Patent ID: 7686395

Claim:
A chair comprising a supporting structure configured to support a seat and a backrest, in which the backrest comprises: a deformable resting portion made of plastic material, which has a non-planar resting surface and is provided with at least one weakened area, which enables an elastic deformation of the resting portion so that the resting portion assumes a configuration bent backwards under the action of a thrust applied backwards by the user, said weakened area having the shape of a line that extends in a transverse direction on said resting portion, two uprights formed integrally on the lateral sides of the resting portion, and two side connection elements formed integrally at the bottom ends of the uprights, wherein the two side connection elements have a tubular shape and are coupled to respective upwardly-projecting portions of tubular supporting members that are non-rotatably fixed to the supporting structure so as to cantilever the backrest to the supporting structure, said upwardly-projecting portions being inserted into corresponding cavities of said side connection elements, wherein elastic stiffening elements are inserted within cavities of the tubular supporting members such that they also extend within an area corresponding to the uprights for at least half a length of each of said uprights, said elastic stiffening elements providing to said uprights a rigidity to bending higher than that of the resting portion.