"Impatience" is a paper automaton created by Rob Ives, built to simulate a hand with four tapping fingers conveying the feeling of impatience. It implements four cam-follower mechanisms, one for each finger, which takes a single counterclockwise motion from a crank as input. The output is vertical motion of the four fingers at alternating times.
The original "Impatience" model by Rob Ives and is shown in the following video. (NOTE: I did not create this model, but used it as inspiration)