Electromagnetic door lock device

摘要

The improvement as in an electromagnetic door lock device. The device includes an electromagnet which is secured to the underside of the top of door frame, and an armature connected to the top of a door hinged in the frame. The armature moves between a resting unlocked down position and a locking position in which the armature extends up toward the electromagnet being attracted thereto. When in that attracted position, the armature is intercepted by one or more tab plates depending from one or both of the opposite sides of the electromagnet so that the door cannot be opened. Deenergizing the electromagnet causes the armature to fall down to the unlocked position. The improvement includes a protrusion from one or both of the opposite sides of the armature, which protrusion fits within a notch on the underside of the tab plate to lock these two parts together. The tab plate may have adjustment slots for aligning the notch and protrusion. Moreover, the back of the tab plate and adjoining side thereof may be toothed and grooved to prevent inadvertent movement of the tab plate. In one embodiment, a separate locking plate secured to the electromagnet side above the tab plate has toothed surfaces which may be stepped facing toothed mating surfaces of the tab plate to hold the tab plate against movement. The teeth may be pointed or square in configuration.