Patent US3529089A successfully refreshed from Google Patents.
US3529089A
Expired / Lapsed
US
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Distributed subscriber carrier-concentrator system
Assignee: AT&T Inc
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Filing: 1968-08-28
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Granted: 1970-09-15
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Expires: 1988-08-28
Abstract
No abstract record available.
Inventors
- 👤 Claude G Davis
- 👤 Donald Hirsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:38
CPC Classifications
H; H04; H04Q; H04Q11/00; H04Q11/04
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) | 1973-09-14 | 1974-03-16 | 1974-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-09-14 | 1978-03-16 | 1978-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-09-14 | 1982-03-16 | 1982-09-15 | $7700.00 | Window Closed / Lapsed |