Patent US3118979A successfully refreshed from Google Patents.
US3118979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic transducer
Assignee: AT&T Inc
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Filing: 1961-08-07
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Granted: 1964-01-21
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Expires: 1981-08-07
Abstract
No abstract record available.
Inventors
- 👤 Gerhard M Sessler
- 👤 James E West
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:11
CPC Classifications
H; H04; H04R; H04R19/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
156 words
A CONDENSER EARPHONE COMPRISING A THIN FLEXIBLE LAYER OF A CONDUCTIVE MATERIAL, A RELATIVELY THICK METALLIC BACK PLATE OF SUBSTANTIALLY THE SAME SURFACE DIMENSIONS AS SAID FLEXIBLE LAYER, SAID BACK PLATE HAVING A PLURALITY OF SPACED WELLS THEREIN, MEANS FOR PERIPHERALLY SECURING SAID LAYER OF CONDUCTIVE MATERIAL IN JUXTAPOSITION TO SAID BACK PLATE, A PLURALITY OF LAYERS OF SUBSTANTIALLY NONCOMPRESSIBLE THIN FILM DIELECTRIC MATERIAL INTIMATELY SANDWICHED BETWEEN SAID LAYER OF CONDUCTIVE MATERIAL AND SAID BACK PLATE TO FORM A COMPLIANT VIBRATILE MEMBER WHICH INCLUDES SAID THIN LAYERS OF DIELECTRIC MATERIAL AND A HIGHLY IRREGULAR CONFIGURATION OF MINUTE STATIC AIR LAYERS TRAPPED BETWEEN SAID THIN LAYERS OF DIELECTRIC MATERIAL, INSULATING COVERING MEANS FOR RIGIDLY SUPPORTING SAID SEVERAL LAYERS AND SAID BACK PLATE, SAID COVERING MEANS HAVING AN OPENING IN PROXIMATE RELATION TO THE SURFACE OF SAID FLEXIBLE LAYER OF CONDUCTIVE MATERIAL, AND MEANS FOR ELECTRICALLY CONNECTING TO SAID LAYER OF CONDUCTIVE MATERIAL AND TO SAID BACK PLATE.
Claim 2
Dependent Claim
156 words
A CONDENSER EARPHONE COMPRISING A THIN FLEXIBLE LAYER OF A CONDUCTIVE MATERIAL, A RELATIVELY THICK METALLIC BACK PLATE OF SUBSTANTIALLY THE SAME SURFACE DIMENSIONS AS SAID FLEXIBLE LAYER, SAID BACK PLATE HAVING A PLURALITY OF SPACED WELLS THEREIN, MEANS FOR PERIPHERALLY SECURING SAID LAYER OF CONDUCTIVE MATERIAL IN JUXTAPOSITION TO SAID BACK PLATE, A PLURALITY OF LAYERS OF SUBSTANTIALLY NONCOMPRESSIBLE THIN FILM DIELECTRIC MATERIAL INTIMATELY SANDWICHED BETWEEN SAID LAYER OF CONDUCTIVE MATERIAL AND SAID BACK PLATE TO FORM A COMPLIANT VIBRATILE MEMBER WHICH INCLUDES SAID THIN LAYERS OF DIELECTRIC MATERIAL AND A HIGHLY IRREGULAR CONFIGURATION OF MINUTE STATIC AIR LAYERS TRAPPED BETWEEN SAID THIN LAYERS OF DIELECTRIC MATERIAL, INSULATING COVERING MEANS FOR RIGIDLY SUPPORTING SAID SEVERAL LAYERS AND SAID BACK PLATE, SAID COVERING MEANS HAVING AN OPENING IN PROXIMATE RELATION TO THE SURFACE OF SAID FLEXIBLE LAYER OF CONDUCTIVE MATERIAL, AND MEANS FOR ELECTRICALLY CONNECTING TO SAID LAYER OF CONDUCTIVE MATERIAL AND TO SAID BACK PLATE.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-01-20 | 1967-07-22 | 1968-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-01-20 | 1971-07-22 | 1972-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-01-20 | 1975-07-22 | 1976-01-21 | $7700.00 | Window Closed / Lapsed |