Abstract: A lock for a sliding door or window including a latching linkage and an inner manual lever, that allows movement of the latching linkage between a locked and an unlocked position by means of the manual lever and by operation of a inside or outside key barrel, but also allows deadlocking of the latching linkage in its locked position so that operation of the manual lever to unlock the latching linkage is prevented. It is however, desirable that the lock be operable to lock the lock from the inside by a convenient operation of the manual lever when the user is inside the house. It is further desirable that the door is able to be deadlocked by a key from the inside or the outside in a manner that prevents unlocking of the door by the manual handle, since a house owner may find it inconvenient to have to walk around the outside of their house locking the doors.

Abstract: A lock for a sliding door or window including a latching linkage and an inner manual lever, that allows movement of the latching linkage between a locked and an unlocked position by means of the manual lever and by operation of a inside or outside key barrel, but also allows deadlocking of the latching linkage in its locked position so that operation of the manual lever to unlock the latching linkage is prevented. It is however, desirable that the lock be operable to lock the lock from the inside by a convenient operation of the manual lever when the user is inside the house. It is further desirable that the door is able to be dead-locked by a key from the inside or the outside in a manner that prevents unlocking of the door by the manual handle, since a house owner may find it inconvenient to have to walk around the outside of their house locking the doors.