(19)

(11)

EP 0 533 769 A1

(12)

(43) Date of publication: 31.03.1993 Bulletin 1993/13 (21) Application number: 91911090.0 (22) Date of filing: 13.06.1991

(51) International Patent Classification (IPC):  B22D 11/ 04( . ) B22D 11/ 049( . ) B22D 11/ 041( . ) B22D 11/ 103( . ) (86) International application number: PCT/CA1991/000216 (87) International publication number: WO 1991/019578 (26.12.1991 Gazette 1991/29)

(84) Designated Contracting States: AT CH DE ES FR GB IT LI NL SE (30) Priority: 13.06.1990 GB 19900013199 (71) Applicant: ALCAN INTERNATIONAL LIMITED Montreal Quebec H3A 3G2 (CA)

(72) Inventors: BRYSON, Neil, Burton Kingston, Ontario K7L 2N1 (CA) McCUBBIN, John, Gordon Kingston, Ontario K7M 7E2 (CA) READ, Charles, Mark Jonquiere, Quebec G7S 4X4 (CA) ENRIGHT, Philip, Graham Kingston, Ontario K7M 3N9 (CA) FLOOD, Stephen, C. Oxford 0X3 8PL (GB) (74) Representative: Gaunt, Robert John  Stevens, Hewlett & Perkins 1 Serjeants' Inn Fleet Street London EC4Y 1LL London EC4Y 1LL (GB)