JP2005070564A - Optical drop cable straight connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a straight connection portion structure of an optical drop cable which has a surplus length processing function and can obtain a sufficient tension even when a support wire is fixed in a state of being covered with a resin coating.
A linear connection portion structure 11 of an optical drop cable 12 in which an optical fiber core wire portion 16 and a support wire 17 are integrated, and the ends of the support wires 17 on both sides are attached to a connection member 20. The bolts 24 are fixed to the connecting member 20 by being wound and tightened. Each support wire 17 is covered with a spiral tube 21. The mechanical splice 22 in which the optical fibers 13a on both sides are connected is rotated around the connection member 20 so that each optical fiber 13a is spirally wound around the outer periphery of the spiral tube 21. It attaches to the attachment part 23. All of them are accommodated in a protective sleeve 28 and end caps 29 are put on both ends.
[Selection] Figure 1

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical drop cable for drawing an optical fiber from an aerial optical cable of an optical communication network into each house, and more particularly to an optical drop cable linear connection structure in which an optical fiber core part and a support line are integrated.

  The above optical drop cable is used in so-called FTTH or the like, but it is necessary to connect the optical drop cable linearly when it is extended due to troubled transfer or disconnection of the optical drop cable. In this case, there are various conventional linear connection structures of the optical drop cable. For example, FIG. 15 shows an example thereof. In the figure, reference numeral 1 denotes an optical drop cable. As shown in FIG. 15A, the optical drop cable 1 has a structure in which the optical fiber core portion 2 and the support wire 3 are integrated. The optical fiber cores 2a that are exposed from the optical fiber core portion 2 are mechanically spliced (optical fiber connection). 4), and the ends of the support wires 3 on both sides are connected and fixed by caulking with a lap crimping tool through the connecting sleeve 6 after removing the resin coating. Then, as shown in FIG. 15 (b), the protective sleeve 7 previously passed through the optical drop cable 1 is slid to cover the entire vicinity of the connection portion, and the end cap 8 also passed through the optical drop cable 1 in advance. Is put on both ends of the protective sleeve 7. Although not shown, taping is applied to the boundary between the protective sleeve 7 and the end cap 8 and the boundary between the end cap 8 and the optical drop cable 1.

In the above-mentioned conventional straight connection structure 9 of the optical drop cable, the extra length processing of the optical fiber core wire 2a is not considered. Therefore, if the connection fails or the surplus length is excessive, the work must be performed again, and the workability is extremely poor.
Further, the support wires 3 on both sides are connected and fixed to each other by caulking of the connecting sleeve. However, in order to obtain a necessary tension, it is necessary to peel off the resin coating of the support wire 3 and press the resin coating. Therefore, workability becomes worse. Moreover, since a special tool called a crimping tool is required, it is complicated.

  In addition, some of the conventional optical drop cable straight-line connection structure has been considered for extra length processing, but in that case, the extra length processing portion becomes bulky, and in terms of appearance, wind pressure, etc. It is not preferable.

Moreover, as a means for fixing the support line, in a method not using caulking, the support line is passed through the hole of the plate-shaped support line fixing bracket, bent into a stepped shape (Z shape), and the vicinity of the bent portion is locked with the bracket. Although there is a method of fixing, in this support line fixing method, the support line may be broken at the bent portion.
In addition, there is a type in which the support wires on both sides are bent into U-shapes and entangled with each other, and a tape is wound around them to connect and fix both support wires. However, in this method, the support wires bent in the U-shape are bent back. There is a possibility that it may occur, and sufficient tension may not be obtained.
There is also a method of peeling the resin coating of the support wire and press-contacting with a bolt, but in this case, since the support wire is exposed to the outside, there is a possibility of disconnection due to corrosion or the like.

  Further, the support wire fixing portion and the optical fiber core wire connecting portion and the optical fiber core wire connecting portion are not housed in the protective sleeve 7 as shown in FIG. There is also a method of providing them separately and integrating them by wrapping PVC tape. However, in such a method, it is necessary to grip the optical fiber core part at a place where the optical fiber core part is separated from the support line. It is complicated.

  The present invention has been made to eliminate the above-mentioned conventional drawbacks, does not require the use of a special tool, has a surplus length processing function, and has sufficient tension without peeling off the resin coating of the support wire. An object of the present invention is to provide a straight connection part structure of an optical drop cable capable of fixing a support line.

