The connector (8) is partially housed in a casing (2) formed by two half-shells (4) whose edges have respective notches (6) which, in the assembled configuration of the two half-shells (4), define an opening between the interior of the casing (2) and the exterior. The connector (8) is formed by a body (10) of elastomeric material having a perimetral groove (12) which is adapted to be fitted in the opening defined by the notches (6) and a plurality of through-holes (16) substantially perpendicular to the general plane of the groove (12) and each having at least one internal portion (18, 20) of enlarged cross-section. The holes (16) are intended to house respective electrically conductive pins (24) whose shapes correspond to those of the holes (16) and the ends of which project from the body (10).