US3535573A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct current heteropolar electrical machines
Assignee: Rolls Royce Power Engineering PLC
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Filing: 1968-10-18
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Granted: 1970-10-20
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Expires: 1988-10-18
Abstract
No abstract record available.
Inventors
- 👤 Anthony D Appleton
- 👤 Bernard K Ginty
- 👤 Robert B Macnab
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:50
CPC Classifications
H; H02; H02K; H02K23/00; H02K23/26
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) | 1973-10-19 | 1974-04-20 | 1974-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-10-19 | 1978-04-20 | 1978-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-10-19 | 1982-04-20 | 1982-10-20 | $7700.00 | Window Closed / Lapsed |