JPH0444489B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sheath gripping portion for maintaining the sheath strength at a connection portion of a communication cable, particularly an optical fiber cable.

[Conventional technology]

FIG. 5 is a sectional view of an example of a conventional communication cable gripping section of this type. The cable sheath 3 is cut into four parts and peeled off from the cable core 5, and the internal gripping fitting 4 is inserted between the cable sheath 3 and the cable core 5. A grip spacer 2 is further sandwiched around the outer periphery of the cable sheath 3, and an external grip 1 is tightened from the outer periphery with a bolt (not shown) to grip the cable core 5 from above the sheath.

[Problem that the invention seeks to solve]

Conventional communication cable gripping parts of this type are applicable to a wide variety of cable outer diameters, and there are more than 20 types of internal gripping fittings 4 and gripping fitting spacers 2 corresponding to various cable outer diameters. It has also become familiar. In connection with this large variety,
Inevitably, the manufacturing cost of each individual item increases, which hinders the ability to reduce the cost of constructing the gripping part.Also, when forming the gripping part, the complicated work of vertically splitting the cable jacket and inserting the internal gripping metal fittings is required. There is a problem that the process requires too much time.

[Means for solving problems]

The present invention solves the conventional problems and provides an inexpensive communication cable gripping part with a small number of parts, easy to form the gripping part, and high work efficiency. , a metal tape having protrusions on both sides, a protrusion on the outer circumferential surface of each layer wound in multiple layers on the outer circumferential surface of the metal tape, and a protrusion on the innermost layer wound in contact with the metal tape; and the second
a spacer tape made of plastic having grooves that fit with protrusions on the outer peripheral surface of each of the layers, starting from the first layer;
It is characterized by having a structure including a groove that engages with a protrusion on the outermost layer surface of the spacer tape, and a gripping fitting that is tightened by engaging the groove with the protrusion on the outermost layer surface of the spacer tape. There is.

[Effect]

The configuration of the communication cable jacket gripping section of the present invention works as follows.

By winding the metal tape with protrusions directly around the cable sheath, the metal tape has the same effect as the conventional internal grip fittings that are fixed to the cable, eliminating the need for multiple types of internal grip fittings.

By winding multiple layers of spacer tape, which have protrusions and grooves on both sides that fit into each other, around the outer periphery of the metal tape in accordance with the inner diameter of the gripping metal, the spacer tape has the same effect as conventional gripping metal spacers. This eliminates the need for holding metal spacers, which require many different types, and reduces manufacturing costs by using plastic spacer tapes.

The gripping hardware has the same external protection function as conventional external gripping hardware.

By wrapping the protruded metal tape directly around the cable sheath, there is no need to split the cable sheath vertically and insert internal gripping metal fittings, making work easier and more efficient. .

The gripping fitting, spacer tape, metal tape, and cable sheath have a tightening structure in which the projections and grooves fit and engage with each other, so the structure is simpler than conventional gripping parts, and the cable It is possible to secure a gripping force sufficient to withstand tension after installation.

In addition, since there are fewer parts than before,
In addition to reducing manufacturing costs and management costs,
Due to the simple structure and ease of assembly, work time can be particularly reduced and workability improved. Examples will be described below based on the drawings.

〔Example〕

FIGS. 1a and 1b are views showing the structure of an embodiment of the communication cable jacket gripping part of the present invention, FIG. 1a is a cross-sectional structural view, and FIG. 1b is a side view of the structure.

A metal tape 9 having protrusions 91 on both sides is wound in one layer on the jacket of the cable 10. Next, wrap around the outer circumference of the metal tape 9 until it reaches the inner diameter of the gripping fitting 6.
Protrusion 9 of metal tape 9 on the surface in contact with metal tape 9
A plurality of layers of spacer tape 8 are wound, each having a groove 82 that fits into the first layer, and a projection 81 and a groove 82 that fit into each other starting from the second layer. From the outer periphery of the spacer tape 8 that has been wound until it almost reaches the inner diameter of the gripping metal 6, the gripping metal 6, which has a groove 61 on the inner surface that engages with the protrusion 81 on the outermost surface of the spacer tape 8, is placed over the spacer tape 8, and then tightened with the bolt 7. .

With the configuration of this embodiment, the protrusion 91 of the metal tape 9 bites into the outer sheath of the cable 10, the protrusion 91 on the other side of the metal tape 9, the groove 82 of the spacer tape 8, and the protrusion between the wound layers of the spacer tape 8. 8
1 and the groove 82, the protrusion 81 on the outermost surface of the spacer tape 8, and the groove 61 of the gripping metal fitting 6 fit and engage with each other, and the cable 10 can be gripped by engaging with each other.

FIG. 2a is a schematic diagram of the cross-sectional structure of the gripping metal fitting 6, and FIG. 2b is a cross-section of a main part taken along the line AA in FIG. 1a.
7 indicates a bolt.

FIG. 3a shows a plan view of the spacer tape 8, and FIG. 3b shows a cross-sectional structure. 81 is a protrusion, and 82 is a groove that fits and engages with the protrusion 81. The spacer tape 8 may be made of, for example, plastic, so that it has a sufficient function and can be made at low cost.

