US3030448A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pcm telephone signaling
Assignee: AT&T Inc
•
Filing: 1960-12-30
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Granted: 1962-04-17
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Expires: 1980-12-30
Abstract
No abstract record available.
Inventors
- 👤 Donald J Leonard
- 👤 Robert H Shennum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:55
CPC Classifications
H; H04; H04Q; H04Q11/00; H04Q11/04; H04J; H04J3/00; H04J3/02; H04J3/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-04-16 | 1965-10-16 | 1966-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-04-16 | 1969-10-16 | 1970-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-04-16 | 1973-10-16 | 1974-04-17 | $7700.00 | Window Closed / Lapsed |