US2212044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for perforating well casings
Assignee: HOWARD W STEPP
•
Filing: 1939-07-24
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Granted: 1940-08-20
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Expires: 1959-07-24
Abstract
No abstract record available.
Inventors
- 👤 Ralph M Ridley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:51
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/11; E21B43/116; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/496; Y10T29/49604
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) | 1943-08-20 | 1944-02-19 | 1944-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-08-20 | 1948-02-19 | 1948-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-08-20 | 1952-02-19 | 1952-08-20 | $7700.00 | Window Closed / Lapsed |