Window Locking Assembly Retention Pawl Alignment

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Solution Overview

Problem

The existing locking assemblies for windows and doors with tilting sashes often have ventilation flaps that inadvertently lock the window before it is fully closed, causing the latching hooks to misalign with the stationary locking members, preventing proper shuttting.

Innovation Solution

A security device with a retention pawl on the latching device and an unlocking member on the strike plate is introduced, which keeps the actuation slider in the unlocking position until the sash is fully closed, ensuring proper alignment and engagement of the latching hooks with the stationary locking members.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the ventilation flap is allowed to pivot freely to actuate the latching device, then the window can be locked securely, but the flap may pivot to the closed position before the sash is fully closed, causing premature locking and misalignment of latching hooks with stationary locking members

Engineering Contradiction:

Improvesecure lockingVSAvoidalignment of latching hooks

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The retention pawl is positioned to engage the actuation slider in advance, preventing the ventilation flap from pivoting until the sash is properly closed. This preliminary engagement ensures that the latching hooks are correctly aligned with the stationary locking members before locking occurs, eliminating premature locking and misalignment issues.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If the actuation slider is constrained to prevent premature locking, then proper alignment is ensured, but the device complexity increases due to the security device with retention pawl and unlocking member

Engineering Contradiction:

Improvealignment of latching hooksVSAvoidstructure of locking assembly

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The retention pawl acts as an intermediary mechanism between the ventilation flap and the actuation slider. It provides a simple yet effective constraint that prevents premature movement of the slider while allowing proper engagement when the sash is closed, maintaining alignment without significantly complicating the overall device structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If the retention pawl is spring-loaded to ensure engagement, then the actuation slider is reliably retained in unlocking position, but the device complexity and manufacturing cost increase

Engineering Contradiction:

Improveengagement of retention pawlVSAvoidcomponents of security device

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The spring-loaded mechanism provides a counteracting force that ensures the retention pawl remains engaged with the actuation slider under normal conditions. This elastic counterforce reliably prevents premature locking while allowing controlled disengagement when needed, ensuring dependable operation through simple mechanical means.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

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 solution prevents premature locking of the ventilation flap, ensuring the window can be fully closed and locked securely by maintaining the actuation slider in its unlocking position until the sash is in the closed position, thus preventing misalignment and allowing proper locking.

Implementation Method 1

said retention pawl being able to occupy a retention position in which it engages a retention part of said actuation slider to retain said actuation slider in its unlocking position

Methodology Applied

Scientific EffectMechanical engagement: Mechanical Fastener

Implementation Method 2

at least in its retention position the retention pawl is urged by elastic means which maintain it in engagement with the retention part of the actuation slide

Methodology Applied

Scientific EffectElastic force: Elasticity

Implementation Method 3

said retention pawl being able to be displaced from said retention position by said unlocking member so that it disengages from said retention part when the sash arrives in the closed position

Methodology Applied

Scientific EffectMechanical force: Mechanical Force

Implementation Method 4

an actuation slider having at least one rack portion engaged with said pinion so that a motion of said actuation slider entails said pinion to rotate

Methodology Applied

Scientific EffectRack and pinion mechanism: Rack and Pinion

Data Source

PatentEP2592210B1Locking assembly for windows or doors

Publication Date: 2015.01.21 DONG ZHIJUN

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Figure 6~11

AI summary

The locking assembly, for windows and doors having a sash arranged to be openable with respect to a main frame, comprising a strike plate designed to be mounted on the main frame and a latching device designed to be mounted on the sash, the latching device comprising a casing and at least one rotatable latching hook (11, 12) and further comprising an actuation slider (4) able to slide between a locking position which locks the sash in the closed position and an unlocking position to allow opening of the sash. The locking assembly further comprises a security device adapted to retain the actuation slider (4) in its unlocking position as long as the sash is in an open position, said security device comprising a retention pawl (30) mounted moveable on the latching device and able to occupy a retention position in which it engages a retention part (45) of the actuation slider, said retention pawl (30) being able to be displaced from said retention position by an unlocking member provided on the strike plate.