Optical cable

Patent metadata

Field	Value
Publication number	US-12585074-B2
Application number	US-202418816008-A
Country	US
Kind code	B2
Filing date	Aug 27, 2024
Priority date	Jun 24, 2021
Publication date	Mar 24, 2026
Grant date	Mar 24, 2026

Abstract

The present disclosure relates to an optical cable in which an optical fiber bundle with clustered or bundled optical fibers is accommodated in a tubular member and the optical fibers are formed in an excess group length (EGL) by modeling considering bending properties of the optical cable or a lossless bending radius of the optical fibers of the optical fiber bundle, thereby minimizing stress, damage or optical loss of the optical fibers in the optical fiber bundle.

First claim

The invention claimed is:

1 . An optical cable comprising:
a plurality of optical fibers; and a tubular member configured to accommodate therein an optical fiber bundle formed by gathering the plurality of optical fibers, wherein a length of each optical fiber of the plurality of optical fibers of the optical fiber bundle is greater than or equal to a length of the tubular member, and
a ratio (ε) of an excess group length of the optical fibers of the optical fiber bundle to the length of the tubular member of the optical cable satisfies the following formula:

ε
≤

2
⁢
R

2
⁢
R

-
H

-
1

,

wherein R denotes a lossless bending radius of each optical fiber of the plurality of optical fibers, and
H denotes a diameter based on a cross-sectional area of the optical cable with a spiral trajectory of a center point on the optical fiber bundle modeled as having a circular cross-section.

2 . The optical cable of claim 1 , further comprising a jacket configured to cover the tubular member.

3 . The optical cable of claim 1 , wherein, when the optical fiber bundle includes a plurality of types of optical fibers, a lossless bending radius of the plurality of types of optical fibers is largest among lossless bending radii of the plurality of types of optical fibers.

4 . The optical cable of claim 1 , wherein the plurality of optical fibers of the optical fiber bundle comprise at least one rollable optical fiber ribbon.

5 . The optical cable of claim 2 , wherein two or more tubular members are provided.

6 . The optical cable of claim 2 , wherein the tubular member is one of a plurality of tubular members, the optical cable further comprising a central tensile member, an outer circumferential surface of which is surrounded by the plurality of tubular members in contact with the plurality of tubular members.

7 . The optical cable of claim 6 , further comprising a binding member configured to bind the plurality of tubular members,
wherein the binding member is provided between the plurality of tubular members and the jacket.

8 . The optical cable of claim 1 , wherein optical fibers of the plurality of optical fibers comprise at least one of G.652 optical fibers, G.657.A1 optical fibers, G.657.A2 optical fiber, or G.657.B3 optical fibers.

9 . The optical cable of claim 8 , wherein R is 40 millimeters (mm) when a type of the optical cable is G.652, is 30 mm when the type of the optical cable is G.657.A1, is 25 mm when the type of the optical cable is G.657.A2, and is 20 mm when the type of the optical cable is G.657.B3.

10 . An optical cable comprising:
a central tensile member; a plurality of optical fiber bundles formed by gathering a plurality of optical fibers; a plurality of tubular members arranged around the central tensile member and accommodating the plurality of optical fiber bundles therein; and a jacket covering the plurality of tubular members, wherein a ratio (ε) of an excess group length of rollable optical fiber ribbons of the plurality of optical fiber bundles to a length of the plurality of tubular members of the optical cable satisfies the following formula:

0
≤
ε
≤

2
⁢
R

2
⁢
R

-
H

-
1

,

wherein R denotes a lossless bending radius of the plurality of optical fibers, and
H denotes a diameter based on a cross-sectional area of the optical cable with a spiral trajectory of a center point on the plurality of optical fiber bundles modeled as having a circular cross section.

11 . The optical cable of claim 10 , wherein optical fibers of the plurality of optical fibers comprise at least one of G.652 optical fibers, G.657.A1 optical fibers, G.657.A2 optical fiber, or G.657.B3 optical fibers.

12 . The optical cable of claim 10 , wherein the plurality of optical fibers of the plurality of optical fiber bundles comprise at least one rollable optical fiber ribbon.

13 . The optical cable of claim 11 , wherein R is 40 millimeters (mm) when a type of the optical cable is G.652, is 30 mm when the type of the optical cable is G.657.A1, is 25 mm when the type of the optical cable is G.657.A2, and is 20 mm when the type of the optical cable is G.657.B3.

14 . A manufacturing method of a multi-fiber optical cable, comprising:
forming an optical fiber bundle by gathering a plurality of optical fibers; forming a tubular member by a first extrusion molding device to surround the optical fiber bundle; forming an optical unit assembly by gathering a plurality of tubular members by a gathering device while twisting the plurality of tubular members, and binding the plurality of tubular members by a binding member; and forming a jacket by a second extrusion molding device to cover the optical unit assembly, wherein, when forming the tubular member, an insertion rate of the optical fiber bundle is V1 and an extrusion rate of the tubular member is V2, the following formula is satisfied:

1
≤

V
⁢
1

V
⁢
2

≤

2
⁢
R

2
⁢
R

-
H

,

wherein R denotes a lossless bending radius of the plurality of optical fibers, and
H denotes a diameter based on a cross-sectional area of the multi-fiber optical cable with a spiral trajectory of a center point on the optical fiber bundle modeled as having a circular cross section.

15 . The manufacturing method of the multi-fiber optical cable of claim 14 , wherein the plurality of optical fibers of the optical

Assignees

• Ls Cable & System Ltd

Inventors

• Lee Man Su

Classifications

• G02B6/448

  Ribbon cables · CPC title

• G02B6/4434

  Central member to take up tensile loads · CPC title

• G02B6/449

  Twisting · CPC title

• G02B6/4486

  Protective covering · CPC title

• G02B6/4433 Primary

  Double reinforcement laying in straight line with optical transmission element · CPC title