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US2783971A
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Apparatus for earth boring with pressurized air
Assignee: ENGINEERING LAB Inc
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Filing: 1953-03-11
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Granted: 1957-03-05
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Expires: 1973-03-11
Abstract
No abstract record available.
Inventors
- 👤 Guy F Carle
- 👤 Buford M Baker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:09
CPC Classifications
E; E21; E21B; E21B19/00; E21B19/08; E21B19/084; E21B21/00; E21B21/16; E21B4/00; E21B4/02; E21B7/00; E21B7/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US1390025A
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US1484065A
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US2340738A
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US2594098A
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US2410959A
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US2401190A
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US2575524A
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US2661932A
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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) | 1960-03-04 | 1960-09-03 | 1961-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-03-04 | 1964-09-03 | 1965-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-03-04 | 1968-09-03 | 1969-03-05 | $7700.00 | Window Closed / Lapsed |