US1546749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone transmitter
Assignee: AT&T Inc
•
Filing: 1921-11-03
•
Granted: 1925-07-21
•
Expires: 1941-11-03
Abstract
No abstract record available.
Inventors
- 👤 John G Roberts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:53
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/32; H04R1/34; H04R1/38
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) | 1928-07-20 | 1929-01-19 | 1929-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1932-07-20 | 1933-01-19 | 1933-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1936-07-20 | 1937-01-19 | 1937-07-21 | $7700.00 | Window Closed / Lapsed |