Paint Can Shaker
 

For liquids with a very high viscocity- such as paints a through mixing is hard to get (sometimes you must use a spool and whirl inside the can, which is quite messy) Mechanism shown shakes the can in all directions, thus obtaining a uniform mix even for jelly-like liquids. The can is placed rigidly onto the green box and the electric motor rotates the red lever (The motion of the can is similar to the belly motion of a good belly dancer.

Gears
 

In many mechanical systems we use gears to change the speed of the electric motor to a speed at which our machine can operate.

Car Wipers
 

Think of using cars without wipers!!!    Of course it was the combustion engine which changed our way of travel but without the wiper and the starter motor I wonder how many of us would be using cars that often with such ease. One can use the car in rainy wheather only with this simple mechanism. Figure shows a simple wiper mechanism used in some Fiat cars. There are several different designs (For example in Mercedes cars there is a single wiper blade).

UMBRELLA
 

Yes! the simple device that we use to protect us from rain or shine uses mechanisms. The one shown is what you usually see at the beaches. The mechanism used in foldable umberellas that we carry has a different mechanism