Patent US2309999A successfully refreshed from Google Patents.
US2309999A
Expired / Lapsed
US
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Rotary drilling apparatus
Assignee: Sullivan Machinery Co
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Filing: 1939-05-23
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Granted: 1943-02-02
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Expires: 1959-05-23
Abstract
No abstract record available.
Inventors
- 👤 Harry H Vanderzee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:57
CPC Classifications
E; E21; E21B; E21B7/00; E21B7/02; E21B7/021
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) | 1946-02-01 | 1946-08-03 | 1947-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1950-02-01 | 1950-08-03 | 1951-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1954-02-01 | 1954-08-03 | 1955-02-02 | $7700.00 | Window Closed / Lapsed |