US3556678A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for low frequency synchronous starting of reversible pump turbines
Assignee: Hitachi Ltd
•
Filing: 1969-06-02
•
Granted: 1971-01-19
•
Expires: 1989-06-02
Abstract
Abstract A METHOD AND APPARATUS FOR THE LOW FREQUENCY SYNCHRONOUS STARTING OF PUMP TURBINES, IN WHICH IN ORDER TO SHORTEN THE TIME BEFORE THE PUMP HAS ACQUIRED A NECESARY ROTATIONAL TORQUE, THE GUIDE VANE OPENING OF A WATER TURBINE IS PROGRESSIVELY INCREASED INCIDENT TO INCREASE IN R.P.M. OF THE PUMP RUNNER SO AS TO INCREASE THE PUMP DRIVING TORQUE CLOSE TO THE ALLOWABLE MAXIMUM TORQUE OF SAID PUMP.
Inventors
- 👤 Asao Oishi
- 👤 Shozoo Sashino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:28
CPC Classifications
F; F03; F03B; F03B15/00; F03B15/005; Y; Y02; Y02E; Y02E10/00; Y02E10/20
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-18 | 1974-07-20 | 1975-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-18 | 1978-07-20 | 1979-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-18 | 1982-07-20 | 1983-01-19 | $7700.00 | Window Closed / Lapsed |