(19)

(11)

EP 0 259 344 A1

(12)

(43) Date of publication: 16.03.1988 Bulletin 1988/11 (21) Application number: 86904896.0 (22) Date of filing: 22.08.1986

(51) International Patent Classification (IPC):  B63H 9/ 06( . ) (86) International application number: PCT/GB1986/000502 (87) International publication number: WO 1987/001088 (26.02.1987 Gazette 1987/05)

(84) Designated Contracting States: DE FR GB IT NL SE (30) Priority: 22.08.1985 GB 19850021085 (71) Applicant: WALKER RESEARCH SYSTEMS LIMITED Netley Abbey, Hampshire (GB)	(72) Inventor: WALKER RESEARCH SYSTEMS LIMITED Netley Abbey, Hampshire (GB) (74) Representative: Bowles, Sharon Margaret  BOWLES HORTON Castle House 89 High Street Berkhamsted Hertfordshire HP4 2DF Berkhamsted Hertfordshire HP4 2DF (GB)