(19)

(11)

EP 0 605 529 A1

(12)

(43) Date of publication: 13.07.1994 Bulletin 1994/28 (21) Application number: 92919920.0 (22) Date of filing: 24.09.1992

(51) International Patent Classification (IPC):  C21D 9/ 08( . ) (86) International application number: PCT/GB1992/001762 (87) International publication number: WO 1993/007301 (15.04.1993 Gazette 1993/10)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IE IT LI LU NL SE (30) Priority: 25.09.1991 GB 19910020424 (71) Applicant: Ball, Daniel Graham Darlington, Durham DL1 2NB (GB)	(72) Inventor: Ball, Daniel Graham Darlington, Durham DL1 2NB (GB) (74) Representative: Sanderson, Michael John, et al  MEWBURN ELLIS York House 23 Kingsway London WC2B 6HP London WC2B 6HP (GB)