Curved Earplug Stem Rotates to Fit Canal Geometry

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Solution Overview

Problem

Existing pre-molded push-in earplugs struggle to accommodate the variability in human ear canal size and geometry, often causing discomfort due to stem contact with the sidewalls during insertion and wear, and require manual bending which increases pressure.

Innovation Solution

A push-in earplug with a crooked or wavy stem configuration that can be rotated during insertion to fit around curved ear canal sections, minimizing contact with the sidewalls and accommodating various ear shapes without the need for bending, using a handle portion for easy manipulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a straight stiff plastic stem is used for insertion, then the earplug structure is simple and manufacturing is easy, but the stem contacts the sidewalls of the curved ear canal causing discomfort and irritation

Engineering Contradiction:
Improvestem manufacturing simplicityVSAvoidinsertion comfort
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The patent applies curvature to the stem by providing a curved section that follows the natural curvature of the ear canal. This curved stem configuration allows the stem to navigate the curved path of the ear canal without contacting the sidewalls, thereby maintaining insertion comfort while remaining manufacturable through standard molding processes.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of operation

If the stem is made flexible to accommodate curved ear canals, then insertion comfort is improved, but the stem may bend inside the ear canal increasing pressure and causing discomfort

Engineering Contradiction:
Improveinsertion comfortVSAvoidpressure on ear canal
Core Design Contradiction:
Ease of operationVSStress or pressure

Solution Approach 1:

The stem is segmented into distinct functional sections: a rigid insertion portion that provides structural support and control, and a curved adaptation section that follows the ear canal geometry. This segmentation allows the stem to maintain its shape and avoid excessive bending while still accommodating the curved path of the ear canal, thereby reducing pressure on the ear canal walls.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If a single type of pre-molded earplug is used, then manufacturing is simple and cost-effective, but it cannot accommodate the broad range of human ear canals in both size and geometry

Engineering Contradiction:
Improveproduction simplicityVSAvoidear canal accommodation
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The earplug design incorporates a universal curved stem configuration that can adapt to various ear canal geometries and sizes. The curved stem section is designed with specific curvature parameters that allow it to follow the natural path of different ear canals, making a single earplug type suitable for a broad range of users while maintaining simple manufacturing processes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Reliability

If the stem is manipulated to insert the front end to the proper position for maximum attenuation, then sound blocking is improved, but the stem touches the sidewall of the ear canal causing irritation

Engineering Contradiction:
Improvesound attenuationVSAvoidear canal irritation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The curved stem configuration enables the earplug to be inserted along the curved path of the ear canal without the stem contacting the sidewalls. This allows the front end to reach the proper position for maximum sound attenuation while the curved geometry prevents sidewall contact, thereby eliminating irritation while maintaining effective noise blocking.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP2484319B1Push-in type of earplug with improved insertion stem
Publication Date: 2016.01.27 MOLDEX METRIC INC
  • EP2484319B1 patent drawingFigure 1~3
  • EP2484319B1 patent drawingFigure 4~7
  • EP2484319B1 patent drawingFigure 8~9(A)

AI summary

A hearing protective earplug for insertion into the human ear canal of a user where the human ear canal has sidewalls and a typical curved portion. A soft resilient body has a main body element with a front end for insertion in the human ear canal. An elongated stem has two ends with one end attached to the main body element. The stem extends outward from the main body element and away from the front end. The other end of the stem forms a handle portion of the stem. The stem is sufficiently stiff as to allow manipulation of the main body element into the ear canal of the user. The stem member has a crooked or wavy configuration within the ear canal as it extends outward from the main body to the handle portion of the stem. As the front end of the main body element is inserted into the ear canal, the stem member is rotated during insertion with the handle portion to fit around the typical curved portion in the human ear canal. This seats the main body to acoustically block the ear canal while at the same time spaces the stem member within the typical curved portion of the ear canal to minimize contact with the sidewalls of the ear canal.