Flush Door Handle Unlocking Cylinder for Fouling Protection

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Solution Overview

Problem

Existing flush door handles with motor-actuated sliding mechanisms are prone to malfunction, leading to manual unlocking mechanisms becoming clogged and inaccessible due to exposure to the elements, compromising manual door opening.

Innovation Solution

A door handle mechanism with a protected unlocking cylinder and a coupling member featuring bevel gears or a universal joint assembly, allowing manual operation even when the motor fails, and ensuring the unlocking mechanism remains operable under normal conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the key mechanism is arranged next to the flush sliding handle, then manual opening access is enabled, but the key mechanism is exposed to weather and fouling

Engineering Contradiction:
Improvemanual opening accessVSAvoidexposure to weather and fouling
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The cylinder is nested within the hollow handle structure. The handle forms a protective housing that encloses the cylinder, allowing the cylinder to be introduced from the outside while being protected from weather and fouling during normal operation. This nesting arrangement resolves the contradiction by providing both access and protection simultaneously.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The hollow handle acts as a protective shell enclosing the cylinder. This shell structure protects the key mechanism from environmental factors while maintaining access capability through the handle's design, thus resolving the exposure issue.

Inventive Principle:
Principle #30Flexible shells and thin films

2Strength

If the cylinder is fixed during door assembly, then structural integrity is maintained, but finishing operations cannot be performed without affecting the unlocking mechanism

Engineering Contradiction:
Improvestructural integrityVSAvoidfinishing operations
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The cylinder mounting transitions from a fixed state during assembly to a removable state during finishing operations. The screw-fastening mechanism allows the cylinder to be easily removed and reinstalled, providing dynamic adaptability that resolves the contradiction between structural integrity and manufacturing flexibility.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The cylinder is designed as a separate, removable component rather than being permanently integrated into the door structure. This segmentation allows the cylinder to be removed during finishing operations and reinstalled afterward, maintaining both structural integrity and manufacturing ease.

Inventive Principle:
Principle #1Segmentation

3Object-affected harmful factors

If the handle is designed to slide between rest and working positions, then the lock is protected from fouling, but the key mechanism remains vulnerable when not in use

Engineering Contradiction:
Improvelock protectionVSAvoidkey mechanism reliability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The cylinder is nested within the hollow handle structure, which provides continuous protection regardless of the handle's position. This nesting arrangement ensures the key mechanism is protected from fouling both when the handle is in the rest position and when it is in the working position, resolving the reliability issue.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 mechanism ensures reliable manual operation by protecting the unlocking mechanism from fouling, maintaining accessibility and functionality even in the event of motor failure.

Implementation Method 1

the coupling member comprises bevel gears

Methodology Applied
Scientific EffectGear mechanism: Gear

Implementation Method 2

the coupling member comprises a universal joint assembly

Methodology Applied
Scientific EffectUniversal joint: Gimbal

Data Source

PatentEP3404176B2Device for unlocking a door latch
Publication Date: 2026.05.13 U SHIN ITALIA SPA
  • EP3404176B2 patent drawingFigure 1~4
  • EP3404176B2 patent drawingFigure 5~6
  • EP3404176B2 patent drawingFigure 7~8

AI summary

The invention relates to a device for unlocking a door lock associated with a door handle (1) mounted to slide in an opening (5) of the door between a rest position in which the handle is flush with the door and a position work in which the handle projects with respect to the door, the unlocking device comprising a cylinder (37) carried by a support directly or indirectly fixed to the door, the cylinder being connected to an unlocking element of the lock by the intermediary of an operating member of the unlocking element of the lock, in which the cylinder (37) is mounted to emerge facing the handle in an inclined manner with respect to a direction normal to the door, the inclination preferably being sufficient to allow the introduction of the cylinder into the box when the handle is in the working position