US1721746A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Safety check valve
Assignee: Individual
•
Filing: 1928-07-19
•
Granted: 1929-07-23
•
Expires: 1948-07-19
Abstract
No abstract record available.
Inventors
- 👤 Pearson Ragnar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:49
CPC Classifications
E; E03; E03F; E03F7/00; E03F7/02; E03F7/04; Y; Y10; Y10T; Y10T137/00; Y10T137/7287; Y10T137/7358; Y10T137/7439; Y10T137/7442; Y10T137/7485; Y10T137/7504
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1932-07-22 | 1933-01-21 | 1933-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1936-07-22 | 1937-01-21 | 1937-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1940-07-22 | 1941-01-21 | 1941-07-23 | $7700.00 | Window Closed / Lapsed |