Semi-Fixed Door Locking Rod Mechanism

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Solution Overview

Problem

Existing locking devices for semi-fixed leaves in doors or windows are complex, require specific cams and mobile locking elements on the fixed frame, leading to potential weakening and dirt-related mobility issues, and fail to provide secure multipoint locking, especially for larger leaves where wind can cause unintended opening.

Innovation Solution

A locking device featuring a rod with locking members and elastic return means, slidably mounted on a fixing support, which is pushed into a locking position by a cam when the mobile leaf closes, ensuring engagement with complementary locking members on the fixed frame, providing secure multipoint locking and resisting wind-induced opening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a latch or bolt with elastic return means is used to lock the semi-fixed leaf, then the leaf can be kept closed when the movable leaf is open, but the device becomes complex and requires mounting brackets or housings that weaken the leaf structure

Engineering Contradiction:
Improvelocking reliabilityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking device merges the rod, locking members, and elastic return means into an integrated assembly that mounts directly to the semi-fixed leaf without requiring separate mounting brackets or housings. This combination eliminates additional components and simplifies the overall structure while maintaining reliable locking functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The rod serves multiple functions: it acts as both the locking mechanism carrier and the operating element, while also providing structural reinforcement to the leaf. The locking members on the rod engage with complementary members on the frame to provide secure locking without requiring complex mounting structures.

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

2Reliability

If a mobile locking element is used on the fixed frame to engage with the bolt, then locking can be achieved, but the frame structure is weakened and dirt accumulation in the rebate causes mobility issues

Engineering Contradiction:
Improvelocking engagementVSAvoiddirt accumulation and structural weakening
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Instead of having the locking element move within a rebate in the frame, the invention inverts the approach by having the rod with locking members mount directly to the semi-fixed leaf and engage with stationary complementary locking members on the frame. This eliminates the rebate cavity where dirt accumulates and removes the mobility issues associated with moving frame elements.

Inventive Principle:
Principle #13The other way round (Inversion)

3Device complexity

If a single locking point is used, then the device is simple, but large leaves cannot resist wind-induced opening forces

Engineering Contradiction:
Improvenumber of locking pointsVSAvoidresistance to wind force
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The locking device is segmented with multiple locking members distributed along the length of the rod, allowing engagement with multiple complementary locking members on the frame at different positions. This segmentation provides multipoint locking capability that can resist wind forces on large leaves while maintaining a relatively simple overall device structure.

Inventive Principle:
Principle #1Segmentation

4Ease of operation

If the bolt is positioned near the upper and lower corners of the front stile, then engagement with the strike plate is achieved, but the leaf remains vulnerable to unintended opening

Engineering Contradiction:
Improvelocking engagementVSAvoidprevention of unintended opening
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The locking members are arranged along the length of the rod in a distributed pattern rather than concentrated at single corner positions. This spatial distribution along the rod's length creates multiple engagement points that work together to prevent unintended opening while maintaining ease of operation through the cam mechanism.

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

The solution effectively maintains the semi-fixed leaf closed on the fixed frame even when the mobile leaf is open, ensuring secure locking at multiple points and reducing stress on the locking mechanism, while allowing easy actuation and accommodating various leaf sizes.

Implementation Method 1

first elastic return means (26) tending to push said rod (12) into a locked position in which said locking member(s) (13) are capable of cooperating, each, with a complementary locking member (14)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a cam (23) defined as being able, during this closing, to cooperate with said end (20), forming an operating member, of the rod (12) of the locking device (9)

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP2907947B1Locking device for semi-fixed door or window leaf
Publication Date: 2021.08.18 FERCO
  • EP2907947B1 patent drawingFigure 1~2
  • EP2907947B1 patent drawingFigure 3~5

AI summary

The invention relates to a locking device for a semi-fixed door or window leaf mounted pivoting on a fixed frame and cooperating, in the closed position of said door or window, with a movable leaf coming over it, characterized in that it comprises a rod having, along its length, at least one locking member and mounted sliding on a fixing support, between an unlocked position and a locking position, said rod further having an end forming an operating member to push it back into the locking position in which the locking member(s) are able to cooperate, each, with a complementary locking member.