(19)
(11) EP 0 038 125 A3

(12) EUROPEAN PATENT APPLICATION

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

(43) Date of publication A2:
21.10.1981 Bulletin 1981/42

(21) Application number: 81301218

(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 132951

(71) Applicant: REED ROCK BIT COMPANY
 ()

(72) Inventor:
  • 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.





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