US2939475A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic check valve
Assignee: Individual
•
Filing: 1957-07-26
•
Granted: 1960-06-07
•
Expires: 1977-07-26
Abstract
No abstract record available.
Inventors
- 👤 Erskine E Roach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:43
CPC Classifications
F; F16; F16K; F16K15/00; F16K15/02; F16K15/04; F16K15/042; F16K31/00; F16K31/02; F16K31/06; F16K31/08; F16K31/084; Y; Y10; Y10T; Y10T137/00; Y10T137/2931; Y10T137/2934; Y10T137/7722; Y10T137/7837; Y10T137/7904; Y10T137/7908; Y10T137/7909; Y10T137/791; Y10T137/7911
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2274968A
Cited
US2661024A
Cited
US2597952A
Cited
US2629401A
Cited
US2668553A
Cited
US2811979A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-06-07 | 1963-12-07 | 1964-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-06-07 | 1967-12-07 | 1968-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-06-07 | 1971-12-07 | 1972-06-07 | $7700.00 | Window Closed / Lapsed |