Cylinder lock

A cylinder lock comprising:

• a housing;
• a plug disposed in the housing and arranged for rotation relative thereto;
• a first plurality of chambers formed in the housing;
• a second plurality of chambers formed in the plug and arranged such that each one of the first plurality of chambers extends coaxially with a corresponding one of the second plurality of chambers, when the plug is in a first rotational orientation relative to the housing;
• a first multi-element pin assembly disposed in said first plurality of chambers;
• and
• a second multi-element pin assembly being disposed in said second plurality of chambers;
• said first multi-element pin assembly comprising:
• an outer pin element having an axial recess, said outer pin element having a forward end facing said plug and a rearward end;
• an inner pin element disposed for selectable axial orientation relative to the outer pin element, said inner pin element having a forward end facing said plug and a rearward end;
• and
• means for retaining the inner pin element against disengagement from and undesired misalignment with respect to the outer pin element, said means for retaining being operative to permit the forward end of said inner pin element to be disposed either substantially outwardly or inwardly of the substantially forward end of the outer pin element, thereby to permit independent positioning of the forward ends of said inner and outer pin elements within said first plurality of chambers.