US3461978A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods and apparatus for borehole drilling
Assignee: Individual
•
Filing: 1967-04-26
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Granted: 1969-08-19
•
Expires: 1987-04-26
Abstract
No abstract record available.
Inventors
- 👤 Frank Whittle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:31
CPC Classifications
E; E21; E21B; E21B47/00; E21B47/007; E21B19/00; E21B19/08; E21B19/084
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-08-18 | 1973-02-17 | 1973-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-08-18 | 1977-02-17 | 1977-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-08-18 | 1981-02-17 | 1981-08-19 | $7700.00 | Window Closed / Lapsed |