(19)

(11)

EP 0 491 806 A1

(12)

(43) Date of publication: 01.07.1992 Bulletin 1992/27 (21) Application number: 90914008.0 (22) Date of filing: 11.09.1990

(51) International Patent Classification (IPC):  H03C 1/ 60( . ) H04L 27/ 04( . ) H03C 1/ 62( . ) (86) International application number: PCT/US1990/005115 (87) International publication number: WO 1991/003899 (21.03.1991 Gazette 1991/07)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI LU NL SE (30) Priority: 11.09.1989 US 19890405455 29.01.1990 US 19900471825 (71) Applicant: ZSB, INC. Minnetonka, MN 55343 (US)	(72) Inventor: ANDERSON, Terry, M. Minnetonka, MN 55345 (US) (74) Representative: Rabus, Werner W., Dipl.-Ing., et al  Eisenführ, Speiser & Partner, Martinistrasse 24 D-28195 Bremen D-28195 Bremen (DE)