(19)

(11)

EP 0 545 933 A1

(12)

(43) Date of publication: 16.06.1993 Bulletin 1993/24 (21) Application number: 91910406.0 (22) Date of filing: 03.06.1991

(51) International Patent Classification (IPC):  F41A 17/ 44( . ) (86) International application number: PCT/GB1991/000880 (87) International publication number: WO 1992/021928 (10.12.1992 Gazette 1992/31)

(84) Designated Contracting States: AT BE CH DE ES FR IT LI (71) Applicant: Royal Ordnance plc Euxton Chorley Lancashire PR7 6AD (GB)	(72) Inventor: Ball, Stephen Congleton Edge, Cheshire CW 12 3NA (GB) (74) Representative: Muir, Henry Joseph  Royal Ordnance plc Patents & Licensing Department Egyptian House 170/173 Piccadilly GB-London W1V 9DD GB-London W1V 9DD (GB)