(19)

(11)

EP 0 417 135 A1

(12)

(43) Date of publication: 20.03.1991 Bulletin 1991/12 (21) Application number: 89905743.0 (22) Date of filing: 19.05.1989

(51) International Patent Classification (IPC):  E02F 5/ 22( . ) (86) International application number: PCT/GB1989/000551 (87) International publication number: WO 1989/011569 (30.11.1989 Gazette 1989/28)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 20.05.1988 GB 19880011991 (71) Applicant: BARKER, Anthony Roy Nr. Ely, Cambridgeshire CB7 4UN (GB)	(72) Inventor: BARKER, Anthony Roy Nr. Ely, Cambridgeshire CB7 4UN (GB) (74) Representative: Wright, Hugh Ronald  Brookes & Martin 52/54 High Holborn London WC1V 6SE London WC1V 6SE (GB)