(19)

(11)

EP 3 612 717 A1

(12)

(43) Date of publication: 26.02.2020 Bulletin 2020/09 (21) Application number: 17718889.3 (22) Date of filing: 20.04.2017

(51) International Patent Classification (IPC):  E21C 25/06(2006.01) E21C 27/24(2006.01) E21C 35/23(2006.01) E21C 25/18(2006.01) E21C 35/22(2006.01) E21D 9/10(2006.01) (86) International application number: PCT/EP2017/059324 (87) International publication number: WO 2018/192653 (25.10.2018 Gazette 2018/43)

(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 Designated Validation States: MA MD (71) Applicant: Sandvik Intellectual Property AB 811 81 Sandviken (SE)	(72) Inventor: GRIEF, Ralf 8740 Weisskirchen in Steiermark (AT) (74) Representative: Sandvik  Sandvik Mining and Construction Oy PL 100 Patent Department 33311 Tampere 33311 Tampere (FI)