An interchangeable cylinder lock core with a mechanism for transferring a torque to a lock unit when a key plug is rotated. The interchangeable cylinder lock core includes a shell having an upper part, provided with a central row of locking pins in associated cavities, and a lower part with a cylindrical bore accommodating the rotatable key plug. At least a part of the cylindrical bore extends through a rotatable retainer sleeve. A back region of the key plug has a minimum length with the adjoining front region of the key plug being located in front of the mechanism for transferring torque. The adjoining front region accommodates, in addition to the central row of locking pins, at least one side locking mechanism which is located in its entirety within the front region of the key plug and interacts with at least one recess in a fixed front end sleeve portion.

A plug assembly including a plug, a sidebar movably mounted on the plug, and a plurality of rack pins seated in the plug. The sidebar is biased to an outer position in which the sidebar extends beyond an outer surface of the plug. Each rack pin is a single-piece unitary structure including a key-following leg and a sidebar-engaging leg. The sidebar-engaging leg includes at least one true gate and a plurality of false gates. When a true gate of each rack pin is aligned with the sidebar, the sidebar is free to move radially inward to an inner position.

A key or key blank includes a key blade having a first edge, a second edge, and first and second opposed sides. The first edge has one or more edge bittings to elevate and/or rotate one or more tumbler pins of a lock with a vertically-oriented keyway, and one of the opposed sides has one or more side bittings to elevate and/or rotate one or more tumbler pins of a lock with a horizontally-oriented keyway. Side warding surfaces on the key blank are shaped and positioned to minimize the interference of peaks between the skewed bitting cuts on the key. A lock has a keyway configured for the key having edge bittings to elevate and/or rotate one or more tumbler pins of a vertical lock and side bittings to elevate and/or rotate one or more tumbler pins of a horizontal lock.

A plug assembly including a plug, a sidebar movably mounted on the plug, and a plurality rack pins seated in the plug. The sidebar is biased to an outer position in which the sidebar extends beyond an outer surface, of the plug. Each rack pin is a single-piece unitary structure including a key-following leg and a sidebar-engaging leg. The sidebar engaging leg includes at least one true, gate and a plurality of false gates. When a true gate of each rack pin is aligned with the sidebar, the sidebar is free to move radially inward to an inner position.

A key or key blank includes a key blade having a first edge, a second edge, and first and second opposed sides. The first edge has one or more edge bittings to elevate and/or rotate one or more tumbler pins of a lock with a vertically-oriented keyway, and one of the opposed sides has one or more side bittings to elevate and/or rotate one or more tumbler pins of a lock with a horizontally-oriented keyway. Side warding surfaces on the key blank are shaped and positioned to minimize the interference of peaks between the skewed bitting cuts on the key. A lock has a keyway configured for the key having edge bittings to elevate and/or rotate one or more tumbler pins of a vertical lock and side bittings to elevate and/or rotate one or more tumbler pins of a horizontal lock.

A lock assembly includes a plug with a keyway, primary pins aligned with the keyway for controlling rotation of the plug, a sidebar for controlling rotation of the plug, secondary pins adjacent the keyway for controlling movement of the sidebar, and at least one supplemental sidebar control element for controlling movement of the sidebar. The lock assembly is operated by simultaneously manipulating the primary pins, the secondary pins, and the supplemental sidebar control element to place each in a respective position and/or orientation to permit rotation of the plug and to permit sufficient movement of the sidebar to permit rotation of the plug and then applying torque to the plug.

A lock set comprising a cylinder lock having a stator and a rotatable member rotatable in the stator and having a key slot and at least one side; a security element with protrusions, pivotally connected to the rotatable member; and one or more fitting keys, each having one or more recesses and one or more extensible members. The distances between the protrusions of the security element correspond to locations of the recess(es) and extendible member(s) of the fitting key for engagement therewith, such that using the fitting key will have the security element positioned in a non-obstructing position allowing free rotation of the rotatable member in the stator and using an unfitting key will cause a portion of the security element to protrude from the outer wall of the rotatable member engaging the inner wall of the stator thereby preventing rotation of the rotatable member in the stator.

The present invention provides a key blank and a key set. The key blank includes one or more telescopic members inserted through corresponding one or more channels of the key shank for fitting to release a security mechanism of a lock unit. The lock set has one or more fitting keys and a lock unit including: a stator; a rotor; a first locking mechanism; and an additional security mechanism including one or more wafer units. The key shank has one or more telescopic members each inserted in a channel perforated in the key shank. The wafer unit of the security mechanism is located and configured for engaging an edge of the telescopic member when the fitting key is used, such that each telescopic member will move the respective wafer unit it engages for releasing the additional security mechanism for allowing the rotor to rotate in the stator.