Patent US5016637A successfully refreshed from Google Patents.
Patent US1424647A successfully refreshed from Google Patents.
Patent US1251646A successfully refreshed from Google Patents.
Patent US5049911A successfully refreshed from Google Patents.
Patent US2239842A successfully refreshed from Google Patents.
US2239842A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Valve indicator
Assignee: Hughes Tool Co
•
Filing: 1938-12-01
•
Granted: 1941-04-29
•
Expires: 1958-12-01
Abstract
No abstract record available.
Inventors
- 👤 Evans Seth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:47
CPC Classifications
F; F16; F16K; F16K37/00; F16K37/0008; F16K37/0016
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) | 1944-04-28 | 1944-10-28 | 1945-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1948-04-28 | 1948-10-28 | 1949-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1952-04-28 | 1952-10-28 | 1953-04-29 | $7700.00 | Window Closed / Lapsed |