US1728745A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric relay apparatus employing thermionic valves
Assignee: Westinghouse Electric Corp
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Filing: 1924-11-08
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Granted: 1929-09-17
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Expires: 1944-11-08
Abstract
No abstract record available.
Inventors
- 👤 Brown Walter John
- 👤 Hubbard Edward John Egerton
- 👤 Robinson Ernest Yeoman
- 👤 Burch Cecil Reginald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:54
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/28; H03K17/288; H03F; H03F1/00; H03F1/42; H03F1/48; H03F1/50
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) | 1932-09-16 | 1933-03-18 | 1933-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1936-09-16 | 1937-03-18 | 1937-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1940-09-16 | 1941-03-18 | 1941-09-17 | $7700.00 | Window Closed / Lapsed |