(19)

(11)

EP 2 646 638 A1

(12)

(43) Date of publication: 09.10.2013 Bulletin 2013/41 (21) Application number: 11845893.4 (22) Date of filing: 16.11.2011

(51) International Patent Classification (IPC):  E21B 7/02(2006.01) E21B 44/00(2006.01) (86) International application number: PCT/FI2011/051011 (87) International publication number: WO 2012/072870 (07.06.2012 Gazette 2012/23)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR (30) Priority: 29.11.2010 FI 20106255 (71) Applicant: Sandvik Mining and Construction Oy 33330 Tampere (FI)	(72) Inventor: PUURA, Jussi FI-33330 Tampere (FI) (74) Representative: Stellberg, Hans Valter  Kolster Oy Ab P.O. Box 148 (Iso Roobertinkatu 23) 00121 Helsinki 00121 Helsinki (FI)