The present invention relates to a joint device (9) for mounting a sign post (95) or the like, comprising a first member (1) being connectable to a basis (99), and a second member (2) being connectable to a base portion (96a) of the sign post (95). A linkage (3) connects the first member (1) to the second member (2) such that the second member (2) is movable with respect to the first member (1) between an alignment position and a tilting position. A restoring means (4) which comprises an elastic element (40) and a deforming element (45) for cooperation with the elastic element (40) returns the two members (1, 2) towards the alignment position. The elastic element (40) is received in an interior pipe storage space (25) which is recessed in the first member (1) and the second member (2).