US3519912A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current regulated speed control system for wound rotor a.c. motors
Assignee: Cutler Hammer Inc
•
Filing: 1967-12-05
•
Granted: 1970-07-07
•
Expires: 1987-12-05
Abstract
No abstract record available.
Inventors
- 👤 Reginald E Charlwood
- 👤 Robert L Risberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:01
CPC Classifications
H; H02; H02P; H02P25/00; H02P25/16; H02P25/24; H02P25/26
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3017554A
Cited
US3227937A
Cited
US3302086A
Cited
US3217222A
Cited
US3365642A
Cited
US3379947A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-06 | 1974-01-05 | 1974-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-06 | 1978-01-05 | 1978-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-06 | 1982-01-05 | 1982-07-07 | $7700.00 | Window Closed / Lapsed |