Optical Fiber Cable with Opposing SZ-Twist Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical fiber cables with SZ-twisted structures face deformation issues due to untwisting forces, leading to noncircular cross-sectional shapes, which affect sealing and installation, and current methods for maintaining the twisted state are costly and prone to accidental cutting.
Innovation Solution
The optical fiber cable design features inner and outer layers with opposing twisting directions and angles, with the inner-layer twisting angle being larger than the outer-layer twisting angle, and a manufacturing method using a fiber distributing board to independently rotate layers and form a sheath that covers the core and tension members, canceling untwisting forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a sheath is used to hold the twisted state of units, then the twisted state is maintained, but the cross-sectional shape deforms to become noncircular due to untwisting forces
Solution Approach 1:
The patent applies counterweight principle by introducing tension members that generate opposing forces to balance the untwisting forces. The tension members are positioned to create counteracting moments that prevent the cross-sectional shape from deforming, thereby maintaining both the twisted state stability and the circular cross-sectional shape simultaneously.
Solution Approach 2:
The patent uses composite material structure combining the sheath, tension members, and units with different rigidity characteristics. The sheath provides external constraint while tension members provide internal counterbalancing forces, creating a composite system that maintains both the twisted state and circular cross-sectional shape under operational conditions.
2Stability of the object's composition
If winding of fibrous interposition is employed to hold twisted state, then the twisted state is maintained, but cost increases and work time increases due to cutting requirements
Solution Approach 1:
The patent extracts and eliminates the fibrous interposition from the cable structure, replacing it with a sheath-based holding mechanism. This removal of the interposition component eliminates the need for cutting operations during installation, thereby reducing work time while maintaining twisted state stability through the sheath and tension member system.
Solution Approach 2:
The patent replaces the expensive and time-consuming fibrous interposition with a more economical sheath structure that serves the same functional purpose. The sheath provides continuous protection without requiring additional components that need to be installed or removed, reducing both material cost and installation time.
3Stability of the object's composition
If winding of fibrous interposition is employed to hold twisted state, then the twisted state is maintained, but the optical fiber core wire may be cut by accident
Solution Approach 1:
The patent removes the fibrous interposition that poses a cutting hazard to the optical fiber core wire. By eliminating this component entirely and replacing it with a sheath-based holding mechanism, the source of accidental cutting is removed while the twisted state stability is maintained through alternative means.
Solution Approach 2:
The patent introduces the sheath as an intermediary structure that provides mechanical support and holding function without directly contacting or posing threat to the optical fiber core wire. The sheath acts as a protective mediator that maintains the twisted state while eliminating the cutting hazard presented by fibrous interposition.
Data Source
Figure 1~2
Figure 3(A)~3(B)
Figure 4A~4B
AI summary
An optical fiber cable includes a core including a plurality of units which are assembled and each of which comprises a plurality of optical fibers which are assembled, a pair of tension members disposed so as to face each other with the core interposed therebetween, and a sheath covering the core and the pair of tension members collectively. The units are twisted so as to form a plurality of layers. The plurality of layers includes a first layer having first-layer units formed in an SZ-twisted shape and a second layer having second-layer units formed in an SZ-twisted shape. A twisting direction of the first-layer units is opposite to a twisting direction of the second-layer units in at least a portion in a cable length direction.