(19)

(11)

EP 0 469 050 A1

(12)

(43) Date of publication: 05.02.1992 Bulletin 1992/06 (21) Application number: 90907203.0 (22) Date of filing: 20.04.1990

(51) International Patent Classification (IPC):  C22C 1/ 00( . ) C23C 14/ 24( . ) C23C 14/ 14( . ) C23C 14/ 54( . ) (86) International application number: PCT/GB1990/000610 (87) International publication number: WO 1990/012485 (01.11.1990 Gazette 1990/25)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI LU NL SE (30) Priority: 21.04.1989 GB 19890009088 (71) Applicant: THE SECRETARY OF STATE FOR DEFENCE IN HER BRITANNIC MAJESTY'S GOVERMENT OF THE UNITED KINGDOM OF GREAT BRITAIN AND London SW6 1TR (GB)

(72) Inventors: BICKERDIKE, Robert, Lewis Winchester Hants SO21 1BE (GB) BISHOP, Alan, William Hants GU14 65H (GB) BRAY, David, John Hampshire GU14 8LA (GB) GARDINER, Robert, William Farnham, Surrey GU9 OLG (GB) VINEY, Brian, William Hants GU14 8ND (GB) (74) Representative: Beckham, Robert William  Defence Research Agency Intellectual Property Department DRA Farnborough Farnborough, Hants. GU14 6TD Farnborough, Hants. GU14 6TD (GB)