The Monroe mechanism
This system has been invented by Monroe in 1911. The driving mechanism consists of two drums that can glide on the same axis they revolve around. The first drum is equipped with 4 teeth of increasing length. The second drum is a 5 teeth gear (the teeth are distributed on the half of the circumference). The two drums play the same role than the Leibniz stepped drum with a reduced size.
To see the movies of the Monroe driving mechanism, clic on the links below.