Door Fitting with Displaceable Mandrel for Thermal Decoupling

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Solution Overview

Problem

Existing door and window locking systems, particularly those for heat-insulated sash and window frame profiles, lack reliable security solutions without compromising thermal decoupling.

Innovation Solution

A corner bracket guide with a longitudinally displaceable locking mandrel, designed to be centrally positioned and symmetrical, featuring a groove for a sealing profile and a screw connection, ensures secure locking without affecting thermal insulation, using materials like plastic for the fitting and steel for the locking mandrel to absorb shear forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a locking mechanism is installed on thermally insulated sash and frame profiles, then security is improved, but thermal decoupling is compromised

Engineering Contradiction:
ImprovesecurityVSAvoidthermal decoupling
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The locking system is divided into separate functional components: a fitting with locking mandrel for security function, and thermal break elements that maintain thermal isolation. The fitting is positioned centrally where it can provide security without creating a thermal bridge through the insulated profile structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A fitting designed as an angle with central positioning acts as an intermediary element that provides locking function while maintaining thermal decoupling. The fitting can be made of plastic or other materials that do not create significant thermal bridges, mediating between the security requirement and thermal insulation requirement.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If a locking mechanism is positioned centrally on the sash, then thermal decoupling is maintained, but installation complexity increases

Engineering Contradiction:
Improvethermal decouplingVSAvoidinstallation complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The fitting is designed as an essentially symmetrical angle piece that can be installed in any orientation without distinction between left- or right-hand mounting. This universal design simplifies installation despite central positioning, as the same component works in all orientations and locations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of operation

If the fitting is made symmetrical for universal installation, then ease of operation is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improveinstallation flexibilityVSAvoidsymmetry tolerance
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

While the overall fitting shape is symmetrical for universal installation, asymmetric features such as grooves for sealing profiles and specific fastening locations are provided on appropriate legs. This allows the fitting to maintain installation flexibility while accommodating manufacturing tolerances through functional asymmetry in non-critical areas.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP2589739B1Door fitting
Publication Date: 2019.06.05 SAPA AS
  • EP2589739B1 patent drawingFigure 1
  • EP2589739B1 patent drawingFigure 2
  • EP2589739B1 patent drawingFigure 3

AI summary

The fitting (1) has a longitudinal leg (5) and a cross arm (4). A recess (8) is extended over the entire length of longitudinal leg. A mandrel (9) is mounted longitudinally displaceable in the recess. A sealing profile (7) is inserted into side edges of fitting grooves (6) formed around the corner of the longitudinal leg and cross arm.