Automatic Darkening Filter Assembly With Nested Gaskets

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Solution Overview

Problem

Existing automatic darkening filters for welding protectors often lack effective mechanical shock resistance and durability, leading to potential damage from handling or drops, and may not adequately protect the switchable light filter from dust and moisture.

Innovation Solution

The automatic darkening filter assembly incorporates a two-part gasket system to securely hold the switchable light filter in place, providing enhanced mechanical shock resistance and protection from dust and moisture, while also utilizing a housing with a frame to clamp the filter securely.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single gasket is used to hold the switchable light filter, then the device complexity is reduced, but the mechanical shock resistance and protection from dust and moisture are insufficient

Engineering Contradiction:
Improvemechanical shock resistanceVSAvoidgasket system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The gasket system is divided into two separate gaskets: a first gasket with a first opening that receives the switchable light filter, and a second gasket with a second opening that receives the first gasket. This segmentation allows each gasket to perform specific protective functions, enhancing mechanical shock resistance and sealing against dust and moisture while maintaining manageable complexity through modular design.

Inventive Principle:
Principle #1Segmentation

2Duration of action of stationary object

If the switchable light filter is held securely with enhanced protection, then the durability and lifetime are improved, but the assembly complexity increases

Engineering Contradiction:
Improvefilter lifetimeVSAvoidassembly structure
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The gasket system employs a nested structure where the first gasket is received within the second gasket, and the switchable light filter is held within the first gasket. This nesting arrangement provides multiple layers of protection against mechanical shock, dust, and moisture, thereby extending filter lifetime while organizing the assembly in a compact, systematic manner that manages complexity through hierarchical structure.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If a two-part gasket system is implemented, then protection from dust and moisture is enhanced, but the manufacturing complexity increases

Engineering Contradiction:
Improveprotection from dust and moistureVSAvoidgasket manufacturing
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Each gasket is designed with specific local qualities tailored to its function: the first gasket has a first opening configured to receive the switchable light filter with appropriate sealing characteristics, while the second gasket has a second opening configured to receive the first gasket with its own sealing features. This localized optimization allows each component to be manufactured with focused quality control for its specific protective role, making the overall two-part system more manufacturable despite the increased number of components.

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 significantly enhances the mechanical shock resistance and durability of the automatic darkening filter assembly, minimizing damage from handling or drops and extending the lifetime of the switchable light filter by preventing dust and moisture ingress.

Implementation Method 1

The photodetector recognizes the presence of the incident light-to-be-filtered, and an electronic module generates a control voltage that, when applied to the switchable filter, causes the filter to change from the light-state to the dark-state

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

Automatic light filters have been designed which contain liquid-crystal cells located between polarizing films. The liquid crystal cell is disposed between the first and second polarizers and contains first and second optically-transparent, flexible, glass layers with the liquid crystal layer being located between these layers. The sensor detects incident light and causes a signal to be sent, which causes molecular rotation within the liquid crystal layer

Methodology Applied
Scientific EffectLiquid Crystals: Liquid Crystals

Data Source

PatentEP3538022B1An automatic darkening filter assembly for a welding protector and a welding protector
Publication Date: 2025.04.23 3M INNOVATIVE PROPERTIES CO
  • EP3538022B1 patent drawingFigure 1
  • EP3538022B1 patent drawingFigure 2
  • EP3538022B1 patent drawingFigure 3

AI summary

An automatic darkening filter assembly for a welding protector and a welding protector that includes the automatic darkening filter assembly. The automatic darkening filter assembly has a housing that forms an opening in which a switchable light filter is arranged. The switchable light filter is retained by a first and a second resilient gasket that are arranged on opposite sides of the switchable light filter and which each extend circumferentially adjacent a periphery of the switchable light filter. The invention helps maximizing the robustness of the welding protector and facilitates assembly.