US2949558A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High efficiency velocity modulation devices
Assignee: AT&T Inc
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Filing: 1957-10-21
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Granted: 1960-08-16
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Expires: 1977-10-21
Abstract
No abstract record available.
Inventors
- 👤 Kompfner Rudolf
- 👤 Calvin F Quate
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:11
CPC Classifications
H; H01; H01J; H01J23/00; H01J23/02; H01J23/027; H01J23/0275; H01J25/00; H01J25/78
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-08-16 | 1964-02-15 | 1964-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-08-16 | 1968-02-15 | 1968-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-08-16 | 1972-02-15 | 1972-08-16 | $7700.00 | Window Closed / Lapsed |