(19)

(11)

EP 0 083 579 A1

(12)

(43) Date of publication: 20.07.1983 Bulletin 1983/29 (21) Application number: 81900567.0 (22) Date of filing: 16.03.1981

(51) International Patent Classification (IPC):  F04B 1/ 04( . ) (86) International application number: PCT/GB1981/000048 (87) International publication number: WO 1982/003253 (30.09.1982 Gazette 1982/23)

(84) Designated Contracting States: AT CH DE FR GB LI LU NL SE (71) Applicant: ANDREW FRASER & COMPANY LIMITED Cambridgeshire PE13 2HL (GB)	(72) Inventors: EVANS, Graham Cambridgeshire PE13 4UN (GB) GOODALL, Ronald George Victor Peterborough PE4 6XJ (GB)