(19)

(11)

EP 0 961 858 A1

(12)

(43) Date of publication: 08.12.1999 Bulletin 1999/49 (21) Application number: 98957037.0 (22) Date of filing: 04.12.1998

(51) International Patent Classification (IPC):  E01C 13/ 08( . ) (86) International application number: PCT/GB1998/003624 (87) International publication number: WO 1999/028557 (10.06.1999 Gazette 1999/23)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 04.12.1997 GB 19970025770 (71) Applicant: Walters, Ian David Ammanford, Carmarthenshire SA18 3PF (GB)	(72) Inventor: Walters, Ian David Ammanford, Carmarthenshire SA18 3PF (GB) (74) Representative: Litchfield, Laura Marie, et al  Haseltine Lake & Co. Imperial House 15-19 Kingsway London WC2B 6UD London WC2B 6UD (GB)