Patent US2788447A successfully refreshed from Google Patents.
US2788447A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio wave tuners
Assignee: Polytechnic Res & Dev Co Inc
•
Filing: 1952-09-12
•
Granted: 1957-04-09
•
Expires: 1972-09-12
Abstract
No abstract record available.
Inventors
- 👤 Stanley A Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:59
CPC Classifications
H; H03; H03C; H03C3/00; H03C3/02; H03C3/09
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2007099A
Cited
US2165483A
Cited
US2160466A
Cited
US2279151A
Cited
US2361657A
Cited
US2306282A
Cited
US2381940A
Cited
US2463417A
Cited
US2597993A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-04-08 | 1960-10-08 | 1961-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-04-08 | 1964-10-08 | 1965-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-04-08 | 1968-10-08 | 1969-04-09 | $7700.00 | Window Closed / Lapsed |