(19)

(11)

EP 4 179 153 A1

(12)

(43) Date of publication: 17.05.2023 Bulletin 2023/20 (21) Application number: 21766508.2 (22) Date of filing: 06.07.2021

(51) International Patent Classification (IPC):  E01C 21/00(2006.01) (52) Cooperative Patent Classification (CPC): E01C 21/00 (86) International application number: PCT/FI2021/050522 (87) International publication number: WO 2022/008798 (13.01.2022 Gazette 2022/02)

(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: 09.07.2020 FI 20205742 (71) Applicant: Betolar OY 43300 Kannonkoski (FI)	(72) Inventor: LEPPÄNEN, Juha 43300 Kannonkoski (FI) (74) Representative: Papula Oy  P.O. Box 981 00101 Helsinki 00101 Helsinki (FI)