Pencils can only write for so long before their graphite tips are worn down to nubs, and then we can’t write anymore. This is when we go to the very helpful machines called ‘pencil sharpeners’. Early pencil sharpeners consisted only of two blades situated in a metal housing that was manually turned around the pencil. More modern pencil sharpeners include a housing, usually composed of plastic, to catch the soft wood shavings as they are cut away. In these sharpeners, the blades are turned by a hand crank protruding outside the housing, or the pencil is manually turned against the blades. Electric pencil sharpeners rotate the blades through use of an electric motor affixed inside the sharpener housing; a sensor or small switch detects the insertion of a pencil and activates the motor.
How does a Pencil Sharpener Work?
