US3556680A
Expired / Lapsed
US
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Aerodynamic pressure-wave machine
Assignee: BBC Brown Boveri AG Germany
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Filing: 1969-01-13
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Granted: 1971-01-19
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Expires: 1989-01-13
Abstract
Abstract AN AERODYNAMIC PRESSURE WAVE MACHINE IN WHICH ONE GAS IS EXPANDED WHILE ANOTHER IS COMPRESSED OPERATES WITH A REDUCED NOISE LEVEL BY ARRANGING THE CELLS OF THE CELL WHEEL INTO CELL GROUPS EXTENDING IN THE CIRCUMFERENTIAL DIRECTION. THE CELLS OF EACH GROUP ARE OF THE SAME WIDTH AS MEASURED IN A CIRCUMFERENTIAL DIRECTION BUT THE CELLS OF ADJACENT GROUPS HAVE DIFFERENT WIDTHS.
Inventors
- 👤 Paul Leutwyler
- 👤 Alfred Wunsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:34
CPC Classifications
F; F04; F04F; F04F13/00
Claims Analysis
Total Claims: 0
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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 |