The invention of claim 1 for solving the above-mentioned problem is a straight connection structure of an optical drop cable in which an optical fiber core part and a support line are integrated,
A connecting member having a supporting wire fixing portion for fixing the supporting wires on both sides and an optical fiber connector attaching portion for attaching an optical fiber connector for connecting the optical fiber core wires on both sides is provided. The end of the support wire is wound around two bolts screwed to the support wire fixing portion of the connection member, respectively, and fixed to the connection member, and the tube is covered in the vicinity of the end of each support wire, An optical fiber connector in which optical fiber cores on both sides are connected to each other is rotated around the connection member, and each optical fiber core wire is spirally wound around the outer periphery of the tube. In this state, the optical fiber connector is connected to the connection member. These are attached to the optical fiber connector attachment portion, and all of them are accommodated in a protective sleeve.

The invention of claim 2 is a straight connection structure of an optical drop cable in which an optical fiber core portion and a support wire are integrated,
An optical fiber connector for connecting a plate-like support line fixing part having at least four slits provided at a side edge portion and an optical fiber core wire on both sides to fix the support lines on both sides is attached. A connecting member having an optical fiber connector mounting portion for linking the support wires on both sides into the slits on the respective sides of the support wire fixing portion of the connecting member, and supporting wires on both sides. An optical fiber connector in which the terminal portion is attached to the support wire on the other side and fixed to the connection member, the tube is covered in the vicinity of the end portion of each support wire, and the optical fiber core wires on both sides are connected to each other. Each optical fiber core wire is spirally wound around the outer periphery of the tube by turning around the connection member, and in this state, the optical fiber connector is attached to the optical fiber connector attachment portion of the connection member, and these are all in the protective sleeve. Accommodated straight connector part structure of an optical drop cable, characterized in that the.

According to a third aspect of the present invention, in the straight line connecting portion structure of the optical drop cable according to the second aspect, a hole is provided in the support wire fixing portion instead of the slit.
A fourth aspect is characterized in that the tube according to the first, second or third aspect is a spiral tube.

According to the first aspect of the present invention, no special tool such as a crimping tool is required in the straight connection operation of the optical drop cable. Therefore, the connection work is simplified.
Further, since the optical fiber is spirally wound around the outer periphery of the tube, this spirally wound portion becomes the extra length storage portion. That is, the extra length processing function is ensured.
Since the support wire is fixed by being wound around a bolt screwed to the connecting member and press-fitting (bolt tightening), sufficient tension can be obtained even if the support wire is fixed with a resin coating. Therefore, the work of stripping the resin coating becomes unnecessary, and the workability is improved. Moreover, since the resin coating is not peeled off, there is no fear of corrosion of the support wire.
Further, since the support wire is simply wound around the bolt in a U shape and is not bent at a steep angle, there is no risk of breakage of the support wire.
In addition, since the entire vicinity of the connecting portion is housed in the protective sleeve, it is not necessary to hold the optical fiber core portion at a place where the optical fiber core portion is separated from the support wire, and it is simple.
Since the extra length process is a process of winding an optical fiber around a tube in a spiral shape, the extra length process is not bulky, and a compact linear connection structure is obtained.

According to the invention of claim 2, as in the case of claim 1, a compact linear connection structure that does not require a special tool, ensures a surplus length processing function, and does not need to grip an optical fiber core portion. Can be obtained.
Since the support line is fixed by weaving the support line into the slit of the plate-like support line fixing part, sufficient tension can be obtained even if the support line is fixed in a state of covering the resin. Since it is not necessary to remove the resin coating, workability is improved and there is no fear of corrosion of the support wire, as in the first aspect. In addition, since it is not bent at a steep angle, there is no fear of breakage of the support line. Further, the weaving operation is extremely simple, and the workability is also good in that respect.

  Hereinafter, a straight connection structure of an optical drop cable embodying the present invention will be described with reference to the drawings.

FIG. 1 shows one embodiment of a straight connection portion structure 11 of an optical drop cable according to an embodiment of the invention of claim 1, wherein (a) is a plan view of a principal part, and (b) is a side view of a principal part. It is. As shown in FIG. 11, the optical drop cable 12 used in the embodiment has a tensile strength material 14 disposed on both sides of a two-core optical fiber ribbon 13 and a resin coating (sheath) 15a such as polyethylene or polyvinyl chloride. The optical fiber core wire portion 16 subjected to the above and the support wire 17 obtained by applying the resin coating 15b to the steel wire 17a are integrally connected via the constricted portion 15c. Further, the resin coating 15a of the optical fiber core portion 16 is provided with a notch 15d, and the optical fiber ribbon 13 can be easily taken out by tearing from the notch 15d.

