(19)

(11)

EP 0 615 569 A1

(12)

(43) Date of publication: 21.09.1994 Bulletin 1994/38 (21) Application number: 92924989.0 (22) Date of filing: 27.11.1992

(51) International Patent Classification (IPC):  E04F 17/ 04( . ) F24F 13/ 02( . ) F16L 59/ 14( . ) (86) International application number: PCT/SE1992/000827 (87) International publication number: WO 1993/011327 (10.06.1993 Gazette 1993/14)

(84) Designated Contracting States: BE DE DK GB (30) Priority: 28.11.1991 SE 19910003539 (71) Applicant: ABB FLÄKT AKTIEBOLAG S-120 86 Stockholm (SE)	(72) Inventor: BERGSTRÖM, Ake S-745 62 Enköping (SE) (74) Representative: Modin, Jan, et al  c/o Axel Ehrners Patentbyra AB Box 10316 S-100 55 Stockholm S-100 55 Stockholm (SE)