(19)

(11)

EP 2 021 580 A1

(12)

(43) Date of publication: 11.02.2009 Bulletin 2009/07 (21) Application number: 07730797.3 (22) Date of filing: 30.05.2007

(51) International Patent Classification (IPC):  E21B 44/06(2006.01) E21B 21/08(2006.01) E21B 44/04(2006.01) (86) International application number: PCT/FI2007/050310 (87) International publication number: WO 2007/138170 (06.12.2007 Gazette 2007/49)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR Designated Extension States: AL BA HR MK RS (30) Priority: 01.06.2006 FI 20065369 (71) Applicant: Sandvik Mining and Construction Oy 33330 Tampere (FI)	(72) Inventor: SALONEN, Markus FI-33270 Tampere (FI) (74) Representative: Rantanen, Reijo Kalervo  Kolster OY AB P.O. Box 148 (Iso Roobertinkatu 23 00121 Helsinki 00121 Helsinki (FI)