(19)

(11)

EP 0 570 431 A1

(12)

(43) Date of publication: 24.11.1993 Bulletin 1993/47 (21) Application number: 92903921.0 (22) Date of filing: 07.02.1992

(51) International Patent Classification (IPC):  G08B 17/ 00( . ) (86) International application number: PCT/AU1992/000042 (87) International publication number: WO 1992/014223 (20.08.1992 Gazette 1992/22)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI NL SE (30) Priority: 07.02.1991 AU 19910004508 (71) Applicant: JAMES HARDIE BUILDING SERVICES & TECHNOLOGIES LIMITED Abbotsford, VIC 3067 (AU)	(72) Inventor: HELLEWELL, Geoff Abbotsford, VIC 3067 (AU) (74) Representative: W.P. Thompson & Co.  Coopers Building, Church Street Liverpool L1 3AB Liverpool L1 3AB (GB)