Patent ID: 8690255

Claim:
A seat back frame for a seat of a vehicle, the seat back frame comprising: a pair of side frames placed at a left side and a right side in a width direction of a seat; an upper portion cross member disposed between an upper portion of the side frames; a supporting plate extending between and interconnecting a lower portion of the side frames; an upper opening defined between the side frames, the upper portion cross member, and the supporting plate and relatively above the supporting plate, the upper opening being opened in a front-rear direction; a planar elastic body extending across the upper opening; and a connection member elastically connecting a lower portion of the planar elastic body to an upper portion of the supporting plate; wherein said planar elastic body is configured to have a lower rigidity as compared to said connection member such that, in the event of a rear end collision, said planar elastic body undergoes greater elastic deformation toward a rear side than does said connection member, and wherein the connection member comprises a wire member, said wire member being connected, at each end, to the side frames and, at an intermediate portion located between the ends, to the supporting plate.