US2500637A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency selective electrical device
Assignee: AT&T Inc
•
Filing: 1946-06-01
•
Granted: 1950-03-14
•
Expires: 1966-06-01
Abstract
No abstract record available.
Inventors
- 👤 John P Kinzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:03
CPC Classifications
H; H03; H03B; H03B5/00; H03B5/18; H03B5/1817; H03B5/1835; H01; H01J; H01J25/00; H01J25/02; H01J25/22; H01J25/24
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1666077A
Cited
US2044413A
Cited
US2245627A
Cited
US2240452A
Cited
US2331892A
Cited
US2411289A
Cited
US2396044A
Cited
US2410109A
Cited
US2405277A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-03-13 | 1953-09-12 | 1954-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-03-13 | 1957-09-12 | 1958-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-03-13 | 1961-09-12 | 1962-03-14 | $7700.00 | Window Closed / Lapsed |