A rekeyable lock includes a lock casing formed with a lock cylinder hole, a pin replacing hole and a plurality of first pin holes; a lock cylinder rotatably arranged in the lock cylinder hole and formed with a plurality of second pin holes; a pin set including a plurality of first pins respectively accommodated in the first pin holes, and a plurality of second pins respectively accommodated in the second pin holes; and a pin cover arranged in the pin replacing hole and including a cover body formed with a groove, and a sliding block arranged in the groove and slidable relative to the cover body. When the sliding block is located at a predetermined position, the sliding block and the cover body are configured to respectively abut against an inner wall of the lock casing to fix the pin cover in the pin replacing hole.

A lockset includes a lock cylinder, a lock casing, a first lock member, a second lock member and an anti-theft member. The lock cylinder includes a key hole and a first lock slot. The lock casing includes a second lock slot. The first lock member is accommodated in the first lock slot. The second lock member is accommodated in the second lock slot. The anti-theft member is sandwiched in between the first lock member and the second lock member. When two ends of the anti-theft member are respectively located in the first lock slot and the second lock slot, the lock cylinder and the lock casing are locked. When a contact surface between the anti-theft member and the first lock member or the second lock member is aligned with a rotation interface between the lock cylinder and the lock casing, the lock cylinder and the lock casing are unlocked.

An apparatus for selectably unlocking a door comprises a base adapted to be mounted within a door, an outer cylinder selectably rotatable relative to the base, the outer cylinder having an central bore therethrough and an inner cylinder selectably rotatably received within the inner bore of the outer cylinder. The inner cylinder has a key slot therethrough and is adapted to unlock a door upon rotation of the inner cylinder. The apparatus further includes a plurality of tumblers extending between the inner and outer sleeves alignable upon insertion of a specific key within the key slot so as to permit rotation of the inner cylinder within the central bore a means for identifying a key inserted within the key slot as an authorized key and a latch operable to selectably couple the outer cylinder to the base wherein the latch uncouples the outer cylinder from the base when an authorized key is located within the key slot.

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.

Lock assemblies having cylinders with interchangeable cores are provided. In one embodiment a lock assembly comprises a cylinder including a keyway and a core. Also, the lock assembly includes a first driver operatively connected to the cylinder. In particular, key cuts of the core are changeable without removing the cylinder from the driver.

A rekeyable lock cylinder with a cylinder body and a plug assembly. The lock cylinder includes a plurality of key followers and a corresponding plurality of racks disposed in the plug assembly. The lock cylinder includes, for example, a locking bar for blocking rotation of the plug assembly with respect to the cylinder body to prevent unlocking of the rekeyable lock cylinder with an unauthorized object. In some embodiments, the locking bar is configured such that torqueing the plug assembly with an unauthorized object applies force to the locking bar without translating such force to the plurality of racks. This type of arrangement enhances torque resistance of the lock cylinder against attempted forced entry.

A rekeyable lock cylinder with a cylinder body and a plug assembly. The lock cylinder includes a plurality of key followers and a corresponding plurality of racks disposed in the plug assembly. Disengaging the racks from the key followers allows rekeying of the lock cylinder.

A lock includes a lock casing having a lock cylinder hole, a pin replacing hole and a plurality of first pin holes; a lock cylinder rotatably arranged in the lock cylinder hole and formed with a plurality of second pin holes; a pin set including a plurality of first pins respectively accommodated in the first pin holes, and a plurality of second pins respectively accommodated in the second pin holes; an outer casing having an inner wall defining an accommodation space for accommodating the lock casing; and a pin plug including a main body having a first side abutting against the lock casing and a second side abutting against the inner wall, and a protruded block protruded from the first side for closing the pin replacing hole. The second side is opposite to the first side, and a shape of the second side corresponds to the inner wall.

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 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.