(19)

(11)

EP 0 413 804 A1

(12)

(43) Date of publication: 27.02.1991 Bulletin 1991/09 (21) Application number: 90904408.0 (22) Date of filing: 09.03.1990

(51) International Patent Classification (IPC):  F03G 7/ 04( . ) F28D 1/ 02( . ) F28F 3/ 14( . ) F28B 1/ 02( . ) F28D 9/ 00( . ) F28F 9/ 26( . ) (86) International application number: PCT/GB1990/000365 (87) International publication number: WO 1990/010839 (20.09.1990 Gazette 1990/22)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI LU NL SE (30) Priority: 09.03.1989 GB 19890005432 (71) Applicants: GEC-MARCONI LIMITED Stanmore, Middlesex HA7 4LY (GB) ALCAN INTERNATIONAL LIMITED Montreal Quebec H3A 3G2 (CA)	(72) Inventors: CLARKE, John, Brian Leicester LE4 3JG (GB) FITZPATRICK, Nigel, Patrick Kingston, Ontario K7M 7V8 (CA) (74) Representative: Lawrence, Brian Richard, et al  The General Electric Company, p.l.c. GEC Patent Department Waterhouse Lane Chelmsford, Essex CM1 2QX Chelmsford, Essex CM1 2QX (GB)