A tube link for a roller shutter apron coupling device for coupling to a winding tube (1, 1a) which includes fastening apertures set apart along the direction of its axis, this tube link including a bottom wall suitable for being applied against the tube, and means for hooking to at least two apertures of the tube, characterised in that: - the bottom wall of the link is passed through by at least three lumens (11, 12, 13), that is a base lumen, and at least to other lumens (12, 13) located at different axial distances from the base lumen and corresponding to one or more pitches of two successive apertures of tubes of at least two types differing in the axial pitch of the apertures, - and the link includes assembling means to fasten a connecting part (16, 16a) adapted to the tube to be fitted and including two hooking lugs (18, 19) respectively passing through the base lumen and another lumen in correspondence with two apertures of the tube, so that a same type of tube link can be used for tubes of different types by assembly with an adequate connecting part, characterised in that: the link is fitted with a connecting part (16, 16a) formed of a tongue, in particular a metallic tongue, a first end of which, suitable for being received by the base lumen, is provided with a lug bent as a hook towards the other end of the part, this other end being provided with an lug bent as an L on the opposite side of the first end, and being received by one of the other lumens (12, 13) of the link according to the type of tube to be fitted, the link being made integral with a tube by simple overlapping, regardless of the assembling mode of the connecting part on the link, and in that the assembling means of the link and connecting part comprise at least two pins suitable for passing through fastening apertures of the connecting part (16, 16a) and for being deformed to ensure the assembly. - the bottom wall of the link is passed through by at least three lumens (11, 12, 13), that is a base lumen, and at least to other lumens (12, 13) located at different axial distances from the base lumen and corresponding to one or more pitches of two successive apertures of tubes of at least two types differing in the axial pitch of the apertures, - and the link includes assembling means to fasten a connecting part (16, 16a) adapted to the tube to be fitted and including two hooking lugs (18, 19) respectively passing through the base lumen and another lumen in correspondence with two apertures of the tube, so that a same type of tube link can be used for tubes of different types by assembly with an adequate connecting part, characterised in that: the link is fitted with a connecting part (16, 16a) formed of a tongue, in particular a metallic tongue, a first end of which, suitable for being received by the base lumen, is provided with a lug bent as a hook towards the other end of the part, this other end being provided with an lug bent as an L on the opposite side of the first end, and being received by one of the other lumens (12, 13) of the link according to the type of tube to be fitted, the link being made integral with a tube by simple overlapping, regardless of the assembling mode of the connecting part on the link, and in that the assembling means of the link and connecting part comprise at least two pins suitable for passing through fastening apertures of the connecting part (16, 16a) and for being deformed to ensure the assembly. the link is fitted with a connecting part (16, 16a) formed of a tongue, in particular a metallic tongue, a first end of which, suitable for being received by the base lumen, is provided with a lug bent as a hook towards the other end of the part, this other end being provided with an lug bent as an L on the opposite side of the first end, and being received by one of the other lumens (12, 13) of the link according to the type of tube to be fitted, the link being made integral with a tube by simple overlapping, regardless of the assembling mode of the connecting part on the link, and in that the assembling means of the link and connecting part comprise at least two pins suitable for passing through fastening apertures of the connecting part (16, 16a) and for being deformed to ensure the assembly.