Fast-Acting Actuator with Magnetic Hold and Spring-Driven Large Stroke

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Solution Overview

Problem

Existing electromagnetic actuators have limitations in switching speed, especially at larger strokes, which affects their performance in applications requiring fast and efficient actuation.

Innovation Solution

A fast-switching actuator device with a mechanical clamping element, armature element, magnetic unit, and reset unit, allowing for a rapid positioning movement with a large stroke, achieved through a combination of mechanical and magnetic forces, and a motor-driven reset mechanism for controlled movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If electromagnetic actuators are used for fast switching, then switching speed is improved, but achievable stroke is limited

Engineering Contradiction:
Improveswitching speedVSAvoidachievable stroke
Core Design Contradiction:
SpeedVSLength of moving object

Solution Approach 1:

The actuator device is divided into two functional segments: a magnetic unit for fast positioning (first end position) and a mechanical clamping element for stroke extension (second end position). This segmentation allows each component to optimize its specific function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent combines electromagnetic actuation (magnetic unit) with mechanical spring storage (clamping element) into a hybrid system. The magnetic unit provides rapid initial movement while the pre-tensioned clamping element delivers extended stroke, achieving both fast switching and large displacement.

Inventive Principle:
Principle #5Merging (Combining)

2Length of moving object

If large stroke is achieved through mechanical means, then switching speed decreases

Engineering Contradiction:
ImprovestrokeVSAvoidswitching speed
Core Design Contradiction:
Length of moving objectVSSpeed

Solution Approach 1:

The mechanical clamping element is pre-tensioned during the fast magnetic positioning phase to store elastic energy. This preliminary action enables the clamping element to rapidly extend the stroke afterward without slowing down the overall switching speed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system maintains continuous useful action by seamlessly transitioning from magnetic actuation to mechanical spring-driven movement. The magnetic unit completes its fast positioning while the clamping element simultaneously extends the stroke, ensuring uninterrupted motion throughout the switching cycle.

Inventive Principle:
Principle #20Continuity of useful action

3Speed

If fast positioning movement with large stroke is achieved, then installation space increases

Engineering Contradiction:
Improvepositioning speedVSAvoidinstallation space
Core Design Contradiction:
SpeedVSArea of stationary object

Solution Approach 1:

The magnetic unit and mechanical clamping element are arranged in a nested configuration where the clamping element surrounds or integrates with the magnetic unit. This nesting allows both components to occupy overlapping spatial volumes, reducing the overall installation footprint.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent utilizes three-dimensional spatial arrangement where the clamping element operates in a direction perpendicular to or overlapping with the magnetic unit's actuation direction. This dimensional optimization allows compact packaging while maintaining full stroke capability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Speed

If mechanical clamping element is used for fast movement, then component wear increases

Engineering Contradiction:
Improvemovement speedVSAvoidservice life
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent replaces direct mechanical contact for the initial fast positioning with a magnetic field-based actuation system. This substitution eliminates wear during the high-speed phase, while the mechanical clamping element only engages for the slower stroke extension where wear is less critical.

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

Solution Approach 2:

The system changes the operating parameters of the mechanical clamping element by pre-tensioning it during the fast magnetic phase. This allows the clamping element to operate in a controlled elastic deformation range that minimizes fatigue and wear while maintaining fast response capability.

Inventive Principle:
Principle #35Parameter changes

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

Enables a fast positioning movement with a large stroke in a compact design, ensuring high switching speed and extended service life by optimizing the actuator's operation and protecting components from excessive wear.

Implementation Method 1

a magnetic unit (18) which is provided to hold the armature element (12) in the first end position (14), preferably directly, by means of a magnetic field generated by the magnetic unit (18)

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

The mechanical clamping element (10) is arranged to be pre-tensioned during a first positioning movement by the armature element (12) from a first end position (14) to a second end position (16) and thereby store elastic energy

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4256595B1Fast-acting actuator device
Publication Date: 2026.03.18 ETO MAGNETIC GMBH
  • EP4256595B1 patent drawingFigure 1
  • EP4256595B1 patent drawingFigure 2
  • EP4256595B1 patent drawingFigure 3

AI summary

A fast-acting actuator device (68), in particular a circuit breaker device, is proposed, having a mechanical clamping element (10), having an armature element (12) which can be preloaded by the mechanical clamping element (10) and which, driven by relaxation of the mechanical clamping element (10), is movable from at least one first end position (14) into at least one second end position (16), having a magnet unit (18) which is provided to hold the armature element (12) in the first end position (14) by means of a magnetic field generated by the magnet unit (18), and having a resetting unit (20) which is provided to move back the armature element (12) at least from the second end position (16) into the first end position (14) by means of a motor-driveable resetting element (22) and, in the process, to preload the mechanical clamping element (10).