(19)
(11) EP 0 106 701 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
05.02.1986 Bulletin 1986/06

(43) Date of publication A2:
25.04.1984 Bulletin 1984/17

(21) Application number: 83306325

(22) Date of filing: 18.10.1983
(84) Designated Contracting States:
AT BE CH DE FR GB IT LI LU NL SE

(30) Priority: 07.04.1983 US 482907
19.10.1982 US 435239

(71) Applicant: DRUMCO
 ()

(72) Inventors:
  • Drummond, Donald David
     ()
  • Wood, Roy Wilbert
     ()
  • Johnsey, Walter Frank
     ()

   


(54) Method and apparatus for lubricating a drill bit


(57) A method and apparatus for providing a flow of lubricating fluid from a surface-mounted lubricating fluid source (20) through a rotatable drill pipe (16) to rotary cutting cones of a rotary drill bit (12) for drilling in an underground formation, including pump means (24) for providing a flow of lubricating fluid from the fluid source to an end of the drill pipe. Drill pipe conduit means extending along the length of the drill pipe is provided for receiving the flow of lubricating fluid and for directing the lubricating fluid flow along the drill pipe to the drill bit. Distribution conduit means at the drill bit extends from the drill pipe conduit means to the cutting cones and receives the flow of lubricating fluid from the drill pipe conduit means for directing the lubricating fluid flow to the cutting cones for lubrication thereof.






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