(19)

(11)

EP 0 563 232 A1

(12)

(43) Date of publication: 06.10.1993 Bulletin 1993/40 (21) Application number: 92902401.0 (22) Date of filing: 23.12.1991

(51) International Patent Classification (IPC):  F42B 10/ 34( . ) F42B 12/ 76( . ) (86) International application number: PCT/GB1991/002306 (87) International publication number: WO 1992/011503 (09.07.1992 Gazette 1992/17)

(84) Designated Contracting States: AT BE DE DK ES FR GB GR IT NL SE (30) Priority: 21.12.1990 GB 19900027823 (71) Applicant: Royal Ordnance plc Euxton Chorley Lancashire PR7 6AD (GB)

(72) Inventors: BRADDOCK, Richard Allan Newcastle-under-Lyme, Staffs ST5 4 EP (GB) BAXTER, James Edward Sandbach, Cheshire CW11 9BA (GB) JERVIS, Michael Thomas Alsager, Stoke-on-Trent ST7 2EY (GB) IZOD, David Collin Asket Royston, Hertfordshire SG8 9EH (GB) (74) Representative: Wildman, David Brian  Royal Ordnance plc Patents & Licensing Department Egyptian House 170/173 Piccadilly London W1V 9DD London W1V 9DD (GB)