US2856956A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pneumatic check valve
Assignee: Individual
•
Filing: 1954-11-22
•
Granted: 1958-10-21
•
Expires: 1974-11-22
Abstract
No abstract record available.
Inventors
- 👤 Smolensky Michael
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:31
CPC Classifications
F; F16; F16K; F16K15/00; F16K15/02; F16K15/03; F16K15/035; Y; Y10; Y10T; Y10T137/00; Y10T137/7504; Y10T137/7722; Y10T137/7837; Y10T137/7838; Y10T137/7839; Y10T137/7854; Y10T137/7898; Y10T137/7903
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US831141A
Cited
GB190926783A
Cited
NL1033C
Cited
US1673831A
Cited
US2068833A
Cited
US2157554A
Cited
US2729238A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-10-20 | 1962-04-21 | 1962-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-10-20 | 1966-04-21 | 1966-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-10-20 | 1970-04-21 | 1970-10-21 | $7700.00 | Window Closed / Lapsed |