Variable-ratio gear drive; plan of the Sforza Castle, Milan
Red-chalk snail-cam transmission with a small castle plan
In red chalk and oriented upside down, this page carries two subjects noted by the e-Leo captions: above, a plan of the Sforza Castle (Castello Sforzesco) of Milan, and below, a transmission of variable ratio built with asymmetric toothed arcs. The dominant drawing is a large toothed wheel meshing with a spiral, snail-shaped cam whose growing radius makes the transmitted ratio change through a turn. A small squared structure is sketched lower on the sheet. The chalk is faint and further construction lines are present but not transcribed.
On this page
Variable-ratio transmission with asymmetric toothed arcs
A large toothed wheel engages a spiral, snail-shaped cam; because the cam's radius grows around its curve, the ratio between driver and driven changes continuously as it turns. The caption describes a transmission of variable ratio built with asymmetric toothed arcs.
Plan of the Sforza Castle of Milan
The caption records that the upper part of the sheet holds a plan of the Castello Sforzesco, the Sforza fortress of Milan; a small squared structure with corner elements is lightly sketched.