JP2001264602A - Method for removing coating cable and intermediate part of cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the easy removal of the coating in the intermediate part of a cable provided with the plastic coating on the outside of a cable core without damaging the cable core. SOLUTION: The inside surface of the plastic coating 2 of the cable having the plastic coating 2 on the outside of the cable core 1 is provided with recessed grooves 2a along the longitudinal direction of the cable and lip cords 3 are inserted and arranged within the recessed grooves 2a. The outer surface of the plastic coating in the segments into which the rip cords 3 is inserted is provided with position displays 2b, such as square projecting lines, indicating the positions of the lip cords.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable containing a rip cord and a method for removing a coating on an intermediate portion of the cable.

[0002]

2. Description of the Related Art When removing a plastic coating from a cable having a plastic coating on a cable core, the plastic coating is first sliced with a knife or the like when removing the plastic coating. Next, use a knife or the like to extend one to two
The plastic coating is peeled off by making a cut in the book and opening the plastic coating from the cut. However, in order to prevent the inner cable core from being damaged in the cutting of the plastic coating and the formation of the vertical cuts, extreme care is required, and skill in the operation is required.

In order to prevent the cable core from being damaged, a special tool for cutting a ring and forming a vertical cut is prepared instead of a knife. When the outer diameter changes, the types of tools that need to be prepared increase, and the mechanism of the tools becomes complicated.

Further, in order to facilitate the operation of removing the plastic coating, a rip cord (tear string) made of tensile strength fiber or the like is arranged inside the plastic coating along the longitudinal direction of the cable core, and the lip cord is used by using it. A method of removing a plastic coating is also used. In this case, by pulling the end of the rip cord taken out at the end of the cable toward the side opposite to the end of the cable, the plastic coating is torn in the longitudinal direction by the rip cord, and the plastic coating of the torn length is applied. Cut off.

[0005]

By the way, in the above-mentioned cable containing a rip cord, since the end of the lip cord can be easily taken out at the end of the cable, the tearing of the plastic coating can be easily started. However, it is not easy to take out the end of the lip cord at the middle of the cable. Because the lip cord is only inserted between the cable core and the plastic coating, its position is not known from the surface of the plastic coating. Therefore, when the end of the rip cord is to be forcibly taken out in the middle part of the cable, it is necessary to cut the plastic cover with a knife or the like to find the lip cord, and take out the end. Therefore, also in this case, careful attention and skill are required so as not to damage the cable core in the round cutting operation of the plastic coating.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the cable according to the prior art, and to provide a cable and a coating removing method which can easily remove the coating even in the middle of the cable.

[0007]

SUMMARY OF THE INVENTION A cable according to the present invention is a cable in which a plastic coating is provided on an outer side of a cable core, and a concave groove is provided on an inner surface of the plastic coating along a longitudinal direction of the cable. A lip cord is inserted into the concave groove, and a position indicator indicating a position of the lip cord is provided on an outer surface of the plastic coating at a portion where the lip cord is inserted.

In addition, the position of the lip cord is fixed by directly bonding the lip cord to the inner surface of the plastic coating without providing a concave groove on the inner surface of the plastic coating,
A position indicator indicating the position of the lip cord may be provided on an outer surface of the plastic coating at a portion where the lip cord is adhered and fixed.

The lip cord-containing cable of the present invention can be applied to a self-supporting cable as follows. The cable consists of a support wire and a meandering cable core and a plastic coating provided on each of them,
The plastic coating on the support wire side and the plastic coating on the cable core side are intermittently connected in the longitudinal direction of the cable with plastic forming a neck. A tensile strength member is incorporated in the longitudinal direction in each of the coating resin closest to the support line and the farthest side of the plastic coating on the cable core side.

