Abstract: A seat slide device for use in an automotive seat which is mounted on the right and left sides of a seat frame to adjust the position of the automotive seat forwardly and backwardly. The seat slide device comprises a first slide rail and a second slide rail to which an anchor of a seat belt is to be attached. A second upper rail included in the second slide rail has in its lower portion a first slide portion identical with that of a first upper rail in the first slide rail as well as a second slide portion fixed on the opposite side of the first slide portion. That is, the second slide rail is constructed such that its upper rail is engageable with its lower rail at the two positions thereof, with the result that the second upper rail of the second slide rail is able to share a removing load by the seat belt anchor at the first and second slide portions.

Abstract: A seat frame for use in an automotive seat. The seat frame is divided into four sections, that is, front, rear, right and left sections, and at least the right and left sections or side frame members are respectively formed in a substantially Z-shaped configuration. Namely, each of the side frame members comprises a vertically extending web, an upper flange and a lower flange projecting in opposing directions to each other with respect to the web, whereby, when loads are applied to the side frame members, the respective centers of shearing thereof are caused to exist in their webs or adjacent portions thereof, resulting in the increased strength.