THUMB-OPERATED MULTILATCH DOOR LOCK

A multipoint lock assembly for securing a door that is hinged along one edge and that has a free, swingable edge opposite the hinged edge. The assembly includes a central latch and at least one remote latch vertically spaced therefrom along the free edge of the door. The retraction of all the latches is controlled by a central latch driving mechanism in response to a manual operation either of an exterior thumb-operated latch lever or of an interior doorknob. A deadbolt is also located proximate the central latch. The deadbolt is controlled either by an externally accessed cylinder lock in response to a manual insertion and rotation of a key or by a manual rotation of an interior-mounted thumb-turn. While the deadbolt is extended, the thumb-operated latch lever and the doorknob are inoperable. At least one of the latches includes a latch trigger. This is tripped when the door is closed, allowing the latch of which it is a part to assume a superextended position. When in this position the latch cannot be forced into its retracted position unless the thumb-operated latch lever or the doorknob has been operated.