US2943681A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fracturing using calcium carbide
Assignee: Individual
•
Filing: 1957-04-29
•
Granted: 1960-07-05
•
Expires: 1977-04-29
Abstract
No abstract record available.
Inventors
- 👤 Michael W Barrett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 02:25
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; E; E21; E21B; E21B43/00; E21B43/25; E21B43/26; E21B43/2605
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1856912A
Cited
US2712355A
Cited
US2766828A
Cited
US2748867A
Cited
US2799342A
Cited
US2811209A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-07-05 | 1964-01-04 | 1964-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-07-05 | 1968-01-04 | 1968-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-07-05 | 1972-01-04 | 1972-07-05 | $7700.00 | Window Closed / Lapsed |