US2454740A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for treating wells
Assignee: Dow Chemical Co
•
Filing: 1945-01-31
•
Granted: 1948-11-23
•
Expires: 1965-01-31
Abstract
No abstract record available.
Inventors
- 👤 Jr Philip J Lehnhard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:37
CPC Classifications
E; E21; E21B; E21B27/00; E21B27/02
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1385760A
Cited
US1552675A
Cited
US2168735A
Cited
US2217857A
Cited
US2171840A
Cited
US2207345A
Cited
US2274297A
Cited
US2210205A
Cited
US2330145A
Cited
US2347589A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-11-23 | 1952-05-24 | 1952-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-11-23 | 1956-05-24 | 1956-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-11-23 | 1960-05-24 | 1960-11-23 | $7700.00 | Window Closed / Lapsed |