US2541879A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuum tube circuits
Assignee: Hitachi Rail STS USA Inc
•
Filing: 1944-07-18
•
Granted: 1951-02-13
•
Expires: 1964-07-18
Abstract
No abstract record available.
Inventors
- 👤 Paul N Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:03
CPC Classifications
B; B61; B61L; B61L23/00; B61L23/08; B61L23/14; B61L23/16; B61L23/166
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1243789A
Cited
US1592612A
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US1964110A
Cited
US2049376A
Cited
US2056769A
Cited
US2112736A
Cited
US2213551A
Cited
US2216623A
Cited
US2216631A
Cited
US2237789A
Cited
US2299272A
Cited
US2359747A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-02-12 | 1954-08-14 | 1955-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-02-12 | 1958-08-14 | 1959-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-02-12 | 1962-08-14 | 1963-02-13 | $7700.00 | Window Closed / Lapsed |