An inviolable system of hinged frames for opening doors and windows comprising a stable frame of a basic profile member and a movable frame of a sash profile member, said movable frame of the sash profile member hingedly attached onto said stable frame of the basic profile member and being provided with a cremone, said cremone being adapted to rotate with a scope of alternatively setting said hinged frames in a locked condition and an unlocked condition, wherein said movable frame of the sash profile member having a first groove adapted to receive a locking profile member in each one of four sides thereof when said hinged frames are brought in an unlocked condition; said stable frame of the basic profile member having a second groove adapted to host said locking profile member in each one of four sides thereof when said hinged frames are brought in a locked condition; said locking profile member being a Π-section member that is inserted within said first groove along each one of four sides of said movable frame of the sash profile member, first accessories being adapted to move said locking profile member from an unlocked condition in which said locking profile member is fully inserted within said first groove of said movable frame of the sash profile member to a locked condition in which it is being extended outwardly thereof and into said second groove of said stable frame of the basic profile member and vice versa, said first accessories being provided with lateral projections adapted to slide within said first groove of said movable frame of the sash profile member, said first accessories having a slope in the direction of movement thereof within said first groove of said movable frame of the sash profile member, said Π-section member being provided with inclined cuts wherefrom material has been removed, said inclined cuts having an inclination similar to the slope of said first accessories, said first accessories being adapted to push said locking profile member to the locked condition or restore it to the unlocked condition during corresponding rotation of said cremone that sets said hinged frames in the locked and the unlocked condition respectively; a second accessory with a through bore being mounted at each one of four corners of said movable frame of the sash profile member, each said second accesory being adapted to restrict lateral movement of said locking profile member; said cremone being connected by means of a pin to a main motion transmission accessory that converts rotation of said cremone to linear motion, said main motion transmission accessory being provided with lateral projections adapted to slide within said first groove of said movable frame of the sash profile member, one end of a drive belt being fixedly mounted within a hole at a first end of said main motion transmission accessory, said drive belt being driven along the perimeter of the movable frame of said sash profile member, passing freely through the through bore of each one of said second accessories at each one of the four corners of the movable frame of said sash profile member and the drive belt being fixedly connected with first accessories, the other end of said drive belt being fixedly mounted within a hole at a second end of said main motion transmission accessory, said first accessories being provided with a through bore wherein passes said drive belt, each one of said first accessories being securely attached to said drive belt by means of a screw passing through a hole thereof, wherein said hinged frames are being set at a locked condition when said locking profile members extend outwardly said first groove of said movable frame of the sash profile member and are being inserted within said second groove of said stable frame of the basic profile member, whereby said movable frame of the sash profile member is being embodied within said stable frame of the basic profile member circumferentially around said hinged frames.