Patent US3421781A successfully refreshed from Google Patents.
US3421781A
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Transition section having a constant cross sectional area
Assignee: United States Department of the Army
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Filing: 1967-01-30
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Granted: 1969-01-14
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Expires: 1987-01-30
Abstract
No abstract record available.
Inventors
- 👤 Joseph H Spurk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:57
CPC Classifications
F; F16; F16L; F16L55/00; F15; F15D; F15D1/00; F15D1/02; F15D1/04; F16L25/00; F16L25/14; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49428; Y10T403/00; Y10T403/57; Y10T403/5706
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) | 1972-01-14 | 1972-07-15 | 1973-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-01-14 | 1976-07-15 | 1977-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-01-14 | 1980-07-15 | 1981-01-14 | $7700.00 | Window Closed / Lapsed |