US3522852A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Expandable drill bit and reamer construction
Assignee: Trident Industries Inc
•
Filing: 1967-08-18
•
Granted: 1970-08-04
•
Expires: 1987-08-18
Abstract
No abstract record available.
Inventors
- 👤 Allen Eugene Bardwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:35
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/36; E21B10/40; E21B10/46; E21B10/56; E21B10/58; E21B10/62
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US1592268A
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US1660201A
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US1969040A
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US2002388A
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US2265472A
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US2579720A
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US2575239A
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US2696973A
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US2864586A
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US3106973A
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US3258077A
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US3311181A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-08-03 | 1974-02-02 | 1974-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-08-03 | 1978-02-02 | 1978-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-08-03 | 1982-02-02 | 1982-08-04 | $7700.00 | Window Closed / Lapsed |