(19)

(11)

EP 2 310 616 A1

(12)

(43) Date of publication: 20.04.2011 Bulletin 2011/16 (21) Application number: 09769417.8 (22) Date of filing: 12.06.2009

(51) International Patent Classification (IPC):  E21B 19/14(2006.01) E21B 19/20(2006.01) E21B 19/18(2006.01) (86) International application number: PCT/FI2009/050508 (87) International publication number: WO 2009/156574 (30.12.2009 Gazette 2009/53)

(84) Designated Contracting States: 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 SE SI SK TR Designated Extension States: AL BA RS (30) Priority: 23.06.2008 FI 20085631 (71) Applicant: Sandvik Mining and Construction Oy 33330 Tampere (FI)	(72) Inventor: SILTALA, Hannu FI-33330Tampere (FI) (74) Representative: Kuosmanen, Timo  Kolster Oy Ab P.O. Box 148 Iso Roobertinkatu 23 00121 Helsinki 00121 Helsinki (FI)