Two-level transformable children's bed

Roll-out beds are designed for the equipment of children's pre-school institutions.
It is made under two sizes of a mattress, 1200?600, 1400?600.
Bed 3-level consists of 4 sections.
1 section - guide cabinet - U-shaped box consists of side walls left, right, front, back and top shields.
Sections small, medium and large - U-shaped boxes consist of side walls, front, back, front and back shields, support strips and bed. .The bed has two positions:
1) All sections are pushed into the box section.
2) All sections are extended for 3 beds.
The 2 level bed consists of 3 sections and has 2 beds respectively.