Metal Cable Guard for Fiber Windings During Building Fires

Solution Overview

Problem

Fire safety issues arise in MDU buildings due to optical fibers and communication lines becoming loose and hazardous during fires, as existing non-metallic fasteners fail, posing risks to responders and occupants.

Innovation Solution

A safety guard device comprising a rigid metallic wire or rod is integrated into the POE module to capture and retain fiber optic cable windings, ensuring they remain secured even if the plastic module parts melt, using existing mounting screws for secure installation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If non-metallic fasteners are used to secure communication lines in POE modules, then the module meets fire safety regulations regarding smoke and flammability, but the fasteners fail during building fires causing lines to become loose and hazardous

Engineering Contradiction:

Improvefire safety complianceVSAvoidline retention during fire

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The retention system is divided into two independent components: non-metallic fasteners for normal operation and a metallic safety guard device as a backup. The safety guard device includes a retention bar with engagement elements that independently secure the cable winding flange, ensuring that if the primary fasteners fail during fire, the secondary metallic retention system remains functional.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The metallic safety guard device is pre-installed in the POE module before fire occurs, positioned to automatically engage and retain the cable winding flange. This beforehand preparation ensures that when fire causes the non-metallic fasteners to fail, the retention force is immediately applied by the metallic guard device, preventing cable droop and hazard to responders.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If metallic fasteners are used to secure communication lines, then line retention during fire is improved, but the module fails to meet fire safety regulations regarding flammability

Engineering Contradiction:

Improveline retention during fireVSAvoidfire safety compliance

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The retention system is divided into two independent components: non-metallic fasteners for normal operation and a metallic safety guard device as a backup. The safety guard device includes a retention bar with engagement elements that independently secure the cable winding flange, ensuring that if the primary fasteners fail during fire, the secondary metallic retention system remains functional.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different parts of the retention system have different material properties optimized for their specific functions. The POE module housing and primary fasteners use flame-retardant non-metallic materials to meet fire safety regulations, while the metallic safety guard device uses heat-resistant metal specifically for the critical function of retaining cables during fire conditions.

Inventive Principle:

Principle #3Local quality

3Temperature

If the plastic module melts during high temperatures, then the module releases stored energy, but the fiber windings become unrestrained and drop into paths of responders

Engineering Contradiction:

Improveheat resistanceVSAvoidcable droop hazard

Core Design Contradiction:

TemperatureVSObject-generated harmful factors

Solution Approach 1:

The metallic safety guard device is pre-installed in the POE module before fire occurs, positioned to automatically engage and retain the cable winding flange. This beforehand preparation ensures that when fire causes the non-metallic fasteners to fail, the retention force is immediately applied by the metallic guard device, preventing cable droop and hazard to responders.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The metallic safety guard device acts as an intermediary retention system between the cable winding and the environment. When the primary plastic module and fasteners fail under heat, the metallic guard device serves as the intermediate structure that continues to hold the cable winding in place, preventing it from dropping into hallways or living units where it would endanger responders and occupants.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP3677940B1Safety guard device for modules storing communication lines

Publication Date: 2023.10.25 OFS FITEL LLC

Figure 1~2
Figure 3~4

AI summary

A safety device for modules that store windings of communication lines, includes a metallic rod whose ends are configured to receive metallic screws to secure the rod on a base of a given module. End sections of the rod extend to a height at least equal to the height of the stored windings. Intermediate sections of the rod extend in opposite directions from the end sections, substantially parallel to the module base. Outer ends of the intermediate sections at least coincide with the outer periphery of the stored windings. A central section of the rod has opposite ends adjoining the outer ends of the intermediate sections. The central section rises over a path that at least coincides with the outer periphery of the stored windings. The end sections of the rod capture the windings, and the central section prevents them from dropping below the module during a building fire.