Selective Attenuating Earplug With Cantilever Switch

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Solution Overview

Problem

Existing hearing protective devices lack the ability to selectively attenuate sound frequencies and intensities, failing to allow intelligible speech or warning signals while blocking dangerous noises effectively, and often require complex mechanisms or precise adjustments.

Innovation Solution

A selective attenuating earplug with a switch mechanism using cantilever spring arms that can be adjusted between open and closed positions to allow or block sound, utilizing a tip and body design with an acoustic channel and filters to manage sound attenuation based on user needs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a switch mechanism is added to enable selective attenuation modes, then the adaptability of the earplug is improved, but the device complexity increases

Engineering Contradiction:
Improveselective attenuation capabilityVSAvoidswitch mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The switch mechanism is divided into separate functional components: a first cantilever spring arm for engagement/disengagement, a second cantilever spring arm with sealing pad for blocking, and respective recesses in the body. This segmentation allows each component to perform its specific function independently, achieving selective attenuation capability while keeping the overall mechanism relatively simple and manageable.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If cantilever spring arms are used for the switch mechanism, then the ease of operation is improved, but the device complexity increases

Engineering Contradiction:
Improveswitch operation simplicityVSAvoidswitch mechanism structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The cantilever spring arms are designed to be self-actuating through their elastic properties. When the user applies force to move the switch, the spring arms automatically engage with the recesses and the sealing pad blocks the aperture without requiring additional actuators, motors, or complex control systems. The spring arms self-regulate their engagement and disengagement, providing ease of operation while maintaining relatively simple device structure.

Inventive Principle:
Principle #25Self-service

3Object-affected harmful factors

If a sealing pad is added to block the aperture completely, then the noise attenuation performance is improved, but the device complexity increases

Engineering Contradiction:
Improvenoise attenuationVSAvoidswitch mechanism structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The sealing pad is implemented as a flexible element attached to the second cantilever spring arm. This flexible sealing pad can conform to the aperture shape and provide effective noise blocking when engaged, while its flexibility allows it to be integrated into a simple cantilever spring mechanism rather than requiring rigid, complex mechanical components. The thin film nature of the sealing pad enables effective attenuation without adding significant structural complexity.

Inventive Principle:
Principle #30Flexible shells and thin films

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 users to choose between modes that allow specific sound frequencies or intensities to pass through while attenuating others, providing effective noise protection without the need for complex mechanisms, ensuring both safety and situational awareness.

Implementation Method 1

a first cantilever spring arm including a shape that interacts with a feature on a surface of the body, and the shape is biased against the feature on the surface of the body to maintain the switch in the first position or the second position

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

an acoustic channel extending from a first end of the tip to an aperture of the body

Methodology Applied
Scientific EffectSound wave propagation: Sound

Implementation Method 3

a filter that restricts high-impulse noise before entering the ear canal

Methodology Applied
Scientific EffectAcoustic filtering: Filter (physical)

Data Source

PatentEP2941229B1Selective attenuating earplug
Publication Date: 2020.01.22 3M INNOVATIVE PROPERTIES CO
  • EP2941229B1 patent drawingFigure 1~2
  • EP2941229B1 patent drawingFigure 3a~3b
  • EP2941229B1 patent drawingFigure 4~5

AI summary

A selective attenuating earplug (300) is provided. In an exemplary embodiment, a selective attenuating earplug includes a switch (330) adjustable between a first position and a second position, and the switch includes at least one cantilever spring arm (333, 334).