(2)-1 Slider crank motion
The left slider goes and returns along the rectilinear ditch during one rotation of the right handle, that is, a rotating move is converted into a linear move. Also, this mechanism can convert a linear move into a rotating move, like a piston used in an automobile's engine, etc. However, some device is necessary not to stop the movement at the dead points, for example, connecting another piston with a different phase.
[Animation: DI JING, Graduate school of informatics, Jul. 2000]