(19)

(11)

EP 0 326 602 A1

(12)

(43) Date of publication: 09.08.1989 Bulletin 1989/32 (21) Application number: 88906966.0 (22) Date of filing: 17.08.1988

(51) International Patent Classification (IPC):  B21C 23/ 21( . ) B21C 23/ 00( . ) (86) International application number: PCT/GB1988/000678 (87) International publication number: WO 1989/001369 (23.02.1989 Gazette 1989/05)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 18.08.1987 GB 19870019518 (71) Applicant: MB GROUP PLC Reading Berkshire RG1 8DN (GB)	(72) Inventors: EAST, John Oxon OX12 9HU (GB) MAXWELL, Ian Reading Berkshire RG4 7LX (GB) (74) Representative: Griffin, Kenneth David, et al  Saunders & Dolleymore 9, Rickmansworth Road Watford Hertfordshire WD1 7HE Watford Hertfordshire WD1 7HE (GB)