The device comprises an interior body adapted to come into obstinate on the side from the interior face (13) of the aforesaid the wall and an external body adapted to come into obstinate against the plate, the external body and the interior body being in addition arranged to be assembled by screwing one in another, while passing by holes (14, 21) appreciably coaxial arranged respectively in the wall and the plate. The interior body (3, 130, 230, 330, 430) is maintained on the wall (1) in an unlosable way by a connection allowing a free rotation compared to the aforementioned wall and comprises a print (31, 131) of low-size swing drive, and an opening of access (12) is spared in a lining (11) of the wall opposite the known as holes (14, 21) to allow the passage of a tool (9) adapted to cooperate with the aforementioned print, for real estate the interior body in rotation during the assembly or disassembling of the plate.