US4995887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cutting elements for rotary drill bits
Assignee: ReedHycalog UK Ltd
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Filing: 1989-04-04
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Granted: 1991-02-26
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Expires: 2009-04-04
Abstract
Abstract A cutting element for a rotary drill bit comprises a layer of polycrystalline diamond material having a front face and a rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof. The front layer is thinner than the backing layer, at least in the vicinity of the cutting edge of the cutting element.
Inventors
- 👤 John D. Barr
- 👤 Thomas A. Newton, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:42
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/46; E21B10/56; E21B10/567; E21B10/5673; B; B23; B23P; B23P15/00; B23P15/28; B23P5/00
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
111 words
A cutting element for a rotary drill bit comprising a layer of polycrystalline diamond material having a front face and a rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof, the front layer being thinner than the backing layer, at least in the vicinity of the cutting edge, and the backing layer, diamond layer and front layer constituting a preformed structure in which the layers have been bonded together in a high temperature, high pressure press.
Claim 2
Dependent Claim
111 words
A cutting element for a rotary drill bit comprising a layer of polycrystalline diamond material having a front face and a rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof, the front layer being thinner than the backing layer, at least in the vicinity of the cutting edge, and the backing layer, diamond layer and front layer constituting a preformed structure in which the layers have been bonded together in a high temperature, high pressure press.
Claim 3
Dependent Claim
24 words
A cutting element according to claim 1, wherein the front layer of the cutting element extends across substantially the whole of the diamond layer.
Claim 4
Dependent Claim
14 words
A cutting element according to claim 1, wherein the diamond layer is substantially continuous.
Claim 5
Dependent Claim
29 words
A cutting element according to claim 1, wherein the diamond layer is formed with a plurality of apertures into which extends the material of the front and/or backing layer.
Claim 6
Dependent Claim
44 words
A cutting element according to claim 1, wherein the diamond layer comprises a plurality of discrete and separate elements spaced apart in a common plane so as to provide between the elements spaces into which extends the material of the front and/or backing layers.
Claim 7
Dependent Claim
25 words
A cutting element according to claim 1, wherein the diamond layer extends across only a part of the backing layer and the front layer respectively.
Claim 8
Dependent Claim
38 words
A cutting element according to claim 6, wherein the portions of the backing layer and front layer across which the diamond layer does not lie extend across the peripheral edge of the diamond layer and are bonded together.
Claim 9
Dependent Claim
19 words
A cutting element according to claim 1, wherein the front and backing layers are formed of the same material.
Claim 10
Dependent Claim
17 words
A cutting element according to claim 1, wherein the diamond layer lies in a substantially flat plane.
Claim 11
Dependent Claim
22 words
A cutting element according to claim 1, wherein the front and/or rear surface of the diamond layer is convexly or concavely curved.
Claim 12
Dependent Claim
16 words
A cutting element according to claim 1, wherein the diamond layer is of substantially constant thickness.
Claim 13
Dependent Claim
32 words
A cutting element according to claim 1, wherein the general plane of the diamond layer is disposed at an angle to the general plane of the front surface of the front layer.
Claim 14
Dependent Claim
31 words
A cutting element according to claim 12, wherein the front surface of the diamond layer intersects the front surface of the front layer adjacent a peripheral edge of the front layer.
Claim 15
Dependent Claim
26 words
A cutting element according to claim 1, wherein the rear surface of the backing layer is substantially parallel to the front surface of the front layer.
Claim 16
Dependent Claim
122 words
A cutting structure for a rotary drill bit comprising a cutting element bonded to a carrier, the cutting element comprising a layer of polycrystalline diamond material having a front face and a rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof, the front layer being thinner than the backing layer, at least in the vicinity of the cutting edge, and the backing layer, diamond layer and front layer constituting a preformed structure in which the layers have been bonded together in a high temperature, high pressure press.
Claim 17
Dependent Claim
122 words
A cutting structure for a rotary drill bit comprising a cutting element bonded to a carrier, the cutting element comprising a layer of polycrystalline diamond material having a front face and a rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof, the front layer being thinner than the backing layer, at least in the vicinity of the cutting edge, and the backing layer, diamond layer and front layer constituting a preformed structure in which the layers have been bonded together in a high temperature, high pressure press.
Claim 18
Dependent Claim
128 words
A rotary drill bit having an operating surface on which are mounted a plurality of cutting elements, at least certain of the cutting elements each comprising a layer of polycrystalline diamond material having a front face and a rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof, the front layer being thinner than the backing layer, at least in the vicinity of the cutting edge, and the backing layer, diamond layer and front layer constituting a preformed structure in which the layers have been bonded together in a high temperature, high pressure press.
Claim 19
Dependent Claim
128 words
A rotary drill bit having an operating surface on which are mounted a plurality of cutting elements, at least certain of the cutting elements each comprising a layer of polycrystalline diamond material having a front face and a rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof, the front layer being thinner than the backing layer, at least in the vicinity of the cutting edge, and the backing layer, diamond layer and front layer constituting a preformed structure in which the layers have been bonded together in a high temperature, high pressure press.
Claim 20
Independent Claim
106 words
A method of forming a cutting element for use in a rotary drill bit comprising the steps of forming in a high temperature, high pressure press an interim structure comprising a layer of polycrystalline diamond material having a front face and rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof, removing the interim structure from the press and then removing from the interim structure at least part of the front layer.
