US Patent 7093901 Seat frame of a vehicle seat

A seat frame of a vehicle seat includes a seat cushion frame on a seat cushion side, a seat back frame on a backrest side, and a reclining device provided between the seat back frame and the seat cushion frame for adjusting an angle of incline of the seat back frame relative to the seat cushion frame. Either one of the seat back frame or the seat cushion frame includes a first member having a first fitting plane portion to the reclining device and a second member connected to the first member by holding a first space therebetween, and a hollow portion connected to the first space provided on an outer periphery of the first fitting plane portion.