Door Fitting Coupling Mechanism for Secure Handle Actuation

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Solution Overview

Problem

Existing door fittings with handle couplings lack efficient mechanisms for securely coupling and decoupling the inner and outer handle spindles, leading to inconsistent operation and potential misalignment.

Innovation Solution

A detachable fitting with a coupling system comprising an active and passive coupling member, where the active member is driven by an electric motor to engage or disengage with the passive member, ensuring secure coupling and easy release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a manual coupling mechanism is used between inner and outer handle spindles, then the structure is simple, but the coupling and decoupling operation is complex and inconsistent

Engineering Contradiction:
Improvecoupling and decoupling operationVSAvoidcoupling mechanism structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces the manual mechanical coupling mechanism with an electromechanical drive system. The electric motor (222) actuates the active coupling member (202) through a gear mechanism (224, 226), automatically engaging or disengaging the restraining element (214) with the restraining recess (204) without manual intervention, thus simplifying operation while using controlled mechanical components.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The coupling mechanism is designed to automatically engage and disengage itself through the electromechanical drive. The active coupling member (202) with its restraining element (214) self-adjusts to engage with or release from the passive coupling member (201)'s restraining recess (204) based on motor actuation, eliminating the need for external manual operation.

Inventive Principle:
Principle #25Self-service

2Reliability

If the handle spindles are firmly coupled, then rotational movement is reliably transmitted, but the ability to switch between left/right operation modes is limited

Engineering Contradiction:
Improverotational movement transmissionVSAvoidleft/right switching capability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The coupling mechanism transitions from a static firmly-coupled state to a dynamic controllable state. The electromechanical drive enables the active coupling member (202) to dynamically adjust its position, engaging the restraining element (214) with the restraining recess (204) for reliable rotation transmission, or disengaging it to allow independent movement for left/right mode switching.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The coupling system is segmented into an active coupling member (202) and a passive coupling member (201) that can be independently positioned. This segmentation allows the active member to be selectively engaged or disengaged from the passive member, enabling both reliable rotational transmission when engaged and mode switching when disengaged.

Inventive Principle:
Principle #1Segmentation

3Manufacturing precision

If a simple coupling structure is used, then manufacturing is easier, but the precision of coupling engagement is insufficient

Engineering Contradiction:
Improvecoupling engagement precisionVSAvoidcoupling structure fabrication
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent extracts the precision engagement function into a dedicated electromechanical actuation system. The electric motor (222) with gear mechanism (224, 226) provides controlled, precise movement of the active coupling member (202), ensuring accurate engagement of the restraining element (214) with the restraining recess (204) without requiring complex precision machining of the entire coupling structure.

Inventive Principle:
Principle #2Taking out (Extraction)

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 efficient mechanism for coupling and decoupling the handle spindles, ensuring consistent operation and preventing misalignment, while also allowing for easy left/right switching without removing covering components.

Implementation Method 1

an active coupling member (202) which can be actuated by means of an electric motor (222)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3988743B1Fitting with a coupling
Publication Date: 2025.06.04 C ED SCHULTE GMBH ZYLINDERSCHLOSSFAB RIK
  • EP3988743B1 patent drawingFigure 1
  • EP3988743B1 patent drawingFigure 2
  • EP3988743B1 patent drawingFigure 3

AI summary

The invention relates to a fitting that can be attached to a door or the like, which supports a coupling having an active coupling member (39) and a passive coupling member (28) cooperating therewith, with which, in a coupling position in which a restraint element (41) of the active coupling member (39) engages in a restraint recess (31) of the passive coupling member (28), a lock can be operated with a push button (10), wherein in a release position of the coupling the restraint element (41) does not engage in the restraint recess (31). According to the invention, the passive coupling member (28) has a coupling cavity (29) surrounded by a cylinder inner surface of a cavity wall (30), in which the active coupling member (39) is mounted, the restraint element (41) of which lies radially within the cavity wall (30) forming the restraint recess (31) in the release position.