Door Handle Fitting with Radially Movable Slide

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Solution Overview

Problem

Existing door and window handle fittings fail to maintain the handle in a horizontal position over time due to wear and require special tools for installation and removal, making them impractical for assembly and maintenance.

Innovation Solution

A fitting design featuring a radially movable slide with a retaining clip that engages in a slot, allowing for a form-fitting connection without play, and utilizing spring elements for preload, enabling easy installation and maintenance with standard tools, and ensuring the handle remains in a horizontal position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a square mandrel connection is used for the handle, then the handle can be connected to the fitting, but the handle position drifts downward over time due to wear and play between components

Engineering Contradiction:
Improvehandle position stabilityVSAvoidservice life before position drift
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The retaining clip is mounted on a radially movable slide that can dynamically adjust its position. During installation, the slide moves radially outward to release the retaining clip from the groove recess, allowing handle insertion. After installation, the slide moves radially inward to engage the retaining clip securely in the groove, preventing position drift. This dynamic adjustment mechanism ensures long-term positional stability without wear-induced play.

Inventive Principle:
Principle #15Dynamics

2Ease of repair

If the retaining clip is designed as an elastic ring that can be pulled apart, then the door handle can be released, but special tools are required and the structure becomes more complex

Engineering Contradiction:
Improvehandle removal easeVSAvoidretaining clip mechanism complexity
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

A radially movable slide is introduced as an intermediary mechanism between the retaining clip and the user. The slide translates radial movement into engagement/disengagement of the retaining clip with the groove recess. During installation, the slide moves radially outward to release the clip; during normal operation, it holds the clip engaged. This intermediary mechanism enables simple tool-free operation while maintaining a relatively compact structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the receiving device has a form-fitting opening for the door handle, then the connection is secure without play, but the handle cannot be easily installed or removed

Engineering Contradiction:
Improveconnection securityVSAvoidinstallation ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The connection system is segmented into three functional components: the form-fitting opening in the receiving device for secure connection, the retaining clip mounted on the movable slide for engagement/release, and the groove recess in the handle for mechanical interlocking. The form-fitting opening provides reliable positional accuracy, while the retaining clip mechanism on the movable slide provides easy installation and removal by temporarily disengaging from the groove recess.

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 ensures the handle remains in a horizontal position, allows for non-destructive assembly and disassembly, and can be installed and maintained using standard tools, improving usability and reliability.

Implementation Method 1

The preload on the receiving device is preferably generated by spring elements, so that the receiving device is moved back into its initial position after the door handle has been actuated.

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP1918492B1Fitting for the mounting of a handle on a door or a window
Publication Date: 2014.06.11 DORMA GMBH & CO KG
  • EP1918492B1 patent drawingFigure 1
  • EP1918492B1 patent drawingFigure 2
  • EP1918492B1 patent drawingFigure 3

AI summary

The fitting has a retainer device for a door handle (2) arranged within a lower part in a rotatable manner, where the retainer device is provided in a rotating direction of the door handle. The retainer device has an opening (22), which corresponds with a guiding surface (4) of the door handle in a positive manner. Pre-stressing is produced on the retainer device by a spring unit, so that the retainer device is movable after operating the door handle. The retainer device is surrounded by a slider unit, where the spring unit influences on the slider unit.