US4699227A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming cutting structures for rotary drill bits
Assignee: NL Petroleum Products Ltd
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Filing: 1985-12-12
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Granted: 1987-10-13
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Expires: 2005-12-12
Abstract
Abstract A method of forming a cutting structure for a rotary drill bit comprises brazing a thermally stable polycrystalline diamond cutting element to a carrier, the carrier being formed of a material such that, at the brazing temperature, the difference in coefficient of thermal expansion between said material and the polycrystalline diamond material is less than the difference in coefficient of thermal expansion between tungsten carbide and the polycrystalline diamond material. A suitable carrier material is silicon carbide.
Inventors
- 👤 Michael T. Wardley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:41
CPC Classifications
B; B23; B23K; B23K31/00; B23K31/02; B23K31/025; B24; B24D; B24D3/00; B24D3/007; C; C04; C04B; C04B37/00; C04B37/003; C04B37/006; C04B2237/00; C04B2237/02; C04B2237/12; C04B2237/122; C04B2237/124; C04B2237/30; C04B2237/32; C04B2237/36; C04B2237/363; C04B2237/365; C04B2237/50; C04B2237/72; C04B2237/76
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
73 words
A method of forming a cutting structure for a rotary drill bit comprising brazing a pre-formed thermally stable polycrystalline diamond cutting element to a separately pre-formed carrier, the carrier being formed of a material such that, at the brazing temperature, the difference in coefficient of thermal expansion between said material and the polycrystalline diamond material is less than the difference in coefficient of thermal expansion between tungsten carbide and the polycrystalline diamond material.
Claim 2
Independent Claim
73 words
A method of forming a cutting structure for a rotary drill bit comprising brazing a pre-formed thermally stable polycrystalline diamond cutting element to a separately pre-formed carrier, the carrier being formed of a material such that, at the brazing temperature, the difference in coefficient of thermal expansion between said material and the polycrystalline diamond material is less than the difference in coefficient of thermal expansion between tungsten carbide and the polycrystalline diamond material.
Claim 3
Dependent Claim
30 words
A method according to claim 1, wherein the difference in coefficient of thermal expansion between said carrier material and the polycrystalline diamond material is less than 3×10 -6 /° C.
Claim 4
Dependent Claim
13 words
A method according to claim 2, wherein the carrier material is silicon carbide.
Claim 5
Dependent Claim
23 words
A method according to claim 3, wherein the brazing material used to braze the cutting element to the carrier is a copper/phosphorus alloy.
Claim 6
Dependent Claim
23 words
A method according to claim 3, wherein the brazing material used to braze the cutting element to the carrier is a germanium/silicon alloy.
Claim 7
Dependent Claim
12 words
A method according to claim 5, wherein the germanium/silicon alloy includes titanium.
Claim 8
Dependent Claim
31 words
A method according to claim 1, including the preliminary step, prior to brazing the cutting element to the carrier, of coating the cutting element with a material to facilitate the brazing.
Claim 9
Dependent Claim
30 words
A method according to claim 7, wherein the material with which the cutting element is coated is a copper-based alloy including an element selected from chromium, vanadium, titanium or boron.
Claim 10
Dependent Claim
44 words
A method according to claim 7, including the steps of applying the coating material to the surface of the cutting element by vapour deposition, and then heating the cutting element until the coating material reacts with the polycrystalline diamond material of the cutting element.
Claim 11
Dependent Claim
18 words
A method according to claim 9, wherein the coating material is selected from chromium, titanium, zirconium and silicon.
Claim 12
Dependent Claim
21 words
A method according to claim 1, wherein the cutting element comprises a flat circular disc of thermally stable polycrystalline diamond material.
Claim 13
Dependent Claim
37 words
A method according to claim 1, wherein the carrier comprises a substantially cylindrical stud having a flat surface inclined at an angle to the longitudinal axis of the stud, to which surface the cutting element is brazed.
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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) | 1990-10-12 | 1991-04-13 | 1991-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-12 | 1995-04-13 | 1995-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-12 | 1999-04-13 | 1999-10-13 | $7700.00 | Window Closed / Lapsed |