Patent US3187190A successfully refreshed from Google Patents.
US3187190A
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Contrarotating hydroelectric machines including synchronous and asynchronous generators
Assignee: Library and Archives Canada
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Filing: 1962-11-20
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Granted: 1965-06-01
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Expires: 1982-11-20
Abstract
No abstract record available.
Inventors
- 👤 Johann H Lang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:06
CPC Classifications
F; F03; F03B; F03B15/00; H; H02; H02K; H02K7/00; H02K7/18; H02K7/1807; H02K7/1823; H02P; H02P23/00; H02P23/16; Y; Y02; Y02E; Y02E10/00; Y02E10/20
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
107 words
IN COMBINATION, A HYDROELECTRIC MACHINE HAVING CONTRAROTATING, AXIAL FLOW, FIXED PITCH, COAXIAL WATER WHEELS OPERATING IN CLOSELY SPACED AXIAL RELATION IN A COMMON WATER STREAM AND A SHAFT FOR EACH WATER WHEEL FOR DRIVING THE MACHINE; MEANS FOR CONTROLLING THE TORQUE RATIO OF SAID SHAFTS COMPRISING MEANS FOR OBTAINING FOR EACH SHAFT A SIGNAL REPRESENTING THE TORQUE DEVELOPED THEREIN; MEANS FOR COMPARING SAID SIGNALS TO OBTAIN A CONTROL SIGNAL REPRESENTING THE DIFFERENCE OF SAID TORQUES; AND MEANS FOR APPLYING SAID CONTROL SIGNAL TO VARY THE SPEED OF ONE WATER WHEEL IN RELATION TO THE OTHER WATER WHEEL SO AS TO MAINTAIN SAID TORQUE RATIO WITHIN PRESET LIMITS.
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) | 1968-05-31 | 1968-11-30 | 1969-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-05-31 | 1972-11-30 | 1973-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-05-31 | 1976-11-30 | 1977-06-01 | $7700.00 | Window Closed / Lapsed |