The joint comprises two spiders 18 and a central core 16 forming a housing 24 for the sliding movement—in a transverse plane—of a basically discoidal constraint member 20 forming the seats 20A for the spherical end heads 1 OC, 14C of the two forks. The constraint member 20 moves about inside the housing 24. Between each of the two surfaces 24A, 24B and the opposing face of the constraint member 20, an elastic laminar ring 40 shaped like a Belleville washer is interposed, its annular edges being in continuous annular contact with the surface 24A or 24B and with the opposing face of the constraint member 20.