The mechanism enables to unfold the surface to the cross – sleeping space, in double sofas. The unfolding consists in uplifting the mechanism and moving it to the front onto the floor, and then pulling out the headrest. This model requires to remove the backrest pillows. Thanks to the possibility of using thick mattresses, the function ensures a high sleeping comfort. The mechanism is constructed such way that the furniture unfolding and folding is supported by work of springs  and synchronizing bars, which makes the function very easy in handling. The mechanism can substitute many old solutions for this kind of furniture.