(19)

(11)

EP 0 020 420 A1

(12)

(43) Date of publication: 07.01.1981 Bulletin 1981/01 (21) Application number: 79901196.0 (22) Date of filing: 18.09.1979

(51) International Patent Classification (IPC):  E04C 1/ 41( . ) E04B 2/ 02( . ) (86) International application number: PCT/SE1979/000191 (87) International publication number: WO 1980/000587 (03.04.1980 Gazette 1980/07)

(84) Designated Contracting States: AT CH DE FR GB LU NL (30) Priority: 19.09.1978 SE 19780009806 19.09.1978 SE 19780009807 (71) Applicants: AB ÖSTGÖTABETONG S-581 10 Linköping (SE) INGESTRÖM, Curt Holger S-446 00 Älvängen (SE)	(72) Inventors: INGESTROM, Curt Holger S-446 00 Älvängen (SE) PETERSSON, Anders Olov Herbert S-585 90 Linköping (SE) (74) Representative: Ström, Tore, et al  Ström & Gulliksson AB Studentgatan 1 P.O. Box 4188 S-203 13 Malmö S-203 13 Malmö (SE)