Electromagnetic door lock system

An electromagnetic door lock system configured for use with a door mounted in a door frame, the door having substantially parallel exterior and interior door surfaces defining a door volume therebetween, the door further having a hole therein extending from the interior door surface into the door volume, comprising:

• an electromagnet configured to be affixed to the door frame for electromagnetically attracting an armature;
• an armature mounting device further comprising:
• a first member configured for being affixed to said door, said first member having an axis normal to said exterior and interior door surfaces, and said first member being disposed at least partially within said door volume through said door volume through said hole in the door when mounted therein;
• a second member retained by said first member, said second member being configured so as to be moveable along said axis such that said second member moves within the door volume to allow opening movement of the door when the armature is held adjacent the electromagnet;
• and
• a bias member disposed within said first member configured for biasing said second member toward said exterior door surface;
• an armature affixed to said second member configured to be adjacent said interior door surface;
• a sensor configured to be mounted to the door frame for detecting movement of the door;
• and
• a controller configured for de-energizing the electromagnet at an egress time after the sensor senses said door movement, the first, second and bias members being configured to cooperate to allow opening movement of the door when the armature is held to the electromagnet.

An electromagnetic door lock system for a door having interior and exterior faces and being mounted in a door frame, comprising:

• an electromagnet configured to be mounted to the door frame;
• an electromagnet armature mountable on the door and cooperating with the electromagnet to provide a locking action when the electromagnet is energized;
• an electromagnet armature door mounting device configured for allowing predetermined limited outward movement of the door when said armature is held against said electromagnet, further comprising:
• a hollow shaft adapted for mounting to a door in a position disposed within the door, the hollow shaft defining an opening adjacent an interior face of the door and an inwardly extending lip;
• a plunger retained within the hollow shaft and configured to be engageable with the armature, said plunger having a head, and said plunger being configured to be moveable within a volume defined by the door when the device is mounted to the door in a direction normal to the interior face of the door, movement of the plunger with respect to the hollow shaft allowing the door to be moved outwardly a predetermined limited distance while said armature is held against said electromagnet, said inwardly extending lip and the head of the plunger acting to limit door movement;
• a sensor configured for sensing opening of the door when the door is opened the predetermined limited distance.

An electronic door lock system for a door mounted in a door frame of the type where an electromagnet is mounted to the door frame and an electromagnet armature is mounted to the door, comprising:

• an electromagnet;
• an armature for cooperating with said electromagnet;
• a sleeve having first and second ends and configured for mounting in a door between the interior and exterior surfaces of the door, the sleeve including an inwardly extending lip positioned adjacent the first end of the sleeve, said first end being configured to be positioned adjacent the interior surface of the door when the sleeve is mounted therein;
• a plunger disposed in the sleeve, the plunger having a first end configured for connection to the electromagnet armature and a second end, and including a head adjacent the second end, the head and the lip cooperating to limit movement of the plunger relative to the sleeve;
• and
• the sleeve and plunger being configured for limited relevant movement, such that when the sleeve and plunger are mounted in a door with an electromagnet plunger attached to the plunger the plunger is moveable in a direction substantially normal to the interior face of the door, whereby the electromagnet armature door mounting device allows substantial opening movement of the door while the electromagnet armature is held against the electromagnet.

An emergency exit door lock system configured for use with a door mounted in a door frame, the system being configured for sensing when a person attempts to open said door, and for allowing said door to open after a subsequent delay, the system comprising:

• a magnetic lock configured for preventing said door from opening, said lock including an electromagnet configured to be mounted on said door frame and an armature configured to be mounted on said door facing said electromagnet;
• an inertia absorbing elastically deformable connection at least partially housed within said door and configured to mount said armature on said door, said connection allowing a predetermined limited movement of said door relative to said armature and biasing said armature and said door toward a first relative position adjacent one another, said connection including lost motion arrangements connected to the armature and coupled to said door when the connection is mounted thereto and an elastic biasing member at least partially housed within said door and configured for resisting relative movement between the lost motion arrangements and said door to which said elastic biasing member is configured to be mounted, the connection allowing relative movement of said door and the armature against resistance provided by the elastic biasing member;
• a sensor configured to be mounted to said door frame for sensing when said door has been urged by an external force away from said fully closed position to an activation position;
• a controller coupled to said sensor, the controller being configured to provide an alarm signal in response to operation of said sensor sensing when said door has been moved away from said fully closed position to an activation position, and for providing a door unlock signal to de-energize said electromagnet at the end of a predetermined egress delay period;
• and
• said system including arrangements for blocking access to said connection to preclude tampering with or interference with the delayed opening of said door.

An emergency exit door lock system configured to cooperate with a door mounted in a door frame, the system being configured for sensing when a person attempts to open said door, and for allowing said door to open after a subsequent delay, the system comprising:

• a magnetic lock configured for preventing said door from opening, said lock including an electromagnet configured to be mounted on said door frame and an armature configured to be mounted on said door facing said electromagnet;
• an inertia absorbing elastically deformable connection at least partially housed within said door and configured to mount said armature on said door, said connection allowing a predetermined limited movement of said door relative to said armature and biasing said armature and said door toward a first relative position adjacent one another, said connection including a plunger at least partially housed within said door, connected to the armature, and configured for extending into said door when the connection is mounted thereto and an elastic biasing member configured for resisting relative movement between the plunger and said door in which said elastic biasing member is configured to be mounted, the connection allowing relative movement of said door and the armature against resistance provided by the elastic biasing member;
• a sensor configured to be mounted to said door frame for sensing when said door has been urged by an external force away from said fully closed position to an activation position;
• a controller coupled to said sensor, the controller being configured to provide an alarm signal in response to operation of said sensor sensing when said door has been moved away from said fully closed position to an activation position, and for providing a door unlock signal to de-energize said electromagnet at the end of a predetermined egress delay period;
• and
• said system including:
• a hollow shaft for extending at least substantially through said door, said plunger being mounted within said hollow shaft, and said elastic biasing member constituting a coil spring configured for mounting wholly within said hollow shaft, said coil spring being mounted on said plunger, said plunger having a head thereon at the end thereof away from said armature, and said spring being confined between the head of said plunger and a stop included within said hollow shaft;
• whereby said door may move a substantial distance while the armature is in engagement with the electromagnet.