LEONARDO DA VINCI - Analysis of gear teeth - Cylindrical antifriction teeth
Codex Atlanticus (BAM), fol. 91r
The teeth of the wheel that drives the two grindstones are composed of a cylinder rotating freely on a pin attached to the wheel. This device lessens the effects of friction between gears. Leonardo copied the design from Brunelleschi, who used it in the three-speed hoist for the construction of the dome of Florence Cathedral. In his drawing of the mechanism (see I.2B.1a1), Leonardo made a detailed structural analysis of these innovative teeth.