(19)

(11)

EP 4 121 714 A1

(12)

(43) Date of publication: 25.01.2023 Bulletin 2023/04 (21) Application number: 21706651.3 (22) Date of filing: 17.02.2021

(51) International Patent Classification (IPC):  F42B 12/32(2006.01) (52) Cooperative Patent Classification (CPC): F42B 12/32 (86) International application number: PCT/GB2021/000017 (87) International publication number: WO 2021/186138 (23.09.2021 Gazette 2021/38)

(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: 19.03.2020 GB 202003965 (71) Applicant: The Secretary of State for Defence Salisbury, Wiltshire SP4 0JQ (GB)	(72) Inventor: GRIFFITHS, Owain Stephen William Salisbury, Wiltshire SP4 OJQ (GB) (74) Representative: Gardner, Emma Elizabeth  Defence Intellectual Property Rights Poplar 2-2214 MOD Abbey Wood (South) Bristol BS34 8JH Bristol BS34 8JH (GB)