(19)

(11)

EP 0 102 379 A1

(12)

(43) Date of publication: 14.03.1984 Bulletin 1984/11 (21) Application number: 83900939.0 (22) Date of filing: 28.02.1983

(51) International Patent Classification (IPC):  H04R 1/ 00( . ) G10C 3/ 06( . ) G10H 3/ 12( . ) G10C 3/ 04( . ) G10C 3/ 16( . ) (86) International application number: PCT/GB1983/000060 (87) International publication number: WO 1983/003022 (01.09.1983 Gazette 1983/20)

(84) Designated Contracting States: AT BE CH DE FR GB LI LU NL SE (30) Priority: 26.02.1982 GB 19820005768 (71) Applicant: PRUTEC LIMITED London EC1N 2NH (GB)	(72) Inventor: STANWELL-SMITH, Colin Howard Middx, TW1 2LY (GB) (74) Representative: Messulam, Alec Moses  A. Messulam & Co. 24 Broadway Leigh on Sea Essex SS9 1BN Leigh on Sea Essex SS9 1BN (GB)