(19)

(11)

EP 0 958 080 A1

(12)

(43) Date of publication: 24.11.1999 Bulletin 1999/47 (21) Application number: 96940754.0 (22) Date of filing: 13.12.1996

(51) International Patent Classification (IPC):  B23B 27/ 22( . ) B23B 25/ 02( . ) (86) International application number: PCT/SG1996/000018 (87) International publication number: WO 1997/022429 (26.06.1997 Gazette 1997/27)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI NL SE (30) Priority: 20.12.1995 SG 19950002241 09.10.1996 US 19960731094 (71) Applicant: NATIONAL UNIVERSITY OF SINGAPORE Singapore 0511 (SG)	(72) Inventor: Li, Xiaoping 660012 Singapore (SG) (74) Representative: Findlay, Alice Rosemary  Lloyd Wise, Tregear & Co., Commonwealth House, 1-19 New Oxford Street London WC1A 1LW London WC1A 1LW (GB)