Pencil Sharpeners, a Variation of Planetary Gearboxs
When I was in high school every classroom was equipped with a mechanical pencil sharpener. Most of the sharpeners worked and were well used but occasionally some kid got the idea it would be funny to stick a tootsie roll in one of them. Mechanical pencils are making pencil sharpeners somewhat obsolete but there will always be a need to sharpen colored pencils or number two pencils for scantrons. Personally, no mechanical pencils will ever replace the Mirado Black Warriors. It was always fun to stand in the corner, interrupting the teacher with the loud grinding noise that pencil sharpeners make while they eat at a pencil.
If one were to open a mechanical pencil sharpener they would discover that it is a variation of a planetary gearbox. This kind of gearbox got its name because the way it works is relative to the solar system. The “sun” gear is in the center and “planet” gears revolve around it. There is also an outer ring gear that meshes with the planets that I like to think of as the asteroid belt. A pencil sharpener is basically a planetary gearbox with extended planet gears turned into merciless cutters.
We did have to make sure our pencils were extra sharp so we could play our favorite game. The objective was to stick as many pencils in the ceiling as you could before getting caught. We used to torment one particular teacher because she gave the best responses. She was a little old Germany lady with a heavy accent. Her favorite thing to say to me was “Git witit Jozef”. Kids used to hang her stuffed animals from the ceiling just to get her to say something funny. The more a teacher got upset, the more kids wanted to goof off. It is a vicious cycle.