Patent US2958831A successfully refreshed from Google Patents.
US2958831A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Equalizer
Assignee: AT&T Inc
•
Filing: 1956-12-17
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Granted: 1960-11-01
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Expires: 1976-12-17
Abstract
No abstract record available.
Inventors
- 👤 Jean H Clark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:48
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/20
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2252002A
Cited
US2233061A
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US2293628A
Cited
US2548913A
Cited
US2776410A
Cited
US2760164A
Cited
US2849546A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-11-01 | 1964-05-02 | 1964-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-11-01 | 1968-05-02 | 1968-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-11-01 | 1972-05-02 | 1972-11-01 | $7700.00 | Window Closed / Lapsed |