[0010] Further, a concave groove is provided on the inner surface of the plastic coating along the longitudinal direction of the cable at two locations circumferentially separated by 90 degrees from the position where the strength member is built in the plastic coating. Either insert the lip cord into the inside or adhesively fix the lip cord to the inner surface of the plastic coating. The cable is provided with a position indication indicating the position of the lip cord on the outer surface of the plastic coating at the portion where the lip cord is inserted or adhered and fixed. The self-supporting cable can easily remove the coating without damaging the cable core in the operation of removing the coating of the intermediate portion, and can cope with wind pressure as an overhead cable. Furthermore, since the cable core can have extra length due to the meandering of the cable core,
This cable is suitable as an optical fiber cable for subscriber wiring.

[0011] Further, after using a cable having a position indication indicating the position of the lip cord on the outer surface of the plastic coating, the cable is extended, and the position indication is displayed at an arbitrary position in the middle of the cable. Then, a part of the plastic coating is scraped off with a knife or the like to expose a part of the lip cord in a longitudinal direction. The plastic coating is then torn in the longitudinal direction of the cable by pulling the lip cord, and the plastic coating of the torn length is cut away to expose the cable core. As a result, the coating can be easily removed even at the middle part of the cable, and the intermediate branching operation becomes easy.

[0012]

1 and 2 are views showing an embodiment of a cable according to the present invention. FIG. 1 (A) and FIG. 2 (A) are cross-sectional views and FIG. 1 (B). FIG. 2B is a perspective view. 1 and 2, 1 is a cable core, 2 is a plastic coating, 2a is a concave groove, 2b, 2
b 'is a position display, and 3 is a lip code.

The cable core 1 is an aggregate of optical fiber core wires, insulated wires for communication, insulated wires for power, insulated wires for control, and the like, and the type of the wire contained therein is not particularly limited. . The plastic coating 2 has a thickness of 1.3 mm to 2.0 mm outside the cable core 1 by extruding a plastic such as polyethylene or vinyl chloride resin.
It is provided as a substantially cylindrical molded body of about mm.

The concave groove 2a is provided on the inner surface of the plastic coating 2 so as to extend in the longitudinal direction of the cable. Inside the concave groove 2a, a lip cord made of aramid fiber cord, polyester fiber cord, metal wire or the like is provided. 3 is inserted. In addition, the concave groove 2a is a substantially circular cavity having a cross section that is partially open in the circumferential direction, and has an inner diameter of 0.8 mm to 0.8 mm.
It is about 1.0 mm. The lip cord 3 inserted into the concave groove 2a is made of a fiber string of about 2,000 dtex to 5,000 dtex, so that the plastic coating 2 can be torn in the longitudinal direction.

The lip cord 3 does not need to completely enter the concave groove 2a, and a part of the lip cord 3 may protrude from the opening of the concave groove 2a.
Further, by making the width of the opening smaller than the thickness of the lip cord, it is possible to prevent the lip cord from jumping out of the concave groove.

Then, on the outer surface of the plastic coating 2 at the position where the lip cord 3 is inserted, a position indication 2b or 2
b 'is provided. A concave groove 2a and a position indicator 2b,
2b 'is formed by designing the shape of the nipple and the die when extruding plastic according to those shapes. The position display 2b in the case of FIG. 1 is a square ridge, and the position display 2b ′ in FIG. 2 is a round ridge. The lip cord 3 is supplied in parallel with the cable core 1 at the same time as the extrusion molding of the plastic coating 2 and inserted into the concave groove 2a.

As shown in FIG. 1 or FIG. 2, the position indications 2b and 2b 'are formed as square or round ridges provided in the longitudinal direction of the surface of the plastic coating so that the length of the cable can be reduced. At any position in the direction, the circumferential position where the lip cord in the plastic coating is inserted can be known. It should be noted that, from the viewpoint of visibility and tactility when confirming the position display, it is easier and better to recognize the position of the square ridge than the round ridge. FIG. 3 (A) (B)
Is a perspective view showing another example of the position display, respectively,
FIG. 3A shows an example in which the position display 2c is formed by a concave stripe.
FIG. 3B is an example in which the position display 2d is formed by dashed line printing.

