Preconnectorized Multi-Fiber Drop Cable Nesting for Compact Duct Deployment

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Solution Overview

Problem

Conventional optical fiber LC connectors are not designed to minimize cross-sectional footprint, making it difficult to push multiple preconnectorized fibers through a duct simultaneously, especially for single mode fibers which require tighter mechanical tolerances and are often pre-terminated due to the time-consuming field termination process.

Innovation Solution

A multi-fiber drop cable design featuring an LC connector sub-assembly with a ferrule basket and outer housing that ensures relative alignment and prevents rotation, allowing for a minimal cross-sectional footprint by positioning fibers in a nested configuration, enabling easy deployment through ducts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If conventional LC connectors are used with standard configuration, then connector functionality is maintained, but cross-sectional footprint is too large for easy duct deployment

Engineering Contradiction:
Improvecross-sectional footprintVSAvoidduct deployment difficulty
Core Design Contradiction:
Area of moving objectVSEase of operation

Solution Approach 1:

The patent applies nesting by placing multiple ferrules (containing fibers) inside a shared basket structure. The ferrules are arranged concentrically or in a compact pattern within the basket, allowing multiple fibers to occupy a smaller cross-sectional area. This nested arrangement significantly reduces the overall footprint compared to conventional side-by-side ferrule configurations, enabling easier push-through deployment through ducts while maintaining individual fiber integrity and alignment capabilities.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Quantity of substance

If multiple fibers are provided in a multi-fiber cable, then fiber capacity is increased, but cross-sectional footprint increases making duct deployment difficult

Engineering Contradiction:
Improvenumber of fibersVSAvoidcross-sectional footprint
Core Design Contradiction:
Quantity of substanceVSArea of moving object

Solution Approach 1:

The patent implements nesting by organizing multiple ferrules within a single basket structure. Instead of providing each fiber with a separate connector housing, multiple ferrules are nested inside the shared basket, allowing 2, 4, or more fibers to be contained within a compact cross-sectional footprint. This dramatically increases fiber capacity while minimizing the area required for duct deployment.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent merges multiple individual fiber connectors into a single integrated multi-fiber connector assembly. The basket structure combines multiple ferrules, alignment features, and housing elements into one unified component. This consolidation reduces the total cross-sectional footprint compared to having separate connectors for each fiber, while maintaining the ability to terminate and deploy multiple fibers simultaneously.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If single mode fiber is terminated in the field, then installation flexibility is improved, but termination time and skill requirements increase significantly

Engineering Contradiction:
Improveinstallation flexibilityVSAvoidtermination time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-terminating all fibers at the factory with high-precision connectors before cable deployment. The multi-fiber connector assembly is completely assembled, tested, and prepared in a controlled manufacturing environment with specialized equipment. This preliminary termination eliminates the need for time-consuming field splicing operations, reducing installation time from 15-20 minutes per fiber to simple plug-and-play connectivity, while maintaining installation flexibility through pre-configured cable lengths and connector types.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4091007B1Preconnectorized multi-fiber drop cables
Publication Date: 2025.08.20 PPC BROADBAND FIBER LTD
  • EP4091007B1 patent drawingFigure 1
  • EP4091007B1 patent drawingFigure 2
  • EP4091007B1 patent drawingFigure 3A~4B

AI summary

An optical fiber connector sub-assembly for an optical fiber connector includes a ferrule configured to hold an optical fiber therein along an axis of the connector, a ferrule basket configured to hold the ferrule at a front portion of the connector, a retaining member having a front end portion configured to hold the ferrule holder and a rear end portion configured to receive a fiber optic cable, and a boot configured to be coupled with retaining member. The ferrule basket includes a base portion and a stem portion that extend rearward from the base portion. An outer periphery of the base portion includes two flat portions arranged at a right angle relative to one another, and first ends of the two flat portions that are nearest to one another along the outer periphery of the base portion are connected to one another by a curved bottom portion. Two side curved portions extend from second ends of the two flat portions that are furthest from one another along the outer periphery of the base portion, and top curved portion connects the two side curved portions.