Patent US3605924A successfully refreshed from Google Patents.
US3605924A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drill bit
Assignee: Thompson Products Ltd
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Filing: 1969-08-26
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Granted: 1971-09-20
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Expires: 1989-08-26
Abstract
Abstract A SINGLE PASS PERCUSSION DRILL BIT HAVING FROM FIVE TO NINE WINGS AROUND A CENTRAL HOLE, EACH CARRYING A SHALLOW, WIDE, HARD INSERT TOOTH IN A FLAT NARROW END FACE THEREOF AND HAVING FREE FLOW CHIP DISCHARGE PASSAGES BETWEEN THE TEETH. THE BIT BODY HAS A FLAT FRONT FACE WITH A SEPARATE SLOT FOR EACH INSERT, AND EACH INSERT HAS ITS INNER END BUTTED AGAINST A SHOULDER AT THE INNER END OF THE SLOT. THE INSERTS ARE WIDE AND SHALLOW TO PROVIDE MAXIMUM CUTTING FACES WITH MINIMUM MATERIAL, MAY BE OF THE SAME OR DIFFERENT LENGTHS, AND WILL BE SPACED IN ACCORDANCE WITH THE PLACEMENT OF A CENTRAL FLUSHING HOLE AND CHIP CLEARANCE GROOVES IN THE BIT BODY.
Inventors
- 👤 Edward A Donegan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:55
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/36; E21B10/38; E21B10/46; E21B10/58
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 |