Multi-fiber, fiber optic cables and cable assemblies providing constrained optical fibers within an optical fiber sub-unit

• US 9,891,397 B2
• Filed: 07/21/2016
• Issued: 02/13/2018
• Est. Priority Date: 06/22/2011
• Status: Active Grant

• Current Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Original Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Inventors: Hurley, William Carl, Yates, Wesley Allan
• Primary Examiner(s): Wong, Tina
• Application Number:
  US15/215,959
• Publication Number:
  US 20160327763A1
• Time in Patent Office: 572 Days
• Field of Search: None
• CPC Class Codes: G02B 6/441 built up from sub-bundles G02B6/4429, G02B6/4439, G02B6/4479 take precedence
• CPC Class Codes: G02B 6/443 Protective covering
• CPC Class Codes: G02B 6/4431 with provision in the protective covering, e.g. weak line, for gaining access to one or more fibres, e.g. for branching or tapping break-out terminations G02B6/4471
• CPC Class Codes: G02B 6/4432 with fibre reinforcements
• CPC Class Codes: G02B 6/4434 Central member to take up tensile loads
• CPC Class Codes: G02B 6/4472 Manifolds
• CPC Class Codes: G02B 6/4486 Protective covering
• CPC Class Codes: G02B 6/46 Processes or apparatus adapted for installing or repairing optical fibres or optical cables installation of cables containing electric conductors and optical fibres H02G
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

Multi-fiber, fiber optic cables and cable assemblies providing constrained optical fibers within an optical fiber sub-unit are disclosed. The optical fiber sub-unit(s) comprises optical fibers disposed adjacent a sub-unit strength member(s) within a sub-unit jacket. Movement of optical fibers within a sub-unit jacket can be constrained. In this manner, the optical fibers in an optical fiber sub-unit can be held together within the optical fiber sub-unit as a unit.

Claims

1. A fiber optic cable assembly, comprising:

a fiber optic cable comprising;

a cable jacket;

one or more cable strength members disposed within the cable jacket in a first length; and

one or more optical fiber sub-units disposed within the cable jacket in a second length that is greater than the first length, wherein;

the one or more optical fiber sub-units each comprise a plurality of optical fibers and one or more sub-unit strength members disposed adjacent to each other in a sub-unit jacket such that movement of the plurality of optical fibers is radially constrained by an interior wall of the sub-unit jacket and the one or more sub-unit strength members;

the plurality of optical fibers are in friction contact with the one or more sub-unit strength members constraining relative longitudinal movement of the plurality of optical fibers within the sub-unit jacket;

the one or more optical fiber sub-units disposed adjacent to the one or more cable strength members within the cable jacket;

the one or more optical fiber sub-units are disposed within the cable jacket adjacent to the one or more cable strength members to allow movement between the one or more optical fiber sub-units and the one or more cable strength members within the cable jacket; and

an end portion of the fiber optic cable comprises end portions of the one or more optical fiber sub-units and end portions of the one or more cable strength members both exposed from an end portion of the cable jacket; and

a furcation assembly receiving the end portion of the fiber optic cable at a first end of the furcation assembly, wherein;

the furcation assembly terminates the end portion of the cable jacket and the end portions of the one or more cable strength members; and

the end portions of the one or more optical fiber sub-units extending through and from a second end of the furcation assembly.

2. The fiber optic cable assembly of claim 1, wherein the one or more optical fiber sub-units are not stranded with the one or more cable strength members disposed within the cable jacket.

3. The fiber optic cable assembly of claim 1, wherein the one or more optical fiber sub-units are disposed loosely within the cable jacket providing freedom of relative motion between the plurality of optical fiber sub-units disposed within the cable jacket.

4. The fiber optic cable assembly of claim 3, wherein the plurality of optical fiber sub-units have freedom of relative motion with respect to the one or more cable strength members in the cable jacket.

5. The fiber optic cable assembly of claim 1, wherein the axial rigidity of the one or more sub-unit strength members of each of the one or more optical fiber sub-units is less than fifteen percent (15%) of the total axial rigidity of the one or more cable strength members and the one or more optical fiber sub-unit strength members of the fiber optic cable.

6. The fiber optic cable assembly of claim 1, wherein an inner diameter of the cable jacket is at least 0.5 mm greater than the outer diameter of the one or more optical fiber sub-units and the one or more cable strength members disposed within the cable jacket.

7. The fiber optic cable assembly of claim 1, wherein the combined axial rigidity of the one or more sub-unit strength members of the one or more optical fiber sub-units is less than fifty percent (50%) of the total axial rigidity of the one or more cable strength members and the one or more optical fiber sub-unit strength members of the fiber optic cable.

8. The fiber optic cable assembly of claim 1, wherein a relative longitudinal movement of the one or more optical fiber sub-units within an end portion of the cable jacket of greater than 4 mm.

9. The fiber optic cable assembly of claim 1, wherein the relative longitudinal movement of the one or more optical fiber sub-units within an end portion of the cable jacket is greater than 10 mm.

10. The fiber optic cable assembly of claim 9, wherein the length of the one or more optical fiber sub-units in any cross-section of the cable jacket orthogonal to a longitudinal axis of the cable jacket is greater than the length of one or more cable strength members.

11. The fiber optic cable assembly of claim 9, wherein the second length of the one or more optical fiber sub-units is greater than the first length of the one or more cable strength members disposed within the cable jacket by 0.10 percent (0.10%) or more.