Patent US1657462A successfully refreshed from Google Patents.
US2225840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drain back flow check
Assignee: PROVIDENCE STEAM TRAP Co
•
Filing: 1938-04-07
•
Granted: 1940-12-24
•
Expires: 1958-04-07
Abstract
No abstract record available.
Inventors
- 👤 Newton Frank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:23
CPC Classifications
F; F16; F16K; F16K15/00; F16K15/02; F16K15/03; F16K15/035; Y; Y10; Y10T; Y10T137/00; Y10T137/2496; Y10T137/2559; Y10T137/2564; Y10T137/2567; Y10T137/7722; Y10T137/7837; Y10T137/7838; Y10T137/7869; Y10T137/7871; Y10T137/7874
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1943-12-24 | 1944-06-24 | 1944-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-12-24 | 1948-06-24 | 1948-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-12-24 | 1952-06-24 | 1952-12-24 | $7700.00 | Window Closed / Lapsed |