(19)

(11)

EP 0 537 334 A1

(12)

(43) Date of publication: 21.04.1993 Bulletin 1993/16 (21) Application number: 92911713.0 (22) Date of filing: 01.05.1992

(51) International Patent Classification (IPC):  F04B 43/ 06( . ) F04B 43/ 073( . ) (86) International application number: PCT/US1992/003603 (87) International publication number: WO 1992/019868 (12.11.1992 Gazette 1992/28)

(84) Designated Contracting States: BE DE ES FR GB IT LU NL SE (30) Priority: 02.05.1991 US 19910694797 19.02.1992 US 19920837552 (71) Applicant: THE ARO CORPORATION Bryan, Ohio 43506-0151 (US)	(72) Inventors: VAN DEN BERGH, Louis B-2950 Kapellen (BE) VERBERCKMOES, Georges B-9140 Temse (BE) DE JONGHE, Werner B-9150 Kruibeke (BE) (74) Representative: Feakins, Graham Allan, et al  RAWORTH, MOSS & COOK RAWORTH HOUSE 36 Sydenham Road Croydon, Surrey CRO 2EF Croydon, Surrey CRO 2EF (GB)