(19)

(11)

EP 0 588 901 A1

(12)

(43) Date of publication: 30.03.1994 Bulletin 1994/13 (21) Application number: 92912596.0 (22) Date of filing: 12.06.1992

(51) International Patent Classification (IPC):  F04D 27/ 00( . ) G01F 1/ 34( . ) F24F 11/ 02( . ) G01P 5/ 14( . ) (86) International application number: PCT/SE1992/000413 (87) International publication number: WO 1992/022790 (23.12.1992 Gazette 1992/32)

(84) Designated Contracting States: BE CH DE DK FR GB LI NL SE (30) Priority: 12.06.1991 SE 19910001801 28.06.1991 SE 19910002016 17.02.1992 SE 19920000486 (71) Applicant: ABB FLÄKT AKTIEBOLAG S-120 86 Stockholm (SE)	(72) Inventors: HOLMBERG, Roy S-552 59 Jönköping (SE) SJÖQVIST, Lennart S-564 00 Bankeryd (SE) (74) Representative: Dahlstrand, Björn, et al  ABB Corporate Research, I.P. Dept., Stockholm Office S-120 86 Stockholm S-120 86 Stockholm (SE)