DIY MECHANIC ELEVATOR BED

In simple terms the project consists in a bed that can be lifted and hided into the celling. Then the bed can be pulled down to the floor when needed. The trick is to do it without attaching the supporting mechanism into the celling.But also, that this supporting mechanism do not be in the way of the people that wants to take advantage of the free room space.
The project is a DIY project and has the goal of saving money and space to those who rent or live in a bedroom.
Also, to provide space that could be used by other furniture at the persons convinience for example, like setting up a table for eating or a living room area, etc.
Some of the tools and mechanism that I would like to involve in its construction would be:
Pulleys mechanism
Malasia Rope or steel cable or heavy duty straps
wood bed base
Folding wood legs or metallic for when bed has to stand in the floor