1
John D Barr: Rotary drill bits with nozzle former and method of manufacturing. NL Petroleum Products, Browning Bushman Zamecki & Anderson, September 22, 1987: US04694919 (79 worldwide citation)

A method of manufacturing by a power metallurgy process a rotary drill bit including a bit body having an external surface on which are mounted a plurality of preform cutting elements, and an inner passage for supplying drilling fluid to at least one nozzle located in a socket at the external surfac ...


2
John Fuller: Rotary drill bits. NL Petroleum Products, Margaret Anderson, January 12, 1988: US04718505 (70 worldwide citation)

A rotary drill bit for use in drilling or coring deep holes in subsurface formations comprises a bit body having a shank for connection to a drill string and a plurality of cutting elements mounted at the surface of the bit body. Each cutting element is bonded to a stud which is received in a socket ...


3
Nigel D Griffin: Manufacture of rotary drill bits. NL Petroleum Products, William E Johnson Jr, June 2, 1987: US04669522 (42 worldwide citation)

A method of making a rotary drill bit comprises forming a hollow mould for moulding at least a portion of the bit body, packing at least a part of the mould with powdered matrix material, and infiltrating the material with a metal alloy in a furnace to form a matrix, the alloy being a copper based a ...


4
John D Barr: Rotary drill bits. NL Petroleum Products, Browning Bushman Zamecki & Anderson, February 14, 1989: US04804049 (39 worldwide citation)

The body of a rotary drill bit is formed from a matrix formed by a powder metallurgy process, and a plurality of cutting elements are mounted on the bit body, each cutting element being in the form of a disc of superhard material which is thermally stable at the temperature of formation of the matri ...


5
John D Barr, John M Fuller, Malcolm R Taylor: Rotary drill bits. NL Petroleum Products, Browning Bushman Zamecki & Anderson, March 29, 1988: US04733735 (37 worldwide citation)

A rotary drill bit comprises a bit body having a leading face and a gauge region, a number of blades on the leading face of the bit body, and a number of cutting elements mounted along each blade. A passage in the bit body supplies drilling fluid to nozzles in the leading face of the bit body for co ...


6
John Fuller: Rotary drill bits. NL Petroleum Products, Browning Bushman Zamecki & Anderson, April 25, 1989: US04823892 (36 worldwide citation)

A rotary drill bit for use in drilling or coring deep holes in subsurface formations comprises a bit body having a shank for connection to a drill string and a plurality of cutting elements mounted at the surface of the bit body. Each cutting element is bonded to a stud which is received in a socket ...


7
John D Barr: Rotary drill bits. NL Petroleum Products, Browning Bushman Zamecki & Anderson, March 25, 1986: US04577706 (28 worldwide citation)

A rotary bit for use in subsurface formations comprises a bit body having a central bore (4), the body having a leading face (1) and a trailing gauge region (2), walls (7) on the bit dividing the face into fluid channels, cutting elements C being present on at least some of the walls, and passageway ...


8
John D Barr, Michael T Wardley: Rotary drill bits and cutting elements for such bits. NL Petroleum Products, Browning Bushman Zamecki & Anderson, July 14, 1987: US04679639 (22 worldwide citation)

A cutting element for a rotary drill bit comprises a thin hard facing layer, defining a front cutting face, bonded to a less hard backing layer. The backing layer is of non-uniform thickness, for example is wedge-shaped, and is thicker adjacent the cutting edge of the facing layer than it is over th ...


9
John D Barr: Manufacture of rotary drill bits. NL Petroleum Products, William E Johnson Jr, November 25, 1986: US04624830 (21 worldwide citation)

A method of manufacturing by a powder metallurgy process a rotary drill bit including a bit body having a plurality of cutting elements mounted on the outer surface thereof comprises the steps of forming a hollow mould for moulding at least a portion of the bit body, packing the mould with powdered ...


10
Michael C Regan: Rotary drill bits. NL Petroleum Products, Browning Bushman Zamecki & Anderson, August 9, 1988: US04762028 (21 worldwide citation)

A method of manufacturing a rotary drill bit of the kind comprising a bit body having a shank for connection to a drill string, a plurality of cutting structures mounted in sockets in the bit body, and a number of nozzles also mounted in sockets in the bit body and communicating with a passage for s ...