US2159595A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency conversion circuits
Assignee: AT&T Inc
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Filing: 1937-07-31
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Granted: 1939-05-23
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Expires: 1957-07-31
Abstract
No abstract record available.
Inventors
- 👤 Ralph L Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:55
CPC Classifications
H; H03; H03B; H03B21/00; H03B21/01; H03B21/02
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) | 1942-05-22 | 1942-11-21 | 1943-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-05-22 | 1946-11-21 | 1947-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-05-22 | 1950-11-21 | 1951-05-23 | $7700.00 | Window Closed / Lapsed |