the futon sofa bed frame featuring a quick assembly system and method for fitting the back - deck into position between the arm panels . a futon sofa bed frame featuring a quick assembly system and method for attaching the seat - deck to the back - deck that may be converted between seating , lounging , and bed positions while standing at the front of the futon frame and the method of assembling a futon sofa bed that is easier to manipulate and is more durable in operating than conventional futons .