Central-Position Espagnolette Lock for Double-Leaf Door Access

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Solution Overview

Problem

Existing motorized locks for double-leaf doors are complex, expensive, and require idle time for full unlocking, especially in emergency situations, lacking immediate and secure access to the active leaf when the passive leaf is locked.

Innovation Solution

A shoot bolt lock mechanism with a lock housing and retractable slides, allowing manual or motorized operation, where the retractable slides are actuated synchronously with bolt and latch ejectors, ensuring continuous motor engagement for rapid unlocking, and manual operation from any position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a motorized lock is used to unlock the active leaf independently, then the active leaf can be opened while the passive leaf remains locked, but the system becomes complex and expensive

Engineering Contradiction:
ImproveIndependent opening capabilityVSAvoidLock system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The passive leaf lock is designed to perform multiple functions: it can lock both door leaves simultaneously and unlock only the active leaf independently. By integrating the bolt ejector and latch ejector into the passive leaf lock mechanism, the system achieves daytime lock functionality without requiring a separate motorized lock on the active leaf, thereby reducing overall system complexity while maintaining versatility

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

2Ease of operation

If sequential actuation is used to unlock the espagnolette rods, then the latch ejector and bolt ejector are unlocked first, but idle time is required before the espagnolette rods can be unlocked

Engineering Contradiction:
ImproveControlled unlocking sequenceVSAvoidIdle time for full unlocking
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The motor is designed to simultaneously actuate the bolt ejector, latch ejector, and espagnolette rods from the beginning of the unlocking sequence. By preparing all components to be unlocked in parallel rather than sequentially, the system eliminates idle time and achieves immediate full unlocking capability, which is critical for emergency release scenarios

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If the motor must reverse actuation direction to unlock the deadbolt rods, then full unlocking is achieved, but immediate and secure unlocking is not possible from every position

Engineering Contradiction:
ImproveFull unlocking capabilityVSAvoidUnlocking speed
Core Design Contradiction:
Adaptability or versatilityVSSpeed

Solution Approach 1:

The motor mechanism is configured to simultaneously engage and actuate all locking components (bolt ejector, latch ejector, and espagnolette rods) from any intermediate position. By designing the drive mechanism to maintain continuous engagement with all components throughout the motor's travel range, the system enables immediate full unlocking without requiring reversal of actuation direction, thereby achieving both versatility and speed

Inventive Principle:
Principle #10Preliminary action

4Adaptability or versatility

If a two-stage movement sequence is used to unlock the shoot-bolt lock, then the lock can be unlocked, but the design becomes very complex with multitude of interacting gear elements

Engineering Contradiction:
ImproveManual and motorized unlockingVSAvoidGear mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent removes the complex multi-stage gear mechanism from the shoot-bolt lock design. Instead of using a two-stage movement sequence with multiple interacting gear elements, the invention directly couples the motor output to the bolt ejector, latch ejector, and espagnolette rods through a simplified drive mechanism. This extraction of unnecessary complexity maintains the versatility of manual and motorized unlocking while dramatically reducing the number of moving parts and potential failure points

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4624705A1Method for operating an espagnolette lock with central position of a double-leaf dooor and espagnolette lock with central position for double-leaf door
Publication Date: 2025.10.01 ASSA ABLOY SICHERHEITSTECHNIK GMBH
  • EP4624705A1 patent drawingFigure 1
  • EP4624705A1 patent drawingFigure 2
  • EP4624705A1 patent drawingFigure 3

AI summary

The invention relates to a drive bolt lock (2) for a passive leaf (14) comprising a lock housing (21) with at least one retracting slide (241) and a drive bolt rod (24) as well as a bolt ejector (5) and/or a latch ejector (4), wherein the drive bolt lock (2) can be manually unlocked by means of a lock nut (23) rotatably mounted in the lock housing (21) and can be motor-unlocked by means of a motor (3) with a control device (7) accommodated in the lock housing (21).In order to create a cost-effective solution for permanently passing through an active leaf (15) of a double-leaf door (11) with the passive leaf (14) locked at the same time, which solution offers a high level of functional reliability, it is proposed that the control device (7) actuates the motor (3) into a central position in which the motor (3) has moved the bolt ejector (5) and/or the latch ejector (4) into the unlocked position, and the espagnolette rod (24) is still in a locked position in order to lock the passive leaf (14).