Patent US2994280A successfully refreshed from Google Patents.
US2994280A
Expired / Lapsed
US
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Equalizing standing valve with hold-down
Assignee: Camco Inc
•
Filing: 1958-03-26
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Granted: 1961-08-01
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Expires: 1978-03-26
Abstract
No abstract record available.
Inventors
- 👤 Douglas E Daffin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:08
CPC Classifications
E; E21; E21B; E21B34/00; E21B34/06; E21B34/14; Y; Y10; Y10T; Y10T137/00; Y10T137/1624; Y10T137/1632; Y10T137/1669; Y10T137/1677; Y10T137/7504; Y10T137/7559
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-07-31 | 1965-01-30 | 1965-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-31 | 1969-01-30 | 1969-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-31 | 1973-01-30 | 1973-08-01 | $7700.00 | Window Closed / Lapsed |