US2434946A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tone supply test circuit
Assignee: AT&T Inc
•
Filing: 1944-03-16
•
Granted: 1948-01-27
•
Expires: 1964-03-16
Abstract
No abstract record available.
Inventors
- 👤 Mckim Burton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:09
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/22; H04M3/24
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1558448A
Cited
US1743795A
Cited
US2152472A
Cited
US2235540A
Cited
US2245342A
Cited
US2329010A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-01-26 | 1951-07-28 | 1952-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-01-26 | 1955-07-28 | 1956-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-01-26 | 1959-07-28 | 1960-01-27 | $7700.00 | Window Closed / Lapsed |