US3470449A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Constant frequency inverter with frequency override
Assignee: Cutler Hammer Inc
•
Filing: 1968-04-08
•
Granted: 1969-09-30
•
Expires: 1988-04-08
Abstract
No abstract record available.
Inventors
- 👤 Robert L Risberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:03
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/505; H02M7/515; H02M7/517
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3264548A
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US3248637A
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US3376493A
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US3350625A
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US3344336A
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US3398352A
Cited
US3355653A
Cited
US3333179A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-09-29 | 1973-03-31 | 1973-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-09-29 | 1977-03-31 | 1977-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-09-29 | 1981-03-31 | 1981-09-30 | $7700.00 | Window Closed / Lapsed |