Espagnolette Drive Pinion Angled Axis Compact Design

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Solution Overview

Problem

Existing window or door locking bar drives have a large overall length due to the need for a minimum distance between the drive pinion and output pinion, which limits their compactness without compromising functionality.

Innovation Solution

The drive pinion is equipped with helical or herringbone gearing, and the drive rack is similarly geared, with the output pinion's axis of rotation positioned obliquely to reduce the center distance between the pinions, allowing for a compact design and enabling the toothed rack to swivel past window frames without obstruction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the output pinion is positioned in line with the drive pinion, then the gear meshing is simple and easy to manufacture, but the overall length of the drive becomes large

Engineering Contradiction:
Improvegear meshing simplicityVSAvoidoverall length of drive
Core Design Contradiction:
Ease of manufactureVSLength of moving object

Solution Approach 1:

The output pinion is positioned at an angle of 45 degrees relative to the drive pinion, changing the spatial arrangement from a linear one-dimensional layout to a two-dimensional angular configuration. This dimensional change allows the gear stages to overlap partially, reducing the overall length of the drive while maintaining proper gear meshing through the angled tooth profiles.

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

2Length of moving object

If the center distance between drive pinion and output pinion is reduced, then the drive becomes more compact, but the gear meshing quality and load distribution deteriorate

Engineering Contradiction:
Improvecenter distance between pinionsVSAvoidgear meshing quality
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The tooth profiles of both the drive pinion and output pinion are designed with specific angular parameters (45-degree inclination) that change the geometry of the gear engagement. This parameter change allows the gears to mesh properly at reduced center distances while maintaining load distribution and meshing quality through the modified tooth contact patterns.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If the toothed rack is designed to swivel with tight radii, then the adaptability to window frames improves, but the structural complexity of the rack increases

Engineering Contradiction:
Improveswiveling capability of toothed rackVSAvoidstructural complexity of toothed rack
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The toothed rack is designed with a curved, arc-shaped tooth profile instead of a straight linear profile. This curvature allows the rack to swivel along arc paths with tight radii when adapting to different window frame configurations, while the continuous curved geometry maintains structural simplicity compared to using multiple discrete components or complex adjustment mechanisms.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 results in a more compact and versatile drive system that can be used on both sides, reducing material and production complexity while maintaining functionality, and allows for easy installation and high prefabrication levels.

Implementation Method 1

the drive pinion is provided with helical or herringbone gearing and the drive rack is equipped with a corresponding helical or herringbone gearing

Methodology Applied
Scientific EffectHelical gearing: Gear

Implementation Method 2

the drive pinion is provided with helical or herringbone gearing and the drive rack is equipped with a corresponding helical or herringbone gearing

Methodology Applied
Scientific EffectHerringbone gearing: Gear

Implementation Method 3

the axis of rotation of the output pinion runs obliquely with respect to the axis of the drive pinion running parallel to the displacement plane of the drive rack

Methodology Applied
Scientific EffectGear meshing: Gear

Data Source

PatentEP2770144B1Drive for an espagnolette fitting of a window or a door
Publication Date: 2017.12.20 SCHUECO INTERNATIONAL KG
  • EP2770144B1 patent drawingFigure 1
  • EP2770144B1 patent drawingFigure 2
  • EP2770144B1 patent drawingFigure 3

AI summary

The drive (5) has a casement frame (3) that is rotatably mounted on a handle (4) and a gear. The housing is provided with a mounted drive pinion meshing with a drive rack and an output gear. The toothed rack is meshed with a tie rod (6) coupled to the housing guided in a longitudinally displaceable portion. The axis of rotation of the driven pinion is parallel with respect to the displacement plane of the driving toothed rod. The extending axis of the drive pinion is oblique to the displacement plane of the handle facing away from an acute angle.