Patent ID: 8083292

Claim:
A seatback frame for vehicles, comprising: a back frame hingedly coupled to a seat frame by a recliner hinge shaft; and a lower cross member coupling opposing sides of a lower end of the back frame to each other, the lower cross member including: an upper reinforcing part having an embossed rib extending in a longitudinal direction of the lower cross member between the opposing sides, wherein the embossed rib is disposed above the recliner hinge shaft and below an upper edge of the lower cross member, and protrudes towards a back pad; and a hinge-shaft cover provided on a lower portion of the lower cross member below the upper reinforcing part, the hinge-shaft cover being curved to surround the recliner hinge shaft and extending continuously in a longitudinal direction thereof; wherein a welding flange is provided on each opposing end of the lower cross member, and is welded to a respective side of the lower end of the back frame; wherein a cross-section of the lower cross member has a hook shape which substantially surrounds the recliner hinge shaft; and wherein a locking projection extends along an edge of the hinge-shaft cover in such a way as to extend upwards relative to the back frame and a radial distance of the locking projection from the recliner hinge shaft is smaller than a diameter of a welding flange from the recliner hinge shaft so as to prevent the back pad from interfering with the recliner hinge shaft when the recliner hinge shaft is operated; and wherein the locking projection has opposing side edges spaced inwardly from the welding flanges of the lower cross member.