(19)

(11)

EP 0 020 603 A1

(12)

(43) Date of publication: 07.01.1981 Bulletin 1981/01 (21) Application number: 79901579.0 (22) Date of filing: 13.11.1979

(51) International Patent Classification (IPC):  G01C 5/ 00( . ) G01C 15/ 00( . ) (86) International application number: PCT/SE1979/000233 (87) International publication number: WO 1980/001106 (29.05.1980 Gazette 1980/12)

(84) Designated Contracting States: AT CH DE GB (30) Priority: 21.11.1978 SE 19780012008 (71) Applicant: ROCKSET AB S-183 06 Täby (SE)	(72) Inventors: NORDGREN, Bo S-183 43 Täby (SE) JOHANSSON, Ivar S-940 20 Öbebyn (SE)