(19)

(11)

EP 0 554 307 A1

(12)

(43) Date of publication: 11.08.1993 Bulletin 1993/32 (21) Application number: 91918498.0 (22) Date of filing: 22.10.1991

(51) International Patent Classification (IPC):  A61F 2/ 28( . ) A61F 2/ 44( . ) C23F 1/ 02( . ) C25F 3/ 26( . ) A61F 2/ 30( . ) C23F 1/ 00( . ) C25F 3/ 24( . ) (86) International application number: PCT/GB1991/001851 (87) International publication number: WO 1992/006654 (30.04.1992 Gazette 1992/10)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IT LI LU NL SE (30) Priority: 23.10.1990 GB 19900022996 (71) Applicant: LEONARD, Ian bolton, Lancashire BL1 6PD (GB)	(72) Inventors: LEONARD, Ian Bolton, Lancashire BL1 6PD (GB) ROSS, Raymond West Didsbury, Manchester M20 8UF (GB) (74) Representative: McNeight, David Leslie, et al  McNeight & Lawrence Regent House Heaton Lane Stockport Cheshire SK4 1BS Stockport Cheshire SK4 1BS (GB)