Since the position indication provided on the outer surface of the plastic coating only needs to indicate the position of the inner lip cord, it extends in the longitudinal direction along the outer surface of the plastic coating where the lip code is located, and is visually inspected. Or, as long as it can be confirmed by tactile sensation, the form of position indication is not particularly limited, whether it is printed, convex or concave.

FIGS. 1 to 3 show the case where the number of the concave grooves 2a, the lip cords 3, and the position indications 2b, 2b ', 2c and 2d is two, respectively. More than a book is fine. In addition, if two lip cords are inserted at positions 180 degrees apart in the circumferential direction of the plastic coating, the plastic coating can be almost evenly divided into two by the lip cord, so even in the case of a relatively hard plastic coating, It can be easily removed from the cable core from within the plastic sheath.

FIGS. 4 and 5 are views showing examples of the form of the concave groove. FIGS. 4A and 4B are cross-sectional views of a plastic-coated portion having a concave groove having a continuous opening. 5 (A), 5 (B), and 5 (C) show X of a plastic-coated portion having a concave groove having a discontinuous opening.
3 shows a position cross-sectional view, a side view, and a Y position cross-sectional view. 2e,
2f is an opening and 2g is a closing part.

In the example shown in FIG. 4, the opening 2e of the concave groove 2a is continuously open in the longitudinal direction. In contrast, FIG.
In the example, the opening 2f of the concave groove 2a is discontinuous in the longitudinal direction, and the opening 2f and the closing portion 2g are alternately formed in the longitudinal direction, and are perforated. Note that the opening 2f and the closing portion 2g do not have to be the same length as each other, and the respective lengths in the longitudinal direction need not be constant.

The lip cord 3 is inserted into the concave groove 2a.
In the normal state, the lip cord 3 is
It does not jump out of a. However, when the cable is bent at the time of laying or the like, the lip cord 3 may jump out of the concave groove 2a and fall into the gap between the cable core 1 and the plastic coating 2. On the contrary,
If the opening of the concave groove 2a is discontinuous and the closing part 2g is partially formed, the closing part 2g functions as a lid, and there is no fear that the lip cord 3 jumps out of the concave groove 2a.

When the concave groove 2a and the lip cord are arranged at two places in the cross section of the plastic coating, in the example of FIG. 4, when the plastic coating 2 is torn by the lip cord 3, the plastic coating 2 is divided into two parts. It is completely split and the inner cable core protrudes from the plastic sheath 2. At this time, if care is not taken, there is a possibility that an accident may occur in which the protruding cable core is caught and damaged by another connecting member or the like.

On the other hand, in the example of FIG. 5, even when the plastic coating 2 is torn by the lip cord 3, the plastic coating 2 is not completely divided into two parts, but is coated with the coating resin forming the closing portion 2g. To be connected,
The cable core does not pop out suddenly. In addition, the resin thickness of the closing portion 2g is extremely thin and can be easily divided into two by pulling the plastic coating 2. Therefore, by gradually performing the division at the closing portion 2g in the longitudinal direction, the cable core can be safely plasticized. It can be removed from within the coating.
The structure in which the opening of the concave groove 2a shown in FIG. 5 is discontinuous is manufactured by intermittently repeating closing and opening of the resin flow path between the nipple and the die when extruding the plastic coating. I can do it.

FIG. 6 is a cross-sectional view showing another embodiment of the cable of the present invention. This cable has a lip cord 3 adhered and fixed to the inner surface of a plastic coating 2 with an adhesive 4 without providing a cable corresponding to the concave groove of the cable shown in FIG. The position display 2b provided on the outer surface of the plastic coating 2 is the same as that in FIG.
The bonding and fixing of the lip cord 3 to the inner surface of the plastic coating 2 by the adhesive 4 is performed by supplying a lip cord coated with an adhesive when the plastic coating 2 is extruded and pressing it against the inner surface of the plastic coating. Can be done.

