US3564945A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drill
Assignee: BARWORTH FLOCKTON Ltd
•
Filing: 1968-10-02
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Granted: 1971-02-23
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Expires: 1988-10-02
Abstract
Abstract A UNITARY CUTTING DRILL DESIGNED FOR CUTTING A PLURALITY OF DIFFERENT SIZED HOLES COMPRISING A FRUSTO-CONICAL BIT HAVING ITS INCLINED SURFACE FORMED OF A SERIES OF STEPS WHICH PROGRESSIVELY INCREASE IN DIAMETER FROM THE SMALL DIAMETER END TO THE BASE THEREOF. THE INCLINED SURFACE IS RELIEVED FO MATERIAL TO FORM A CUTTING EDGE FOR EACH STEP OF THE SERIES.
Inventors
- 👤 Harry Edwin Bradley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:59
CPC Classifications
B; B23; B23B; B23B51/00; B23B51/009; B23B2251/00; B23B2251/40; B23B2251/406; Y; Y10; Y10T; Y10T408/00; Y10T408/89; Y10T408/905; Y10T408/906; Y10T408/909
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 |