Pressure snap fastener with a bivalent closure

A pressure snap fastener with a bivalent closure, comprising a first portion, comprising a first active element adapted to be associated with a first flap, and a second portion, adapted to be associated with a second flap;

• said first and second portions as associated with one another joining said first and second flaps;
• said pressure snap fastener being characterized in that it further comprises first temporary engagement means, adapted to provide a first temporary closure, in which said first and second portions are joined by a weak joining and are free of partially swinging, and second stable engagement means, adapted to provide a second stable closure, allowing said first and second portions to be tightly coupled wherein said first active element includes a first active element pin having a pin head, enlarged in comparison with a diameter of said pin, and fastened to a disc-shaped body, said first active element comprising moreover a first active element cap which, by cooperating with a groove of said disc-shaped body, operates as an active female element of the second stable closure means;
• wherein said second portion comprises a second active element formed by a body including an axial inner hole having a narrowed portion comprising an inner edge and adapted to operate as an active female element of the first temporary engagement means, said body comprising a cylindric pin having a radial enlarged portion and operating as an active male element of the second stable engagement means;
• wherein said cylindric pin comprises a plurality of cut-outs, facilitating a resilient deforming of said cylindric pin in performing closure operations;
• said cut-outs operating, in a temporary closure operation, for facilitating an enlargement of the axial inner hole for engaging therein the head of the first active element pin;
• in a stable closure operation, said cut-outs facilitating a narrowing of said cylindric pin of said second active element as said second active element is engaged in a hole of said a first active element cap, being counter-biased by a tightness edge of said hole of said first active element cap;
• wherein said first active element pin has a minimum diameter which is sufficiently smaller than a diameter of an inner axial hole of said second active element thereby leaving a space allowing said cylindric pin cross-section to be narrowed as said cylindric pin is caused to pass through the hole of the first active element;
• wherein said first active element is clamped to said first flap by a first clamping head, comprising a cap including a plurality of tip portions engaging in a corresponding seat formed on the first active element.