1967 - 1972 Heinrich KuperHeinrich KUPER GmbH & Co. KGGermany
1982 - 1988Jann Bjoerne senA. Falkenberg Eftf. A/SNorway
1972 - 1974Hans HeidHeid AGSwitzerland
1989 - 1990Hans Heinrich KuperHeinrich Kuper GmbH & Co. KGGermany
1975 - 1978Eugène ChambonChambon S.A.France
1991 - 2006 Joseph RosaRomac N.V.Belgium
1979 - 1981Sven G. StenbergAB Sigfrid StenbergSweden
since 2007Fritz PeineHeinrich Kuper GmbH & Co. KGGermany