公开(公告)号：CA2246511A1

公开(公告)日：1999-03-04

申请号：CA2246511

申请日：1998-09-03

Applicant: SMITH INTERNATIONAL

Inventor： MINIKUS JAMES C ,  CAWTHORNE CHRIS E ,  MORAN DAVID P ,  GARCIA GARY E ,  PORTWOOD GARY R ,  STEINKE STEPHEN C

IPC: E21B10/16 ,  E21B10/52 ,  E21B10/12

Abstract: A cutter element for a drill bit. The cutter element has a non-rectilinear crest . The non-rectilinear or curvilinear crest provides an advantageous distribution o f the cutting forces across the body of the cutter elements and thus improves bit life . The curvilinear crest also allows the cutter element to more efficiently lift the po rtion of the formation that is being cut, thereby improving cutting action in certain formati ons. The cutter elements can have either positive or non-positive draft and can be tungst en carbide inserts.

公开(公告)号：GB2324556A

公开(公告)日：1998-10-28

申请号：GB9807159

申请日：1998-04-02

Applicant: SMITH INTERNATIONAL

Inventor： CISNEROS DENNIS ,  MCDONOUGH SCOTT D ,  MINIKUS JAMES C ,  CAWTHORNE CHRIS E

IPC: E21B10/16 ,  E21B10/50

Abstract: A tooth, particularly suited for use in a rolling cone bit, includes a root region (83), a cutting tip (86) spaced from the root region (83) and a gage facing surface therebetween. The gage facing surface includes a knee (90) and is configured such that the cutting tip (86) is maintained at a position off the gage curve (99). So positioned, the cutting tip (86) is freed from having to perform any substantial cutting duty in the corner on the borehole corner, and instead may be configured and optimised for bottom hole cutting duty. The knee (90) on the gage facing surface is configured and positioned so as to serve primarily to cut the borehole wall. It is preferred that the knee (90) be positioned off gage, but that it be closer to the gage curve (99) than the cutting tip (86).

公开(公告)号：CA2151685C

公开(公告)日：1998-05-05

申请号：CA2151685

申请日：1995-06-13

Applicant: SMITH INTERNATIONAL

Inventor： KAR NARESH J ,  CAWTHORNE CHRIS E ,  PETERSON STEVE ,  KESHAVAN MADAPUSI K

IPC: E21B10/22 ,  E21B10/25

Abstract: A rock bit for drilling subterranean formations has an improved dynamic O-ring seal for retaining lubricant around the rock bit bearings during operation of the rock bit. Such a bit has a plurality of journal pins, each having a bearing surface, and a cutter cone mounted on each journal pin and including a bearing surface. A grease reservoir is in communication with such bearing surfaces for maintaining grease adjacent to the bearing surfaces. The grease is sealed in with dynamic O-ring seals rotating against a sealing surface with a Vickers hardness of at least 1000 and vibratory burnished to have a surface finish in the range of from 5 to 32 microinches (0.13 to 0.8 micrometers) AA. Preferably, the sealing surface is formed on a seal ring interposed between the cone and journal. Preferably the sealing surface comprises a tungsten carbide composite sprayed onto the outside surface of a steel ring which is then welded to a journal.

公开(公告)号：AU3998997A

公开(公告)日：1998-04-23

申请号：AU3998997

申请日：1997-10-08

Applicant: SMITH INTERNATIONAL

Inventor： CAWTHORNE CHRIS E ,  FANG ZHIGANG ,  KYKER STEVE ,  HUANG SUJIAN ,  JAMES BRIAN A ,  DENTON ROBERT

IPC: E21B10/22 ,  E21B10/25 ,  E21B10/24 ,  F16J9/20 ,  F16J9/28

公开(公告)号：GB2318137A

公开(公告)日：1998-04-15

申请号：GB9721174

申请日：1997-10-06

Applicant: SMITH INTERNATIONAL

Inventor： CAWTHORNE CHRIS E ,  HUANG SUJIAN ,  FANG ZHIGANG ,  JAMES BRIAN A ,  KYKER G STEVE ,  DENTON ROBERT

IPC: E21B10/22 ,  E21B10/25 ,  F16J15/32

Abstract: A high performance rock bit journal seal 50 is formed from a composite material 52 comprising an elastomeric material and a nonelastomeric polymeric material. The polymeric material is preferably in the form of fibres woven into a sheet. The elastomeric material includes at least one lubricant additive. The composite 'seal' material 52 comprises a number of repeating sheets of polymeric fabric that are bonded together with the elastomeric material. Cross sections other than circular are also disclosed (see figs 5-7).

