Patent US2742535A successfully refreshed from Google Patents.
US2742535A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic telephone system
Assignee: North Electric Co
•
Filing: 1951-05-15
•
Granted: 1956-04-17
•
Expires: 1971-05-15
Abstract
No abstract record available.
Inventors
- 👤 James M Blackhall
- 👤 Maurice G Ryon
- 👤 Donald S Baker
- 👤 George P Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:30
CPC Classifications
H; H04; H04Q; H04Q1/00; H04Q1/02; H04Q1/08; H04Q1/023
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1714611A
Cited
US1863376A
Cited
US1809025A
Cited
US1874566A
Cited
US1886296A
Cited
US2027743A
Cited
US2415437A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-04-17 | 1959-10-17 | 1960-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-04-17 | 1963-10-17 | 1964-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-04-17 | 1967-10-17 | 1968-04-17 | $7700.00 | Window Closed / Lapsed |