Patent US3521094A successfully refreshed from Google Patents.
US3521094A
Expired / Lapsed
US
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Cooling device for electrical machine rotors
Assignee: Licentia Patent Verwaltungs GmbH
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Filing: 1968-08-26
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Granted: 1970-07-21
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Expires: 1988-08-26
Abstract
No abstract record available.
Inventors
- 👤 Eugen Renz
- 👤 Helmut Widder
- 👤 Hubert Rothert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:22
CPC Classifications
H; H02; H02K; H02K9/00; H02K9/19; H02K9/197
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1733379A
Cited
US2381122A
Cited
US2991377A
Cited
US3043901A
Cited
US3075104A
Cited
US3320447A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-20 | 1974-01-19 | 1974-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-20 | 1978-01-19 | 1978-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-20 | 1982-01-19 | 1982-07-21 | $7700.00 | Window Closed / Lapsed |