Optical Fiber Cable Twist Structure for Untwisting Suppression
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Solution Overview
Problem
Existing optical fiber cables face issues with untwisting of optical fiber units and individual fibers, leading to increased transmission loss and exposure of fibers, which affects the cable's structural integrity and performance.
Innovation Solution
The optical fiber cable design incorporates a core with multiple aggregate layers of optical fiber units twisted in alternating directions and with varying twist pitches, using rip cords and tension members to maintain the twisted state, thereby canceling untwisting forces and enhancing structural stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If optical fiber units are twisted together to form cable cores, then the cable structure is formed and fibers are organized, but untwisting occurs leading to increased transmission loss and fiber exposure
Solution Approach 1:
The patent applies preliminary anti-action by introducing a counter-twist in the outer cable core that opposes the twist direction of the inner cable core. This pre-established counteracting force prevents untwisting during cable deployment and usage, thereby maintaining the twisted state stability and preventing fiber exposure that would lead to transmission loss.
Solution Approach 2:
The patent implements the counterweight principle by creating a balance between opposing twist forces. The outer cable core is twisted in the opposite direction to the inner cable core, generating counterbalancing torques that neutralize each other. This force equilibrium prevents spontaneous untwisting and maintains the structural integrity of the optical fiber units throughout the cable.
2Quantity of substance
If multiple aggregate layers are used to increase fiber density, then higher fiber capacity is achieved, but structural complexity and difficulty in controlling twist stability increase
Solution Approach 1:
The patent applies segmentation by dividing the cable core into multiple distinct aggregate layers, with each layer containing specific optical fiber units twisted in predetermined directions. This segmentation allows independent control of twist characteristics in each layer, enabling the outer layers to counterbalance inner layers while achieving high fiber density through systematic organization.
Solution Approach 2:
The patent employs asymmetry by configuring different aggregate layers with different twist directions and twist pitches. The inner cable core and outer cable core are twisted in opposite directions with different pitch values, creating an asymmetric structure that achieves force balance while maximizing fiber capacity through optimized spatial arrangement.
3Stability of the object's composition
If varying twist pitches are used in different aggregate layers, then untwisting forces are canceled and structural stability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies parameter changes by varying the twist pitch values between different aggregate layers. Each layer is assigned a specific twist pitch parameter that, when combined with the opposite twist direction, creates a balanced force system. This parameter optimization allows effective untwisting force cancellation while establishing clear manufacturing specifications for each layer.
Data Source
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Figure 3(a)~3(d)
AI summary
An optical fiber cable includes a first aggregate layer including a plurality of first optical fiber units that are helically twisted together in a first direction without strand-back, and each of the plurality of first optical fiber units has a plurality of optical fibers twisted together in a second direction, and the first direction and the second direction are different from each other.