Abstract: A dual backset deadbolt assembly comprises a deadbolt mounted in a deadbolt housing for movement to a locking position or an unlocking position, an extension housing having two parallel side walls which are provided with two cam guide slots located at two different backset distances, a transmission plate means having a front engaging member to connect with the deadbolt and a rear forked portion, the rear forked portion having two rearwardly extending strip members and an elongated opening between the strip members, the strip members having at least one pair of engagement members, the engagement members being formed respectively on the strip members, a single cam member mounted in the extension housing and having at least one spindle slot to be put in an alignment with at least one of the cam guide slots, the cam member having at least one pair of camming members which can engage with the engagement members to actuate the transmission plate.

Abstract: A dual backset deadbolt assembly to be associated with a lock having a rotatable cylinder which has two axially extending crank members for actuating a deadbolt to move in two opposite directions, wherein the deadbolt assembly comprises a deadbolt housing holding a deadbolt, a rear extension housing having two side plates with aligned crank holes therein, a transmission plate having a front end engaging with the deadbolt, and two independently movable axial strip members slideably provided between two side plates on either side of the crank holes provided in the side plates, the strip members being connected to the rear forked portion of the transmission plate and having a plurality of teeth each extending into each crank hole, the strip members being selectable for cooperation with the operative crank member by the engagement of one of the teeth and the operative crank member.

Abstract: A dual backset latch bolt assembly includes at least one pair of cam members mounted on at least one side plate of a latch housing. The latch bolt assembly is provided with positioning holes and engaging notches so that the assembly can be used in combination with a lock having either positioning female screws or guide plates for attachment. The latch bolt assembly may be arranged such that two pairs of cam members are mounted respectively on two side plates of the housing, thereby permitting the latch assembly to cooperate with a lock having either a single rotary spindle or two rotary spindles which are respectively associated with two parts of the lock operable from the outside and inside of a door.

Abstract: The invention relates to improvements for an adjustable dead bolt assembly which includes an adjustable bolt extension member connected to a bolt and an extension housing connected to a bolt casing for accommodating the bolt extension member, wherein the bolt is provided with a uniform height and width throughout the length of the bolt for reducing the cost of the material and simplifying the processing steps.

Abstract: A cylinder lock which includes pin-tumblers to lock a cylinder against rotation relative to a housing, wherein the pin-tumblers and tumbler bores are arranged such that the axes thereof lie in different parallel longitudinal planes normal to a diametrical plane of the cylinder and each tumbler bore receives a plurality of pin-tumblers.

Abstract: The mechanism is used with a latch-bolt unit (including a latch-bolt head) and a latch-handle assembly, for installation in a door. The novel mechanism includes a retracting member (connected to retract the latch-bolt head), with two different sets of extracting teeth to accommodate two different standard door-lock backset configurations of standard commercial doors. A connecting device, made up of first and second coupling members as well as a movable configuration-selector plate, is connected at the rear of the latch-bolt unit. The connecting device has two different sets of screw openings and clearing spaces. Its selector plate selectively effectuates either of these two different sets of connecting points, corresponding to the two standard backsets. The selector plate is thus used to adjust the latch-bolt mechanism quickly and easily, to accommodate the preferred door-lock backset--without any modification such as cutting or bending.

Abstract: An improvement for a dead bolt assembly having a dead bolt mounted movably in a bolt casing and a crank plate mounted in an extension housing at the rear side of the bolt casing to move the dead bolt upon actuation of a lock, comprises an adjustable bolt extension member which has a fixed plate member and an extensible channel member pivoted to the fixed plate member, and a crank plate mounting means which is mounted movably in the extension housing to hold the crank plate in a movable position so that the crank plate can be kept in a cooperative relationship with the extensible member.