Patent US1985999A successfully refreshed from Google Patents.
US1985999A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Audio frequency amplifier
Assignee: Siemens and Halske AG
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Filing: 1930-07-16
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Granted: 1935-01-01
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Expires: 1950-07-16
Abstract
No abstract record available.
Inventors
- 👤 Krambeer Karl Heinrich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:08
CPC Classifications
H; H03; H03G; H03G5/00; H03G5/02; H03G5/04; H03G5/06
Claims Analysis
Total Claims: 0
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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) | 1937-12-31 | 1938-07-02 | 1939-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1941-12-31 | 1942-07-02 | 1943-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1945-12-31 | 1946-07-02 | 1947-01-01 | $7700.00 | Window Closed / Lapsed |