A lock for pick prevention includes a set of cylinder pins aligned in a row in a cylinder. A first set of security pins are in a first carriage assembly. The security pins are aligned to a keyed displacement in cooperation with the set of cylinder pins. A second carriage assembly is positioned angularly displaced from the position of the first carriage assembly. One of the second set of security pins is aligned to the same keyed displacement as a corresponding one of the first set of security pins. An obstructive device is coupled to the second set of security pins, which is disposed to obstruct the cylinder from reaching an unlocked position in the event, a displacement of the second set of security pins does not align with the same keyed displacement as the first set of security pins.

A trapped key interlock system is disclosed. A pair of hollow tubular casings located one inside the other and each having a series of elongate slots are used. When the lock is in a locked condition the elongate slots are aligned as inner and outer pairs with engaging members extending through the pairs of slots is preventing rotational movement of the tubular casings relative to each other. The engaging members are biased towards this locked condition. On insertion of the correctly coded key the engaging members are caused to move against the biasing force out of engagement with the slots in the outer tubular casing thereby allowing the inner tubular casing to rotate relative to the outer tubular casing and moving the lock to an unlocked condition.

A rekeyable master keyable lock includes a plurality of key followers, a plurality of user racks and a plurality of master racks. One user rack and one master rack are associated with each key follower and are configured to be selectively disengaged from, and reengaged with, the key follower. When the user racks are disenggaged from the key follower, the valid user key can be replaced with a new user key. Reengaging the user racks with the key followers rekeys the lock cylinder to the new user key and invalidates the original user key. Similar functionality applies to rekeying the master key. Either the user key or the master key can be rekeyed without rekeying the other.

The present disclosure provides for a lock cylinder having a rotatable spindle with at least one disc and at least one wafer housing rotatingly engaged therewith. A slidable wafer is carried on the wafer housing. A locking bar is operable to prevent rotation of the lock cylinder in a locked position and permit rotation of the lock cylinder in an unlocked position.

A bridge tumbler lock has tumblers that both slide and pivot, with their motion controlled by pairs of key interfaces. A sidebar is released to permit lock opening movement when all tumblers are in their correct positions. This results in a lock that is resistant to release of information due to partially correct key combinations occurring in the course of a lock picking attempt and thus enables enhanced security in an economical, effective lock construction.

A cylinder lock assembly includes a lock cylinder inserted into a cylindrical chamber of a lock housing, the lock cylinder being formed with plate mounting slots, a latch slot, and a main key slot; primary locking plates inserted in the respective plate mounting slots, each of the primary locking plates being formed with a secondary plate recess, a first key slot, and a first latch groove; secondary locking plates inserted in the respective secondary plate recesses, each of the secondary locking plates being formed with a second key slot and a second latch groove, springs being provided between the primary locking plates and the lock cylinder and between the secondary locking plates and the lock cylinder respectively; and a latch inserted into the latch slot, a latch return spring being provided between the latch and the lock cylinder.

A rekeyable master lock includes a plurality of pin gears, with each pin gear engaged with a corresponding key follower. As each key follower rides up and down on the key bitting, it causes a corresponding pin gear to rotate. Each pin gear engages a user gear and a master gear so that, as the pin gear rotates, the user and master gears rotate. Each user and master gear, in turn, drives a corresponding user rack and a master rack. When a valid user key is inserted and rotated, the user racks or master racks are aligned along a common axis and held in alignment by a locking bar. Longitudinal movement of the user gear or master gear allows the rekeying function by decoupling and recoupling the user gear or master gear with the user racks or master racks.

An exemplary locking cartridge includes a generally cylindrical housing, first and second plates, and a sliding member. The plates are rotatable with respect to the housing, and at least one of the plates is movable in the axial direction of the housing. The housing and the movable plate include cam surfaces that interact to cause the movable plate to move toward the other plate when the movable plate is rotated. The sliding member is slidingly coupled to one of the plates and operable in a blocked state in which the sliding member resists axial motion of the movable plate, and an unblocked state in which the sliding member does not resist axial motion of the movable plate.

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.