(19)

(11)

EP 0 890 001 A1

(12)

(43) Date of publication: 13.01.1999 Bulletin 1999/02 (21) Application number: 97915549.0 (22) Date of filing: 27.03.1997

(51) International Patent Classification (IPC):  E02D 29/ 14( . ) (86) International application number: PCT/GB1997/000887 (87) International publication number: WO 1997/037086 (09.10.1997 Gazette 1997/43)

(84) Designated Contracting States: AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 29.03.1996 GB 19960006746 (71) Applicant: CSR LIMITED Sydney, NSW 2000 (AU)	(72) Inventor: HAWKINS, David, John, Drake London N12 0DG (GB) (74) Representative: Mayes, Stuart David, et al  BOULT WADE TENNANT, 27 Furnival Street London EC4A 1PQ London EC4A 1PQ (GB)