(19)

(11)

EP 0 710 320 A1

(12)

(43) Date of publication: 08.05.1996 Bulletin 1996/19 (21) Application number: 94922168.0 (22) Date of filing: 26.07.1994

(51) International Patent Classification (IPC):  E21D 21/ 00( . ) (86) International application number: PCT/AU1994/000419 (87) International publication number: WO 1995/003477 (02.02.1995 Gazette 1995/06)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 26.07.1993 AU 1993PM00170 (71) Applicant: BHP ENGINEERING PTY. LTD North Sydney, NSW 2060 (AU)	(72) Inventor: GRAY, Peter, Andrew Fig Tree Heights, NSW 2525 (AU) (74) Representative: Jenkins, Peter David, et al  PAGE WHITE & FARRER 54 Doughty Street London WC1N 2LS London WC1N 2LS (GB)