Thickened Rim Bonding for Hearing Device Face Plate

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Solution Overview

Problem

Hearing devices with thin shells face challenges in securely attaching a face plate without risking separation during removal or repair, due to the limited space and thinness of the shell.

Innovation Solution

A hearing device design featuring a shell with a thickened rim at the opening, providing a bonding surface for the face plate, which is adapted in size and shape to achieve a predetermined bonding force using adhesive, and optionally incorporating a groove or recess to adjust the bonding force, with a vent having thickened and rounded rims to facilitate component placement and user comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the wall thickness of the shell is reduced to minimize the size of the hearing device, then the device becomes more compact and suitable for the ear canal, but the bonding surface area decreases making it difficult to securely attach the face plate

Engineering Contradiction:
Improvesize of hearing deviceVSAvoidbonding strength between face plate and shell
Core Design Contradiction:
Volume of moving objectVSStrength

Solution Approach 1:

The patent applies local quality by thickening the wall only at specific locations where the face plate bonds to the shell, rather than increasing the overall wall thickness throughout. This creates localized bonding surfaces with sufficient area for strong adhesive attachment while keeping the rest of the shell thin and compact for ear canal suitability.

Inventive Principle:
Principle #3Local quality

2Reliability

If the bonding force between face plate and shell is increased to prevent separation during removal or repair, then the attachment becomes more secure, but the components cannot be separated again when necessary for repair

Engineering Contradiction:
Improvesecurity of face plate attachmentVSAvoidseparability of components
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The patent uses parameter changes by carefully controlling the adhesive properties and bonding surface characteristics to achieve optimal bonding strength. The thickened rim provides sufficient bonding area for reliable attachment during normal use, while the bonding parameters are selected to allow controlled separation when repair is needed, balancing security and reparability.

Inventive Principle:
Principle #35Parameter changes

3Area of stationary object

If the wall thickness is increased to provide a larger bonding surface area, then the face plate can be securely attached, but the hearing device becomes too large for comfortable wear in the ear canal

Engineering Contradiction:
Improvebonding surface areaVSAvoidsize of hearing device
Core Design Contradiction:
Area of stationary objectVSVolume of moving object

Solution Approach 1:

The patent resolves this contradiction by applying local quality - the wall is thickened only at the specific locations where the face plate bonds to the shell, creating localized bonding surfaces with adequate area. The rest of the shell maintains thin walls to keep the overall device size small and comfortable for ear canal wear.

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

Ensures secure attachment of the face plate to the shell, allowing easy removal and repair while maintaining a thin shell structure, ensuring a strong yet adjustable bond and minimizing irritation to the ear canal.

Implementation Method 1

the face plate being bonded to the shell at the bonding surface by means of an adhesive, wherein an area of the bonding surface is adapted in dependence of a bonding characteristic of the adhesive such that the shell and the face plate are bonded together by means of the adhesive with a predetermined bonding force

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3326388B1A hearing device for being worn at least partly within an ear canal and a method for manufacturing such a hearing device
Publication Date: 2021.01.27 SONOVA AG
  • EP3326388B1 patent drawingFigure 1~2
  • EP3326388B1 patent drawingFigure 3a~4
  • EP3326388B1 patent drawingFigure 5a~6

AI summary

The present invention provides a hearing device (1) for being worn at least partly within an ear canal of a user of the hearing device (1), the hearing device (1) comprising a shell (2) with a wall and an opening (4), wherein the wall has a rim (11) at the opening (4), and wherein the wall is thickened along at least part of the rim (11). Furthermore, a method for manufacturing such a hearing device (1) is specified, especially comprising determining an area of a bonding surface (12) at the rim (11) for bonding a face plate (3) to the shell at the opening (4).