Abstract: A rotatable disc having a tubular lock assembly including a tubular sleeve and a number of disc tumblers located within the sleeve. A side locking bar is operative to prevent rotation of the assembly relative to a body, and that bar is rendered inoperative by insertion of a correct key into the lock keyway. The disc tumblers include a number of standard tumblers and a special tumbler. The locking bar is inoperative when each standard tumbler is at a service position of rotation and the special tumbler is at either a service position or a second function position of rotation. A service key is operable to place all tumblers at the service position, and a special change key is operable to place the special tumbler at the second function position to allow removal of the barrel assembly.

Abstract: The invention is concerned with a lock mechanism of the kind having a deadbolt (9) which is operable by either an inside actuator or an outside actuator. The inside actuator usually includes a turn knob or the like, and the outside actuator usually includes a key operated lock. The lock mechanism includes a gear train (8) through which each of the two actuators is drivably connected to the deadbolt (9). The gear train includes two drive gears (13, 14) which are independently rotatable about a common axis of rotation, and each is connected to a respective one of the two actuators so as to rotate in response to operation of that actuator. The gear train (8) also includes two driven gear (17, 18) which are united to form a single piece composite gear (16), and each driven gear (17, 18) is cooperable with a respective one of the two drive gears (13, 14).

Abstract: Latch assemblies are disclosed including a latch bolt mounted on a casing for relative movement between an extended latching position and a retracted release position, a first actuator operable from the inner side of the assembly to cause movement of the latch bolt to the release position, a lock operable from the inner side of the assembly to adopt an active condition thus render the first actuator inoperable, a second actuator operable from an outer side of the assembly to cause movement of the latch bolt to the release position, and a lock release responsive to operation of the second actuator to render the lock inactive.