Abstract: The invention relates to a system (1) for transferring a magnetic link (2) between a first element and a second element rotatable relative to the first element, a first end of said link being adapted to be attached to the first element and a second end of the link being adapted to be attached to the second element, characterised in that it comprises: a first part (11, 13) adapted to be rigidly connected to the first element; a second part (21, 23) rotatable relative to the first part and adapted to be rigidly connected to the second element so as to be rotationally driven at the rotational speed of said second element; a third part (30, 31) rotatable relative to the first and second parts, a member for coupling (40, 45) the second and third parts, adapted to rotationally drive the third part at a speed equal to half the rotational speed of the second element, two sets of two coaxial ferromagnetic surfaces for winding the magnetic link (2), a first set comprising a first surface integral with the first

Abstract: The switch (15) which is placed at a feeding device (F) for access from the exterior is situated in a front part (10) of a housing (1) at a side of a withdrawal axis (Y) which is remote from a mounting device (5). The housing (1) has the mounting device (5), a housing bracket (6), the cantilevering front part (10) at the housing bracket, a withdrawal axis (Y) defining withdrawal eyelet (13) which is placed in the front part, and a light permeable cover (14).