PURPOSE: To restrict resilient eccentricity without impairing a functional lateral clearance by securing the mechanical restriction of resilient eccentricity by the contact of a ring integrated with an inner half ball joint and having small backlash in relation to a rigid annular surface.

CONSTITUTION: The mechanical restriction of resilient eccentricity is secured by the contact of a ring 20 integrated with an inner half ball joint 19 and having small back lash in relation to a rigid annular surface 25 integrated with an outer spherical cap 21. The outer spherical cap 21 collides with one shoulder part 26 constituted of the rigid annular surface 25 for forming a part of a metallic assembling pipe 18 under prestress, and rotational fitting of this pipe on the shoulder part 26 of the outer spherical cap 21 integrates all components of the ball joint 19. Accordingly, the realized attachment enables rotational rigidity and oscillation around a common axis of the outside diameter D and boring E.