(19)

(11)

EP 4 118 290 A1

(12)

(43) Date of publication: 18.01.2023 Bulletin 2023/03 (21) Application number: 21718929.9 (22) Date of filing: 05.03.2021

(51) International Patent Classification (IPC):  E21B 17/02(2006.01) E21B 19/087(2006.01) E21B 19/00(2006.01) (52) Cooperative Patent Classification (CPC): E21B 19/00; E21B 19/087; E21B 17/02 (86) International application number: PCT/FI2021/050165 (87) International publication number: WO 2021/181004 (16.09.2021 Gazette 2021/37)

(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: KH MA MD TN (30) Priority: 12.03.2020 FI 20205259 (71) Applicant: OY Kati AB Kalajoki 85160 Rautio (FI)	(72) Inventor: KAUPPILA, Simo 85100 Kalajoki (FI) (74) Representative: Berggren Oy  P.O. Box 16 Eteläinen Rautatiekatu 10A 00101 Helsinki 00101 Helsinki (FI)