FIG. 7 shows an example in which the present invention is applied to a self-supporting cable for an optical fiber.
7 is a perspective view, FIG. 7B is a cross-sectional view at the X position, and FIG. 7C is a cross-sectional view at the Y position. In FIG. 7, 5 is a support line, 6
Is a cable core, 6a is a tape-shaped optical fiber core, 6b
Is a protective fiber cord, 7 is a plastic coating, 7a is a plastic coating on a support line side, 7b is a plastic coating on a cable core side, 7c is a neck, 7d is a concave groove, 7e is a position display, 7f is a window, and 8 is tensile strength. The body, 9 is a lip cord.

In the cable shown in FIG. 7, the cable core 6 is formed by laminating a plurality of tape-shaped optical fiber cores 6a and protecting them along a protective fiber cord 6b such as a polypropylene cord. Although covered with the plastic coating 7b on the cable core side, the cable core 6 may be formed of an aggregate of insulated wires for communication or the like. Also,
In the cable of FIG. 1, the cable core 6 is provided with an extra length with respect to the support wire 5, so that the cable core 6 is meanderingly connected to the support wire 5 at the neck 7 c intermittently in the longitudinal direction. are doing. The portion without the neck 7c in the longitudinal direction is a window 7f, which serves to reduce stress due to wind pressure or the like when laid aerial. Note that the support wire 5 is made of a galvanized steel strand, FRP, or the like.

Further, two places, a side closest to the support line of the plastic coating 7b on the cable core side and a side farthest from the support line,
A strength member 8 such as a steel wire is embedded in the coating resin in the longitudinal direction. This strength member 8 holds the plastic coating 7b so as not to shrink in the longitudinal direction,
It serves to keep the extra length of the cable core at a predetermined value. Moreover, the plastic coating 7b is formed from the two tensile members 8.
At two locations 90 degrees apart from each other in the circumferential direction, a concave groove 7d is provided on the inner surface of the plastic coating 7b.
The lip cord 9 is inserted and arranged in d.

The concave groove 7d may be provided with an opening and a closing part as illustrated in FIG. 5, so that the lip cord 9 does not protrude from the concave groove 7d. A position indicator 7e indicating the position of the lip cord is provided on the outer surface of the plastic covering 7b on which the lip cord 9 is arranged. As the type of the position display 7e, various examples shown in FIGS. 1 to 3 can be adopted. Further, the lip cord can be arranged by bonding and fixing the lip cord 9 to the inner surface of the plastic coating 7b without depending on the formation of the concave groove and the insertion of the lip cord into the concave groove. The self-supporting type cable shown in FIG. 7 described above is extremely useful because it is suitable for work such as intermediate branching as a subscriber wiring cable containing an optical fiber.

In all of the cables described above with reference to FIGS. 1 to 7, the lip cords are arranged at predetermined positions in the longitudinal direction along the inner surface of the plastic coating provided outside the cable core. This is a cable provided with a position indicator indicating the position of the lip cord on the outer surface of the plastic coating at the position shown. Therefore, at an arbitrary position in the middle of the cable, if the plastic coating is scraped with a knife or the like at the display position as a guide, a portion of the lip cord in the longitudinal direction can be exposed and pulled out without damaging the cable core. .

Then, the plastic coating can be torn in the longitudinal direction by pulling the lip cord drawn from the shaved portion of the plastic coating in the longitudinal direction of the cable. If one or two tears can be formed in the plastic coating, the cable core is removed therefrom, and the plastic coating of the portion from which the cable core has been removed is cut off. In this way, at an arbitrary position in the middle portion in the longitudinal direction of the cable, a portion where the plastic coating is easily removed and the cable core for the middle branch is exposed can be formed.

When the rip cord is made of a tensile strength fiber string, when the lip cord is pulled out from the shaved portion of the plastic coating, it may happen that only a part of the fiber is drawn out and not all the fiber is drawn out. Therefore, if the tensile strength fiber cord of the rip cord is provided with a coating such as an ultraviolet curable resin, a part of the fiber does not remain in the plastic coating when the rip cord is pulled out, and the lip cord can be completely pulled out. .

