US4872520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flat bottom drilling bit with polycrystalline cutters
Assignee: NELSON JACK RICHARD
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Filing: 1988-10-13
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Granted: 1989-10-10
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Expires: 2008-10-13
Abstract
Abstract An earth drilling bit with a body having a flat bottom. A plurality of cutting elements positioned on the flat bottom including a polycrystalline diamond cutter. The cutters include an elongate apex with a face on both sides of the apex extending backwardly from the apex. The apex extends generally vertically with a slight rake for providing a chisel surface for acting on the earth even when when the cutter becomes worn. The cutter may include multiple apexes and have zero side rake. A plurality of fluid circulating channels are provided in the flat bottom and vertically along the outside of the body and a plurality of fluid nozzles are directed outwardly at an angle to the longitudinal axis of the body.
Inventors
- 👤 Jack R. Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:52
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/46; E21B10/56; E21B10/567; E21B10/5673; E21B10/60
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
100 words
An earth drilling bit comprising, a body, said body having a flat bottom, a plurality of cutting elements positioned on the flat bottom, said elements including a stud carrying a polycrystalline diamond cutter, said cutters including an elongate straight, sharp chisel edged apex with a face on both sides of the apex extending backwardly from the apex, said apex extending generally vertically with a slight back rake for providing a chisel surface for acting on the earth even when the cutter becomes worn, wherein the cutters include multiple apexes with a face extending backwardly on both sides of each apex.
Claim 2
Dependent Claim
100 words
An earth drilling bit comprising, a body, said body having a flat bottom, a plurality of cutting elements positioned on the flat bottom, said elements including a stud carrying a polycrystalline diamond cutter, said cutters including an elongate straight, sharp chisel edged apex with a face on both sides of the apex extending backwardly from the apex, said apex extending generally vertically with a slight back rake for providing a chisel surface for acting on the earth even when the cutter becomes worn, wherein the cutters include multiple apexes with a face extending backwardly on both sides of each apex.
Claim 3
Dependent Claim
110 words
An earth drilling bit comprising, a body, said body including a flat bottom, a plurality of cutting elements positioned on the flat bottom, said elements including a stud carrying a polycrystalline diamond cutter, some of said cutters including a single straight sharp chisel edged apex with a face on both sides of the apex extending backwardly from the apex, and some of the cutters including multiple straight sharp chisel edged apexes with a face extending backwardly on both sides of each apex, all of said apexes extending generally vertically with a slight back rake for providing a chisel surface for acting on the earth even when the cutter becomes worn.
Claim 4
Dependent Claim
110 words
An earth drilling bit comprising, a body, said body including a flat bottom, a plurality of cutting elements positioned on the flat bottom, said elements including a stud carrying a polycrystalline diamond cutter, some of said cutters including a single straight sharp chisel edged apex with a face on both sides of the apex extending backwardly from the apex, and some of the cutters including multiple straight sharp chisel edged apexes with a face extending backwardly on both sides of each apex, all of said apexes extending generally vertically with a slight back rake for providing a chisel surface for acting on the earth even when the cutter becomes worn.
Claim 5
Dependent Claim
46 words
The apparatus of claim 2 wherein the plurality of cutting element are all in the same horizontal plane, and the cutters with a single apex are alternately positioned outwardly in a radial direction from the horizontal axis of the body with the cutters having multiple apexes.
Claim 6
Dependent Claim
104 words
An earth drilling bit comprising, a body having a bottom, a plurality of cutting elements positioned on the bottom, said elements including a stud carrying a polycrystalline diamond cutter, said cutters including an elongate straight sharp chisel edged apex with a face on both sides of the apex extending backwardly from the apex, said apex extending generally vertically with a slight back rake for providing a chisel surface which maintains its shape while acting on the earth even when the cutter becomes worn, wherein some of said cutters include multiple straight sharp apexes with a face extending backwardly on both sides of each apex.
Claim 7
Dependent Claim
104 words
An earth drilling bit comprising, a body having a bottom, a plurality of cutting elements positioned on the bottom, said elements including a stud carrying a polycrystalline diamond cutter, said cutters including an elongate straight sharp chisel edged apex with a face on both sides of the apex extending backwardly from the apex, said apex extending generally vertically with a slight back rake for providing a chisel surface which maintains its shape while acting on the earth even when the cutter becomes worn, wherein some of said cutters include multiple straight sharp apexes with a face extending backwardly on both sides of each apex.
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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) | 1992-10-09 | 1993-04-10 | 1993-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-09 | 1997-04-10 | 1997-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-09 | 2001-04-10 | 2001-10-10 | $7700.00 | Window Closed / Lapsed |