(19)

(11)

EP 1 446 554 A1

(12)

(43) Date of publication: 18.08.2004 Bulletin 2004/34 (21) Application number: 02783930.7 (22) Date of filing: 07.11.2002

(51) International Patent Classification (IPC)7: E21B 44/00 (86) International application number: PCT/SE2002/002028 (87) International publication number: WO 2003/044319 (30.05.2003 Gazette 2003/22)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LI LU MC NL PT SE SK TR Designated Extension States: AL LT LV MK RO SI (30) Priority: 22.11.2001 SE 0103880 (71) Applicant: Atlas Copco Rock Drills AB 701 91 Örebro (SE)	(72) Inventors: ANDERSSON, Kurt S-135 54 Tyresö (SE) OLSSON, Magnus S-694 92 Hallsberg (SE) (74) Representative: Grundfelt, Erik Gunnar et al Atlas Copco Rock Drills AB,Patents 701 91 Örebro 701 91 Örebro (SE)