(19)
(11) EP 0 905 348 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
30.06.1999 Bulletin 1999/26

(43) Date of publication A2:
31.03.1999 Bulletin 1999/13

(21) Application number: 98122696.2

(22) Date of filing: 31.10.1995
(51) International Patent Classification (IPC)6: E21B 10/32, E21B 10/56, E21B 47/18
(84) Designated Contracting States:
FR NL

(30) Priority: 31.10.1994 GB 9422022
17.03.1995 GB 9505430

(62) Application number of the earlier application in accordance with Art. 76 EPC:
95935506.6 / 0788578

(71) Applicants:
  • The Red Baron (Oil Tools Rental) Limited
    Altens Aberdeen AB1 4PG (GB)
  • SMITH INTERNATIONAL, INC.
    Houston, TX 77205-0068 (US)

(72) Inventor:
  • The designation of the inventor has not yet been filed
     ()

(74) Representative: Goodenough, Nigel et al
A.A. Thornton & Co. Northumberland House 303-306 High Holborn
London WC1V 7LE
London WC1V 7LE (GB)

 
Remarks:
This application was filed on 30 - 11 - 1999 as a divisional application to the application mentioned under INID code 62.
 


(54) Underreamer blade


(57) A blade (5A) for an underreamer (1) comprises an arm of steel and a multiplicity of wear resistant assemblies secured to the arm, the wear resistant assemblies being provided on a gauge face (D) and on an adjacent cutting face (A,C) of the blade. The multiplicity of wear resistant assemblies are secured to the arm as an integral unitary member by means of a single base component (51) in which the multiplicity of wear resistant assemblies is embedded. The base component is secured to the arm by welding or brazing.









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