Patent US2172887A successfully refreshed from Google Patents.
US2172887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical rectifier
Assignee: Hitachi Rail STS USA Inc
•
Filing: 1937-10-21
•
Granted: 1939-09-12
•
Expires: 1957-10-21
Abstract
No abstract record available.
Inventors
- 👤 Richard A Hartley
- 👤 Craig M Bouton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:58
CPC Classifications
H; H10; H10D; H10D48/00; H10D48/01; H10D48/07; H10D48/071; H10D48/076
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) | 1942-09-11 | 1943-03-13 | 1943-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-09-11 | 1947-03-13 | 1947-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-09-11 | 1951-03-13 | 1951-09-12 | $7700.00 | Window Closed / Lapsed |