Abstract: A seat construction including a composite inner/outer frame to which at least two seat pans are secured. The composite frame includes three horizontal cross members, located at the front ends of bottom portions of the seat pans, at the junctions of the bottom portions and back portions of the seat pans, and at the top ends of the back portions of the seat pans. A pair of boomerang-shaped side members are fixed at their distal ends and their bent centers to the opposing ends of the cross members and an intermediate member is fixed to the mid-ways of the cross members, so that an inner frame is formed by the side members, cross members, and intermediate member. The side members the front cross member and the intermediate frame member are covered by their corresponding outer frame members to construct the composite inner/outer frame which is light in weight but rigid in construction.

Abstract: A flip-up seat construction includes a frame unit having a seat-back assembly, supporting a seat-back portion of a seat pan, and a bottom assembly, supporting a bottom portion of the seat pan and swingably attached to the seat-back assembly to move the bottom portion between a horizontal seat position and a stand-up position. The seat-back assembly includes, first and second horizontal members, horizontally extending at positions corresponding to the upper and lower ends of the seat-back portion of the seat pan, first and second side members, respectively connected to the ends of each of the first and second horizontal members, and a swingably supporting member, integrally constructed with the first and second side members of the seat-back assembly and swingably supporting the bottom assembly.