Patent US1530633A successfully refreshed from Google Patents.
US1530633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical circuits, apparatus, and method
Assignee: AT&T Inc
•
Filing: 1920-08-30
•
Granted: 1925-03-24
•
Expires: 1940-08-30
Abstract
No abstract record available.
Inventors
- 👤 Whiting Donald Fairfax
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:24
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/02; H03G3/04; H03G3/06
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1928-03-23 | 1928-09-22 | 1929-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1932-03-23 | 1932-09-22 | 1933-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1936-03-23 | 1936-09-22 | 1937-03-24 | $7700.00 | Window Closed / Lapsed |