Spring-Loaded Drive Mechanism for Narrow Window Sash

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Solution Overview

Problem

Existing door and window mechanisms face limitations in narrow rotary sash elements due to collisions with other components, leading to restricted functionality and reduced service life, as well as high bending stresses and wear on the drive system.

Innovation Solution

A spring-loaded drive mechanism is introduced, where a torsion spring presses the drive against the sash, maintaining a defined position and reducing vibrations and loads, allowing for a longer service life and improved reliability by using a torsion spring engaging the lever and console, and a spacer sleeve to prevent catching, enabling the use of narrow rotary elements and arc-deflected linear chains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the drive is rigidly connected to the sash to prevent collisions during pivoting, then collision prevention is improved, but high bending stresses occur at the drive's output gear reducing fatigue strength

Engineering Contradiction:
Improvecollision preventionVSAvoidfatigue strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The drive is made dynamically connectable and disconnectable from the sash through a lever mechanism that can pivot between a connected position (during opening/closing) and a disconnected position (at end positions). This dynamic connection allows the drive to be rigidly connected only when necessary for collision prevention, while allowing stress relief when disconnected, thereby resolving the contradiction between collision prevention and fatigue strength.

Inventive Principle:
Principle #15Dynamics

2Duration of action of stationary object

If the drive is made pivotable to reduce stresses and extend service life, then service life is improved, but the drive may collide with the frame during closing due to lack of defined positioning

Engineering Contradiction:
Improveservice lifeVSAvoidoperational reliability
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The mechanical positioning system is replaced with a magnetic positioning system. A magnetic attraction device (electromagnet or permanent magnet) actively attracts the drive to a defined end position on the sash, providing precise positioning without mechanical contact or collision. This substitution maintains the benefits of pivotability for stress reduction while ensuring reliable positioning to prevent collisions with the frame.

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

3Object-affected harmful factors

If a spring is added to press the drive against the sash to eliminate rattling noise, then noise reduction is improved, but the device complexity increases

Engineering Contradiction:
Improverattling noiseVSAvoiddevice complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The spring pressing mechanism is merged with the existing magnetic positioning system. The spring provides continuous pressing force to eliminate rattling noise, while the magnetic attraction device provides precise positioning. These two functions are combined in a compact arrangement where the spring-loaded drive is magnetically attracted to the sash, achieving noise reduction without significant increase in overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

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 enhances the usability and reliability of the door or window by preventing rattling noise, reducing wear, and extending the service life of the drive mechanism, while allowing for the use of narrow rotary elements and avoiding collisions with construction parts.

Implementation Method 1

a spring may be provided to compensate for the weight of the drive

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a torsion spring is provided to apply the spring force, which engages on the one hand in the lever carrying the drive and on the other hand in the console connected to the wing or the frame

Methodology Applied
Scientific EffectTorsion spring: Torsion Spring

Data Source

PatentEP3045645B1Door or window with a drive device
Publication Date: 2021.04.14 SCHUECO INTERNATIONAL KG
  • EP3045645B1 patent drawingFigure 1
  • EP3045645B1 patent drawingFigure 2
  • EP3045645B1 patent drawingFigure 3

AI summary

The invention relates to a drive device for a sash (3) of a window or door which is pivotably mounted on a frame (1), with an electric drive (5) arranged concealed between the frame (1) and the sash (3) when the sash (3) is in the closed position, which engages with a traction element (6) which is fixed on one side for pivoting the sash (3), wherein the drive (5) is spring-loaded and pivotable about a remote pivot axis (10) on the frame (1) or sash (3).