(19)

(11)

EP 4 423 342 A1

(12)

(43) Date of publication: 04.09.2024 Bulletin 2024/36 (21) Application number: 22886210.8 (22) Date of filing: 26.10.2022

(51) International Patent Classification (IPC):  E01C 23/08(2006.01) E02F 3/76(2006.01) E01H 5/06(2006.01) (52) Cooperative Patent Classification (CPC): E01H 5/065; E01H 5/066 (86) International application number: PCT/FI2022/000005 (87) International publication number: WO 2023/073278 (04.05.2023 Gazette 2023/18)

(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 ME MK MT NL NO PL PT RO RS SE SI SK SM TR Designated Extension States: BA Designated Validation States: KH MA MD TN (30) Priority: 27.10.2021 FI 20217160 (71) Applicant: Innosteel Oy 91500 Muhos (FI)	(72) Inventors: KARVONEN, Kyösti 89200 Puolanka (FI) LEINONEN, Ville 91500 Muhos (FI) (74) Representative: Berggren Oy  P.O. Box 16 Eteläinen Rautatiekatu 10A 00101 Helsinki 00101 Helsinki (FI)