What is "cherepanovs"

Cherepanov, Yefim Alekseyevich (1774–1842), and Miron Yefimovich (1803–1849), his son, were Russian inventors and industrial engineers. They were serfs of the Demidovs – a famous family of factory owners. In 1810s, Yefim built a progressive machine-building plant, equipped with a full range of innovative metal-cutting lathes (such as screw-cutters, gear-cutting serrating machines and others). From 1822 until his death, Yefim was chief mechanic for all the factories in the town of Nizhny Tagil. Miron was his apprentice and in 1819 was appointed his deputy. Miron became chief mechanic his father's death.