(19)

(11)

EP 0 349 577 A1

(12)

(43) Date of publication: 10.01.1990 Bulletin 1990/02 (21) Application number: 88902995.0 (22) Date of filing: 27.01.1988

(51) International Patent Classification (IPC):  F04B 37/ 08( . ) (86) International application number: PCT/US1988/000225 (87) International publication number: WO 1988/005500 (28.07.1988 Gazette 1988/17)

(84) Designated Contracting States: CH DE FR GB IT LI NL (30) Priority: 27.01.1987 US 19870007370 (71) Applicant: HELIX TECHNOLOGY CORPORATION Waltham Massachusetts 02254 (US)	(72) Inventors: LESSARD, Philip, A. Boxboro, MA 01719 (US) DUNN, Thomas Avon, MA 02322 (US) (74) Representative: Pendlebury, Anthony, et al  PAGE, WHITE & FARRER 54 Doughty Street London WC1N 2LS London WC1N 2LS (GB)