US3506909A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement for the excitation of a dc machine
Assignee: Siemens AG
•
Filing: 1968-07-22
•
Granted: 1970-04-14
•
Expires: 1988-07-22
Abstract
No abstract record available.
Inventors
- 👤 Klaus Bohm
- 👤 Gerhard Rumold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:50
CPC Classifications
H; H02; H02K; H02K23/00; H02K23/02; H02K23/22; H02P; H02P9/00; H02P9/14; H02P9/26; H02P9/30
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2796580A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-04-13 | 1973-10-13 | 1974-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-04-13 | 1977-10-13 | 1978-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-04-13 | 1981-10-13 | 1982-04-14 | $7700.00 | Window Closed / Lapsed |