Patent attributes
A closure device includes a first part forming a fastening base for fastening to the container neck and having at least one peripheral fastening groove and a second part forming a lid, a fastening ring defining a reference geometrical axis, and a hinge connecting the fastening ring to the lid for guiding the lid relative to the fastening ring between a closed position and an open position, the fastening ring being engaged by snap-in action into the fastening groove of the first part. The second part additionally also forms a first-opening indicator and a frangible connection between the first-opening indicator and a peripheral rim flange of the lid, a free space being maintained in the axial direction between the fastening ring and the first-opening indicator in the closed position prior to the first opening, the first-opening indicator being retained by at least one lock zone of the first part so as to be separated from the lid and drop into the free space upon the first opening.