US Patent 6904628 Convertible sofa-bed

A sofa-bed has: a frame with opposing arms; a seat; a subseat hinged to the seat; a connecting rod that pivotally interconnects the subseat and the backrest; pairs of center legs and end legs pivotally attached to, respectively, the subseat and seat; and mechanisms for folding and unfolding the center and end legs. The sofa-bed is movable between a folded position and an unfolded position. The mechanisms for the center legs and the end legs are configured to move the legs from a generally horizontal folded position between the seat and subseat when the sofa-bed is in the folded position to a generally upright position beneath, respectively, the subseat and seat when the bed is in the unfolded position.