Closure device with a curtain having flexible lateral edges

This is related to a device comprising a curtain (2) having flexible side edges (4) that has an excess thickness (4 '), this curtain (2) being equipped with a cable or with several superimposed cables (21), that are incompressible in a longitudinal direction, extending parallel to the side edges (4) of the curtain so as to enable the application of a pushing force on these side edges (4) in their longitudinal direction to move the curtain to its closed position, this cable being or these cables (21) located on the neutral surface (24) of said edges (4) which is formed by flexing the latter and which is fixed to the curtain (2) in a non-removable form; the thickening comprising a flexible strip (8) made of elastic material, in which the cable or the cables (21) are incorporated, as well as two belts (9, 10 ') with notches located one with respect to the other on each one on both sides of the curtain (2).