US2591528A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure responsive valve
Assignee: ARMSTRONG COALBREAK Co
•
Filing: 1948-10-08
•
Granted: 1952-04-01
•
Expires: 1968-10-08
Abstract
No abstract record available.
Inventors
- 👤 Jr Edward C Filstrup
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:25
CPC Classifications
F; F16; F16K; F16K17/00; F16K17/02; F16K17/04; F16K17/10; F16K15/00; F16K15/02; F16K15/025; F16K15/06; F16K15/063; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7738; Y10T137/7837; Y10T137/7904; Y10T137/7922; Y10T137/7923; Y10T137/7925
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US382469A
Cited
US948404A
Cited
US969803A
Cited
US1293858A
Cited
US1385019A
Cited
US1656670A
Cited
US1841029A
Cited
US2251275A
Cited
US2124374A
Cited
US2292294A
Cited
US2360733A
Cited
US2371793A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-04-01 | 1955-10-01 | 1956-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-04-01 | 1959-10-01 | 1960-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-04-01 | 1963-10-01 | 1964-04-01 | $7700.00 | Window Closed / Lapsed |