(19)

(11)

EP 0 970 290 A1

(12)

(43) Date of publication: 12.01.2000 Bulletin 2000/02 (21) Application number: 98906999.2 (22) Date of filing: 04.03.1998

(51) International Patent Classification (IPC)7: E21C 35/193 (86) International application number: PCT/GB9800/493 (87) International publication number: WO 9839/553 (11.09.1998 Gazette 1998/36)

(84) Designated Contracting States: BE DE ES FR GB NL (30) Priority: 05.03.1997 GB 9704554 (71) Applicant: Bingham Engineering Ltd. East Hardwick,Pontefract WF8 3EQ (GB)	(72) Inventors: BINGHAM, Mark-Bingham Engineering Limited East Hardwick,Pontefract WF8 3EQ (GB) BINGHAM, Terence-Bingham Engineering Limited East Hardwick,Pontefract WF8 3EQ (GB) (74) Representative: Belcher, Simon James  Urquhart-Dykes & LordTower HouseMerrion Way Leeds LS2 8PA Leeds LS2 8PA (GB)