Dual-Layer Fiber-Optic Buffer for Low Insertion Force and Kink Resistance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

High-density fiber-optic connectors require significant engagement forces due to cumulative buffer insertion forces, making manual connection challenging, and existing cables lack sufficient kink resistance, which is critical in aerospace applications where space and weight are limited.

Innovation Solution

A fiber-optic cable design featuring a semi-loose buffer system with a low-density expanded PTFE first layer and a continuous high-modulus polyimide second layer, along with a slip layer and a strength member, reduces buffer insertion force and enhances kink resistance without compromising optical, mechanical, or thermal performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If high-density fiber-optic connectors are used to increase cable density, then the quantity of cables transmitted increases, but the engagement force increases linearly making manual connection difficult

Engineering Contradiction:
Improvecable densityVSAvoidengagement force
Core Design Contradiction:
Quantity of substanceVSForce

Solution Approach 1:

The buffer is segmented into two distinct layers: an inner buffer layer (22) and an outer buffer layer (24). The inner buffer layer is formed of a soft, compliant material that allows the fiber to telescope easily, reducing the force required. The outer buffer layer provides structural support while maintaining low friction. This segmentation allows each layer to perform its specific function optimally, resolving the contradiction between high cable density and manageable engagement force.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the material parameters of the buffer layers, specifically using a soft, compliant material for the inner buffer layer with low friction characteristics. This parameter change enables the fiber to slide smoothly during connector mating, significantly reducing the engagement force even when multiple cables are connected in high-density configurations.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If the buffer material is made softer to reduce buffer insertion force, then the ease of operation improves, but the kink resistance deteriorates

Engineering Contradiction:
Improvebuffer insertion forceVSAvoidkink resistance
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The buffer is divided into two layers with different material properties. The inner buffer layer (22) is made of a soft, compliant material that reduces buffer insertion force and allows easy telescope of the fiber during connector mating. The outer buffer layer (24) is made of a tougher material that provides kink resistance and structural protection. This segmentation allows the system to achieve both ease of operation and adequate strength simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses a composite buffer structure combining two different materials: a soft, compliant inner buffer layer material and a tougher outer buffer layer material. This composite construction allows the inner layer to provide low friction for easy insertion while the outer layer provides mechanical strength and kink resistance, resolving the contradiction between softness for ease of operation and strength for kink resistance.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP2193396B1Fiber-optic cable and method of manufacture
Publication Date: 2018.11.28 CARLISLE INTERCONNECT TECHNOLOGIES INC
  • EP2193396B1 patent drawingFigure 1
  • EP2193396B1 patent drawingFigure 2~3
  • EP2193396B1 patent drawingFigure 4~5

AI summary

A fiber-optic cable with low buffer insertion force, significant kink resistance, and improved thermal performance incorporating a dual layer buffer of a low density material (62) beneath a continuous seamless high modulus material (64) without compromising low smoke, toxicity, and f lammability. The fiber-optic cabl also may comprise a slip layer (66), a strength layer (68) and an oute jacket (70).