Patent US1859924A successfully refreshed from Google Patents.
US1859924A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Call charging telephone exchange system
Assignee: AT&T Inc
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Filing: 1930-06-28
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Granted: 1932-05-24
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Expires: 1950-06-28
Abstract
No abstract record available.
Inventors
- 👤 Lewis H Johnson
- 👤 Earl S Gibson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:37
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/42
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) | 1935-05-24 | 1935-11-23 | 1936-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1939-05-24 | 1939-11-23 | 1940-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1943-05-24 | 1943-11-23 | 1944-05-24 | $7700.00 | Window Closed / Lapsed |