Patent US3468394A successfully refreshed from Google Patents.
US3468394A
Expired / Lapsed
US
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Centrifugal fans and air cushion vehicles incorporating such fans
Assignee: Britten Norman Ltd
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Filing: 1967-02-28
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Granted: 1969-09-23
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Expires: 1987-02-28
Abstract
No abstract record available.
Inventors
- 👤 Peter H Winter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:07
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/40; F04D29/42; F04D29/44; F04D29/441; B; B60; B60V; B60V1/00; B60V1/14
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) | 1972-09-22 | 1973-03-24 | 1973-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-09-22 | 1977-03-24 | 1977-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-09-22 | 1981-03-24 | 1981-09-23 | $7700.00 | Window Closed / Lapsed |