| 摘要 |
PROBLEM TO BE SOLVED: To rotatably support a support plate member provided on a seat back for supporting a back part of a seated person to be able to change a rotation locus.SOLUTION: In a seat back structure in which a support plate member 18 for supporting a seated person is arranged to be rotatable in a seating surface direction of the seated person, rotation locus changing means for changing a rotation locus of the support plate member 18 is equipped between the support plate member 18 and a frame member 14. The rotation locus changing means is configured in such a manner that a position of a rotary shaft (fulcrum) 24 is movable in a vertical direction relatively to the frame member 14 of the support plate member 18 and that the rotary movements of the support plate member 18 are performed along a guide locus defined by a deformable rotation guide plate member 34 arranged on the side of the frame member 14. The rotation locus of the support plate member 18 is changed by deforming the rotation guide plate member 34. |
