Patent ID: 7412860

Claim:
A key blank for cutting to form a key to operate within a hierarchical lock system, the key blank having a bow connected to a generally flat-sided blade which has a top edge for cutting key bits therein, a bottom edge, and opposite sides for receiving grooves and ridges which define a cross-sectional shape of the key blade, wherein the blade is divided into three or more sections between the bottom edge and the top edge, and wherein the sections comprise: a first section having a registry groove for registering the key blade by holding the key blank in a reference position during machining; a second section having a groove that determines a primary family of a hierarchical lock system; and a third section having different formed configurations on opposite sides of the key blank blade, one side having only curved longitudinal grooves and ridges both defining a curvilinear profile which can be used to determine the secondary and subgroups of the hierarchical lock system, and the other side of the blade in the third section having grooves with only substantially rectangular or straight angular shapes which vary in depth into the side of the blade so that the position and depth of such grooves can determine the individual location in the subgroup of the hierarchical lock system.