Optical Fiber Cable With Rollable Ribbons

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Solution Overview

Problem

Conventional optical fiber cables face challenges in achieving high fiber packing density and facilitating mid-span access while providing sufficient tensile strength and protection against mechanical stresses.

Innovation Solution

The optical fiber cable design features a rigid tensile reinforcement member centrally located within a cable jacket, with rollable or partially bonded ribbons stranded around it, and cushioning layers between the ribbons and the jacket, eliminating buffer tubes for increased flexibility and ease of access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If flat (encapsulated) optical fiber ribbons are used, then fiber protection is improved, but fiber packing density and cable flexibility deteriorate

Engineering Contradiction:

Improvefiber protectionVSAvoidfiber packing density

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The matrix material is applied locally at specific intervals along the fibers rather than continuously encapsulating them. This intermittent bonding provides protection where needed while maintaining flexibility and rollability in other sections, resolving the contradiction between protection and packing density.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The continuous matrix encapsulation is segmented into discrete intervals. The matrix material is applied in separate sections along the fiber length, creating a segmented structure that allows the ribbon to be rolled and compacted while still providing protection at critical points.

Inventive Principle:

Principle #1Segmentation

2Reliability

If buffer tubes are used to organize fibers, then fiber protection is improved, but cable flexibility and ease of access deteriorate

Engineering Contradiction:

Improvefiber protectionVSAvoidease of access

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The buffer tubes are completely removed from the cable structure. Fibers are organized directly into ribbons without the intermediate buffer tube layer, eliminating the barrier to access while maintaining protection through the matrix material and cable construction.

Inventive Principle:

Principle #2Taking out (Extraction)

3Strength

If conventional flat ribbons are used, then fiber strength is improved, but cable flexibility and bendability deteriorate

Engineering Contradiction:

Improvefiber strengthVSAvoidcable flexibility

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The ribbon structure transitions from a static, rigid flat configuration to a dynamic, adaptable form that can be rolled and bent. The intermittent matrix bonding allows the ribbon to change shape and conform to different cable configurations while maintaining fiber strength where the matrix is present.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP3884326B1Optical fiber cable having rollable ribbons and central strength member

Publication Date: 2025.01.01 OFS FITEL LLC

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AI summary

An optical fiber cable may include a cable jacket, a rigid tensile reinforcement member centered within the cable jacket, and a plurality of partially bonded optical fiber ribbons around the rigid tensile reinforcement member. The optical fiber cable does not include any buffer tubes but may include a cushioning layer adjacent the ribbons.