Electromagnetic Door Opening Device for Household Appliances

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Solution Overview

Problem

Existing household appliances lack an efficient and safe method for automatically opening doors with a simple button press, often requiring power supply to the door hinges and risking user safety due to protruding components.

Innovation Solution

An electric door opening device featuring a movable ferromagnetic core slidably arranged in a guide sleeve with a coil, an attacking element that penetrates the sleeve to open the door, and a return spring system to ensure safe retraction, allowing door opening by button press without power to the door and reducing wear and contamination risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a button press mechanism is implemented for automatic door opening, then ease of operation is improved, but device complexity increases due to additional electromagnetic components

Engineering Contradiction:
Improvedoor opening operationVSAvoiddoor opening device structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The ferromagnetic core is nested within the guide sleeve, and the attack element is integrated with the core. This nested arrangement allows multiple functional elements to occupy the same spatial envelope, achieving automatic door opening functionality without significantly increasing the overall device footprint or visual complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent replaces traditional mechanical actuation mechanisms (motors, gears, linkages) with an electromagnetic field-based system. The coil generates a magnetic field that acts on the ferromagnetic core, converting electrical energy directly into mechanical motion of the attack element, thereby simplifying the mechanical structure while enabling button-press operation.

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

2Ease of operation

If power supply is routed to the door for actuation, then ease of operation is improved, but reliability deteriorates due to wear-prone power supply through door hinge

Engineering Contradiction:
Improvedoor opening operationVSAvoidpower supply connection
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent extracts the power supply connection from the door assembly and relocates it to the stationary housing. The coil is mounted on the housing and receives power from the main appliance circuitry, eliminating the need for flexible power connections through the door hinge. This extraction of the power supply function from the moving door component resolves the reliability issue.

Inventive Principle:
Principle #2Taking out (Extraction)

3Device complexity

If the attack element is connected to the ferromagnetic core, then device complexity is reduced, but wear increases at the connection point

Engineering Contradiction:
Improvedoor opening device structureVSAvoidconnection durability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the door opening mechanism into distinct functional elements: the ferromagnetic core that responds to the magnetic field, and the attack element that physically engages the door. By separating these functions into unconnected components, the design eliminates wear at connection points while maintaining structural simplicity through functional integration.

Inventive Principle:
Principle #1Segmentation

4Ease of manufacture

If the ferromagnetic core extends through a large opening in the housing wall, then ease of manufacture is improved, but contamination and moisture ingress increase

Engineering Contradiction:
Improvehousing assemblyVSAvoidcontamination and moisture
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The ferromagnetic core is nested within the guide sleeve, which itself is positioned within the housing opening. This nested arrangement allows the core to extend through a smaller opening than its full diameter would require, while the guide sleeve provides a protective barrier against contamination and moisture ingress.

Inventive Principle:
Principle #7Nested doll (Nesting)

5Reliability

If a pressure piston is added to extend the ferromagnetic core, then reliability is improved by reducing wear, but device complexity increases

Engineering Contradiction:
Improvedoor opening device durabilityVSAvoiddoor opening device structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pressure piston provides a controlled, wear-free method for extending the ferromagnetic core. Instead of relying on direct mechanical contact and manual manipulation, the piston uses fluid pressure or elastic force to push the core forward, eliminating wear at the extension interface while maintaining a relatively simple additive structure.

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

Enables safe and efficient automatic door opening by button press, eliminating the need for power supply to the door, reducing wear and contamination risks, and integrating seamlessly with existing appliances without significant production changes.

Implementation Method 1

a coil (107) for moving the movable ferromagnetic core (103), and an attack element (109) for penetrating the guide sleeve (105)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

designed such that the inductive force of the coil (107), when switched on, overcomes the force of the return spring (113)

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3102764B1Household appliance
Publication Date: 2019.03.13 BOSCH SIEMENS HAUSGERATE GMBH
  • EP3102764B1 patent drawingFigure 1~2
  • EP3102764B1 patent drawingFigure 3~4

AI summary

The invention relates to a household appliance comprising an electrical door-opening device (101), said device (101) having a mobile ferromagnetic core (103) slidingly housed in a guide sleeve (105) provided with a coil (107) for moving the mobile magnetic core (103), and having an engagement element (109) for penetrating the guide sleeve (105), said engagement element being displaceable by means of the mobile ferromagnetic core (103) in order to open a door (111).