A cylinder lock comprises a cylinder housing (11) and a cylinder core (13) which is rotatably mounted in the cylinder housing. A plurality of plate tumblers (21) are provided in the cylinder core, wherein each of the plurality of plate tumblers is movable between a locking position and an unlocking position. At least one of the plurality of plate tumblers has a bolt-receiving depression (47). The cylinder lock further comprises at least one bolt element (27) which has a bolt tip (35), wherein the bolt element is movable between a blocking position and a release position. In the release position, the bolt tip engages in the bolt-receiving depression of the plate tumbler. The plate tumbler has, adjacent to the bolt-receiving depression, at least one bolt latch-in depression (45) in which the bolt tip of the bolt element engages in a latching manner when the at least one plate tumbler is moved out of the unlocking position, wherein the bolt latch-in depression is less deep than the bolt-receiving depression.

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 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 disc tumbler lock assembly includes a lock cylinder inserted in a lock cylinder chamber of a lock housing, the lock cylinder being formed with a disc cavity and a lug groove; inner locking discs each having a first key hole with a first locking tooth therein, a side of each inner locking disc being formed with a first latch notch and a first lug located in the lug groove; outer locking discs each having an inner locking disc room and a second key hole with a second locking tooth therein, a side of each outer locking disc being formed with a second latch notch and a second lug located in the lug groove; the inner and outer locking discs being arranged in pairs, a corresponding one of the inner locking discs being disposed in the inner locking disc room of a corresponding one of the outer locking discs.

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 key including at least one coding cavity (55) defining a hollow geometry for coding the key. The geometry includes at least one internal undercut (60a, 60b). The lock for validating a key comprises blocking means (21, 22) coupled to a driving part (14) and validating means (25, 26) which are coupled to the blocking means so as to change the state of the blocking means when the key used with the lock has a correct coding. The validating means (25, 26) protrude at least partially into the key cavity of the lock in order to introduce the validating means at least partially into the coding cavity (55) of the key and to sense the inner face of the coding cavity.

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 method for mutually controlling and unlocking a dual plug in a lock includes: unlocking a code of a first plug first, the first plug restricting unlocking of a second plug, the second plug restricting rotating of the first plug before the code of the first plug is unlocked. after unlocking the code of the first plug, the first plug translating to a second position from a first position using a preset position difference, the first plug being unable to rotate during the translation; after moving the first plug to the second position, the first plug releasing a restriction on the second plug, the second plug still restricting the rotating of the first plug; and unlocking the code of the second plug, the first plug and the second plug being able to rotate synchronously so as to unlock the lock after unlocking the code of the second plug.

A key or a key blank for a disk cylinder having a plurality of rotatably supported disk tumblers has a key shaft having a shaft cross-section that comprises a first end section, a second end section and a connection section along a longitudinal axis, said connection section connecting the first end section and the second end section to one another. The connection section is narrower than the two end sections and has two longitudinal edges that are aligned in parallel with one another and that extend obliquely to the longitudinal axis of the shaft cross-section between the two end sections.