Double-Armed Lever Locking Element for Window Tilt Fitting Stability

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Solution Overview

Problem

Existing tilt fittings for windows and doors face sealing issues due to inadequate contact pressure in less stressed areas, leading to reduced service life when attempting to increase prestress, which compromises energy efficiency.

Innovation Solution

A double-armed lever locking element is articulated to the first scissor link, engaging behind an abutment and guided on a guide pin or track, stabilizing the tilt fitting and eliminating play in the closed position, thereby enhancing contact pressure and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the preload in the contact area of the tilt fitting is increased to increase contact pressure in less stressed areas, then sealing performance is improved, but the load on the pivot joints becomes so high that service life is reduced

Engineering Contradiction:
Improvesealing performanceVSAvoidservice life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The locking element is divided into two separate arms: a first arm that engages with the abutment to provide locking action, and a second arm that guides along the guide pin or guide track to distribute loads. This segmentation allows the contact pressure to be increased for better sealing while the guide arm distributes the load across multiple contact points, preventing excessive stress on single pivot joints and extending service life.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If the tilt mechanism is placed in the upper area of the sash or frame furthest from the opening to simplify construction, then device complexity is reduced, but contact pressure decreases towards the farther side leading to sealing problems

Engineering Contradiction:
Improveconstruction simplicityVSAvoidsealing performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The locking element acts as an intermediary mechanism between the scissor element and the abutment. It transmits and distributes the contact pressure generated by the tilt mechanism throughout the connection structure, ensuring uniform pressure distribution across the contact area even when the mechanism is positioned in the upper area. This intermediary component prevents pressure concentration and maintains sealing performance without complicating the overall construction.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the tilt fitting is designed with traditional single-armed locking to reduce complexity, then device complexity is reduced, but play remains in the closed position reducing stability

Engineering Contradiction:
Improvelocking mechanism simplicityVSAvoidstability in closed position
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The locking element is segmented into two functional arms: the first arm engages with the abutment to eliminate play and provide stability, while the second arm guides along the guide pin or guide track to maintain proper alignment. This segmentation allows the mechanism to remain relatively simple while achieving both stability and precision through the coordinated action of the two arms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The locking element introduces a new dimensional aspect to the traditional single-point locking mechanism. By using two arms operating in different spatial dimensions (one for engagement, one for guidance), the system achieves multi-dimensional constraint that eliminates play while maintaining simplicity. The guide arm adds a guidance dimension that works together with the engagement arm to provide comprehensive stabilization.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

This design ensures a stable and play-free operation of the tilt fitting, maintaining a tight contact between the sash and frame, thus improving sealing and reducing wear, leading to increased service life and energy efficiency.

Implementation Method 1

a double-armed lever (31) which is articulated to the first scissor link (2), which forms a locking element, since one of the arms (31a) engages a support in the closed position of the tilt fitting and is guided with its other arm (31b) on a guide pin or guide track

Methodology Applied
Scientific EffectLever: Lever

Implementation Method 2

a first scissor link (2) and a second scissor link (3) pivotably connected to it by means of a pivot pin (8), wherein the first scissor link (2) is held longitudinally displaceable in the connecting rail (6), while the second scissor link (3) is hinged to the connecting rail (6) via a pivot pin (10)

Methodology Applied
Scientific EffectHinge: Hinge

Data Source

PatentEP3339544B1Tilt fitting for wing of a window or a door
Publication Date: 2020.11.11 SCHUECO INTERNATIONAL KG
  • EP3339544B1 patent drawingFigure 1
  • EP3339544B1 patent drawingFigure 2~3
  • EP3339544B1 patent drawingFigure 4~6

AI summary

The invention relates to a tilt fitting for a window or door sash, with a connecting rail (6) to which a scissor element (1) with a first (2) and a second scissor member (3) is connected, wherein a support rail (4) is hinged to the free end of the first scissor member (2) and the tilt fitting is provided with a locking element, wherein the locking element is designed as a double-armed lever (31) hinged to the first scissor member (2), which engages a support with one of its arms (31a) in the closing position and is guided with its other arm (31b) on a guide pin or a guide track.