Door Fitting Assembly Wear Reduction via Elastic Torque Transmission

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Solution Overview

Problem

Conventional flip-up door locking systems wear down quickly due to repeated contact between elements and stops, leading to reliability issues, especially in public toilets where the door handle gets scratched.

Innovation Solution

A door fitting assembly with a rotating shaft and a door rosette that includes a rotation-limiting mechanism using a guide track and mechanical stops, coupled with an elastic torque transmission system to prevent wear and enhance longevity, allowing for easy disassembly and replacement of components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional flip-up door locking systems use repeated contact between elements and stops for rotation limitation, then the door handle can be locked and unlocked, but the elements and stops wear down quickly leading to short lifetime

Engineering Contradiction:
Improvelocking reliabilityVSAvoidservice lifetime
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent introduces a resilient element (spring) between the door handle and the stop mechanism. This cushioning element absorbs the impact and wear that would otherwise occur during repeated locking/unlocking operations. The spring deforms elastically during operation, preventing direct metal-to-metal contact and reducing wear on both the handle and stop, thereby extending service lifetime while maintaining reliable locking function.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Device complexity

If conventional flip-up door locking systems use direct mechanical connection between door handle and locking mechanism, then the structure is simple, but the door handle gets scratched and damaged due to repeated friction

Engineering Contradiction:
Improvestructural simplicityVSAvoidsurface damage
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a resilient element as an intermediary component between the door handle and the rigid locking mechanism. This mediator absorbs friction and impact forces, preventing direct contact between the handle surface and the stop mechanism. The resilient element protects the handle surface from scratching and damage while maintaining the simplicity of the overall structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the entire door locking assembly is replaced when components wear out, then reliability is restored, but costs and time are increased

Engineering Contradiction:
Improvelocking reliabilityVSAvoidmaintenance time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent divides the door locking assembly into separable components: the door handle assembly and the locking mechanism with stop. The resilient element is positioned to allow the handle to be removed and replaced independently from the locking mechanism. When wear occurs, only the handle or specific worn components need to be replaced, not the entire assembly, reducing maintenance time and costs while restoring reliability.

Inventive Principle:
Principle #1Segmentation

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 a reliable and long-lasting door locking mechanism that reduces wear on the rotation plate and mechanical stops, ensuring consistent operation while allowing for cost-effective maintenance by enabling the exchange of individual components rather than the entire assembly.

Implementation Method 1

coupled with an elastic torque transmission system to prevent wear and enhance longevity

Methodology Applied
Scientific EffectElastic torque transmission: Elasticity

Data Source

PatentEP4124707A1Door fitting assembly and flip-up door locking system
Publication Date: 2023.02.01 DORMAKABA DANMARK
  • EP4124707A1 patent drawingFigure 1
  • EP4124707A1 patent drawingFigure 2
  • EP4124707A1 patent drawingFigure 3

AI summary

The invention relates to a door fitting assembly (1) of a door, the door fitting assembly (1) comprising a door rosette (4) into which a rotating shaft (3) is insertable, wherein the door rosette (4) comprises a rotation-limiting portion (5), and a rotation plate (8) arranged in the door rosette (4), wherein the rotation-limiting portion (5) stops the rotation of the rotation plate (8) at least in a first circumferential direction (12), and wherein the door fitting assembly (1) comprises fixing means (35) for fixing a handle rosette (32) supporting the door handle (2) in a reversibly dismountable manner.