JPH0650007U - Fiber optic cable - Google Patents

Abstract

(57) [Abstract] [Purpose] Mainly used for indoor wiring, drop-out line, small number of subscriber lines, etc., mainly about 4 to 8 cores, easy to manufacture, inexpensive, thin and light, high mechanical strength Provided is an optical fiber cable which is easy to install, easy to expose, and can be stapled. [Structure] The cross-sectional shape of the slot 32 is made into a flat barrel shape or an oval shape, a tension member 36 is provided at an eccentric position along its major axis, and a groove 38 is provided at the opposite end, and an optical fiber core wire 40 is provided therein. To store. Since the tension member is in the eccentric position and the optical fiber is not arranged around it, a thick tension member can be used.
Therefore, the mechanical strength is high even if the cable is thin. If the diameter b of the tension member is made larger than the lateral width a of the groove, the tension member guards when the staple is stopped, and no force acts on the optical fiber in the groove.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical fiber cable of about 4 to 8 cores, which is mainly used for indoor wiring, drop lines, and subscriber lines of optical fibers in optical communication lines.

[0002]

[Problems to be solved by conventional techniques and devices]

 The properties required for optical cables such as the above-mentioned indoor wiring, drop lines and small-core subscriber lines are easy to manufacture, inexpensive, thin and light, high mechanical strength, easy to lay, and easy to find , Can be stopped with a staple, and so on.

However, an optical cable having such a property has not been announced so far. Fig. 3 shows an example of a conventionally announced 8-core cable. Reference numeral 12 is a tension member, 14 is a spacer, 16 is a groove, and 18 is an optical fiber core wire. 20 is a presser winding, and 22 is a sheath.

This structure is an application of the structure of a multi-fiber optical fiber cable. The tension member 12 is at the center of the spacer 14, and the optical fiber core wire 18 is arranged around the spacer 14. Therefore, the diameter of the tension member 12 cannot be made too large with respect to the outer diameter of the cable, and it is difficult to increase the mechanical strength of the cable. Further, since the groove 16 needs to be formed in a spiral shape, it is difficult and expensive to manufacture a cable.

FIG. 4 also shows another example of the conventionally announced 8-core cable. The optical fiber core wire 18 and the interposition core 24 are twisted together and assembled around the tension member 12, and a buffer layer 26, a presser winding 20, and a sheath 22 are provided on it.

This is also made of a conventional multi-core (for example, 40 core or 100 core) cable structure. Therefore, the same point as above becomes a problem. Further, when the staple is stopped, a force is applied to the optical fiber, which easily causes microbend and bending loss.

[0007]

[Means for Solving the Problems]

 Like the optical fiber cable 30 of FIG. 1, the cross-sectional shape of the slot 32 is a flat barrel shape or an oval shape. A tension member 36 is provided at an eccentric position along the major axis 34. A groove 38 is provided at an end of the long diameter 34 opposite to the tension member 36, and an optical fiber core wire 40 is housed in the groove 38. A sheath 44 is provided on the outside.

The slot 32 is made of polyolefin resin such as HDPE or LDPE. The cross-sectional shape is, for example, a flat barrel shape. The flat barrel shape is a shape in which a circle is cut along both ends of a diameter along a straight line orthogonal to the diameter, and the outer bow is removed from the straight line to make it flat. The tension member 36 is made of a material having high tensile strength, such as steel wire or FRP. The groove 38 may be straight and need not be helical. The width a of the groove 38 is made smaller than the diameter b of the tension member 36. In the groove 38, for example, a tape-shaped optical fiber core wire 40 having about 4 to 8 cores is loosely housed. A presser roll 42 (water-absorbing tape, mylar tape, etc.) is applied thereon. The sheath 44 is made of PE, PVC, or the like.

FIG. 2 shows a state in which the optical fiber cable 30 is fixed to the structure 46 by the staple 48. Since the cross-sectional shape of the optical fiber cable 30 itself is a flat barrel shape, stability is good. Further, since the diameter b of the tension member 36 is greater than the width a of the groove 38, the force when driving the step 48 is guarded by the tension member 36 and does not reach the tape core wire 40 in the groove 38.

[0010]

[Function and effect of the device]

 (1) Since the tension member is in the eccentric position and the optical fiber is not arranged around it, a thick tension member can be used. Therefore, even if the cable is thin, it has high mechanical strength. To put it the other way around, it is possible to make the product thinner and lighter by pressing down the dimensions and weight for the mechanical properties. (2) If the diameter b of the tension member is increased with respect to the lateral width a of the groove as described above, the tension member guards and prevents the optical fiber in the groove from being exerted when the staple is stopped. prevent.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of this invention.

FIG. 2 is an explanatory view of a usage state of the optical cable of the present invention.

FIG. 3 is an explanatory diagram of an example of a conventional technique.

FIG. 4 is an explanatory diagram of another example of the conventional technique.

[Explanation of symbols]

 12, 36 Tension member 14, 38 Spacer 16 Groove 18, 40 Optical fiber core wire 20, 42 Presser winding 22, 44 Sheath 24 Interposer core 26 Buffer layer 30 Optical cable 32 Slot 34 Long diameter 46 Indoor structure 48 Staple

Claims (1)

[Scope of utility model registration request] 1. A tension member is provided at an eccentric position along a major axis of a slot having a flat barrel shape or an oval cross section,
An optical fiber cable, wherein a groove is provided at an end of the long diameter opposite to the tension member, an optical fiber core wire is housed in the groove, and a sheath is provided outside thereof.