Patent US3536862A successfully refreshed from Google Patents.
US3536862A
Expired / Lapsed
US
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Microphone having a variable unidirectional characteristic
Assignee: AKG Acoustics GmbH
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Filing: 1967-08-09
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Granted: 1970-10-27
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Expires: 1987-08-09
Abstract
No abstract record available.
Inventors
- 👤 Bernhard Weingartner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:59
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/32; H04R1/34; H04R1/38
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2787671A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-10-26 | 1974-04-27 | 1974-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-10-26 | 1978-04-27 | 1978-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-10-26 | 1982-04-27 | 1982-10-27 | $7700.00 | Window Closed / Lapsed |