(19)

(11)

EP 0 785 845 A1

(12)

(43) Date of publication: 30.07.1997 Bulletin 1997/31 (21) Application number: 95934224.0 (22) Date of filing: 17.10.1995

(51) International Patent Classification (IPC):  B25D 9/ 14( . ) E21B 1/ 26( . ) E21B 1/ 00( . ) (86) International application number: PCT/GB1995/002453 (87) International publication number: WO 1996/011775 (25.04.1996 Gazette 1996/18)

(84) Designated Contracting States: AT DE ES FR GB IE IT PT SE (30) Priority: 17.10.1994 ZA 19940008118 (71) Applicants: BRIGGS, Roger Robarts Germiston (ZA) LEPPANEN, Jarmo Uolevi Germiston, Transvaal (ZA)	(72) Inventors: BRIGGS, Roger Robarts Germiston (ZA) LEPPANEN, Jarmo Uolevi Germiston, Transvaal (ZA) (74) Representative: Williamson, Brian, et al  Hepworth Lawrence Bryer & Bizley Merlin House Falconry Court Baker's Lane Epping Essex CM16 5DQ Epping Essex CM16 5DQ (GB)