Josef “Seppi” Imhof worked as a technician at the Von Roll steel factory, where Jean Tinguely had collected the wooden wheels for his Meta-Harmonies. In 1964, he discovered Jean Tinguely's sculpture Eureka at the Swiss National Exhibition in Lausanne, where he also bought a drawing. He arrived at Le Cyclop’s construction site in 1971, answering an advert for a welder placed in the Bern newspaper by Jean Tinguely. Though initially planning to stay in France for only a year, Seppi Imhof ended up staying with Jean Tinguely until the latter's death in 1991. A great friendship and complementarity developed between the two men. Seppi Imhof subsequently became curator of the Jean Tinguely Museum up until 2008, donating his own collection of letters, drawings, collages and sketches.
- Période d'activité dans le Cyclopfrom 1971 to 1994