How Clutches Work | HowStuffWorks
If you drive a manual transmission car, you may be surprised to find out that it has more than one it turns out that folks with automatic transmission cars have clutches, too. In fact, there are clutches in many things you probably see or use every day: Many cordless drills have a clutch, chain saws have a centrifugal clutch and even some yoyos have a clutch.