US2826637A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic level equalizer
Assignee: AT&T Inc
•
Filing: 1952-11-14
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Granted: 1958-03-11
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Expires: 1972-11-14
Abstract
No abstract record available.
Inventors
- 👤 Walter K Macadam
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:32
CPC Classifications
H; H04; H04J; H04J1/00; H04J1/02; H04J1/12; H04B; H04B3/00; H04B3/02; H04B3/32
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) | 1961-03-10 | 1961-09-09 | 1962-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-03-10 | 1965-09-09 | 1966-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-03-10 | 1969-09-09 | 1970-03-11 | $7700.00 | Window Closed / Lapsed |