(19)

(11)

EP 0 056 045 A1

(12)

(43) Date of publication: 21.07.1982 Bulletin 1982/29 (21) Application number: 81902037.0 (22) Date of filing: 15.07.1981

(51) International Patent Classification (IPC):  G07C 9/ 00( . ) G08B 13/ 24( . ) (86) International application number: PCT/GB1981/000142 (87) International publication number: WO 1982/000377 (04.02.1982 Gazette 1982/04)

(84) Designated Contracting States: CH DE FR GB LI LU NL SE (30) Priority: 21.07.1980 GB 19800023780 (71) Applicant: MASTIFF SECURITY SYSTEMS LIMITED Leatherhead, Surrey KT22 7RX (GB)	(72) Inventor: TAYLOR, Derek Reginald Banstead Surrey (GB) (74) Representative: Arthur, George Fitzgerald, et al  KILBURN & STRODE 30, John Street London WC1N 2DD London WC1N 2DD (GB)