(19)

(11)

EP 0 506 735 A1

(12)

(43) Date of publication: 07.10.1992 Bulletin 1992/41 (21) Application number: 91900963.0 (22) Date of filing: 29.11.1990

(51) International Patent Classification (IPC):  E01F 9/ 014( . ) E04H 17/ 26( . ) (86) International application number: PCT/NO1990/000176 (87) International publication number: WO 1991/009194 (27.06.1991 Gazette 1991/14)

(84) Designated Contracting States: AT DE SE (30) Priority: 20.12.1989 NO 19890005133 (71) Applicant: RISA, Steinar N-4342 Undheim (NO)	(72) Inventor: RISA, Steinar N-4342 Undheim (NO) (74) Representative: Patentanwälte Dr. Solf & Zapf  Candidplatz 15 D-81543 München D-81543 München (DE)