(19)

(11)

EP 0 606 409 A1

(12)

(43) Date of publication: 20.07.1994 Bulletin 1994/29 (21) Application number: 93906332.0 (22) Date of filing: 25.09.1992

(51) International Patent Classification (IPC):  H01C 7/ 12( . ) (86) International application number: PCT/SE1992/000667 (87) International publication number: WO 1993/007630 (15.04.1993 Gazette 1993/10)

(84) Designated Contracting States: DE FR IT (30) Priority: 04.10.1991 SE 19910002881 (71) Applicant: ASEA BROWN BOVERI AB S-721 83 Västeras (SE)	(72) Inventors: LUNDQUIST, Jan S-771 43 Ludvika (SE) WIECK, H kan S-771 30 Ludvika (SE) (74) Representative: Boecker, Joachim, Dr.-Ing.  Adelonstrasse 58 D-65929 Frankfurt am Main D-65929 Frankfurt am Main (DE)