US4889017A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary drill bit for use in drilling holes in subsurface earth formations
Assignee: ReedHycalog UK Ltd
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Filing: 1988-04-29
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Granted: 1989-12-26
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Expires: 2008-04-29
Abstract
Abstract A rotary drill bit for use in drilling holes in subsurface earth formations comprises a bit body having a shank at one end for connection to a drill string and an operating end face at the other end. A plurality of first cutting structures, each comprising a preform cutting element, is mounted in the bit body at the end face thereof, and each has a superhard front cutting face. The bit body includes a plurality of protuberances projecting outwardly from the adjacent portions of the end face, the protuberances forming a plurality of second cutting structures disposed in generally trailing relation, respectively, to at least some of the first cutting structures. Each of the protuberances is impregnated with superhard particles through a significant depth measured from the outermost extremity of the protuberance. At least a major operative portion of each of the second cutting structures is circumferencially separated from the respective leading first cutting structure by an open space, and is likewise radially separated from the nearest adjacent second cutting structure or structures.
Inventors
- 👤 John Fuller
- 👤 Joseph A. Gasan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:05
CPC Classifications
B; B22; B22F; B22F7/00; B22F7/06; B22F7/08; E; E21; E21B; E21B10/00; E21B10/46; E21B10/56; E21B10/567; E21B10/60
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
138 words
A method of making a drill bit for drilling holes in subsurface earth formations comprising the steps of: providing a mold configured to form a substantial body portion of said bit and having a first plurality of recesses therein; placing in each of said recesses a quantity of spacer material having a plurality of superhard particles dispersed therein through a significant depth measured from the bottom of the recess; forming said bit body portion in said mold of a tungsten carbide matrix so as to cause said matrix to become integrated with said spacer material and to form therewith abrasive protuberances projecting outwardly from the adjacent surfaces of said bit body portion; and mounting a plurality of preform cutting structures in said body portion in spaced leading relation to major operative portions of respective ones of said protuberances.
Claim 2
Independent Claim
138 words
A method of making a drill bit for drilling holes in subsurface earth formations comprising the steps of: providing a mold configured to form a substantial body portion of said bit and having a first plurality of recesses therein; placing in each of said recesses a quantity of spacer material having a plurality of superhard particles dispersed therein through a significant depth measured from the bottom of the recess; forming said bit body portion in said mold of a tungsten carbide matrix so as to cause said matrix to become integrated with said spacer material and to form therewith abrasive protuberances projecting outwardly from the adjacent surfaces of said bit body portion; and mounting a plurality of preform cutting structures in said body portion in spaced leading relation to major operative portions of respective ones of said protuberances.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein said spacer material comprises tungsten carbide.
Claim 4
Dependent Claim
81 words
The method of claim 2 wherein said formation of said main body portion and integration of said spacer material therewith comprises: placing in the mold a charge of powdered tungsten carbide in contact with said spacer material; placing a metallic infiltrant in contact with said charge of tungsten carbide; and heating said mold and its contents to at least the melting point of said infiltrant to cause said infiltrant to infiltrate said charge of tungsten carbide and contact said spacer material.
Claim 5
Dependent Claim
15 words
The method of claim 3 wherein said infiltrant is caused to infiltrate said spacer material.
Claim 6
Dependent Claim
45 words
The method of claim 3 wherein said spacer material and superhard particles, as placed in said recess, are mixed with a temporary binder which is volatile at the temperature to which the mold is subsequently heated, said infiltrant replacing said temporary binder during said heating.
Claim 7
Dependent Claim
55 words
The method of claim 3 wherein said spacer material is formed into a self-supporting body, one end of which is disposed in the respective mold recess, and the other end of which protrudes into the mold cavity, said charge of tungsten carbide being placed in surrounding relation to said other end of said self-supporting body.
Claim 8
Dependent Claim
32 words
The method of claim 6 comprising using as said self-supporting body a body of cold pressed tungsten carbide with interstices therein, said infiltrant being caused to enter said interstices during said heating.
Claim 9
Dependent Claim
54 words
The method of claim 6 comprising using as said self-supporting body a preform of tungsten carbide matrix with an infiltrant amalgamable with the infiltrant to be placed on said charge of tunsten carbide; and wherein said heating is to a temperature greater than or equal to the melting points of both of said infiltrants.
Claim 10
Dependent Claim
11 words
The method of claim 8 wherein said two infiltrants are similar.
Claim 11
Dependent Claim
38 words
The method of claim 8 comprising using as said self-supporting body a body comprised of hot pressed tungsten carbide with a permanent binder whose melting point is greater than that to which the mold is to be heated.
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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) | 1992-12-25 | 1993-06-26 | 1993-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-25 | 1997-06-26 | 1997-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-25 | 2001-06-26 | 2001-12-26 | $7700.00 | Window Closed / Lapsed |