(19)
(11) EP 0 036 772 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
11.11.1981 Bulletin 1981/45

(43) Date of publication A2:
30.09.1981 Bulletin 1981/39

(21) Application number: 81301217

(22) Date of filing: 23.03.1981
(84) Designated Contracting States:
AT BE CH DE FR GB IT LI LU NL SE

(30) Priority: 24.03.1980 US 133164

(71) Applicant: REED ROCK BIT COMPANY
 ()

(72) Inventors:
  • Taylor, Philip Alan
     ()
  • Carter, Mark Warren
     ()
  • Childers, John Stevenson
     ()
  • Pastusek, Paul Ernest
     ()
  • Schumacher, Percy William
     ()

   


(54) Rolling cutter drill bit


(57) This invention discloses a rolling cone drilling bit (10) having a plurality of cutters (16) which have inserted therein hard metal cutting elements (22) preferably formed of tungsten carbide alloy; and in which bit the rolling cone cutters (16) are located in such a manner that their rotational axes (32) are greatly offset from the rotational axis (34) of the drill bit. In addition, a fluid jetting system is provided in the invention that directs a pressurized fluid spray (46) across the main cutting inserts and against the formation face so that when the drill bit (10) is used in its most advantageous areas, such as the soft, medium-soft and plastic formations, the jetting system prevents "balling up» of the cutters (16) and greatly increases the drilling efficiency of the bit.






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