Optical Fiber Cable SZ Twisting Pressing Mechanism

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Solution Overview

Problem

The increasing number of optical fibers in optical fiber cables leads to untwisting issues due to the rigidity of the fibers, causing tension and side pressure reduction, which complicates winding and installation, and existing solutions either increase manufacturing costs or require complex apparatus.

Innovation Solution

A manufacturing method and apparatus that incorporates a pressing portion with rollers to restrict the relative movement of optical fibers within the SZ-twisted bundle, maintaining the twisted state without the need for additional holding members, thus preventing untwisting and meandering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the number of optical fibers in the cable is increased, then the cable capacity is improved, but the rigidity of the twisted optical fiber bundle increases causing untwisting phenomenon

Engineering Contradiction:
Improvenumber of optical fibersVSAvoidtwisted state stability
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

A pressing portion is introduced as an intermediary mechanism between the SZ twisting device and the extrusion molding device. This pressing portion applies controlled pressure to the optical fiber bundle to suppress the untwisting force generated by the increased rigidity of multiple optical fibers, thereby maintaining the twisted state without compromising cable capacity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The pressing portion applies a counteracting force in advance to prevent the untwisting phenomenon before it can significantly affect the cable structure. By pressing the optical fiber bundle during the manufacturing process, the system counteracts the natural tendency of rigid fiber bundles to release their twist when containing a large number of fibers

Inventive Principle:
Principle #9Preliminary anti-action

2Stability of the object's composition

If the swing angle of the SZ twisting device is increased to maintain twisted state, then the untwisting resistance is improved, but the untwisting force and displacement in the sheath increase causing meander

Engineering Contradiction:
Improvetwisted state maintenanceVSAvoidmeander and displacement
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

Instead of increasing the swing angle of the SZ twisting device, the invention changes the parameter of applying axial pressing force through the pressing portion. This alternative parameter adjustment maintains the twisted state without generating excessive untwisting force that would cause meander and displacement of optical fibers in the sheath

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If a holding member is wound around the optical fiber bundle to prevent untwisting, then the twisted state stability is improved, but the manufacturing apparatus complexity increases

Engineering Contradiction:
Improvetwisted state stabilityVSAvoidmanufacturing apparatus complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The pressing portion is merged with the existing manufacturing apparatus structure, combining the untwisting prevention function with the existing SZ twisting device and extrusion molding device. This integration avoids adding separate holding member winding mechanisms, thereby preventing increased apparatus complexity while maintaining twisted state stability

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3611545B1Manufacturing method for optical fiber cable and manufacturing device for optical fiber cable
Publication Date: 2023.09.27 FUJIKURA LTD
  • EP3611545B1 patent drawingFigure 1
  • EP3611545B1 patent drawingFigure 2
  • EP3611545B1 patent drawingFigure 3

AI summary

A manufacturing method of an optical fiber cable includes an SZ twisting step of twisting a plurality of optical fibers(3) or a plurality of optical fiber units (5) in an SZ manner by an SZ twisting device, and forming an optical fiber bundle (B), and a covering step of covering the optical fiber bundle with a sheath (101) by an extrusion molding device (14), and in the covering step, the optical fiber bundle is covered with the sheath while pressing the optical fiber bundle, by a pressing portion (13) disposed between the SZ twisting device and the extrusion molding device.