[0033]

According to the cable of the present invention, a concave groove is provided on the inner surface of a plastic coating provided outside a cable core, a lip cord is inserted into the concave groove, and a plastic coating corresponding to the insertion position of the lip cord is provided. Since the cable is provided with a position indicator on the outer surface of the cable, even at the middle of the cable, only a part of the plastic coating is scraped off with a knife etc. using the position indicator as a guide, so that the lip cord can be Can be withdrawn. In addition, if the lip cord is pulled to tear the plastic coating, the cable core is taken out from the plastic coating, and the coating is cut off, the coating can be removed without damaging the cable core.

Also, instead of forming a concave groove on the inner surface of the plastic coating and inserting the lip cord therein, the position of the lip cord is fixed by directly bonding the lip cord to the inner surface of the plastic coating. Even in this case, the coating removal operation of the intermediate portion can be performed in the same manner. Also, since the lip cord adhered and fixed does not slide in the longitudinal direction, the lip cord does not slide in the longitudinal direction when the cable is torn, even if the position of the stripping of the cable middle part is close to the end of the cable and the lip cord is short. The lip cord allows the plastic coating to be torn because it is not pulled out.

In a cable in which a lip cord is arranged at a predetermined position inside a plastic coating and a position indicator is provided on the outer surface, the supporting wire and the meandering cable core are coated with a plastic coating, respectively. The plastic coating on the side of the cable and the plastic coating on the side of the cable core can also be applied to a self-supporting cable that is intermittently connected in the longitudinal direction of the cable with a plastic forming a neck. In this case, when tensile strength members are respectively incorporated in the coating resin on the side closest to the support wire and the farthest side of the plastic coating on the cable core side in the longitudinal direction, the shrinkage of the meandering cable core plastic coating is suppressed. In addition, since the extra length of the cable core can be maintained, the optical fiber cable can be optimally formed as a self-supporting optical fiber cable for a subscriber.

[0036] Further, if a high-strength fiber cord coated with a resin is used as the lip cord, when the lip cord is pulled out from the shaved portion of the plastic coating, the fiber of the lip cord partially remains in the plastic coating. And the entire fiber cord of the lip cord can be pulled out completely. Various forms of position indication are possible, but if a rectangular projection is provided in the longitudinal direction of the outer surface of the plastic coating to indicate the position of the lip cord, the position indication is excellent in visibility and tactility. Therefore, it is easy and reliable to confirm the display position, and it is possible to prevent errors in the operation.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of a cable according to the present invention, wherein (A) is a cross-sectional view and (B) is a perspective view.

FIG. 2 is a view showing another embodiment of the cable of the present invention, wherein (A) is a cross-sectional view and (B) is a perspective view.

FIGS. 3A and 3B are perspective views each showing another example of the position display of the cable according to the present invention.

FIG. 4 is a view showing an example of a plastic-coated portion having a concave groove having a continuous opening of a cable according to the present invention, wherein (A) and (B) are a cross-sectional view and a side view.

FIG. 5 is a view showing an example of a plastic-coated portion having a concave groove having a discontinuous opening in a cable according to the present invention, wherein (A), (B) and (C) are cross-sectional views at an X position; It is a side view, a Y position cross-sectional view.

FIG. 6 is a cross-sectional view showing another embodiment of the cable of the present invention.

7A and 7B are diagrams showing an example in which the present invention is applied to a self-supporting cable for an optical fiber, wherein FIG. 7A is a perspective view, and FIG.
Is a cross sectional view at the X position, and (C) is a cross sectional view at the Y position.

