Fire Door Retaining Device for Consistent 90° Infill Grip

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Solution Overview

Problem

Existing retaining devices for infill panels in fire doors suffer from slipping during installation, leading to inconsistent bending angles, increased installation difficulty, and reduced panel retention, which compromises fire resistance.

Innovation Solution

A retaining device made of high-temperature material with a protrusion or additional piece for glazing tool support, ensuring consistent bending of legs at a 90° angle to securely grip infill panels between frame members.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a glazing tool is used to bend the retaining device against the infill panel, then the infill panel can be retained in the frame, but the glazing tool slips during installation causing inconsistent bending angles and reduced retention

Engineering Contradiction:
Improveinfill panel retentionVSAvoidinstallation ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent introduces an intermediary component (the retaining device with specifically designed geometry and material properties) that mediates between the glazing tool and the infill panel. The retaining device includes a channel that guides the glazing tool and a flange that provides a consistent bending surface, ensuring reliable panel retention while making the installation process easier and more consistent.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If the glazing tool applies force to bend the retaining device, then the infill panel is gripped tighter, but the tool slips increasing installation time and physical exertion

Engineering Contradiction:
Improveinfill panel grip strengthVSAvoidinstallation time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The retaining device is pre-configured with a channel and flange geometry that prepares the structure for consistent bending. The channel guides the glazing tool into the correct position, and the flange is pre-positioned to provide a consistent bending surface, eliminating the need for repeated adjustments and reducing installation time while maintaining strong panel grip.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the retaining device is bent to grip the infill panel, then panel retention improves, but the desired 90° bending angle cannot be achieved consistently due to tool slippage

Engineering Contradiction:
Improvepanel retention consistencyVSAvoidbending angle precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The retaining device structure serves itself by incorporating a channel that automatically guides the glazing tool and a flange that provides a self-aligning bending surface. This self-guiding mechanism ensures that the 90° bending angle is achieved consistently without requiring precise manual control or specialized tooling, improving both retention reliability and angular precision.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4455437B1System to assist with fire resistance of a door
Publication Date: 2025.08.06 ARCONIC TECHNOLOGIES LLC
  • EP4455437B1 patent drawingFigure 1A~1B
  • EP4455437B1 patent drawingFigure 2
  • EP4455437B1 patent drawingFigure 3A

AI summary

A fire door comprising a door leaf, wherein the door leaf comprises a retaining device for retaining an infill panel within a frame of the door leaf, wherein the infill panel is gripped between a wall and an at least one leg of the retaining device. A retaining device for use in retaining an infill panel in a fire door and a method of installing an infill panel in a fire door using the retaining device, the retaining device comprising a protrusion or an additional piece to aid in bending an at least one leg of the retaining device using a glazing tool so as to reduce both the installation time and the physical exertion required of the installer.