Abstract: A seat backrest frame (10) having an integrally formed rigid peripheral frame structure which, relative to an in-use orientation, has a plurality of frame portions, namely a pair of side portions (20) and transverse portions (22 and 24). Each of the frame portions (20, 22 and 24) has an elongate channel form defined by respective side flanges (20a, 22a, 24a, 20b, 22b, 24b), and an interconnecting web (20c, 22c, 24c). Each web (20c, 22c, 24c) being disposed forwardly of the frame structure with the channel of each frame portion opening rearwardly. Each side portion (20) defines a forwardly projecting wing (36) over at least the lower half of its length, such that the depth of each side portion channel in at least the region of the wing (36) is substantially greater than the depth of the channels of the transverse portions (22 and 24).

Abstract: A seat mounting mechanism for mounting a seat for adjustable fore and aft movement, the mechanism having an elongate fixed rail which is adapted to be securable to a substructure, pan or floor, a movable rail which is engageable with the fixed rail and adapted to be securable to a seat, and at least one locking member mounted on a first one of the fixed rail and the movable rails. The locking member is pivotable between an engagement position in which it locks the movable rail relative to the fixed rail and a retracted position in which it frees the movable rail for adjustment along the fixed rail. The locking member is mounted on the first rail for pivotable movement, between the engagement and retracted positions, about a pivot axis extending substantially parallel to the rails. The locking member has an engagement mechanism by which it is selectively engageable with an engagement mechanism of, and disposed along, a second one of the rails when the locking member is in its engagement position.