Abstract: A vehicle seat back frame including two bracing members, one being linearly extended from the lower end of the outboard upright member to the upper end of the inboard upright member and the other being extended linearly from the lower end of the inboard upright member to the upper end of the outboard upright member, the bracing members being connected together at a point intermediate their ends so that a side impact load applied to the seat back frame will place one of the bracing members fully, and the upper half of the other member, in tension substantially instantaneously upon the application of the load to the seat back frame, enabling the seat back frame to resist lateral deformation due to side impact forces applied to the seat back frame.

Abstract: Continuously adjustable pivoted hinge, such as employed for automotive vehicle recliner seat back, wherein a toothed sector on one hinge element is retained by a toothed pawl on the other which has freedom of mounting connection at least equal to the pitch of one tooth in order to accommodate full tooth engagement for any continuously variable relative position of the sector. A pair of pivotally anchored cam elements engage angularly related cam surfaces on the pawl after its full tooth engagement with the sector. Variable travel of cam surface to accommodate fully engaged prepositioned pawl with self-locking angle resisting pawl displacement in either angular direction from sector tooth pressure, is sufficient to accommodate at least one tooth displacement of the pawl in order to lock the pawl in any position of initial full tooth engagement. The pawl is pivotally mounted at the hinge pivot with a radial slot to accommodate tooth disengagement.