(19)

(11)

EP 0 828 891 A1

(12)

(43) Date of publication: 18.03.1998 Bulletin 1998/12 (21) Application number: 96909213.0 (22) Date of filing: 27.03.1996

(51) International Patent Classification (IPC):  E01B 9/ 30( . ) (86) International application number: PCT/GB1996/000739 (87) International publication number: WO 1997/036055 (02.10.1997 Gazette 1997/42)

(84) Designated Contracting States: BE GB IT SE (71) Applicant: PANDROL LIMITED Addlestone, Surrey KT15 2AR (GB)	(72) Inventors: WOOD, Timothy, Alan Lincolnshire NG31 7JU (GB) STUBBS, Kevin Sheffield S8 0PL (GB) COX, Stephen, John Surrey TW9 2HB (GB) SOMERSET, Martin, David Nottinghamshire S80 3QX (GB) CONROY, Brian, George Nottinghamshire S80 1XD (GB) (74) Representative: Fenlon, Christine Lesley, et al  Haseltine Lake & Co., Imperial House, 15-19 Kingsway London WC2B 6UD London WC2B 6UD (GB)