Espagnolette Lock Flush Support Surface Design

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Solution Overview

Problem

Existing window and door closure mechanisms either have protruding hooks that complicate cleaning and pose a risk of injury when open, or they fail to ensure even tightening against the frame when closed due to misaligned pivot axes.

Innovation Solution

A lock design featuring a locking element with a flush support surface in the open position, merging with the housing, and a stop for reliable positioning, along with a pot-shaped housing and peripheral fastening flange to ensure even closure and reduced air gaps, and optional features like ramps and chamfers for smooth operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the locking element has a protruding hook design to ensure secure locking, then the locking reliability is improved, but the ease of cleaning and safety in open position deteriorates

Engineering Contradiction:
Improvelocking reliabilityVSAvoidease of cleaning
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The locking element transitions between two dynamic states: protruding in closed position for secure locking, and retracted in open position for safety and cleaning. The element is displaceable between these positions, allowing it to adapt its geometry based on operational requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The locking element is designed as a separate, movable component that can be independently positioned relative to the housing. This segmentation allows the locking element to be retracted into the housing when not in use, separating the locking function from the open position geometry.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If the pivot axis is arranged parallel to the connecting rod for even tightening, then the uniformity of closure is improved, but the device complexity increases

Engineering Contradiction:
Improveuniformity of closureVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The connecting rod serves multiple functions: it acts as both the drive mechanism for the locking element and the pivot axis for the locking element itself. This multi-functionality eliminates the need for a separate pivot axis component, reducing device complexity while maintaining the parallel arrangement for even tightening.

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

3Object-affected harmful factors

If the locking element is completely countersunk in open position to eliminate protrusions, then the safety and ease of cleaning are improved, but the positioning reliability deteriorates

Engineering Contradiction:
ImprovesafetyVSAvoidpositioning reliability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The locking element automatically positions itself in the retracted state when in the open position through the mechanical connection with the connecting rod. The geometry of the connecting rod and locking element ensures that when the rod is in its open position orientation, the locking element is forced into the retracted position, providing self-positioning without additional components.

Inventive Principle:
Principle #25Self-service

4Reliability

If the housing is pot-shaped with peripheral fastening flange to reduce air gaps, then the sealing performance is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvesealing performanceVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The fastening flange is merged with the pot-shaped housing as an integrated feature rather than a separate component. The flange extends from the housing body and provides both structural support and sealing surface, combining multiple functions into a single manufactured part that reduces air gaps while maintaining ease of manufacture.

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 design allows for easy cleaning and even tightening of the sash against the frame, eliminating protruding hazards and ensuring reliable positioning, while maintaining structural stability and minimizing material usage.

Implementation Method 1

The bolt is biased into a protruding position by means of a spring element

Methodology Applied
Scientific EffectSpring element bias: Spring

Implementation Method 2

the locking element prestresses the counter bearing in the closed position in such a way that the sash of the window or French door is pressed against the frame

Methodology Applied
Scientific EffectPrestress: Mechanical Force

Data Source

PatentEP2458120B1Closure of espagnolette
Publication Date: 2018.10.17 WINKHAUS
  • EP2458120B1 patent drawingFigure 1~2
  • EP2458120B1 patent drawingFigure 3~4

AI summary

The lock has a housing (12) and a locking element (7) pivoting around a pivot axis (10), where the locking element is arranged parallel to a drive rod. The housing is driven by the longitudinally displaced drive rod. The locking element has a support surface (8), with which the locking element closes fully with the housing in the open position and passes the upper surfaces (16,17) of the locking element and the housing continuously into each another.