(19)

(11)

EP 0 052 136 A1

(12)

(43) Date of publication: 26.05.1982 Bulletin 1982/21 (21) Application number: 81901551.0 (22) Date of filing: 25.05.1981

(51) International Patent Classification (IPC):  G09B 27/ 08( . ) G09B 29/ 02( . ) (86) International application number: PCT/NL1981/000016 (87) International publication number: WO 1981/003391 (26.11.1981 Gazette 1981/28)

(84) Designated Contracting States: AT CH DE FR GB LI LU NL SE (30) Priority: 23.05.1980 NL 19800002994 (71) Applicant: VISSER, Franciscus Gerardus Godefridus NL-2286 HG Rijswijk (NL)	(72) Inventor: VISSER, Franciscus Gerardus Godefridus NL-2286 HG Rijswijk (NL)