US3500057A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct current power transmission between a number of converter stations
Assignee: ABB Norden Holding AB
•
Filing: 1968-11-22
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Granted: 1970-03-10
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Expires: 1988-11-22
Abstract
No abstract record available.
Inventors
- 👤 Hans A Stackegard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:01
CPC Classifications
H; H02; H02M; H02M5/00; H02M5/40; H02M5/42; H02J; H02J1/00; H02J1/14; H02J1/16; H02J3/00; H02J3/36; Y; Y02; Y02E; Y02E60/00; Y02E60/60
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-03-09 | 1973-09-08 | 1974-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-03-09 | 1977-09-08 | 1978-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-03-09 | 1981-09-08 | 1982-03-10 | $7700.00 | Window Closed / Lapsed |