FIG. 4a shows a plan view of the metal tape 9, FIG. 4b shows a side view, and FIG. 4c shows a cross section. Reference numeral 91 indicates protrusions on both sides. Note that the shape of the protrusion 91 is not particularly limited to this embodiment, and is a shape that bites into the outer sheath of the cable and that fits into the groove 82 of the spacer tape 8.
Any shape that fits can be used.

The working procedure for forming the communication cable jacket gripping portion of the present invention shown in FIGS. 1a and 1b is as follows.

A metal tape 9 is further wrapped around a predetermined position on the outer periphery of the cable 10, that is, at a position on the outer periphery of the outer sheath applied to the outer periphery of a branch point or a connection point of the cable, for example. Next, in order to fill the gap between the cable 10 and the grip 6, spacer tape 8 is wound in multiple layers around the outer periphery of the metal tape 9 until it reaches approximately the inner diameter of the grip 6, with the protrusion 81 fitting into the groove 82. Finally, cover the outer circumference of the outermost layer of the spacer tape 8 with the gripping metal fitting 6 by engaging the groove 61 provided on the inner surface of the gripping metal fitting 6 with the protrusion 81 on the surface of the outermost layer of the spacer tape 8, and tighten with the bolt 7. Attach to form a grip for the cable jacket.

The grip part formed by the above procedure is such that the protrusion 91 on the inner surface of the metal tape 9 bites into the outer sheath of the cable 10 and the metal tape 9 is fixed to the cable 10, and the protrusion 91 on the outer surface of the metal tape 9 and the spacer tape 8, the mutual grooves 82 and protrusions 81 in each layer from the second layer to the outermost layer of the spacer tape, and the protrusions 81 on the outermost layer of the spacer tape 8 and the grooves 61 provided on the inner surface of the gripping metal fitting 6. By fitting, engaging, and interlocking with each other,
The gripping force is sufficient to withstand tension after cable installation.

Note that the protrusions 91 of the metal tape 9 and the grooves 82 on the innermost layer of the spacer tape 8 fit together, and the grooves 82 and protrusions 8 from the second layer to the outermost layer of the spacer tape 8 fit together.
1, and the protrusion 81 on the surface of the outermost layer of the spacer tape 8 and the groove 61 provided on the inner surface of the gripping metal fitting 6.
By selecting a pitch that matches the positional relationship between each groove and protrusion that is sufficient to satisfy the engagement, the protrusion and groove will mesh reliably, and the cable, metal tape, spacer tape, and gripping metal will be protected against tension. No mutual slippage occurs.

Next, an example of a specifically formed gripping portion will be shown.

We made prototype gripping fittings, spacer tape, and metal tape, and conducted a tensile test to evaluate the gripping force. sample,
The method and results are shown below.

Sample Gripping bracket Material: Al, inner diameter 72mmφ Spacer tape Material: Polyethylene, thickness 2mm,

8-layer winding Metal tape Material: stainless steel, thickness: 0.4 mm Cable: Outer diameter: 31 mm φ Method: Grip the cable according to Figure 1 and pull at a speed of 10
Perform a tensile test at mm/min until the cable breaks to determine the maximum gripping force.

result The maximum gripping force was 350Kg.

〔Effect of the invention〕

As explained above, the sheath gripping portion of the communication cable according to the present invention involves winding a metal tape and a spacer tape, each having protrusions and grooves that fit into each other, on the cable sheath, and then engaging the metal tape and the spacer tape with a gripping fitting. Because it has a tightening structure, the number of parts is reduced compared to conventional cable grips, which reduces manufacturing costs and improves workability by simplifying the grip structure. .

[Brief explanation of the drawing]

Figures 1a and b are configuration diagrams of the communication cable jacket gripping part of the present invention, Figures 2a and b are schematic diagrams of the gripping fitting structure,
Figures 3a and b are schematic diagrams of the spacer tape structure;
Figures a, b, and c are schematic diagrams of the metal tape structure, and Figure 5 is a sectional view of a conventional communication cable grip. 1...External gripping metal fitting, 2...Gripping metal fitting spacer, 3...Cable jacket, 4...Internal gripping metal fitting,
5... Cable core, 6... Gripping fitting, 61...
Groove, 7... Bolt, 8... Spacer tape, 81
... Protrusion, 82 ... Groove, 9 ... Metal tape, 91
... protrusion, 10 ... cable.

Claims (1)

[Scope of Claims] 1. A jacket gripping part for protecting a communication cable connection part, comprising: a metal tape having protrusions on both sides, which is wound around the outer circumference of a cable jacket of a communication cable; Each layer wound in multiple layers has a protrusion on the outer circumferential surface, and the innermost layer wound in contact with the metal tape fits with the protrusion of the metal tape, and the outer circumferential surface of each layer from the second layer onwards. a spacer tape made of plastic having a groove that engages with the protrusion of the spacer tape; a groove that engages with the protrusion on the outermost surface of the spacer tape; and the groove engages with the protrusion on the outermost surface of the spacer tape. What is claimed is: 1. An outer covering gripping portion for a communication cable, comprising: a gripping fitting that is tightened by a gripper;