Abstract: A door lock includes a deadbolt assembly and a lock housing assembly. The deadbolt assembly has a bolt member which includes a metal inner sleeve, a metal outer sleeve fitted over the inner sleeve and made of a material which is different from that of the metal inner sleeve and which has anti-corrosion properties, and a security bar disposed axially in the inner sleeve. The lock housing assembly includes an exterior housing section with a cylindrical chamber that receives rotatably an exterior lock cylinder unit therein. The lock cylinder unit has a key-operated rotary plug with a rearwardly projecting spindle that is connected operably to the deadbolt assembly. An interior sleeve member is formed as a cylindrical wall with a front end which is secured to the rear side of the lock cylinder unit and a rear end which is formed with diametrically opposite notches. The deadbolt assembly extends through the sleeve member via the notches.

Abstract: Two first engagement members are formed on a first side of a transmission plate of a dual backset deadbolt assembly, while two second engagement members are formed on an opposite second side of the transmission plate posterior to the first engagement members. A first cam drive unit is retained rotatably in a first backset position relative to the transmission plate and is disposed adjacent to the first side. A second cam drive unit is movable between first and second backset positions relative to the transmission plate and is disposed adjacent to the second side. A deadbolt operating spindle of a lock extends through the first and second cam drive units so as to permit engagement of the first cam drive unit with one of the first engagement members in order to actuate the transmission plate when the second cam drive unit is in the first backset position and the deadbolt assembly is adjusted to a shorter backset length.

Abstract: A lock set for use with a deadbolt which includes an improved spindle mechanism is disclosed. The improved spindle mechanism permits the lock set to unlatch the deadbolt by rotating an inner knob without the need to operate a spindle-turning button.

Abstract: A code lock includes an intermediate bead seat, upper and lower bead seats, all of which are provided with tumbler bead holes receiving tumbler beads. The upper and lower bead seats are slidable relative to the intermediate bead seat between a normal position in which the bead holes of the upper and lower bead seats are aligned with first bead holes of the intermediate bead seat and a resetting position in which the bead holes thereof are aligned with second bead holes of the intermediate bead seat. The combination of the tumbler beads can be changed by using a code key which selectively transfers some tumbler beads from the first to the second bead holes.

Abstract: A latch bolt operating device incorporating lever handles and rotary plates cooperatively rotatable with the lever handles to control the angle of the rotation of the handles. The device is provided with a simplified privacy lock mechanism to prevent the opening of a door at one side thereof. The lock mechanism is directly mounted to the assembly of the lever handles, thereby eliminating the need of an additional housing to hold the mechanism. One of the rotary plates is provided with a cam face to actuate a lock shaft of the lock mechanism. The lock shaft is telescopic so that the device accommodates door panels of different thickness.

Abstract: An improved duplex latch-bolt mechanism is composed of a latch-bolt head assembly and a latch-bolt transfer device adapted to make a selectable connection with a standard latch-handle assembly having a square transfer member and a pair of cylindrical support nuts provided for use in a door fitting arrangement.

Abstract: In a lock handle assembly, a lever handle has a rotary shaft to actuate a deadbolt which latches a door. The angular movement of the lever handle is limited by a mechanism including a rotary plate having radially projecting engaging members and mounted on the shaft, a fixed stop member to limit the forward movement of the rotary plate and a releasable stop member to limit the backward movement of the rotary plate. The shaft of the handle is detachably mounted to a casing by being fitted in a sleeve which in turned is mounted to the casing, thereby facilitating the replacement of the handle of the assembly.