Optical Fiber Cable Sheath Layout for Small Bending Diameter
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Solution Overview
Problem
Existing optical fiber cables with embedded tensile strength members in a sheath face issues with reduced sheath thickness and increased allowable bending diameter, particularly when recesses and protrusions are formed on the sheath surface.
Innovation Solution
The optical fiber cable design includes a sheath with alternately disposed recesses and protrusions, embedding tensile strength members only in portions of the sheath facing outward from the core, ensuring they do not coincide with the core's position, thereby reducing the allowable bending diameter while maintaining sheath strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the tensile strength member is disposed inside each protrusion to increase installing density, then the optical fiber density increases, but the allowable bending diameter increases
Solution Approach 1:
The patent applies local quality by differentiating the placement of tensile strength members based on location. Tensile strength members are embedded only in the recesses, not in the protrusions, creating a non-uniform distribution that optimizes both fiber density and bending characteristics. This localized differentiation resolves the contradiction by allowing high fiber density in protrusion regions while maintaining small bending diameter through proper tensile strength member placement in recesses.
2Quantity of substance
If the tensile strength member is embedded in the sheath, then the optical fiber density increases, but the sheath thickness becomes excessively small
Solution Approach 1:
The patent embeds tensile strength members only in the recesses of the sheath, not uniformly throughout. This localized embedding approach allows the sheath to maintain adequate thickness in critical areas (protrusions and regions between recesses) while still providing tensile strength reinforcement where needed. The result is preserved sheath strength with improved optical fiber density.
3Ease of operation
If recesses and protrusions are formed on the sheath surface to reduce friction, then installation ease improves, but the structural complexity increases
Solution Approach 1:
The sheath surface is segmented into alternating recesses and protrusions, creating a periodic structure that reduces friction during installation. This segmentation approach simplifies the overall design compared to other friction-reduction methods while effectively lowering the coefficient of friction between the sheath and installation conduit, thereby improving installation ease with minimal increase in structural complexity.
Data Source
AI summary
An optical fiber cable includes: a sheath including recesses and protrusions that are alternately disposed in a circumferential direction on an outer circumferential surface of the sheath; a core that includes optical fibers and is accommodated in the sheath; tensile strength members embedded in the sheath; and a ripcord that is embedded in the sheath. A marking portion protruding outward in a radial direction is disposed in the sheath. The ripcord is disposed between the marking portion and the core.