US Patent 9706847 Chair with a tilting backrest

A chair comprising: a support structure, a seat fixed to the support structure, and a backrest connected to the seat by means of at least one upright of plastic material, wherein said at least one upright is elastically deformable to allow a movement of the backrest between a rest position and a tilted position, wherein said at least one upright is provided with at least one vertical rib having at least one localized bending zone wherein at least one through-cut is formed, which allows bending of the vertical rib, and wherein said at least one through-cut has a first and a second stop surface that come into mutual contact in the backwards inclined position of the backrest to stop the backward bending of the upright, wherein said at least one through-cut has the shape of a closed arched slot, which extends generally along a vertical axis of said upright.