Flat Drop Cable With Angular Cavity for Hand-Tear Fiber Access

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Solution Overview

Problem

Conventional optical-fiber drop cables face challenges in easy access and sealing, with external notches or grooves leading to potential failure and increased manufacturing complexity, while internal components like yarns or plastic components complicate manufacturing and increase costs.

Innovation Solution

A flat drop cable design featuring an angular longitudinal cavity with upper and lower vertices, allowing manual tearing for easy access to optical fibers, and a polymeric jacket with reduced thickness at these vertices, along with embedded strength members, facilitating easy deployment and sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If external notches or grooves are added to the cable jacket, then access to optical fibers is facilitated, but the cable structure becomes more complex and reliability decreases due to potential failure points

Engineering Contradiction:
Improveaccess to optical fibersVSAvoidcable structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The cable jacket incorporates vertices with localized reduced thickness at specific positions, creating areas of different structural properties. These vertices provide easy access points for fiber extraction while maintaining the integrity of the rest of the cable jacket, thus facilitating access without adding overall structural complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Instead of adding external notches or grooves to the cable jacket to facilitate access, the invention inverts the approach by creating vertices with reduced thickness from the interior molding process. This internal structural feature naturally creates access points without requiring external modifications or additional components.

Inventive Principle:
Principle #13The other way round (Inversion)

2Ease of operation

If internal components like yarns or plastic components are added to facilitate access, then fiber access is improved, but manufacturing complexity and costs increase

Engineering Contradiction:
Improvefiber accessVSAvoidmanufacturing process
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The invention merges the access facilitation function directly into the cable jacket structure itself. The vertices with reduced thickness are formed as an integral part of the jacket during the extrusion or molding process, eliminating the need for separate internal components like yarns or plastic elements. This integration simplifies manufacturing while maintaining ease of fiber access.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cable jacket serves multiple functions: it provides mechanical protection, structural support, and built-in access facilitation through its vertices. The vertices perform the dual role of maintaining cable integrity while enabling easy fiber extraction, eliminating the need for dedicated access components and simplifying the overall manufacturing process.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of operation

If the cable jacket thickness is reduced at vertices, then hand tearing for access is facilitated, but the structural strength may be compromised

Engineering Contradiction:
Improvehand tearing capabilityVSAvoidcable jacket strength
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The cable jacket features vertices with locally reduced thickness at specific positions, creating controlled weak points that facilitate hand tearing. The reduced thickness areas are strategically positioned to enable easy access without compromising the overall structural integrity of the cable jacket, as the majority of the jacket maintains its full thickness and strength.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4625017A1Easy-access flat drop cable
Publication Date: 2025.10.01 PRYSMIAN SPA
  • EP4625017A1 patent drawingFigure 1
  • EP4625017A1 patent drawingFigure 2
  • EP4625017A1 patent drawingFigure 3

AI summary

An exemplary flat drop cable (10) includes a polymeric cable jacket (11) that defines an angular longitudinal cavity (12) having an upper vertex (13a) and a lower vertex (13b), such as a rhombus-like cross-sectional shape with distinctive upper and lower vertices. One or more optical fibers (14) are positioned lengthwise within the angular longitudinal cavity (12), and typically two parallel strength members (15a,15b) are embedded in the polymeric cable jacket (11) opposite one another relative to the angular longitudinal cavity (12). The distinctive upper and lower vertices (13a,13b) reduce the polymeric jacketing (11) above and below the angular longitudinal cavity, which facilitates hand tearing of the cable jacket (11) to access the one or more optical fibers (14).