High Fiber Density Ribbon Cable With Flexible Sheath

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

High fiber count optical communication cables face challenges in fitting into existing ducts with small inside diameters, and there is a need for higher fiber density to reduce installation costs. Conventional ribbon cables have limitations in fiber density and handling, leading to increased implementation costs and difficulties in mass fusion splicing.

Innovation Solution

The development of an optical fiber cable with a flexible sheath made of extruded PVC material, which allows for high density ribbon cable designs with fiber densities ranging from 19 to 23% of the jacket outer diameter, while maintaining acceptable attenuation performance using G.652.D fiber. This design includes a core subunit configuration with optical fiber groups and a sheath that enables longitudinal translation of ribbons during cable bending, preventing buckling and maintaining fiber alignment for efficient splicing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional ribbon cable designs are used, then cable structure is simple and manufacturing is easy, but fiber density is low and installation costs increase

Engineering Contradiction:
Improvefiber densityVSAvoidcable structure complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The cable is divided into multiple core subunits, each containing a bundle of ribbons. This segmentation allows high fiber density to be achieved through modular assembly, where each subunit can be independently manufactured and then combined. The core subunit structure enables scaling fiber count without proportionally increasing overall cable complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple ribbons are bundled together within core subunits, creating a nested structure where individual ribbons are contained within larger organizational units. This nesting approach allows efficient space utilization and high fiber density while maintaining structured organization that simplifies handling and installation.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Quantity of substance

If rollable ribbon concepts are used to increase fiber density, then more fibers fit in the same space, but handling becomes difficult and splicing efficiency decreases

Engineering Contradiction:
Improvefiber densityVSAvoidhandling and splicing ease
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

The ribbon bundles within core subunits are designed to be flexible and capable of longitudinal translation. This dynamic characteristic allows the ribbons to move and adjust during handling and installation, enabling easy extraction and positioning for splicing operations while maintaining high density packing within the cable structure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

By organizing ribbons into discrete core subunits, the system enables selective access to specific ribbon bundles. This segmentation allows installers to work with smaller, manageable units rather than attempting to handle all ribbons simultaneously, significantly improving splicing efficiency and ease of operation.

Inventive Principle:
Principle #1Segmentation

3Quantity of substance

If higher fiber density is achieved through tighter packing, then installation costs are reduced, but fiber attenuation performance deteriorates

Engineering Contradiction:
Improvefiber densityVSAvoidattenuation performance
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The cable structure provides different local environments for different components. Core subunits offer localized organization and protection for ribbon bundles, while the overall cable structure provides macro-level support and stress distribution. This multi-level local quality approach maintains fiber integrity despite high density packing.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The cable employs composite construction with multiple materials serving different functions: the jacket provides external protection, core subunits provide structural organization, and internal materials provide ribbon support and stress relief. This composite approach allows high fiber density while maintaining attenuation performance through appropriate material selection and configuration.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP3649497B1High fiber density ribbon cable
Publication Date: 2025.02.19 CORNING RES & DEV CORP
  • EP3649497B1 patent drawingFigure 1~2
  • EP3649497B1 patent drawingFigure 3~4
  • EP3649497B1 patent drawingFigure 5A~5E

AI summary

An optical fiber cable includes a jacket and a plurality of stranded core subunits, each core subunit comprising a flexible sheath and a plurality of ribbons arranged in a ribbon group, wherein each ribbon of the plurality of ribbons comprises a plurality of connected fibers such that 50-70% of the cross-sectional area inside the sheath is occupied by the connected fibers. The flexible sheath may be an extruded PVC material that conforms to the shape of the ribbon stack and keeps all of the ribbons acting as a unitary body during bending.