Patent ID: 7717512

Claim:
A seat back for a vehicular seat comprising: a plate member for supporting a back of a pad; and an elastic support mechanism capable of elastically supporting the plate member for moving the plate member in a forward and backward direction with respect to a seat back frame, wherein the plate member includes a first plate portion positioned to be proximate a scapulae of a user seated on the vehicular seat, a second plate portion positioned on a lower side of the first plate portion, and a third plate portion positioned on a lower side of the second plate portion and positioned to be proximate a kidney of the user, wherein the first and third plate portions are more narrow than the second plate portion, wherein the elastic support mechanism includes a rod-shaped elastic bridge member extending horizontally over the seat back frame on a back of the second plate portion, wherein the elastic bridge member includes a bent portion at a center position, the bent portion being positioned along the second plate portion toward the first plate portion, wherein the rod-shaped elastic bridge member has left and right horizontal portions extending substantially horizontally from left and right end portions of the bent portion, wherein the bent portion has left and right rising portions extended toward the first plate portion from the left and right horizontal portions, and a connecting portion for connecting the left and right rising portions, and wherein the second plate portion has left and right hook portions to be engaged with the horizontal portions, and left and right positioning portions protruded at corners of the rising portions and the connecting portion, so that the elastic bridge member is held by the hook portions and the positioning portions.