I've seen "gears" that were part geneva mechanism and part gear. Before the advent of stepper and servo motors manufacturing machines used cams and gears to do the movements that are now done electronically. Everything was done mechanically. Oval gears, square gears, rotary to linear mechs, linear to rotary, all kinds of ideas that got the job done.

http://www.dself.dsl.pipex.com/MUSEU...alveIC.htm#mel