US2644904A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crystal unit
Assignee: AT&T Inc
•
Filing: 1950-07-28
•
Granted: 1953-07-07
•
Expires: 1970-07-28
Abstract
No abstract record available.
Inventors
- 👤 Joseph F Barry
- 👤 David M Ruggles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:43
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/05; H03H9/09
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1827994A
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US1885062A
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US1869178A
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US2038804A
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US2029358A
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US2073951A
Cited
FR813593A
Cited
US2203322A
Cited
US2242755A
Cited
US2313379A
Cited
US2415832A
Cited
US2597797A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-07-06 | 1957-01-05 | 1957-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-07-06 | 1961-01-05 | 1961-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-07-06 | 1965-01-05 | 1965-07-07 | $7700.00 | Window Closed / Lapsed |