公开(公告)号：SE9703653D0

公开(公告)日：1997-10-08

申请号：SE9703653

申请日：1997-10-08

Applicant: SMITH INTERNATIONAL

Inventor： CAWTHORNE CHRIS E ,  FANG ZHIGANG ,  HUANG SUJIAN ,  SIRACKI MICHAEL A

IPC: E21B10/22 ,  E21B10/25 ,  F16J15/32 ,  F16J15/34 ,  E21B

Abstract: Dual functioning seals for use in forming a lubricant seal in a rotary rock bit comprise an annular elastomeric seal body having a dynamic seal surface for sealing against a dynamic surface and a static seal surface for sealing against a static surface. The seal body has an asymmetric axial cross-sectional geometry the dynamic seal surface having a greater radius of curvature than that of the static seal surface. The dynamic and static seal surfaces are formed from different elastomeric materials, and the dynamic seal surface is formed from an elastomeric material that is harder and more wear resistant than the elastomeric material used to form the static seal surface. A rotary rock bit seal constructed in this manner is well adapted to accommodate the different operating conditions and sealing requirements that exist both at the dynamic and static surfaces of the seal to ensure optimal seal performance and, thereby enhance the service life of the rock bit.

公开(公告)号：GB2279095B

公开(公告)日：1996-08-21

申请号：GB9411505

申请日：1994-06-09

Applicant: SMITH INTERNATIONAL

Inventor： SIRACKI MICHAEL A ,  CAWTHORNE CHRIS E ,  MCDONOUGH SCOTT D ,  PORTWOOD GARY

IPC: E21B10/16 ,  E21B10/52 ,  E21B10/56 ,  E21B10/567

Abstract: A rotary cone rock bit for drilling boreholes in an earthen formation is disclosed. One or more rotary cones are rotatively retained on a journal bearing connected to the rock bit. These rotary cones form a circumferential heel row with extended ultra hard shaped cutters spaced within the heel row. Each of the shaped cutters form a cutting surface that extends above the heel row or is angled with respect to the formation to maintain the cutters in compression while the cutters shear a borehole wall. The shaped cutters serve to maintain the borehole diameter.

公开(公告)号：CA2125335A1

公开(公告)日：1994-12-16

申请号：CA2125335

申请日：1994-06-07

Applicant: SMITH INTERNATIONAL

Inventor： CAWTHORNE CHRIS E ,  MCDONOUGH SCOTT D ,  PORTWOOD GARY ,  SIRACKI MICHAEL A

IPC: E21B10/16 ,  E21B10/52 ,  E21B10/56 ,  E21B10/567 ,  E21B10/50

Abstract: A rotary cone rock bit for drilling boreholes in an earthen formation is disclosed. One or more rotary cones are rotatively retained on a journal bearing connected to the rock bit. These rotary cones form a circumferential heel row with extended ultra hard shaped cutters spaced within the heel row. Each of the shaped cutters form a cutting surface that extends above the heel row or is angled with respect to the formation to maintain the cutters in compression while the cutters shear a borehole wall. The shaped cutters serve to maintain the borehole diameter.

公开(公告)号：DE3811370A1

公开(公告)日：1988-10-27

申请号：DE3811370

申请日：1988-04-05

Applicant: SMITH INTERNATIONAL

Inventor： CAWTHORNE CHRIS E ,  ERPENBECK GERHARD P ,  NGUYEN IRVINE VAN

IPC: E21B10/08 ,  E21B10/18 ,  E21B10/52 ,  E21B17/10

Abstract: A drill bit is assembled from a plurality of machined forgings that are welded together to form a unitary structure. Each forging comprises an upper body portion (12) and a lower leg portion (16). The lower leg portion is machined to form a shirttail section (24) and a journal section (18), which in turn is adapted to rotatively support a cone shaped cutter (20). In operation, the cutter (20) is oriented to describe a circular path, the outer diameter of which forms the gage diameter of the bit. The upper body portion (12) is machined to include a stabilizer lug (30) extending radially outward to substantially the same diameter as that formed by the cutters. The lower section of the lug (30) co-operates with a recessed portion of the leg to form a flow passage for enabling drilling fluid to more easily pass upwardly through the borehole annulus during operation. A plurality of polycrystalline diamond inserts are mounted within the surface of each stabilizer lug (30).

公开(公告)号：CA2617384C

公开(公告)日：2010-04-06

申请号：CA2617384

申请日：2004-09-24

Applicant: SMITH INTERNATIONAL

Inventor： RICHMAN LANCE T ,  CAWTHORNE CHRIS E ,  NORRIS KIRK A ,  SLAUGHTER ROBERT H

IPC: E21B10/24 ,  F16C33/10 ,  F16N1/00

Abstract: Methods and apparatus for maintaining lubrication of rolling cone cutters mounted on journal pins. Embodiments comprise a rotating cone disposed on a journal pin and forming a journal gap there between. A cylindrical journal sleeve is disposed in the journal gap. The journal sleeve has a longitudinal gap forming opposing end portions, which are continuously contoured. A lubrication port is disposed in the journal pin and in fluid communication with a lubrication supply. The lubrication port has an outlet located in a recess in the journal gap. Each end of the recess comprises a transitioning surface extending between the bottom of the recess and the outer surface of the journal pin to prevent sharp transitions. In certain embodiments, the journal pin may comprise two or more lubrication ports, each located in a recess with transitioning surfaces.