Patent ID: 7066552

Claim:
A seat back frame for a vehicle seat comprising: first and second side members spaced apart from each other; each of said first and second side members being made of ultra-high tensile strength steel; said first side member having a first longitudinal body of a substantially U-shape in cross-section; said first longitudinal body comprising a pair of first spaced apart flange sections and a first main plate section interconnecting said first spaced apart flange sections; said first side member having a first upper region, a first lower region, and a middle region between said first upper region and said first lower region; said second side member having a second longitudinal body of a substantially U-shape in cross-section; said second longitudinal body comprising a pair of second spaced apart flange sections and a second main plate section interconnecting said second spaced apart flange sections; said second side member having a second upper region, a second lower region, and a second middle region between said second upper region and said second lower region; an upper member arranged between said first and second upper regions of said first and second side members; said upper member being made of ultra-high tensile strength steel; said upper member having first and second end portions; said upper member being mounted, by spot-welding, to said first and second upper regions of said first and second side members with said first and second end portions thereof being fitted in said first and second side members; and a lower member arranged between said first and second lower regions of said first and second side members; said lower member being made of ultra-high tensile strength steel; said lower member having third and fourth end portions; and said lower member being mounted, by spot-welding, to said first and second lower regions of said first and second side members with said third and fourth end portions thereof being fitted in said first and second side members.