Emergency Door Securing Device with Switchable Freewheel

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Solution Overview

Problem

Existing door security devices for escape and rescue routes fail to balance high safety and comfort, particularly in fire and smoke protection applications, as they often require significant effort to open during emergencies and lack compact, easy-to-assemble designs.

Innovation Solution

A safety device with an electrically switchable freewheel device and locking mechanism, controlled by a separate control device, allowing for easy door operation during normal conditions and automatic closure during emergencies, featuring a door closer with a spring drive and optional integration with fire and smoke detection systems for enhanced security.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a door closer with locking mechanism is used to secure doors in fire protection applications, then fire protection and smoke protection are improved, but the effort required to open the door during emergencies increases

Engineering Contradiction:
Improvefire protectionVSAvoiddoor opening effort
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The door closing device dynamically switches between two operational modes: In fire protection mode, the locking mechanism engages to secure the door against forced opening. In emergency mode, the locking mechanism automatically disengages and the door closer is deactivated, allowing effortless door opening. This dynamic switching resolves the contradiction by adapting the system's behavior to different operational requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system performs preliminary actions by automatically detecting emergency conditions (smoke, heat, alarm signals) and preemptively disengaging the locking mechanism and deactivating the door closer before anyone attempts to open the door. This ensures that when emergency occupants need to exit, the door is already prepared for effortless opening, eliminating the need to force open a locked door during panic situations.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a door closer with locking mechanism is used to secure doors, then automatic closure in emergencies is improved, but the device complexity increases

Engineering Contradiction:
Improveautomatic closureVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges the door closer and locking mechanism into a single integrated door closing device. The door closer includes both the closing mechanism and the locking mechanism as unified components, with shared control logic that responds to emergency signals. This merging reduces overall system complexity compared to having separate door closer and locking device systems, while maintaining reliable automatic closure functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The door closing device performs multiple functions: normal door closing, fire protection locking, emergency automatic closure, and emergency automatic unlocking. By designing a universal device that handles all these functions through integrated control logic and shared mechanical components, the system achieves reliable automatic closure without proportionally increasing complexity. The single control unit processes different signal types (smoke detectors, heat detectors, alarm systems) and responds appropriately.

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

3Ease of manufacture

If a door closer with spring drive is used, then ease of manufacture is improved, but the ability to hold door in open position during emergencies is worsened

Engineering Contradiction:
Improvedoor closer productionVSAvoiddoor holding capability
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The spring-driven door closer dynamically adjusts its behavior based on operational mode. In normal operation, the spring provides closing force. In emergency mode, the control unit deactivates the door closer mechanism, allowing the spring to remain compressed while the door is held open by the disengaged locking mechanism. This dynamic deactivation allows the simple spring drive to provide both ease of manufacture and emergency door holding capability.

Inventive Principle:
Principle #15Dynamics

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

Ensures secure, easy access and effective fire/smoke protection by allowing effortless door opening during emergencies while maintaining automatic closure, ensuring safety and comfort without the need for mechanical changes or additional electronic controls.

Implementation Method 1

a door closer with an electrically switchable freewheel device and, in addition, a switchable locking device, which can be switched separately via a control device

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

a door closer with an electrically switchable freewheel device which switchably prevents and/or releases a force transmission from the closer spring to the linkage

Methodology Applied
Scientific EffectFreewheel mechanism: Ratchet

Data Source

PatentEP3245371B1Emergency device to secure a door in escape and rescue routes
Publication Date: 2020.01.15 ASSA ABLOY SICHERHEITSTECHNIK GMBH
  • EP3245371B1 patent drawingFigure 1
  • EP3245371B1 patent drawingFigure 2
  • EP3245371B1 patent drawingFigure 3

AI summary

The invention relates to a securing device (1) for securing a fire protection door (11) in escape and rescue routes. A locking device (4) of the door can be released by means of a rescue-route-system terminal (5) having an emergency button (51). It is also provided that the door (11) has a door closer (2), which has an electrically switchable freewheel apparatus (3) in order to enable comfortable operation of a door leaf (12) of the door. Universal use of the securing device (1), along with simultaneously high security requirements, is enabled in that a control apparatus (6) is provided, which interacts with the freewheel apparatus (3) and the locking device (4) in such a way that the control apparatus (6) switches both the locking device (4) and the freewheel apparatus (3) separately.