Patent US3564947A successfully refreshed from Google Patents.
US3564947A
Expired / Lapsed
US
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Twist drilis
Assignee: Individual
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Filing: 1968-05-17
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Granted: 1971-02-23
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Expires: 1988-05-17
Abstract
Abstract A TWIST DRILL PROVIDING A GOOD CENTERING ACTION AND COMPRISING AT LEAST TWO CUTTING LIPS WHICH ARE CONNECTED TOGETHER BY CENTERING LIPS, IN WHICH THE CUTTING LIPS ARE FOLLOWED, IN THE DIRECTION OF ROTATION OF THE DRILL, BY A MAIN LAND OF THE DRILL AND BY A FURTHER GROUND SURFACE OF GREATER RAKE THAN THE MAIN LAND. EACH CENTERING LIP DIVIDING THE MAIN LAND FOLLOWING THE OPPOSITE CUTTING THE FURTHER GROUND SURFACE FOLLOWING THE OPPOSITE CUTTING LIP, AND EACH CENTERING LIP BEING UNDERCUT BY THE RESPECTIVE FURTHER GROUND SURFACE WHICH IT MEETS AND THUS BEING PROVIDED WITH A POSITIVE CUTTING ANGLE.
Inventors
- 👤 Karl Stephan Maier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:47
CPC Classifications
B; B24; B24B; B24B3/00; B24B3/24; B24B3/26; B24B3/32; B23; B23B; B23B51/00; B23B51/02; B23B2251/00; B23B2251/18; Y; Y10; Y10T; Y10T408/00; Y10T408/89; Y10T408/899; Y10T408/909; Y10T408/9095; Y10T408/9097
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) | 1974-02-22 | 1974-08-24 | 1975-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-22 | 1978-08-24 | 1979-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-22 | 1982-08-24 | 1983-02-23 | $7700.00 | Window Closed / Lapsed |