(19)

(11)

EP 2 961 910 A2

(12)

(88) Date of publication A3: 15.01.2015 (43) Date of publication: 06.01.2016 Bulletin 2016/01 (21) Application number: 14726218.2 (22) Date of filing: 25.02.2014

(51) International Patent Classification (IPC):  E21B 7/02(2006.01) (86) International application number: PCT/SE2014/050230 (87) International publication number: WO 2014/133439 (04.09.2014 Gazette 2014/36)

(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 Designated Extension States: BA ME (30) Priority: 01.03.2013 SE 1350251 (71) Applicant: Atlas Copco Rock Drills AB 701 91 Örebro (SE)	(72) Inventors: KÄMPE, Ulf S-692 33 Kumla (SE) JORMVIK, Fredrik S-719 94 Vintrosa (SE) (74) Representative: Zacco Sweden AB  P.O. Box 5581 114 85 Stockholm 114 85 Stockholm (SE)