[Explanation of symbols]

 1: cable core 2: plastic coating 2a: concave groove 2b: position display (square convex line) 2b ': position display (round convex line) 2c: position display (concave line) 2d: position display (dashed line print) 2e 2f: Opening 2g: Closure 3: Lip cord 4: Adhesive 5: Support wire 6: Cable core 6a: Tape-shaped optical fiber core 6b: Protective fiber cord 7: Plastic coating 7a: Plastic coating on the support wire side 7b: Plastic coating on the cable core side 7c: Neck 7d: Concave groove 7e: Position indication 7f: Window 8: Strength member 9: Rip cord

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02G 1/12 306 H02G 1/12 306 (72) Inventor Yoshiyuki Suetsugu 1 Tayacho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Sumitomo (72) Inventor, Masahiro Eguchi 1 in Tayacho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture, Sumitomo Electric Industries, Ltd. (72) Inventor, Seika Nishioka 1-chome, Shimaya, Konohana-ku, Osaka, Osaka No. 1-3 Sumitomo Electric Industries, Ltd. Osaka Works (72) Inventor Hideyuki Iwata 2-3-1 Otemachi, Chiyoda-ku, Tokyo Inside Nippon Telegraph and Telephone Corporation (72) Inventor Kazuo Hokari Major in Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (8)

[Claims] 1. A cable in which a plastic coating is provided outside a cable core, wherein a concave groove is provided along a longitudinal direction of the cable on an inner surface of the plastic coating, and a lip cord is inserted into the concave groove. A cable, wherein a position indication indicating a position of the lip cord is provided on an outer surface of the plastic covering at a portion where the lip cord is inserted. 2. The support wire and the meandering cable core are each covered with a plastic coating, and the plastic coating on the support wire and the plastic coating on the cable core are intermittently connected in the longitudinal direction of the cable with a plastic forming a neck. In the cable, the strength member is built in the longitudinal direction in each of the coating resin closest to the support line and the farthest side of the plastic core of the cable core, and the strength member of the plastic coating is built in the resin. At two locations 90 degrees circumferentially away from the set position, a concave groove is provided on the inner surface of the plastic coating along the longitudinal direction of the cable, and a lip cord is inserted into the concave groove. A position indicator indicating the position of the lip cord is provided on the outer surface of the plastic coating at the portion where the is inserted. And a cable. 3. The cable according to claim 1, wherein the lip cord is formed by providing a resin coating on a tensile strength fiber. 4. The cable according to claim 1, wherein an opening of the concave groove is discontinuous in a longitudinal direction of the cable. 5. A cable in which a plastic coating is provided outside a cable core, wherein a lip cord is adhesively fixed to an inner surface of the plastic coating along a longitudinal direction of the cable, and the lip cord is adhesively fixed. A cable, characterized in that a position indicator indicating a position of a lip cord is provided on an outer surface of the plastic covering of the portion. 6. The support wire and the meandering cable core are respectively covered with a plastic coating, and the plastic coating on the support wire side and the plastic coating on the cable core are connected to each other with a plastic intermittently forming a neck in the longitudinal direction of the cable. In the cable, the strength member is built in the longitudinal direction in each of the coating resin closest to the support line and the farthest side of the plastic core of the cable core, and the strength member of the plastic coating is built in the resin. A lip cord is adhesively fixed along the longitudinal direction of the cable to the inner surface of the plastic coating at two locations circumferentially separated by 90 degrees from the set position, and the plastic coating is applied to the portion where the lip cord is adhesively fixed. Characterized in that a position indication indicating the position of the lip cord is provided on the outer surface of the cable. . 7. The method according to claim 1, wherein the position indication is a square ridge provided on an outer surface of the plastic covering.
Cable described in section. 8. A plastic coating is provided outside the cable core, a lip cord is disposed along a longitudinal direction of an inner surface of the plastic coating, and an outer surface of the plastic coating at a position where the lip cord is disposed. Using a cable provided with a position indicator indicating the position of the lip cord, after extending the cable, shaving off a part of the plastic coating at the arbitrary position of the middle part of the cable using the position indicator as a guide Exposing a longitudinal portion of the ripcord, then tearing the plastic sheath in the longitudinal direction of the cable by pulling the ripcord, and cutting off the plastic sheath of the torn length to expose the cable core. A method for removing coating on an intermediate portion of a cable.