Keys and corresponding key assemblies

Key comprising a bow and a blade to take the signature pattern which is a longitudinal extension of said bow, projecting beyond a shoulder formed by a neck between the bow and the blade, said blade having a signature pattern specific to the key resulting from a combination of different bittings,

• in which the blade designed to take the signature pattern comprises at least two interchangeable blade elements each of which has its own particular bitting and are mounted by inserting them one into the other along a central shaft which is common to all of them and is fixed inside the bow or handle of the key,
• said blade also comprising a fixed distal element which is integral with said shaft at its free end opposite said bow and has a locksmith's key code that is specific to a particular set of keys to be produced with signature patterns all comprising the same locksmith's key code but being differentiated by the bittings on the interchangeable blade elements to be mounted on the shaft.