Optical Fiber Cable Low Thermal Shrinkage Linear Body
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Solution Overview
Problem
Optical fiber cables experience increased transmission loss and potential fiber breakage due to thermal shrinkage of the linear body wound around the wrapping member, which tightens the fibers beyond their elasticity range.
Innovation Solution
Winding multiple linear bodies with a low thermal shrinkage ratio around the outer periphery of the wrapping member, allowing for a larger winding pitch and intermittent bonding of optical fiber ribbons to prevent excessive stress and distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a linear body is wound around the outer periphery of the wrapping member to suppress shifting of optical fibers, then the core pulling force is improved, but the transmission loss increases due to thermal shrinkage tightening the fibers beyond their elasticity range
Solution Approach 1:
The patent changes the thermal shrinkage ratio parameter of the linear body from a conventional high value to a low value (specifically, a thermal shrinkage ratio of less than a predetermined value). This parameter change allows the linear body to maintain its length stability during temperature changes, preventing excessive tightening of the optical fibers while still providing sufficient core pulling force to suppress fiber shifting.
2Stability of the object's composition
If the winding pitch of the linear body is reduced to increase the number of windings and improve fiber holding, then the fiber shifting is suppressed, but the manufacturing complexity and time increase
Solution Approach 1:
The patent changes the thermal shrinkage ratio parameter of the linear body to a low value. This parameter change allows the use of a larger winding pitch while still achieving effective fiber holding, because the low thermal shrinkage prevents excessive tightening that would occur with multiple windings of high-shrinkage material. This resolves the contradiction by allowing fewer windings with larger pitch to suffice.
3Stability of the object's composition
If multiple linear bodies are wound around the wrapping member to improve fiber holding, then the fiber shifting is suppressed, but the device complexity and manufacturing time increase
Solution Approach 1:
The patent changes the thermal shrinkage ratio parameter of the linear body to a low value. This parameter change allows a single linear body or fewer linear bodies to provide sufficient fiber holding capability, eliminating the need to increase the number of linear bodies. The low thermal shrinkage ensures that even with fewer windings, the fiber shifting is effectively suppressed without excessive tightening.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach suppresses the increase in transmission loss and prevents fiber breakage by minimizing thermal shrinkage-induced distortion, while improving manufacturability and reducing the tightening force on the fibers.
Implementation Method 1
when the optical fiber cable is under a temperature change, there may be a case in which the linear body winding around the outer periphery of the wrapping member thermally shrinks
Implementation Method 2
the linear body can hold the optical fibers that are wrapped by the wrapping member. Also, the thermal shrinkage of the linear body under temperature change is small
Data Source
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AI summary
An optical fiber cable (1) is a slot-less type optical fiber cable not using a slot, and is provided with: a plurality of optical fiber core wires (3); a presser-winding member (5); a linear body (7); a tension member (9); a tear cord (11); a jacket (13), etc. The presser-winding member (5) is provided to the outer circumference of the optical fiber core wires (3). A cable core (15) on which the linear body (7) is wound is formed on the outer circumference of the presser-winding member (5). The linear member (7) wound on the outside of the presser-winding member (5) has a thermal shrinkage of 0.2 % or lower at a temperature of -40 °C to +85 °C.