Optical Cable Protective Tube Fitting Device with Tapered Guiding Wall

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Solution Overview

Problem

The installation of optical access networks, particularly FTTH and FTTP, faces challenges in handling bare optical fibers exposed after removing the cable external sheath, as they are prone to breakage due to mechanical stress and require precise handling, which can be time-consuming and demanding even for skilled operators.

Innovation Solution

A device that connects a protective tube onto a bare optical fiber, featuring a tapered guiding wall for easy insertion and a longitudinally opened channel for simple and secure fixation of the cable external sheath, manufactured as a single integral body to provide a rigid connection and prevent fiber breakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If bare optical fibers are directly arranged within the external sheath of the optical cable, then the cable structure is simplified and installation is easier, but the fibers are prone to breakage due to mechanical stress and require precise handling

Engineering Contradiction:
Improvecable structureVSAvoidfiber strength
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies nesting by placing the bare optical fiber inside a protective tube that is inserted into a channel within the external sheath. This nested structure allows the fiber to be protected while maintaining the simplified cable architecture, resolving the contradiction between structural simplicity and fiber protection.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The protective tube acts as an intermediary element between the bare optical fiber and the external environment. It provides mechanical protection and stress relief to the fiber without requiring complex cable construction, enabling easier installation while improving fiber reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If protective tubes are fitted onto bare optical fibers to prevent breakage, then fiber protection is improved, but the operation requires time, precision and care

Engineering Contradiction:
Improvefiber protectionVSAvoidinstallation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The protective tube is pre-formed with a tapered entry section and the external sheath includes a pre-configured channel, preparing the structure in advance to guide and receive the fiber. This preliminary preparation eliminates the need for complex real-time alignment operations, reducing installation time while maintaining protection quality.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The tapered entry section of the protective tube serves as a mediator that guides the bare fiber into the tube without requiring precise manual alignment. This design simplifies the fitting operation, reducing the time and skill needed while ensuring proper fiber protection.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the protective tube is fixed firmly to the cable external sheath to prevent fiber breakage, then fiber safety is improved, but the fixation operation becomes more complex

Engineering Contradiction:
Improvefiber safetyVSAvoidfixation structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The protective tube and external sheath are merged into a single integrated structure where the tube is inserted into a channel within the sheath. This combination provides firm fixation and fiber protection without requiring separate fixation components or complex assembly operations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The protective tube is nested within a channel of the external sheath, creating a built-in fixation structure. This nested arrangement provides secure fiber anchoring while maintaining structural simplicity, avoiding the need for additional fixation devices or complex assembly steps.

Inventive Principle:
Principle #7Nested doll (Nesting)

4Reliability

If a rigid connection structure is used to connect the protective tube and cable external sheath, then fiber breakage is prevented, but the device complexity increases

Engineering Contradiction:
Improvefiber breakage preventionVSAvoidconnection structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The connection structure is merged into the external sheath itself through an integrated channel that receives and anchors the protective tube. This unified structure provides rigid connection and fiber breakage prevention while maintaining overall structural simplicity, avoiding additional complex connection components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The protective tube is nested within the external sheath channel, creating a built-in rigid connection. This nested configuration provides structural integrity and fiber protection without requiring separate connection devices, maintaining device simplicity while ensuring fiber safety.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP3221730B1Device for connecting an optical cable and a protective tube
Publication Date: 2020.09.23 PRYSMIAN SPA
  • EP3221730B1 patent drawingFigure 1~3
  • EP3221730B1 patent drawingFigure 4~5
  • EP3221730B1 patent drawingFigure 6~7

AI summary

It is disclosed a device (1) for connecting an optical cable (7) and a protective tube (6) fitted onto a bare optical fiber protruding from the optical cable (7). The device (1) comprises two end portions (2,4) and a central portion (3). One end portion (2) comprises a channel for housing a cut end of the cable external sheath, from which the bare fiber exits. This channel is longitudinally opened. The opposite end portion (4) receives the protective tube (6). The central portion (3) comprises a second channel (30) with a tapered guiding wall aligning the bare optical fiber with the protective tube (6). It is also disclosed an optical fiber protection assembly (100) comprising the device (1) and a protective tube (6) arranged in the device. Such device and assembly ease the operation of fitting the protective tube (6) onto the bare optical fiber and allow firmly and stably fixing the protective tube (6) to the cut end of the cable external sheath, in a easy way.