That table top fan you have next to you is more interesting than you think! I took mine apart so I could show you how it works. The "four speed mechanism" releases any other button that was previously pressed down. Once a button is pressed a signal (voltage) is sent to the motor at the top of the fan. The oscillation motion is produced through the 4 bar mechanism. The last part of the video covers the gears that turn the 4 bar mechanism. The pin is part of the gears - when it is lifted the gears don't connect and the fan will no longer oscillate back and forth.
⌚Timestamps:
0:00-Intro
0:20 - Fan Intro
1:20 - Button Mechanism
2:26 - Signal to the top
3:03 - Four Bar Mechanism
4:03 - Fan Oscillation
4:35 - Gear Box
5:57 - Ball Bearings Again
6:32 - Speed of the Fan