(19)

(11)

EP 0 971 648 A1

(12)

(43) Date of publication: 19.01.2000 Bulletin 2000/03 (21) Application number: 99901776.7 (22) Date of filing: 22.01.1999

(51) International Patent Classification (IPC)7: A61F 2/16 (86) International application number: PCT/GB9900/216 (87) International publication number: WO 9937/247 (29.07.1999 Gazette 1999/30)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 22.01.1998 GB 9801214 (71) Applicant: Duckworth & Kent Limited Baldock,Hertfordshire SG7 6XL (GB)	(72) Inventor: WALDOCK, Terence Arnold Meppershall,Bedfordshire SG17 5NA (GB) (74) Representative: W.P. THOMPSON & CO.  Eastcheap HouseCentral Approach Letchworth,Hertfordshire SG6 3DS Letchworth,Hertfordshire SG6 3DS (GB)