2 is an enlarged view of the main part of FIG. 1 (a), and FIG. 3 is a bottom view of the main part of FIG. 4A is a cross-sectional view taken along the line AA of the main part of FIG. 2, and FIG. 4B is an enlarged cross-sectional view showing only the mechanical splice (optical fiber connector) in FIG. FIG. 5 is an enlarged view of the main part of FIG.
In these drawings, reference numeral 20 denotes a connecting member. As shown in FIGS. 3, 4 (b), etc., the connecting member 20 includes support wire fixing portions 23 in which two bolts 24 are screwed, and the support wires 17 on both sides are respectively connected to the bolts 24. It is fixed to the connecting member 20 by winding and tightening. The support wire 17 is covered with a spiral tube 21. A spiral tube is a flexible part made of plastic such as polyethylene, nylon, or fluororesin, for example, a spiral band formed by extrusion molding, and is a member that can be wound around a linear material or the like and covered thereon.

Moreover, the connection member 20 is provided with the mechanical splice attachment part (optical fiber connector attachment part) 25 which provided the holding | suppressing part 25a, as shown also in FIG. 2, FIG. The two optical fibers 13a respectively taken out from the optical fiber core portions 16 of the optical drop cables 12 on both sides are connected by the mechanical splice 22, and after the connection, the portion of the mechanical splice 22 is rotated around the connection member 20. The optical fiber 13 a is spirally wound around the outer periphery of the spiral tube 21, and the mechanical splice 22 is attached to the mechanical splice attachment portion 25 of the connecting member 20 in this state. Thus, the extra length of the optical fiber 13a is ensured by the optical fiber 13a being spirally wound around the outer periphery of the spiral tube 21. The structure of the mechanical splice 22 used in the present invention will be described next. FIG. 4B schematically shows a cross section.

The mechanical splice (optical fiber connector) used in the present invention will be described. The connection of the optical fiber is roughly divided into a method of melting the optical fiber and a method of mechanically positioning the optical fiber by a fixing member and mechanical splice is a general term for the latter method. Here, as a mechanical splice suitably used in the present invention, for example, Japanese Patent Application No. 7-313247 (optical fiber connector) can be cited. Here, as shown in FIGS. 12 to 14, the mechanical splice 22 includes a base 61, a presser lid 62, and a base 61 and a presser lid 62 that are clamped to the optical fiber fixing member. It is comprised with the C-type spring 63 as a clamp means which provides force. And, between the base 61 and the holding lid 62, a positioning groove 64 by a precision V-groove for aligning and positioning the optical fiber cores on both sides is formed on any one of the fixing members 61 and 62, and An optical fiber sandwiched between the fixing members 61 and 62 is mechanically and optically positioned and connected. The presser lid 62 is divided into three parts, a central part 62a that presses and fixes the optical fiber connection part, and a side part 62b that presses the optical fiber covering part on both sides thereof, and these parts are combined. As a whole, it is a single member. It is well known that the reason for the division into three is that the outer diameter of each part of the optical fiber is different and the pressing force required for each part is different. On the other hand, on the side surface of the mechanical splice, four opening grooves 65 are formed in a portion facing the boundary line between the base 61 and the pressing lid 62. The opening groove 65 is used to press-fit the wedge-shaped opening member against the clamping force when the optical fiber is inserted, and is distributed in each part of the mechanical splice body. An optimum opening / closing amount necessary for alignment positioning can be realized.
Note that the three-divided structure is an example, and depending on the required specifications, a single lid can be adopted, and the number of opening grooves can also be other than four. Furthermore, there are various other types of mechanical splices other than the method of sandwiching between two upper and lower fixing members, but the present invention is in that a mechanical splice is used for connecting a drop cable. There is no intention to exclude the use of splices.

These are all accommodated in a protective sleeve 28, and end caps 29 are put on both ends of the protective sleeve 28. A taping process is performed between the protective sleeve 28 and the end face cap 29 and at the boundary between the end face cap 29 and the optical drop cable 12. Taping processing units are indicated by 31 and 32.

A procedure for obtaining the straight connection structure 11 will be described. The end face cap 29 and the protective sleeve 28 are passed through one optical drop cable 12 of the optical drop cables 12 on both sides to be connected, and the opposite end face cap 29 is passed through the other optical drop cable 12. In each optical drop cable 12, a predetermined length portion of the support wire 17 and the optical fiber core wire portion 16 is torn and separated by a constricted portion 15c.
Next, the support wires 17 on both sides are wound around the bolts 24 of the support wire fixing portion 23 of the connection member 20 as they are (with the resin coating 15 b covered), and are fastened to fix the connection wires to the connection member 20. Thereafter, the spiral tube 21 is wrapped around the end portion of the support wire 17 and covered. The spiral tube 21 is preferably covered until it substantially contacts the connecting member 20. The spiral tube 21 may be covered with the support line 17 in advance. A simple tube may be used instead of the spiral tube 21. However, in the case of a simple tube, the support wire 17 is passed through the support wire 17 in advance before fixing the support wire 17 to the connecting member 20.

