, bending has been controlled only by appropriately arranging spacers and multiple tensile strength members for this type of SP cable (for example, "THETRANSACTIO").
NS OF THE IECE OF JA
PAN, VOL, E69. NO, 4 APRIL
1986 PP357-359″).

FIG. 5 is a schematic diagram of a conventional SP cable spacer structure. It is composed of a sheath material 9 having a groove having a continuous linear opening on the outer periphery and incorporating a tensile strength member 11 for controlling the bending direction.

Since the SP cable spacer and the opening of the optical cable storage groove are not twisted in the longitudinal direction, optical cables can be assembled at high speed, so the process of assembling optical cables and sheathing can be performed in a series. is possible,
This cable shortens the manufacturing process and improves production efficiency. Therefore, although it is possible to produce a low-cost cable, there is a problem with bending properties since it does not have twist. To solve this problem, we controlled the bending direction by storing multiple tensile strength members in a spacer, and by appropriately winding the manufactured SPP cable around a drum, we were able to store the desired excess length during wire stretching. In practice, it has been carried out to add this to optical fibers.

[Problem that the invention seeks to solve]

Conventionally, in this type of SPP cable, when the tensile strength body is in close contact with the spacer material, or when the cable is long enough and the cable is cut away from the bend,
Although bending can be adequately controlled, bending may be difficult if the cable is stored with a gap between the tensile strength member and the spacer material, or if the cable needs to be cut near the bend. Insufficient control causes the cable to bend in undesirable directions, causing increased transmission loss.
In some cases, there is a risk of wire breakage.

[Means for solving problems]

The present invention solves the conventional problems and provides a spacer for an optical cable having excellent performance in controlling the direction of bending, and a method for manufacturing the same. In the optical cable spacer equipped with an optical cable storage groove having an opening continuous to the optical cable storage groove, the optical cable storage groove has a side wall having alternating low side wall portions and high side wall portions, and the spacer body has a The present invention is characterized in that it includes an embodiment having a tensile strength member inside, an embodiment made of polyethylene, and an embodiment in which the cable storage groove maintains a straight shape without twisting when external force is released.

Further, the invention of the manufacturing method for producing an optical cable spacer according to the present invention extrudes spacer material from an extruder, and removes both sides of the extruded spacer material at predetermined intervals and with a predetermined width to form a gear-shaped cutting part. and bending the gear-shaped cutting parts formed on both sides of the spacer material in the same direction with respect to the spacer material, the step of forming the gear-shaped cutting parts on both sides of the spacer material. In this method, a predetermined width is set on both sides of the spacer material, and gears arranged perpendicularly to the plane of the spacer material are rotated as the spacer material is extruded, and a gear-shaped gear formed on both sides of the spacer body is provided. The step of bending the cut portion in the same direction relative to the spacer material involves holding down the center portion of the spacer material to be extruded with a groove holder, and then bending both sides of the spacer material on which the gear-shaped cut portion has been formed to both sides of the groove bottom holder. It is characterized in that it includes an embodiment in which it is folded in the same direction.

[For production]

Since the optical cable spacer of the present invention has a structure in which the side walls of the optical cable storage groove have alternately low side wall parts and high side wall parts, the low side wall part allows the optical cable storage groove to be bent in the depth direction. In addition to significantly reducing the strength, the bending strength in the width direction of the optical cable storage groove is kept to a minimum, improving control of the bending direction as a whole, and improving ease of bending. When manufacturing the optical cable spacer of the present invention, it is possible to avoid a decrease in the storage capacity of optical tape fibers or single fibers, and it has excellent performance in controlling the bending direction. The optical tape fibers and single fibers inserted and stored are protected from being bent in unreasonable directions, and can be manufactured in a single process.

The effects of the present invention will be explained below. Generally, the bending strength R of a beam
is expressed as the product of the second moment of area t around the bending axis and the Young's modulus E.

R=IE second moment of area) T is the minute area dS of the cross section of the beam,
It is expressed as 1=J d"dS using the distance d from the neutral axis. Here, A is the entire cross section of the beam.

By reducing the height of the side wall, the low side wall portion of the groove side wall of the present invention can reduce the term dt and reduce the bending strength in the depth direction of the optical cable storage groove. At the same time, the bending strength in the width direction of the optical cable storage groove also decreases, but since the bending strength in the width direction only reduces dS by integrating, the decrease in the bending strength in the width direction can be suppressed to a low level. That is, there is a dual effect of improving the ability to control the bending direction as a whole and also improving the ease of bending.

Further, the high side wall portions, which are provided alternately with the low side wall portions, have the function of preventing a decrease in the storage capacity of the tape core wire or single fiber wire to be stored in the groove. Examples will be described below based on the drawings.

〔Example〕

FIG. 1 is a structural outline of an embodiment of the optical cable spacer of the present invention. The optical cable spacer 10 is a tensile strength member 1
A low side wall part 2 and a high side wall part 3 are attached to the side wall of the groove with a built-in bottom part.
Since these are provided alternately, the bending direction can be controlled reliably and easily. That is, as illustrated in FIG. 2a, even when the optical cable spacer 10 of the present invention is curved in the length direction, as illustrated in FIG. Even when the groove is curved relative to the groove, the optical tape core wire or the single fiber core housed in the groove can be curved without applying unreasonable external pressure. When the external force is released, the optical cable spacer 10
returns to its original state, and the groove becomes straight with no twist.

