Patent US4365679A successfully refreshed from Google Patents.
US4365679A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drill bit
Assignee: SKF Engineering and Research Centre BV
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Filing: 1980-12-02
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Granted: 1982-12-28
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Expires: 2000-12-02
Abstract
Abstract A drill bit with cutting teeth for drilling in rock comprising: a core member having raceways for rolling elements for rotation of the drill bit, a supporting layer exteriorly shaped to define cutting teeth and formed of highly compacted sintered powder material of substantially 90% density, isostatically bonded to said core member, a wear resistant layer applied by thermal spraying and covering only the portions of the cutting teeth which upon drilling directly contact the rock, said wear resistant layer and said supporting layer being isostatically compacted hot which combined are of substantially 99% density, said layers having a solid bond therebetween providing a drill bit of superior mechanical properties including high resistance to wear and chipping.
Inventors
- 👤 Hans B. van Nederveen
- 👤 Martin B. Verburgh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:42
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/24; B22F7/00; B22F7/06; C; C23; C23C; C23C4/00; C23C4/02; E; E21; E21B; E21B10/00; E21B10/08; E21B10/22; E21B10/46; E21B10/50; B22F2998/00; B22F2998/10
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
117 words
A drill bit with cutting teeth for drilling in rock comprising: a core member having raceways for rolling elements for rotation of the drill bit, a supporting layer exteriorly shaped to define cutting teeth and formed of highly compacted sintered powder material of substantially 90% density, isostatically bonded to said core member, a wear resistant layer applied by thermal spraying and covering only the portions of the cutting teeth which upon drilling directly contact the rock, said wear resistant layer and said supporting layer being isostatically compacted hot which combined are of substantially 99% density, said layers having a solid bond therebetween providing a drill bit of superior mechanical properties including high resistance to wear and chipping.
Claim 2
Dependent Claim
117 words
A drill bit with cutting teeth for drilling in rock comprising: a core member having raceways for rolling elements for rotation of the drill bit, a supporting layer exteriorly shaped to define cutting teeth and formed of highly compacted sintered powder material of substantially 90% density, isostatically bonded to said core member, a wear resistant layer applied by thermal spraying and covering only the portions of the cutting teeth which upon drilling directly contact the rock, said wear resistant layer and said supporting layer being isostatically compacted hot which combined are of substantially 99% density, said layers having a solid bond therebetween providing a drill bit of superior mechanical properties including high resistance to wear and chipping.
Claim 3
Dependent Claim
19 words
A drill bit as claimed in claim 1 wherein the said supporting layer consists of a nickel-containing alloy steel.
Claim 4
Dependent Claim
17 words
A drill bit as claimed in claim 2 wherein said nickel-containing alloy steel contains about 3.5% nickel.
Claim 5
Dependent Claim
31 words
A drill bit as claimed in claim 1 wherein said core member is formed by mechanical operations and heat treatment into a bearing for the bearing system of the drill bit.
References Cited (Backward Citations)
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Cited
US3757879A
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US4054426A
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US4276788A
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US4198233A
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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) | 1985-12-27 | 1986-06-28 | 1986-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-27 | 1990-06-28 | 1990-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-27 | 1994-06-28 | 1994-12-28 | $7700.00 | Window Closed / Lapsed |