The coupling comprises first gripping members (7) which are connected, facing on one and the same level on corresponding mounting bodies (2), to respective structures, and second gripping members (15) mounted so as to slide vertically on the first gripping members (7) in order to secure tyres (14) in two diametrically opposed regions thereof with the collaboration of threaded rods (22). The gripping members (7) and (15) provide retention walls (10 and 19) that extend towards the mounting bodies (2) by means of horizontal retention flanges (11 and 20). The second gripping members (15) have walls (17) with holes for the passage of screws during fitting thereof to the mounting bodies (2).
