(19)

(11)

EP 0 681 652 A1

(12)

(43) Date of publication: 15.11.1995 Bulletin 1995/46 (21) Application number: 92921411.0 (22) Date of filing: 23.09.1992

(51) International Patent Classification (IPC):  F04B 1/ 02( . ) F04B 17/ 03( . ) F04B 53/ 16( . ) F04B 9/ 04( . ) F04B 53/ 10( . ) (86) International application number: PCT/US1992/008179 (87) International publication number: WO 1993/006368 (01.04.1993 Gazette 1993/09)

(84) Designated Contracting States: DE FR GB IT (30) Priority: 27.09.1991 US 19910766323 27.09.1991 US 19910766331 (71) Applicants: COOK, James E. Anoka, MN 55303 (US) ERIKSEN, Harald O. S. Brooklyn Park, MN 55428 (US)	(72) Inventors: COOK, James E. Anoka, MN 55303 (US) ERIKSEN, Harald O. S. Brooklyn Park, MN 55428 (US) (74) Representative: Altenburg, Udo, Dipl.-Phys., et al  Patent- und Rechtsanwälte, Bardehle . Pagenberg . Dost . Altenburg . Frohwitter . Geissler & Partner, Galileiplatz 1 D-81679 München D-81679 München (DE)