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US1640335A
Expired / Lapsed
US
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Unidirectional current-carrying device
Assignee: Hitachi Rail STS USA Inc
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Filing: 1925-01-07
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Granted: 1927-08-23
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Expires: 1945-01-07
Abstract
No abstract record available.
Inventors
- 👤 Lars O Grondahl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:10
CPC Classifications
H; H10; H10W; H10W90/00
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) | 1930-08-22 | 1931-02-21 | 1931-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1934-08-22 | 1935-02-21 | 1935-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1938-08-22 | 1939-02-21 | 1939-08-23 | $7700.00 | Window Closed / Lapsed |