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US4069401A Expired / Lapsed US ⏱️ 0.0 years remaining

Acoustical frictional resistance construction and apparatus for manufacturing an acoustical resistance and an associated magnetic system

Assignee: AKG Acoustics GmbH
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Filing: 1976-09-30
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Granted: 1978-01-17
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Expires: 1996-09-30
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Abstract

Abstract An acoustical frictional resistance for electroacoustical transducers, comprises a blank sheet having a first plurality of impressions on its one surface which partially extends into the sheet and having an opposite surface with a second plurality of impressions which extend partially into the opposite surface and meet the first plurality of impressions. The first and second impressions are made so that they partially overlap and define acoustical passages through the sheet at the overlapping areas. The resistances are advantageously made of a thermoplastic material and they may be incorporated in a magnetic system, preferably by molding them integrally with an encapsulation of a magnet and its associated pot and by simultaneously forming passages in which the frictional resistances are placed. An apparatus for forming the individual resistances advantageously includes two separable mold parts defining a cavity therebetween into which the blank material may be placed or may be fed in the form of a plasticized material and which includes a punch and a counterpunch arranged in opposition and mounted for relative rotation about a concentric circle so that they may engage into the blank from respective opposite sides which are offset by amounts to form overlapped areas which are impressed deep enough so that they communicate from one side to the other and form acoustical resistance passages.

Inventors

  • 👤 Fritz Vogelsinger

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 08:52
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/02; B; B29; B29C; B29C45/00; B29C45/17; B29C45/26; H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R2201/00; H04R2201/34; H04R2400/00; H04R2400/11; H04R9/00; H04R9/02

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 72 words
An acoustical frictional resistance for electroacoustical transducers, comprising a thermoplastic sheet having one surface with a first plurality of impressions partially extending into said sheet, and having an opposite surface having a second plurality of impressions extending partially into said opposite surface and meeting said first plurality of impressions in said sheet, said first and second plurality of impressions overlapping partially and defining acoustical passages through said sheet at the overlapping areas.
Claim 2
Dependent Claim 72 words
An acoustical frictional resistance for electroacoustical transducers, comprising a thermoplastic sheet having one surface with a first plurality of impressions partially extending into said sheet, and having an opposite surface having a second plurality of impressions extending partially into said opposite surface and meeting said first plurality of impressions in said sheet, said first and second plurality of impressions overlapping partially and defining acoustical passages through said sheet at the overlapping areas.
Claim 3
Dependent Claim 13 words
An acoustical frictional resistance, according to claim 1, wherein said impressions are cylindrical.
Claim 4
Dependent Claim 15 words
An acoustical frictional resistance, according to claim 1, wherein said impressions are truncated conical impressions.
Claim 5
Dependent Claim 19 words
An acoustical frictional resistance, according to claim 1, wherein said thermoplastic sheet comprises an encapsulation for a magnetic system.
Claim 6
Dependent Claim 74 words
An acoustical frictional resistance, according to claim 4, including a diagram encapsulated by said magnetic system, said magnetic system including a magnet having a magnetic pot arranged therearound and spaced therefrom by a plastic coating and having at least one passage extending outwardly from said diaphragm and including a separate sheet held by said encapsulation in said passage, said separate sheet having said first and second opposite impressions and defining said acoustical passages therethrough.
Claim 7
Dependent Claim 55 words
An acoustical frictional resistance, according to claim 4, wherein said encapsulation includes a diaphragm held thereby in spaced relationship to said magnetic system and having a passage extending outwardly from said diaphragm and including a sheet extending across said passage having said one surface and said opposite surface with said first and second impressions therein.
Claim 8
Dependent Claim 136 words
A magnetic system comprising a magnet having an annular exterior surface, a plastic coating on said surface, a pot surrounding said plastic surface, a bottom plate abuting said magnet and said pot, an encapsulation around said pot and said pate, a diaphragm held by said encapsulation, at least one passage extending through said encapsulation from said diaphragm and means defining an acoustical frictional resistance in said passage comprising a thermoplastic sheet having one surface with a first plurality of impressions on said one surface partially extending into said sheet and having an opposite surface having a second plurality of impressions extending partially into said opposite surface and meeting said first plurality of impressions in said sheet, said first and second plurality of impressions overlapping partially and defining acoustical passages through said sheet at the overlapping areas.
Claim 9
Dependent Claim 136 words
A magnetic system comprising a magnet having an annular exterior surface, a plastic coating on said surface, a pot surrounding said plastic surface, a bottom plate abuting said magnet and said pot, an encapsulation around said pot and said pate, a diaphragm held by said encapsulation, at least one passage extending through said encapsulation from said diaphragm and means defining an acoustical frictional resistance in said passage comprising a thermoplastic sheet having one surface with a first plurality of impressions on said one surface partially extending into said sheet and having an opposite surface having a second plurality of impressions extending partially into said opposite surface and meeting said first plurality of impressions in said sheet, said first and second plurality of impressions overlapping partially and defining acoustical passages through said sheet at the overlapping areas.
Claim 10
Dependent Claim 16 words
A magnetic system, according to claim 7, wherein said thermoplastic sheet is defined by said encapsulation.
Claim 11
Dependent Claim 21 words
A magnetic system, according to claim 7, wherein said thermoplastic sheet includes a sheet held in said encapsulation in said passage.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-01-16 1981-07-18 1982-01-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-01-16 1985-07-18 1986-01-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-01-16 1989-07-18 1990-01-17 $7700.00 Window Closed / Lapsed

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