An electric toothbrush simple mechanism patent
Has a main shaft that does two things:
a. Turns a "brush shaft" that causes the brush to "roll" sideways and back and forth.
b. Pushes a pin that causes the brush to rock sideways and up and down.
If your not afraid of a heart attack, here's a preview of what the original looked like:
|From Latent Patents website|
If you want to see this patent in action see here: