(19)

(11)

EP 0 072 825 A1

(12)

(43) Date of publication: 02.03.1983 Bulletin 1983/09 (21) Application number: 82900552.0 (22) Date of filing: 18.02.1982

(51) International Patent Classification (IPC):  G08B 23/ 00( . ) G08B 25/ 00( . ) G08B 3/ 10( . ) G08B 27/ 00( . ) (86) International application number: PCT/GB1982/000042 (87) International publication number: WO 1982/002971 (02.09.1982 Gazette 1982/21)

(84) Designated Contracting States: AT BE DE FR NL SE (30) Priority: 18.02.1981 GB 19810005012 (71) Applicant: BLUE CIRCLE INDUSTRIES PLC London SW1E 5BJ (GB)	(72) Inventors: COPPEN, Anthony Roland Meopham Kent (GB) FORCE, Roger Greenhithe Kent (GB) (74) Representative: Grundy, Derek George Ritchie, et al  CARPMAELS & RANSFORD 43, Bloomsbury Square London WC1A 2RA London WC1A 2RA (GB)