Abstract: It is required for a door to attach a door key assembly for the sake of caution and locking. The door key assembly to be attached to a door opposed to a door frame comprises a key body secured to an end face of the door and provided with a dead bolt and a fixing plate secured inside the door frame so as to oppose to the end face of the door. The fixing plate is provided with a vertically elongated recess having an opening facing the end face of the door and having a narrow portion and a groove formed on one side of the narrow portion. The recess and the groove are arranged vertically side by side so as to communicate with each other through a vertically elongated window portion.

Abstract: A door locking mechanism which comprises a key body to be secured to the hem of a door, a slide key slidably mounted in the key body, the head of the slide key being protrudable out of the key body toward a door frame upon rotation of a locking knob so as to be shifted to its half-locked and complete-locked positions, a key latch to be secured to the door frame, and a half-locking arm anchored to the key latch and provided with an opening to receive the head of the slide key,wherein a pair of inlets are formed on the slide key and one of a pair of pins provided on the locking knob selectively engage one of the pair of inlets on the slide key to force the slide key to slide toward the door frame upon rotation of the locking knob, and a slide plate is vertically slidably mounted inside the key body and biased to hold the pins of the locking knob in a position where the pins disengage with the one of the inlets on the slide key, the slide plate being provided with means for positioning the slide key to its unloc