US1623769A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone-exchange system
Assignee: AT&T Inc
•
Filing: 1924-03-29
•
Granted: 1927-04-05
•
Expires: 1944-03-29
Abstract
No abstract record available.
Inventors
- 👤 Samuel B Williams
- 👤 Earl S Gibson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:08
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/0004
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) | 1930-04-04 | 1930-10-04 | 1931-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1934-04-04 | 1934-10-04 | 1935-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1938-04-04 | 1938-10-04 | 1939-04-05 | $7700.00 | Window Closed / Lapsed |