US Patent 9173502 Tri-fold sofa

A convertible sofa and sofa frame deployable between a sofa orientation and a bed orientation. The frame has a base frame with a seat extension frame comprising a seat frame and a mid-frame pivotally secured to the base frame. Cushioning is on one side of the base frame. A seat back frame is pivotally secured to the base frame, the second cushioning on what is a back side when in the sofa orientation. Removable seat back cushions engage the front side of the seat back frame in the sofa orientation. In the bed orientation, the seat frame is extended, the seat back portion is pivoted horizontally, and the removable seat back cushions are located on the mid-frame between the seat frame and the seat back frame.