Patent US3605923A successfully refreshed from Google Patents.
US3605923A
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Diamond bits having diamonds positioned in concentric circles on the drilling face
Assignee: Shell USA Inc
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Filing: 1969-01-24
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Granted: 1971-09-20
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Expires: 1989-01-24
Abstract
Abstract A DRILLING BIT HAVING DIAMONDS EMBEDDED IN THE DRILLING FACE, WITH THE DIAMONDS ARRANGED IN A PATTERN OF CONCENTRIC CIRCLES HAVING AXIS COINCIDING WITH THE AXIS OF THE BIT. ALL OF THE DIAMONDS IN A GIVEN CIRCLE WILL SUBSCRIBE A COMMON PATH IN THE FACE OF THE MATERIAL BEING DRILLED. A METHOF OF MANUFACTURE OF SUCH A BIT IS DISCLOSED, ALONG WITH A SPECIAL MOLD FOR PRACTING THE METHOD.
Inventors
- 👤 Robijn Feenstra
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:31
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/46
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) | 1974-09-19 | 1975-03-21 | 1975-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-19 | 1979-03-21 | 1979-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-19 | 1983-03-21 | 1983-09-20 | $7700.00 | Window Closed / Lapsed |