(19)

(11)

EP 0 109 422 A1

(12)

(43) Date of publication: 30.05.1984 Bulletin 1984/22 (21) Application number: 83901722.0 (22) Date of filing: 25.05.1983

(51) International Patent Classification (IPC):  G01C 17/ 28( . ) (86) International application number: PCT/GB1983/000147 (87) International publication number: WO 1983/004304 (08.12.1983 Gazette 1983/28)

(84) Designated Contracting States: AT BE CH DE FR GB LI LU NL SE (30) Priority: 25.05.1982 GB 19820015272 (71) Applicant: DOULTON, Romm Monte Carlo (MC)	(72) Inventor: CHAPMAN, Robert Arthur Newbury Berkshire (GB) (74) Representative: Butler, Michael John  FRANK B. DEHN & CO. Imperial House 15-19 Kingsway London, WC2B 6UZ London, WC2B 6UZ (GB)