Patent ID: 7104607

Claim:
A seat, comprising: a seat cushion; a seat back frame connected to said seat cushion, the seat back frame being adapted to bend in a range of a specific bending angle in a direction of moving a top end thereof backward by a backward load over a predetermined value, by way of a joint provided at an intermediate portion in the vertical direction, such that the seat back frame receives a reaction force corresponding to the bending angle, wherein said seat back frame comprises a lower frame connected to the seat cushion, an upper frame whose bottom end portion is connected to a top end portion of said lower frame such that the upper frame is capable of bending in the front-rear direction by way of said joint, and a buffering member which generates a reaction force in said upper frame corresponding to an angle at which said upper frame is bent backward relative to the lower frame; and a stopper positioned to restrict a forward limit of the specific bending angle of the seat back frame to an angle wherein the direction of the length of a portion of said upper frame adjacent said lower frame is substantially an extension of the direction of the length of a portion of said lower frame adjacent said upper frame, whereby the bending of the seat back frame in the range of a specific bending angle in a direction of moving the top end thereof backward by a backward load over a predetermined value comprises moving the top end backward from a position wherein the direction of the length of the portion of said upper frame adjacent said lower frame is substantially an extension of the direction of the length of the portion of said lower frame adjacent said upper frame.