(19)

(11)

EP 1 060 324 A1

(12)

(43) Date of publication: 20.12.2000 Bulletin 2000/51 (21) Application number: 99912193.2 (22) Date of filing: 04.03.1999

(51) International Patent Classification (IPC)7: E21B 33/12 (86) International application number: PCT/SE9900/328 (87) International publication number: WO 9945/233 (10.09.1999 Gazette 1999/36)

(84) Designated Contracting States: AT BE CH DE DK ES FI FR GB IT LI NL SE (30) Priority: 04.03.1998 SE 9800684 (71) Applicant: ALEXANDERSSON, Hans S-513 00 Fristad (SE)	(72) Inventor: ALEXANDERSSON, Hans S-513 00 Fristad (SE) (74) Representative: Lindberg, Klas Valter Bo  Awapatent ABP.O. Box 11394 404 28 Göteborg 404 28 Göteborg (SE)