Dielectric Armor for Fiber Optic Assemblies
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fiber optic cables require mechanical and flame-retardant properties while maintaining optical performance, especially in indoor environments like riser and plenum spaces, where existing solutions fail to balance crush resistance, flexibility, and flame/smoke ratings effectively.
Innovation Solution
An armored fiber optic assembly is created with a dielectric armor comprising an inner and outer layer, where the inner layer is spirally wound and more rigid, providing tensile strength and crush resistance, while the outer layer is less rigid, allowing flexibility and ease of bending, and both layers are bonded together to form a unitary, non-conductive armor profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a rigid armor is used to provide crush resistance, then the crush resistance is improved, but the flexibility and ease of bending deteriorate
Solution Approach 1:
The armor is divided into multiple discrete elements (individual armor rods or wires) rather than a single continuous rigid structure. These segmented elements are arranged in a spiral or zigzag pattern around the cable, providing crush resistance through their collective structural integrity while allowing the cable to bend flexibly as the elements can shift relative to each other during bending.
Solution Approach 2:
The armor combines different materials with complementary properties - typically a rigid or semi-rigid core material (such as steel, aluminum, or glass-reinforced polymer) providing crush resistance, combined with a more flexible outer jacket material (such as polyethylene or polypropylene) that allows bending. This composite structure integrates the strengths of both rigid and flexible materials to simultaneously achieve crush resistance and flexibility.
2Strength
If metal armor is used to provide mechanical strength, then the crush resistance is improved, but the need for electrical grounding arises
Solution Approach 1:
The patent replaces metal armor (which conducts electricity and requires grounding) with non-conductive armor materials such as glass-reinforced polymer, aramid fibers, or other dielectric materials. This substitution maintains the mechanical strength and crush resistance functions of the armor while eliminating electrical conductivity, thereby removing the requirement for electrical grounding and simplifying the overall system.
3Device complexity
If a single-layer armor is used to reduce complexity, then the device complexity is reduced, but the balance between crush resistance and flexibility is compromised
Solution Approach 1:
The armor structure is segmented into multiple functional layers, each with specific properties. The inner layer typically consists of rigid or semi-rigid armor elements providing crush resistance, while the outer layer consists of a flexible jacket providing bendability and environmental protection. This layered segmentation allows each layer to optimize its function without requiring complex integration, achieving performance balance through simple layering.
Solution Approach 2:
The multi-layer armor uses composite material construction where each layer is made from materials optimized for its specific function. The inner armor layer uses high-strength, rigid materials for crush resistance, while the outer jacket uses flexible, durable materials for bendability and environmental resistance. This composite approach achieves versatile performance across different installation environments without requiring overly complex structural designs.
Data Source
AI summary
Cables have dielectric armors with armor profiles that provide additional crush and impact resistance for the optical fibers and/or fiber optic assembly therein, while retaining flexibility to aid during installation. The armored cables recover substantially from deformation caused by crush loads.