Electromechanical Actuator With Bistable Magnetic Mode Switching

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electromechanical actuators for concealment devices, such as Venetian blinds, face challenges with complex mechanical devices that are difficult to install and maintain, and magnetic switches that are unstable and prone to false triggering due to vibrations, making them unreliable for switching between operating modes.

Innovation Solution

A compact and reliable electromechanical actuator design featuring a tilt control device with a permanent magnet and Hall effect sensor, integrated into the actuator, which ensures stable operation and easy integration, using a bistable shutter mechanism to maintain position stability and prevent false activations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical device with gears is used to control switching between operating modes, then the device is reliable and stable in position, but the device complexity increases and installation becomes difficult

Engineering Contradiction:
Improveswitching stabilityVSAvoidmechanical device complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical switching devices with magnetic field-based detection. A permanent magnet is mounted on the output shaft, and a magnetic sensor detects its position to determine operating modes, eliminating gears and mechanical linkages while maintaining reliable switching between normal and learning modes

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

Solution Approach 2:

The patent introduces a permanent magnet as an intermediary element that transmits positional information from the output shaft to the magnetic sensor without direct mechanical contact. This intermediary enables mode detection through magnetic field interaction rather than mechanical coupling, reducing complexity while preserving reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If a magnetic switch is used to reduce device complexity, then the device becomes more compact and easier to install, but the reliability decreases due to vibration-induced false switching

Engineering Contradiction:
Improveswitching device complexityVSAvoidswitching stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent replaces contact-based magnetic switches with non-contact magnetic field sensing. The magnetic sensor detects the position of the permanent magnet on the output shaft without physical contact, eliminating the bouncing and false triggering problems associated with mechanical switches while maintaining compact design

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

Solution Approach 2:

The permanent magnet mounted on the output shaft serves dual purposes: it indicates the operating mode through its position relative to the magnetic sensor, and it provides inherent mechanical stability through its fixed mounting on the rotating shaft, eliminating the need for separate stabilization mechanisms

Inventive Principle:
Principle #25Self-service

3Reliability

If the permanent magnet is mounted on the output shaft, then the magnetic field detection becomes more stable and reliable, but the risk of the magnet detaching increases

Engineering Contradiction:
Improvemagnetic field detection stabilityVSAvoidmagnet retention strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent enhances the local mounting structure at the magnet attachment point with reinforced features such as countersunk holes, recesses, or interference-fit geometries. These localized structural enhancements provide strong mechanical retention while keeping the rest of the output shaft design simple and maintaining the magnetic field detection functionality

Inventive Principle:
Principle #3Local quality

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 stable and reliable switching mechanism between operating modes, enhancing the reliability and ease of integration of the electromechanical actuator, reducing the risk of false activations and improving the overall performance of concealment devices.

Implementation Method 1

a magnetic sensor configured to detect a position of the permanent magnet

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP4174276B9Electromechanical actuator, blackout device comprising such an actuator and method for controlling such an actuator
Publication Date: 2024.11.13 SOMFY ACTIVITES SA
  • EP4174276B9 patent drawingFigure 1
  • EP4174276B9 patent drawingFigure 2
  • EP4174276B9 patent drawingFigure 3

AI summary

An electromechanical actuator includes an electric motor, an electronic control unit (19), and a toggle control device (25) for switching the electronic control unit (19) between first and second operating modes. The toggle control device (25) includes a flap (26), pivoting relative to a housing (17F) between first and second positions, a permanent magnet (27) mounted on the flap (26), and a magnetic sensor (28) for detecting the position of the permanent magnet (27). The flap (26) includes a retaining tab (268) in position relative to the housing (17F) in each of the first and second positions of the flap (26), such that each of the first and second positions of the flap (26) is stable.