US4726432A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differentially hardfaced rock bit
Assignee: Enron Chemical Co
•
Filing: 1987-07-13
•
Granted: 1988-02-23
•
Expires: 2007-07-13
Abstract
Abstract A method for manufacturing an earth boring drill bit and bit produced thereby are shown. The bit has rotatable cutters with a plurality of milled teeth, each of the teeth having opposing flanks. A first tube hardfacing is applied to a selected one of the opposing flanks, the hardfacing comprising a metallic binder with wear-resistant particles dispersed throughout the binder. The other of the opposing flanks has a second tube hardfacing applied thereto. The particle size of the wear-resistant particles differs between the first and second tube hardfacings so that the resulting difference in abrasion resistance of the tooth flanks produces a self-sharpening effect as the tooth wears.
Inventors
- 👤 Danny E. Scott
- 👤 Eric C. Sullivan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:16
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/46; E21B10/50; B; B23; B23K; B23K35/00; B23K35/22; B23K35/24; B23K35/32; B23K35/327; C; C21; C21D; C21D9/00; C21D9/22; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4998; Y10T29/49982; Y10T29/49986
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
134 words
A method of manufacturing an earth boring drill bit of the type having rotatable cutters, the method comprising the steps of: forming a cutter having a plurality of teeth, each of the teeth having opposing flanks; applying a first tube hardfacing to a selected one of the opposing flanks, the tube hardfacing comprising a metallic binder having wear resistant particles dispersed therein; applying a second tube hardfacing to the other of the opposing flanks, the second tube hardfacing comprising a metallic binder having wear resistant particles dispersed therein, the wear resistant particles in the first tube hardfacing being selected to differ in mean particle size from the wear resistant particles in the second hardfacing so that the resulting difference in abrasion resistance of the tooth flanks produces a self-sharpening effect as the tooth wears.
Claim 2
Independent Claim
134 words
A method of manufacturing an earth boring drill bit of the type having rotatable cutters, the method comprising the steps of: forming a cutter having a plurality of teeth, each of the teeth having opposing flanks; applying a first tube hardfacing to a selected one of the opposing flanks, the tube hardfacing comprising a metallic binder having wear resistant particles dispersed therein; applying a second tube hardfacing to the other of the opposing flanks, the second tube hardfacing comprising a metallic binder having wear resistant particles dispersed therein, the wear resistant particles in the first tube hardfacing being selected to differ in mean particle size from the wear resistant particles in the second hardfacing so that the resulting difference in abrasion resistance of the tooth flanks produces a self-sharpening effect as the tooth wears.
Claim 3
Independent Claim
158 words
A method of manufacturing an earth boring drill bit of the type having rotatable cutters, the method comprising the steps of: forging a steel cutter; machining a plurality of teeth on each cutter, each of the teeth having opposing flanks; applying a coarse tube hardfacing to a selected one of the opposing flanks, the coarse tube hardfacing comprising an alloy steel matrix having wear resistant, tungsten carbide particles dispersed therein; applying a finer tube hardfacing to the other of the opposing flanks, the finer tube hardfacing comprising an alloy steel matrix having wear resistant, tungsten carbide particles dispersed therein, the wear resistant particles in the coarse tube hardfacing being selected to differ in mean particle size from the wear resistant particles in the finer tube hardfacing by at least 30% so that the resulting difference in abrasion resistance of the tooth flanks produces a self-sharpening effect as the tooth wears; carburizing the cutter; and heat treating the cutter.
Claim 4
Independent Claim
158 words
A method of manufacturing an earth boring drill bit of the type having rotatable cutters, the method comprising the steps of: forging a steel cutter; machining a plurality of teeth on each cutter, each of the teeth having opposing flanks; applying a coarse tube hardfacing to a selected one of the opposing flanks, the coarse tube hardfacing comprising an alloy steel matrix having wear resistant, tungsten carbide particles dispersed therein; applying a finer tube hardfacing to the other of the opposing flanks, the finer tube hardfacing comprising an alloy steel matrix having wear resistant, tungsten carbide particles dispersed therein, the wear resistant particles in the coarse tube hardfacing being selected to differ in mean particle size from the wear resistant particles in the finer tube hardfacing by at least 30% so that the resulting difference in abrasion resistance of the tooth flanks produces a self-sharpening effect as the tooth wears; carburizing the cutter; and heat treating the cutter.