The optical fiber ribbons 13 are respectively taken out from the optical fiber core portions 16 of the optical drop cables 12 on both sides, and the optical fibers 13a on both sides are connected by a mechanical splice 22. Description of the connection work by the mechanical splice 22 is omitted. Thereafter, the portion of the mechanical splice 22 is turned around the connecting member 20, and the optical fiber 13 a is spirally wound around the outer periphery of the spiral tube 21 as shown in FIG. 2, and in this state, the mechanical splice 22 is attached to the connecting member 20. Install by pushing into the mechanical splice mounting part 25. In FIG. 2, the spiral winding pitch of the optical fiber 13a is shown exaggeratedly short, but the mode of spiral winding is arbitrary within the range of the allowable bending radius of the optical fiber.
Next, the protective sleeve 28 is slid to cover the entire vicinity of the connection portion, the end caps 29 are slid on both ends of the protective sleeve 28 to cover the ends of the protective sleeve 28, and then the protective sleeve 28 and the end cap 29 are connected. A taping process such as winding a sealing tape and winding a polyvinyl chloride (PVC) tape thereon is performed between the end cap 29 and the optical drop cable 12. As described above, the straight connection of the optical drop cables 12 on both sides is performed.

In the above-described straight connection operation of the optical drop cable 12, unlike the conventional structure shown in FIG. 15, no special tool such as a crimping tool is required.
Further, since the optical fiber 13a is spirally wound around the outer periphery of the spiral tube 21, the spirally wound portion becomes an extra length storage portion, and can be easily reconnected even if the optical fiber connection fails. In that case, the number of spiral windings of the optical fiber 13a may be reduced.
Since the support line 17 is fixed by being wound around the bolt 24 of the connecting member 20 and press-contacting (bolt tightening), the support line 17 can obtain a sufficient tension even when it is covered with the resin coating 15b.
Further, since the support wire 17 and the optical fiber core portion 16 are accommodated in the protective sleeve 28, it is necessary to grip the optical fiber core portion at a location where the optical fiber core portion is separated from the support wire. It does not become and is convenient. Moreover, a compact connection part structure is obtained without being bulky.

FIG. 6 shows one embodiment of a straight connection part structure 41 of an optical drop cable according to an embodiment of the invention of claim 2, wherein (a) is a plan view of a principal part, and (b) is a side view of a principal part. It is. The optical drop cable 12 is the same as that of the first embodiment.

7 is an enlarged view of the main part of FIG. 6 (a), FIG. 8 (b) is a cross-sectional view taken along the line BB of the main part of FIG. 7, and (b) is a state in which the support line is knitted into the support line fixing part. FIG. 9 is a schematic explanatory view, and FIG. 9 is an enlarged view of a main part of FIG.
The second embodiment is different from the first embodiment only in the connection member 50, and the other portions are the same. Therefore, the same portions are denoted by the same reference numerals and the description thereof is omitted. As shown in FIGS. 7 to 9, the connecting member 50 has a plate-like support line fixing portion 53 provided with four slits 51 at intervals on the side edge portion. Mechanical splice attachment portions 55 are provided on both sides. As shown in FIG. 9, the slit 51 of the embodiment has an inverted T shape in which the rear end portion is widened to the left and right (left and right in FIG. 9) in order to prevent lifting (in FIG. 8 (b)). The slit 51 is not represented in an inverted T shape). The mechanical splice mounting portion 55 is basically the same mounting method as that of the first embodiment, but includes a pressing portion 55a facing inward in FIG.
As schematically shown in FIG. 8B, the ends of the support wires 17 on both sides are knitted into the two slits 51 on each side while covering the resin coating 15b (the two slits 51 are S-shaped or inverted. The support wire 17 is fixed to the connecting member 50 by attaching the terminal portion of each support wire 17 to the other support wire 17 and binding them with a binding member 56 such as an insulation lock tie. ing.

According to the fixing of the support wire 17 by the connection member 50, the support wire 17 is knitted into the slit 51 of the support wire fixing portion 53. Therefore, the support wire 17 is knitted as it is without peeling off the resin coating 17b. 50 can be fixed. The weaving operation is very simple.

