Electromagnetic Locking Device for Automatic Door Drive

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Solution Overview

Problem

Existing locking devices for automatic door closure systems, particularly in fire protection doors, are mechanically complex, prone to errors, and have high internal friction losses, making them less reliable and more difficult to manufacture with precise tolerances.

Innovation Solution

A simplified locking device with a blocking element and a stunning electromagnet, coupled with a compact coupling gear that translates magnetic force into a holding force to block the slide stone's movement, reducing the need for complex mechanical structures and spring elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional locking mechanisms with spring elements are used to generate holding force, then the locking device can maintain the door in an open position, but the mechanical design becomes complex and susceptible to errors

Engineering Contradiction:
Improveoperational reliabilityVSAvoidmechanical design complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the conventional spring-based mechanical holding system with an electromagnet-based system. The electromagnet generates the holding force electrically, eliminating the need for complex spring elements and mechanical energy storage devices. This substitution reduces mechanical complexity while maintaining reliability, as the electromagnet provides direct and controllable holding force without mechanical friction or wear issues.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the fundamental parameter of force generation from mechanical (spring elasticity) to electromagnetic (magnetic field). This parameter change allows for a simpler design where the holding force is generated on-demand through electrical activation, eliminating the need for pre-loaded mechanical elements and reducing the overall mechanical complexity of the locking device.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If spring elements are used to provide holding force, then the locking function is achieved, but the size of spring elements complicates the compact design

Engineering Contradiction:
Improveholding force reliabilityVSAvoidholding device volume
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The electromagnet replaces bulky spring elements with a compact electromagnetic actuator. The armature rod and electromagnet assembly occupy significantly less space than the spring elements required to generate equivalent holding force, enabling a more compact overall design of the locking device while maintaining reliable holding capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If conventional locking mechanisms are used, then the sliding block can be locked, but internal friction losses occur that are not negligible

Engineering Contradiction:
Improvelocking functionVSAvoidinternal friction losses
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent replaces friction-prone mechanical components with an electromagnet that generates holding force through magnetic field interaction. This eliminates or significantly reduces internal friction losses associated with spring elements, pivot points, and mechanical linkages, improving energy efficiency while maintaining reliable locking function.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If precise manufacturing tolerances are maintained to ensure high operational reliability, then the locking device functions correctly, but the manufacturing process becomes more difficult

Engineering Contradiction:
Improveoperational reliabilityVSAvoidmanufacturing difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The electromagnet-based system reduces sensitivity to manufacturing tolerances compared to precision mechanical assemblies. The magnetic field generation and armature rod actuation are less susceptible to cumulative tolerance errors than multi-component mechanical linkages, making the device easier to manufacture while maintaining high operational reliability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 provides a mechanically simple, compact, and reliable locking mechanism with low error susceptibility and high operating safety, effectively addressing the complexities and inefficiencies of existing systems.

Implementation Method 1

the electromagnet (60), in its energized state, displaces the armature rod (64) into an active position in which the armature rod locks the blocking element (14) in its blocking position

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Implementation Method 2

a coupling mechanism (20) with which a magnetic force (72) of the electromagnet (60) is translated into a holding force (18)

Methodology Applied
Scientific EffectForce transmission through mechanical advantage: Mechanical Advantage

Data Source

PatentEP4325015B1Fixing device and door drive
Publication Date: 2025.05.07 GEZE GMBH
  • EP4325015B1 patent drawingFigure 1
  • EP4325015B1 patent drawingFigure 2
  • EP4325015B1 patent drawingFigure 3

AI summary

The present invention relates to a locking device (10) for locking a sliding block (80) of a door drive (100) for automatically closing a door, which is slidably mounted in a slide rail (110), wherein the locking device (10) has a locking element (14) with a locking section (16) and an energizable electromagnet (60), wherein the locking element (14) is movable between a release position and a locking position and, in the mounted state, in its locking position, together with the locking section (16), blocks a movement of the sliding block (80) past the locking element (14) coupled with a closing movement (82) of the door, and wherein the electromagnet (60), in its energized state, locks the locking element (14) in its locking position.Furthermore, the invention relates to a door drive (100) for automatically closing a door, comprising a slide rail (110) and a sliding block (80) slidably mounted in the slide rail (110) as well as a locking device (10) for locking the sliding block (80).