(19)

(11)

EP 0 640 224 A1

(12)

(43) Date of publication: 01.03.1995 Bulletin 1995/09 (21) Application number: 93910199.0 (22) Date of filing: 14.05.1993

(51) International Patent Classification (IPC):  F16B 2/ 04( . ) G01B 9/ 02( . ) G02B 7/ 182( . ) F16B 5/ 10( . ) G02B 7/ 00( . ) G12B 9/ 08( . ) (86) International application number: PCT/GB1993/000991 (87) International publication number: WO 1993/023780 (25.11.1993 Gazette 1993/28)

(84) Designated Contracting States: DE FR GB IT (30) Priority: 15.05.1992 GB 19920010488 (71) Applicant: BRITISH TECHNOLOGY GROUP LIMITED London SE1 6BU (GB)	(72) Inventor: DOWNS, Michael, John 37 Shepherds Way Hampshire GU30 7HF (GB) (74) Representative: Cullis, Roger  Patents Department British Technology Group Ltd 101 Newington Causeway London SE1 6BU London SE1 6BU (GB)