(19)

(11)

EP 0 483 208 A1

(12)

(43) Date of publication: 06.05.1992 Bulletin 1992/19 (21) Application number: 90910835.0 (22) Date of filing: 18.07.1990

(51) International Patent Classification (IPC):  B21C 37/ 10( . ) B21C 37/ 15( . ) (86) International application number: PCT/GB1990/001103 (87) International publication number: WO 1991/001187 (07.02.1991 Gazette 1991/04)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI LU NL SE (30) Priority: 20.07.1989 GB 19890016547 (71) Applicant: FIRMAC LIMITED Scarborough, Yorkshire YO12 4HA (GB)	(72) Inventor: FIRTH, Colin Scarborough, North Yorkshire YO13 OPT (GB) (74) Representative: Denmark, James  Bailey, Walsh & Co. 5 York Place Leeds LS1 2SD Yorkshire Leeds LS1 2SD Yorkshire (GB)