(19)

(11)

EP 0 560 756 A1

(12)

(43) Date of publication: 22.09.1993 Bulletin 1993/38 (21) Application number: 90908582.0 (22) Date of filing: 25.05.1990

(51) International Patent Classification (IPC):  A61F 6/ 04( . ) A61F 6/ 06( . ) (86) International application number: PCT/GB1990/000821 (87) International publication number: WO 1990/014058 (29.11.1990 Gazette 1990/27)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI LU NL SE (30) Priority: 26.05.1989 GB 19890012185 23.11.1989 GB 19890026504 (71) Applicant: DURAVEND LTD South Kirkby, West Yorkshire WF9 3NR (GB)	(72) Inventor: RICHARDSON, John, Phillip Cuddington Cheshire CW8 2XA (GB) (74) Representative: Browne, Robin Forsythe, Dr.  Urquhart-Dykes & Lord Tower House Merrion Way Leeds LS2 8PA West Yorkshire Leeds LS2 8PA West Yorkshire (GB)