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Battery Door for Hearing Instruments Made of Two Parts

IP.com Disclosure Number: IPCOM000202216D
Original Publication Date: 2010-Dec-09
Included in the Prior Art Database: 2010-Dec-09
Document File: 2 page(s) / 171K

Publishing Venue

Siemens

Related People

Juergen Carstens: CONTACT

Abstract

In order to be able to change the battery, hearing aids normally have a battery door. The development of battery doors for different housings, e. g. for different brands with the same internal construction, is costly and time-consuming because of the fine tuning of the functional areas. Up to now, a complete redesign of the entire battery door for each brand is done. Currently most hearing aid housing parts are made of ABS plastics because this material can be coated easily and has a good visual appearance (ABS: Acrylonitrile Butadiene Styrene). However, ABS plastic does not have as good mechanical properties as other engineering plastics, like LCP (LCP: Liquid Crystal Polymer). For this reason, the wall thickness of critical areas is currently increased when using ABS plastic parts. Furthermore, ABS is not a good choice for multi-component injection molded parts with an elastic component. Thus, other materials are used, which are not as easily coatable and have a minor visual appearance compared to ABS. Since the locking mechanism of the battery doors scratches the ABS which leads to failures of the locking functionality, a costly additional tampon printing in the affected areas is currently used to create a more scratch resistant surface. Because of tight gap tolerance requirements different productions tools are essential for the manufacturing of coated and of uncoated battery doors.

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Battery Door for Hearing Instruments Made of Two Parts

Idea: Joachim Roland Barth; DE-Erlangen

In order to be able to change the battery, hearing aids normally have a battery door. The development of battery doors for different housings, e. g. for different brands with the same internal construction, is costly and time-consuming because of the fine tuning of the functional areas. Up to now, a complete redesign of the entire battery door for each brand is done. Currently most hearing aid housing parts are made of ABS plastics because this material can be coated easily and has a good visual appearance (ABS: Acrylonitrile Butadiene Styrene). However, ABS plastic does not have as good mechanical properties as other engineering plastics, like LCP (LCP: Liquid Crystal Polymer). For this reason, the wall thickness of critical areas is currently increased when using ABS plastic parts. Furthermore, ABS is not a good choice for multi-component injection molded parts with an elastic component. Thus, other materials are used, which are not as easily coatable and have a minor visual appearance compared to ABS. Since the locking mechanism of the battery doors scratches the ABS which leads to failures of the locking functionality, a costly additional tampon printing in the affected areas is currently used to create a more scratch resistant surface. Because of tight gap tolerance requirements different productions tools are essential for the manufacturing of coated and of uncoated battery doors.

In the following it is proposed to separate the battery door into two parts, a core part for all functional areas and an outer part which defines the outward appearance, as shown in Figure 1. Thus, the outer part can be designed quicker and easier, which will make brand differentiation less costly and time- consuming. Furthermore, it is proposed to use different materials for both of these parts. So, for example the outer part can be made of ABS or a similar plastic material for a good visual appearance, whereas the core pa...