Magnetic Closure with Concentric Interlocking for Automatic Centering

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Solution Overview

Problem

Existing magnetic closure devices for leather goods and textiles face issues such as axial alignment requirements, surface damage, unattractive thickness, incomplete insertion, and premature wear due to the contact of fragile magnet parts, which compromise magnetic holding force and aesthetic appeal.

Innovation Solution

A magnetic closure device with concentric interlocking components featuring proportional and complementary parts, allowing automatic centering and double insertion, where each assembly has a permanent magnet with axial magnetization and a non-magnetic capsule to protect the magnet, ensuring the central ferromagnetic parts connect without direct contact, enhancing magnetic retention and reducing wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the protruding ferromagnetic part is attracted to the magnet on the outer periphery, then magnetic coupling occurs, but axial alignment cannot be achieved automatically and surface damage occurs

Engineering Contradiction:
Improveautomatic axial alignmentVSAvoidsurface damage and scratches
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The magnetic assembly is segmented into distinct functional parts: an outer magnet providing magnetic attraction and an inner ferromagnetic protruding part providing mechanical alignment. This segmentation allows the magnetic force and alignment function to be separated, enabling automatic centering without surface contact damage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The inner ferromagnetic protruding part acts as an intermediary between the outer magnet and the opposing assembly. It is attracted to the magnet but provides a centered interface that prevents direct contact between opposing surfaces, eliminating scratches while maintaining magnetic coupling.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the two magnets overlap completely, then axial alignment is achieved, but the closure becomes thick and unsightly

Engineering Contradiction:
Improveautomatic axial alignmentVSAvoidclosure thickness
Core Design Contradiction:
Ease of operationVSLength of stationary object

Solution Approach 1:

The inner ferromagnetic protruding part is nested within the outer magnet structure. This nested configuration allows the magnetic assembly to achieve automatic alignment while maintaining a compact, thin profile, as the components are concentric rather than overlapping.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Force

If the ferromagnetic parts do not contact each other, then magnetic holding force is sufficient, but the fragile magnets experience premature wear

Engineering Contradiction:
Improvemagnetic holding forceVSAvoidmagnet durability
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

Instead of having the fragile magnets contact each other directly, the design inverts the contact arrangement: the durable ferromagnetic protruding parts contact each other, while the magnets remain separated. This transfers the mechanical wear to the more durable ferromagnetic components.

Inventive Principle:
Principle #13The other way round (Inversion)

4Force

If larger and more powerful magnets are used, then magnetic holding force increases, but damage risk to electronic devices and credit cards increases

Engineering Contradiction:
Improvemagnetic holding forceVSAvoiddamage to electronic devices and credit cards
Core Design Contradiction:
ForceVSObject-affected harmful factors

Solution Approach 1:

The magnetic field is concentrated locally at the inner ferromagnetic protruding part rather than being distributed across a large magnet surface. This allows sufficient holding force to be achieved with smaller magnets, reducing the risk of damage to nearby electronic devices and credit cards.

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 achieves automatic centering and increased magnetic holding force, allowing for a thin and aesthetically pleasing closure with enhanced shear holding, reducing wear on appearance parts and maintaining magnetic retention with smaller magnets.

Implementation Method 1

a first permanent magnet with axial magnetization... said first magnet being disposed on the surface of the first ferromagnetic base... Magnetic engagement occurs when the two parts are perfectly aligned axially

Methodology Applied
Scientific EffectMagnetic attraction: Magnetism

Implementation Method 2

the protruding ferromagnetic part of the second assembly is irresistibly attracted to the magnet located on the outer periphery of the central opening of the first assembly

Methodology Applied
Scientific EffectMagnetic attraction: Magnetism

Data Source

PatentEP3651597B1Magnetic closure device using concentric interlocking of the parts forming the magnetic assemblies with automatic centring and double insertion
Publication Date: 2021.06.02 F B S FOX BRANDS SERVICES
  • EP3651597B1 patent drawingFigure 1~2
  • EP3651597B1 patent drawingFigure 3~12
  • EP3651597B1 patent drawingFigure 13~14

AI summary

A magnetic closure device using concentric interlocking of the parts forming the magnetic assemblies with automatic centring and double insertion, intended to removably connect a first surface (15) and a second surface (15A). In such a way that, when the two magnetic assemblies are moved towards each other, the first magnetic assembly (F) and the second magnetic assembly (M) are automatically aligned axially, the second magnetic assembly (M) is inserted into the first central opening (5E) of the first capsule (5) of the first magnetic assembly (F), thus providing a first insertion and, at the same time, the first protruding central ferromagnetic portion (2A) of the first magnetic assembly (F) is inserted into the second central opening (10E) of the second capsule (10) of the second magnetic assembly (M), thus providing the second insertion, the first (4) and second (9) magnets, respectively, of the first (F) and second (M) magnetic assemblies, are situated more or less on a same horizontal plane, the first (2A) and the second (7A) protruding ferromagnetic portions, respectively of the first and second magnetic assemblies, are connected to each other and hold the first and second magnetic assemblies together magnetically. The present invention produces a double insertion closure that is extremely thin and aesthetic. Said closure device is mainly intended for removably connecting a first surface (15) and a second surface (15A) of an article or accessory.