(19)

(11)

EP 4 816 766 A1

(12)

(43) Date of publication: 07.10.2026 Bulletin 2026/41 (21) Application number: 24896819.0 (22) Date of filing: 27.11.2024

(51) International Patent Classification (IPC):  F42D 1/22(2006.01) F42D 3/04(2006.01) F42D 1/04(2006.01) F42B 3/26(2006.01) (52) Cooperative Patent Classification (CPC): F42D 3/04; F42D 1/22; F42D 1/08 (86) International application number: PCT/FI2024/050640 (87) International publication number: WO 2025/114641 (05.06.2025 Gazette 2025/23)

(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: GE KH MA MD TN (30) Priority: 28.11.2023 FI 20236312 (71) Applicant: Normet OY 74510 Iisalmi (FI)	(72) Inventor: MYKKÄNEN, Anssi 74510 IISALMI (FI) (74) Representative: Berggren Oy  P.O. Box 16 Fabianinkatu 21 00101 Helsinki 00101 Helsinki (FI)