Furthermore, as shown in Fig. 4 a, b, and c, which show cross-sectional states when the spacer is bent, when the side wall does not have a low side wall portion like the conventional groove structure, as shown in Fig. 4 a or Fig. 4 S, Pressure on the optical tape core fibers due to deformation and disordered alignment can be prevented by providing the structure in which the low side wall portion 2 of the present invention is provided between the high side wall portions 3. That is, since the low side wall portions 2 and the high side wall portions 3 are provided alternately, even if the spacer is deformed as shown in FIG. 4a or 4S, the state close to that shown in FIG. This is because it can be maintained.

FIG. 3 shows the configuration of an embodiment of the manufacturing method for producing an optical cable spacer according to the present invention. A spacer material 8 made of, for example, polyethylene (PR) is extruded from the extruder 6, and both sides of the extruded spacer material 8 are cut by a cutting machine, for example, a gear 5, at predetermined intervals and widths determined in advance according to the purpose of use. Cut to form a gear-shaped cutting part. Subsequently, the center part of the spacer material is held down with a groove bottom presser 4 if necessary, and gear-shaped cutting parts formed on both sides of the spacer material 8 are forced into the side wall processing groove 7 on both sides of the groove bottom presser 4. A spacer for an optical cable is manufactured by folding and folding it to form a groove.

〔Effect of the invention〕

As explained above, the optical cable spacer of the present invention has a structure in which the side walls of the optical cable storage groove have alternately low side wall parts and helmet side wall parts. It has excellent performance in controlling the bending direction by reducing the bending strength in the horizontal direction, and the optical tape fibers and single fibers inserted and stored in the groove are protected from being bent in unreasonable directions. The anti-pacer for optical cables of the present invention can be manufactured in one low-cost process, and the high side wall portion does not reduce the storage capacity of optical tape fibers or single fibers.
For example, it is highly effective when applied to spacers for SP cables.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the structure of the optical cable spacer of the present invention, Fig. 2 a and b are explanatory diagrams of the state when bending is applied to the optical cable spacer of the present invention, and Fig. 3 is the manufacturing method of the optical cable spacer of the present invention. Fig. 4 a, b, and c are cross-sectional diagrams of the spacer when the spacer is bent, and Fig. 5 is the conventional S
There is a schematic diagram of the spacer structure for P cable. 1... Tensile strength body, 2... Low side wall part, 3... High side wall part, 4... Groove bottom presser, 5... Gear, 6... Extruder, 7... Side wall processing Groove, 8... spacer material,
9... Sheath material, 10... Spacer for optical cable, 11... Tensile strength body patent applicant Sumitomo Electric Industries Co., Ltd. agent Patent attorney Kugobe Tamamushi Spacer structure for optical cable of the present invention [Factor 1
Fig. α The state of the optical cable spacer of the present invention after being bent once. tl1 Fig. 2 Fig. 4s of the embodiment of the manufacturing method of the optical cable spacer of the present invention Fig. 3 Fig. a b C IFr surface condition diagram Figure 4 Schematic of spacer structure for backwater SP cable! ! Figure 5
figure

Claims (7)

[Claims] (1) In an optical cable spacer having an optical cable storage groove having an opening continuous in the longitudinal direction on the outer periphery of the spacer body, the optical cable storage groove has a low side wall portion and a high side wall portion alternately on the side wall. An optical cable spacer characterized by: (2) The spacer for an optical cable according to claim 1, wherein the spacer main body has a tensile strength member inside. (3) The optical cable spacer according to claim 1, wherein the spacer body is made of polyethylene. (4) The optical cable spacer according to claim 1, wherein the spacer main body is such that the cable storage groove maintains a straight shape without twisting when an external force is released. . (5) In a method for manufacturing an optical cable spacer having an optical cable housing groove having a continuous opening in the longitudinal direction on the outer periphery of the spacer body, extrude spacer material from an extruder, and press both sides of the extruded spacer material. The step includes forming gear-shaped cut portions by removing a predetermined width at predetermined intervals, and bending the gear-shaped cut portions formed on both sides of the spacer material in the same direction with respect to the spacer material. A method for manufacturing an optical cable spacer characterized by: (6) In the step of forming gear-shaped cutting parts on both sides of the spacer material, a predetermined width is set on both sides of the spacer material, and gears arranged perpendicularly to the surface of the spacer material are cut into the spacer material. 6. The method of manufacturing an optical cable spacer according to claim 5, wherein the spacer is rotated as the spacer is extruded. (7) The step of bending the gear-shaped cutting parts formed on both sides of the spacer body in the same direction with respect to the spacer material is performed by bending the gear-shaped cutting parts formed on both sides of the spacer body while pressing the center part of the extruded spacer material with a groove bottom presser. Claim 5, characterized in that both sides of the spacer material forming the part are folded up in the same direction on both sides of the groove bottom presser.
1. Method for manufacturing an optical cable spacer as described in .