Chair, with a seat and a backrest, is composed of two trapezoid closed frames with spring elasticity at their corners to give a dynamic and active seating without moving parts

摘要

The chair has a frame of two closed trapezoid frames (12,13), to lock the seat (10) and backrest (20) together. The corners (31-38) of the two frames have a spring elasticity. Both frames have stiff sections (16,22,26,28;17,23,27,29) to prevent bending, using another material e.g. wood covering all their surfaces for added stiffness and two frame sections (28,29) are stiffened by distortion of their cross section. The rear legs (24,25) are in one piece with the backrest.