Abstract: A seat structure for a chair which has a frame with a front frame section and a rear frame section, the front frame section and rear frame section being joined by an articulation joint such that the front frame section may be articulately moved with respect to the rear frame section. There are provided stopper means to limit the degree of articulation of the front frame section. There is also provided means for connecting the front and rear frame sections together.

Abstract: A composite support frame structure for the construction of a seat. The support structure comprises a rigid continuous rod-like frame formed in a closed loop and having opposed diverging rod-like side members which lie in a common plane and opposed rod-like end members formed integral with the side members. At least one of the end members is arced outwardly. A belt of substantially non-extensible material forms a slightly truncated sleeve, narrower that the frame, to apply a compression force between the side members and to flex the arced end member. The sleeve is retained in tension about the opposed diverging rod-like side members by restoring spring force between the side members exerted by the arced end member.