Patent US2420903A successfully refreshed from Google Patents.
Patent US1902234A successfully refreshed from Google Patents.
US1902234A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Receiver for continuous waves
Assignee: Heintz & Kaufman Ltd
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Filing: 1930-03-12
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Granted: 1933-03-21
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Expires: 1950-03-12
Abstract
No abstract record available.
Inventors
- 👤 Ralph M Heintz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:00
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/16
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) | 1936-03-20 | 1936-09-19 | 1937-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1940-03-20 | 1940-09-19 | 1941-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1944-03-20 | 1944-09-19 | 1945-03-21 | $7700.00 | Window Closed / Lapsed |