US2863950A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone service concentrator
Assignee: AT&T Inc
•
Filing: 1954-05-27
•
Granted: 1958-12-09
•
Expires: 1974-05-27
Abstract
No abstract record available.
Inventors
- 👤 Sanford F Dunning
- 👤 Donald H Macpherson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:29
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/64; H04M1/65; H04M1/6515; H04M3/00; H04M3/42; H04M3/54
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USRE23054E
Cited
US745734A
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US1779748A
Cited
US1922879A
Cited
US2685614A
Cited
US2724744A
Cited
US2783307A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-12-08 | 1962-06-09 | 1962-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-12-08 | 1966-06-09 | 1966-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-12-08 | 1970-06-09 | 1970-12-09 | $7700.00 | Window Closed / Lapsed |