Patent ID: 7926872

Claim:
A vehicle seat comprising: a seat cushion; a seat back which is provided behind the seat cushion, and which is provided with a seat back frame having left and right side frame units; a headrest provided at an upper end of the seat back frame; a plane spring structure which is provided inside the seat back frame, and which includes left and right side wires extending in a vertical direction, and horizontal wires provided between the left and right side wires at intervals in the vertical direction, wherein upper end portions of the side wires are secured to an upper part of the seat back frame, lower ends of the side wires are set free without being secured to the seat back frame, whereby when a rearward load is applied from the seat back to the plane spring structure, the plane spring structure is moved rearward about the upper end portions of the side wires and a lower half part of the plane spring structure is moved farther than an upper half part of the plane spring structure; a pad member provided on a front side of the plane spring structure; and connection wires which are provided between the side frame units of the seat back frame and the side wires of the plane spring structure, wherein the connection wires include detachable portions, and wherein at least one of the detachable portions is detachable from the plane spring structure or the seat back frame when a load is applied to the seat back from an occupant sitting on the seat cushion due to a vehicle in which the vehicle seat is provided being bumped from behind.