Spheric joint or spherical hinge (30; 130) for coupling together two members that are spatially orientable relative to each other, in which a head (84; 184) of the first member (80; 180) is retained in an accommodation (46; 146) of the second member (40; 140) by at least four points of contact located on a spherical surface according to the vertices of a pyramid containing the centre thereof, about which said head (84; 184) is adapted to rotate without translating. The hinge is characterized in that said accommodation (46; 146) or said head (84; 184) has a projecting boss (52; 152) confined in a gap (85; 186) of said head (84; 184) or said accommodation (46; 146), said gap (85; 186) having at least two consecutive distinct spaces (85a, 85b; 187, 188) that define a travelling path (85; 186) for said boss (52; 152).