Claim 5
Dependent Claim
63 words
The method of claim 2, wherein each machined tooth on the cutter has a tooth crest defined between a leading flank and trailing flank and wherein the coarse tube hardfacing is applied to a selected one of the leading and trailing flanks of each tooth, the finer hardfacing being applied to the other of the respective leading and trailing flanks of each tooth.
Claim 6
Dependent Claim
99 words
In an earth boring drill bit of the type having rotatable cutters with a plurality of milled teeth, each of the teeth having opposing flanks, the improvement comprising: a first tube hardfacing bonded to a selected one of the opposing teeth flanks, the tube hardfacing comprising a metallic binder with wear-resistant particles dispersed throughout the binder, the other of the opposing teeth flanks having a second tube hardfacing applied thereto, and wherein the wear resistant particles in the first tube hardfacing differ in mean particle size from the wear resistant particles in the second hardfacing by at least 30%.
Claim 7
Dependent Claim
99 words
In an earth boring drill bit of the type having rotatable cutters with a plurality of milled teeth, each of the teeth having opposing flanks, the improvement comprising: a first tube hardfacing bonded to a selected one of the opposing teeth flanks, the tube hardfacing comprising a metallic binder with wear-resistant particles dispersed throughout the binder, the other of the opposing teeth flanks having a second tube hardfacing applied thereto, and wherein the wear resistant particles in the first tube hardfacing differ in mean particle size from the wear resistant particles in the second hardfacing by at least 30%.
Claim 8
Dependent Claim
138 words
In an earth boring drill bit of the type having rotatable cutters with a plurality of machined steel teeth, each of the teeth having opposing flanks, the improvement comprising: a first tube hardfacing bonded to a selected one of the opposing flanks, the tube hardfacing comprising an alloy steel matrix having wear resistant, tungsten carbide particles dispersed therein, the other of the opposing flanks having a second tube hardfacing applied thereto, the second tube hardfacing comprising an alloy steel matrix having wear resistant, tungsten carbide particles dispersed therein, and wherein the wear resistant particles in the first tube hardfacing differ in mean particle size from the wear resistant particles in the second tube hardfacing by at least 30% so that the resulting difference in abrasion resistance of the tooth flanks produces a self-sharpening effect as the tooth wears.
Claim 9
Dependent Claim
138 words
In an earth boring drill bit of the type having rotatable cutters with a plurality of machined steel teeth, each of the teeth having opposing flanks, the improvement comprising: a first tube hardfacing bonded to a selected one of the opposing flanks, the tube hardfacing comprising an alloy steel matrix having wear resistant, tungsten carbide particles dispersed therein, the other of the opposing flanks having a second tube hardfacing applied thereto, the second tube hardfacing comprising an alloy steel matrix having wear resistant, tungsten carbide particles dispersed therein, and wherein the wear resistant particles in the first tube hardfacing differ in mean particle size from the wear resistant particles in the second tube hardfacing by at least 30% so that the resulting difference in abrasion resistance of the tooth flanks produces a self-sharpening effect as the tooth wears.
Claim 10
Dependent Claim
62 words
The earth boring drill bit of claim 5, wherein each tooth has a tooth crest defined between a leading and a trailing flank of the tooth, and wherein the first tube hardfacing is applied to a selected one of the leading and trailing flanks of each tooth, the second hardfacing being applied to the other of the respective flanks of each tooth.
Claim 11
Dependent Claim
52 words
The earth boring drill bit of claim 5, wherein the wear resistant particles in the first tube hardfacing are in the range from about 0.023 to 0.065 inches in diameter and wherein the wear-resistant particles in the second tube hardfacing are in the range from about 0.020 to 0.032 inches in diameter.
Claim 12
Dependent Claim
49 words
The earth boring drill bit of claim 5, wherein the wear-resistant particles in the first tube hardfacing are in the range from about 0.020 to 0.032 inches and wherein the wear-resistant particles in the second tube hardfacing are in the range from about 0.007 to 0.028 inches in diameter.
References Cited (Backward Citations)
US2043142A
Cited
US2306683A
Cited
US2371488A
Cited
US2660405A
Cited
US3127945A
Cited
US3260579A
Cited
US3800891A
Cited
US3778580A
Cited
US3946817A
Cited
US4274769A
Cited
US4262761A
Cited
US4533004A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-22 | 1991-08-24 | 1992-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-22 | 1995-08-24 | 1996-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-22 | 1999-08-24 | 2000-02-23 | $7700.00 | Window Closed / Lapsed |