L-Shaped Flexible Element for Door Leaf Finger Protection

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Solution Overview

Problem

Conventional door designs lack comprehensive finger protection, especially at the secondary closing edge, while also failing to provide optimal stability, soundproofing, fire and smoke protection, and suitability for wet and damp environments without compromising room closure or sealing functions.

Innovation Solution

A door panel with an L-shaped flexible element that covers the crush-critical areas on the door leaf, detachably connected via a tongue and groove or adhesive method, ensuring flexibility for finger protection and stability for sealing and soundproofing, made from materials like aluminum to enhance durability without significant weight increase.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a hollow profile is inserted in a cutout in the door leaf edge to protect against finger crushing, then finger protection is improved, but the stability and sealing function of the door leaf deteriorates

Engineering Contradiction:
Improvefinger crushing riskVSAvoiddoor leaf stability
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The flexible element is divided into two perpendicular arms forming an L-shape: one arm extends along the hinge edge and the other along the band edge. This segmentation allows each arm to independently protect specific crush-critical areas while maintaining overall structural integrity of the door leaf

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The L-shaped flexible element is inserted into an L-shaped recess that is milled into the door leaf edge. The flexible element nests within this pre-formed recess, allowing finger protection without requiring extensive material removal and preserving the door leaf's external geometry and stability

Inventive Principle:
Principle #7Nested doll (Nesting)

2Object-affected harmful factors

If the flexible element covers the entire crush-critical area including the hinge edge, then finger protection is improved, but the room closure and sealing function deteriorate

Engineering Contradiction:
Improvefinger crushing riskVSAvoidsealing function
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The flexible element is positioned locally at the crush-critical areas (hinge edge and band edge) rather than covering the entire door leaf. The L-shaped recess is strategically located to accommodate the flexible element while preserving the door leaf's external geometry and sealing surfaces, ensuring both finger protection and maintained sealing function

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution provides enhanced finger protection, maintains door stability and sealing effectiveness, and can be retrofitted into existing door assemblies, ensuring safety and performance in various environmental conditions.

Implementation Method 1

the resilience of the plastic profile is selected such that the resistance forces exerted by a human finger against compression are readily sufficient for the complete compression of the hollow profile

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2806094B1Door leaf for a door assembly
Publication Date: 2016.11.02 KUFFNER ALUZARGEN GMBH & CO OHG
  • EP2806094B1 patent drawingFigure 1a~1b
  • EP2806094B1 patent drawingFigure 2a~3
  • EP2806094B1 patent drawingFigure 4

AI summary

A door leaf (7) is provided for a door assembly (1) comprising a hinge side (71), a hinge opposite side (72), a hinge edge (73), a lock edge (74), and a flexible element (9), wherein the flexible element (9) is provided on the hinge opposite side (72) and the hinge edge (73) of the door leaf (7). The object of the present invention is to provide a door leaf (7) for a door assembly (1) that, with optimal stability regarding room closure and airtightness and without compromising door functions such as sound insulation, fire and smoke protection, and/or suitability for wet and humid rooms, ensures improved finger protection. For this purpose, the flexible element (9), which is preferably to be used on the secondary closing edge, is essentially L-shaped in cross-section.