Backward compatible lock system, key blanks and keys therefor

摘要

A cylinder and key combination including a pin operated cylinder including a cylinder body, a plug rotatable within the cylinder body and defining a keyway and first pin assemblies and at least one second pin assembly communicating with the keyway and being selectably positionable by key cuts on a key inserted into the keyway for positioning the pin assemblies with respect to a shear line between the cylinder body and the plug to permit rotation of the plug with respect to the cylinder body and a key, including a shank defining at least one planar surface configured to define a longitudinally extending key-cut region thereon, the longitudinally extending region having formed thereon a plurality of first key cuts configured to position a plurality of first pins at a desired shear line position and having pre-formed thereon at least one second key cut configured to position a corresponding at least one second pin assembly at a desired shear line position.