Patent US3679986A successfully refreshed from Google Patents.
US3516640A
Expired / Lapsed
US
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Butterfly valve
Assignee: National Research Development Corp UK
•
Filing: 1967-09-06
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Granted: 1970-06-23
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Expires: 1987-09-06
Abstract
No abstract record available.
Inventors
- 👤 Denis William Bryer
- 👤 Denis Eugene Joseph Walshe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:47
CPC Classifications
F; F16; F16K; F16K1/00; F16K1/16; F16K1/18; F16K1/22; F16K1/222
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2114168A
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US3049335A
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FR1166545A
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FR1233654A
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US3053543A
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US3176704A
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GB983179A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-06-22 | 1973-12-22 | 1974-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-06-22 | 1977-12-22 | 1978-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-06-22 | 1981-12-22 | 1982-06-23 | $7700.00 | Window Closed / Lapsed |