Claim 21
Independent Claim
106 words
A method of forming a cutting element for use in a rotary drill bit comprising the steps of forming in a high temperature, high pressure press an interim structure comprising a layer of polycrystalline diamond material having a front face and rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof, removing the interim structure from the press and then removing from the interim structure at least part of the front layer.
Claim 22
Dependent Claim
20 words
A method according to claim 17, including the step of removing at least part of the front layer by grinding.
Claim 23
Dependent Claim
27 words
A method according to claim 17, wherein sufficient of the front layer is removed to reveal at least part of the front surface of the diamond layer.
Claim 24
Dependent Claim
23 words
A method according to claim 17, wherein the interim structure is of substantially constant thickness and has substantially flat front and rear surfaces.
Claim 25
Dependent Claim
48 words
A method according to claim 17, wherein the front face of the diamond layer is concavely curved and sufficient of the front layer is removed to provide a front layer of substantially constant thickness, having a concave front surface, over at least a part of the diamond layer.
Claim 26
Dependent Claim
40 words
A method according to claim 17, wherein the front face of the diamond layer is concavely curved and sufficient of the front layer is removed to reveal at least a portion of the concave front face of the diamond layer.
Claim 27
Dependent Claim
31 words
A method according to claim 17, including the step of bonding the interim structure to a carrier before removing from the interim structure said at least part of the front layer.
Claim 28
Dependent Claim
94 words
A cutting element for a rotary drill bit comprising a layer of polycrystalline diamond material having a front face and a rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof, the front layer being thinner than the backing layer, at least in the vicinity of the cutting edge, and being formed of the same material as the backing layer.
Claim 29
Dependent Claim
94 words
A cutting element for a rotary drill bit comprising a layer of polycrystalline diamond material having a front face and a rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof, the front layer being thinner than the backing layer, at least in the vicinity of the cutting edge, and being formed of the same material as the backing layer.
Claim 30
Dependent Claim
24 words
A cutting element according to claim 24, wherein the front layer of the cutting element extends across substantially the whole of the diamond layer.
Claim 31
Dependent Claim
14 words
A cutting element according to claim 24, wherein the diamond layer is substantially continuous.
Claim 32
Dependent Claim
29 words
A cutting element according to claim 24, wherein the diamond layer is formed with a plurality of apertures into which extends the material of the front and/or backing layer.
Claim 33
Dependent Claim
44 words
A cutting element according to claim 24, wherein the diamond layer comprises a plurality of discrete and separate elements spaced apart in a common plane so as to provide between the elements spaces into which extends the material of the front and/or backing layers.
Claim 34
Dependent Claim
25 words
A cutting element according to claim 24, wherein the diamond layer extends across only a part of the backing layer and the front layer respectively.
Claim 35
Dependent Claim
38 words
A cutting element according to claim 29, wherein the portions of the backing layer and front layer across which the diamond layer does not lie extend across the peripheral edge of the diamond layer and are bonded together.
Claim 36
Dependent Claim
17 words
A cutting element according to claim 24, wherein the diamond layer lies in a substantially flat plane.
Claim 37
Dependent Claim
22 words
A cutting element according to claim 24, wherein the front and/or rear surface of the diamond layer is convexly or concavely curved.
Claim 38
Dependent Claim
16 words
A cutting element according to claim 24, wherein the diamond layer is of substantially constant thickness.
Claim 39
Dependent Claim
32 words
A cutting element according to claim 24, wherein the general plane of the diamond layer is disposed at an angle to the general plane of the front surface of the front layer.
Claim 40
Dependent Claim
31 words
A cutting element according to claim 34, wherein the front surface of the diamond layer intersects the front surface of the front layer adjacent a peripheral edge of the front layer.
Claim 41
Dependent Claim
26 words
A cutting element according to claim 24, wherein the rear surface of the backing layer is substantially parallel to the front surface of the front layer.
Claim 42
Dependent Claim
105 words
A cutting structure for a rotary drill bit comprising a cutting element bonded to a carrier, the cutting element comprising a layer of polycrystalline diamond material having a front face and a rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof, the front layer being thinner than the backing layer, at least in the vicinity of the cutting edge, and being formed of the same material as the backing layer.
Claim 43
Dependent Claim
105 words
A cutting structure for a rotary drill bit comprising a cutting element bonded to a carrier, the cutting element comprising a layer of polycrystalline diamond material having a front face and a rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof, the front layer being thinner than the backing layer, at least in the vicinity of the cutting edge, and being formed of the same material as the backing layer.
Claim 44
Dependent Claim
111 words
A rotary drill bit having an operating surface on which are mounted a plurality of cutting elements, at least certain of the cutting elements each comprising a layer of polycrystalline diamond material having a front face and a rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof, the front layer being thinner than the backing layer, at least in the vicinity of the cutting edge, and being formed of the same material as the backing layer.
Claim 45
Dependent Claim
111 words
A rotary drill bit having an operating surface on which are mounted a plurality of cutting elements, at least certain of the cutting elements each comprising a layer of polycrystalline diamond material having a front face and a rear face, a backing layer of less hard material bonded to the rear face of the diamond layer, and a front layer of less hard material bonded to the front face of the diamond layer and extending across at least the major part thereof, the front layer being thinner than the backing layer, at least in the vicinity of the cutting edge, and being formed of the same material as the backing layer.
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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) | 1994-02-25 | 1994-08-27 | 1995-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-25 | 1998-08-27 | 1999-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-25 | 2002-08-27 | 2003-02-26 | $7700.00 | Window Closed / Lapsed |