(19)

(11)

EP 0 114 828 A1

(12)

(43) Date of publication: 08.08.1984 Bulletin 1984/32 (21) Application number: 83901058.0 (22) Date of filing: 31.03.1983

(51) International Patent Classification (IPC):  H04R 1/ 46( . ) H04R 3/ 00( . ) (86) International application number: PCT/AU1983/000039 (87) International publication number: WO 1983/003733 (27.10.1983 Gazette 1983/25)

(84) Designated Contracting States: AT BE CH DE FR GB LI LU NL SE (30) Priority: 05.04.1982 AU 19820003464 (71) Applicant: HEYDEN SPIKE CO.PTY.LIMITED Brookvale, New South Wales 2100 (AU)	(72) Inventors: VANDER HEYDEN, Paulus Petrus Adamus Clifton Gardens, NSW 2080 (AU) SPIKE, Robert Graeme Clifton Gardens, NSW 2080 (AU) (74) Representative: Pilch, Adam John Michael  D. YOUNG & CO., 21 New Fetter Lane London EC4A 1DA London EC4A 1DA (GB)