  In addition, sufficient tension | tensile_strength can be ensured if the slit 51 provided in the support wire fixing | fixed part 53 is at least 2 or more on one side.

  As in the connection member 50 ′ shown in FIG. 10, a hole 51 ′ may be provided in the plate-like support line fixing portion 53 ′ instead of the slit 51 of the support line fixing portion 53 of the second embodiment. In this case, the support line 17 is knitted through the two holes 51 'alternately from opposite directions.

BRIEF DESCRIPTION OF THE DRAWINGS The straight connection part structure of the optical drop cable of Example 1 of this invention is shown, (A) is a principal part notch top view, (B) It is a principal part notch side view. It is a principal part enlarged view of FIG. It is a bottom view about the principal part of FIG. (A) is AA sectional drawing about the principal part of FIG. 2, (b) is an expanded sectional view which showed only the mechanical splice in (a). It is a principal part enlarged view of FIG. The straight connection part structure of the optical drop cable of Example 2 of this invention is shown, (A) is a principal part notch top view, (B) It is a principal part notch side view. It is a principal part enlarged view of FIG. (A) is BB sectional drawing about the principal part of FIG. 7, (b) is explanatory drawing which illustrates typically the state by which the support line was knitted by the support line fixing | fixed part. It is a principal part enlarged view of FIG. FIG. 9 shows Embodiment 3 of the present invention and corresponds to FIG. It is sectional drawing of the optical drop cable used in the Example. DESCRIPTION OF EXEMPLARY EMBODIMENTS Preferred mechanical splices (optical fiber connectors) used in the present invention will be described, wherein (a) is a front view of the mechanical splice and (b) is a plan view. It is a longitudinal cross-sectional view of the mechanical splice of FIG. It is an enlarged view of the vicinity of the positioning groove of the mechanical splice of FIG. An example of the linear connection part structure of the conventional optical drop cable is shown, (A) is a perspective view explaining an internal structure, (B) is a side view explaining the point which covers a protection sleeve.

Explanation of symbols

12 optical drop cable 13 optical fiber tape core wire 13a optical fiber 14 tensile strength material 15a, 15b resin coating 15c constricted portion 15d notch 16 optical fiber core wire portion 17 support wire 17a steel wire 20, 50, 50 'connecting member 21 spiral tube 22 Mechanical splice (optical fiber connector)
23, 53, 53 ′ Support wire fixing part 24 Bolt 25, 55 Mechanical splice attachment part (optical fiber connector attachment part)
25a, 55a Holding part 28 Protective sleeve 29 End face cap 31, 32 Taping processing part

Claims (4)

An optical drop cable linear connection structure in which an optical fiber core portion and a support wire are integrated,
A connection member having a support line fixing portion for fixing the support wires on both sides and an optical fiber connector attachment portion for attaching an optical fiber connector for connecting the optical fiber core wires on both sides;
The support wires on both sides are fixed to the connection member by winding and tightening each of the two bolts in which the end portions of the support wires are screwed into the support wire fixing portion of the connection member,
Put a tube near the end of each support wire,
An optical fiber connector in which optical fiber cores on both sides are connected to each other is rotated around the connecting member, and each optical fiber core is spirally wound around the outer periphery of the tube,
In that state, attach the optical fiber connector to the optical fiber connector mounting portion of the connection member,
An optical drop cable linear connection structure characterized in that the entirety is housed in a protective sleeve. An optical drop cable linear connection structure in which an optical fiber core portion and a support wire are integrated,
An optical fiber connector for connecting a plate-like support line fixing part having at least four slits provided at a side edge portion and an optical fiber core wire on both sides to fix the support lines on both sides is attached. A connecting member having an optical fiber connector mounting portion for
By braiding the support wires on both sides, knitting the ends of the support wires into the slits on the respective sides of the support wire fixing portion of the connecting member and binding the end portions of the support wires together with the other support wires, Fixed to the connecting member,
Put a tube near the end of each support wire,
An optical fiber connector in which optical fiber cores on both sides are connected to each other is rotated around the connection member, and each optical fiber core wire is spirally wound around the outer periphery of the tube. In this state, the optical fiber connector is connected to the connection member. Attach to the optical fiber connector mounting part of
An optical drop cable linear connection structure characterized in that the entirety is housed in a protective sleeve.   The straight connection part structure of the optical drop cable according to claim 2, wherein a hole is provided in the support line fixing part instead of the slit.   4. The straight connection structure for an optical drop cable according to claim 1, wherein the tube is a spiral tube.

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