ELECTROMAGNETIC LOCK HAVING DISTANCE-SENSING MONITORING SYSTEM

• US 20100218569A1
• Filed: 03/02/2009
• Published: 09/02/2010
• Est. Priority Date: 03/02/2009
• Status: Active Grant

• Current Assignee: Hanchett Entry Systems Incorporated (Assa Abloy AB)
• Original Assignee: Hanchett Entry Systems Incorporated (Assa Abloy AB)
• Inventors: Hunt, Robert C., Roth, Thomas Edward
• Granted Patent: US 8,820,803 B2
• Time in Patent Office: Days
• US Class Current: 70/263
• CPC Class Codes: E05B 43/005 Timer devices controlling electrically operated locks
• CPC Class Codes: E05B 65/108 Electronically controlled emergency exits
• CPC Class Codes: E05C 19/166 electromagnetic
• CPC Class Codes: Y10S 292/65 Emergency or safety
• CPC Class Codes: Y10T 292/11 Magnetic
• CPC Class Codes: Y10T 70/625 Operation and control
• CPC Class Codes: Y10T 70/7028 Electric
• CPC Class Codes: Y10T 70/7057 Permanent magnet

Abstract

An emergency exit door lock system configured to cooperate with a door hinged in a door frame for sensing when a person attempts to open the door, and for allowing the door to open after a subsequent delay. The system comprises an electromagnet affixable to a door frame for electromagnetically attracting an armature resiliently affixed at a variable armature separation distance to an armature mounting device, the device being affixable to the door. A proximity sensor including an analog Hall Effect device is mountable to the frame for detecting movement of the door away from a closed position. A controller, such as a micro-controller, receives a signal from the sensor and causes an alarm as a function of the signal. The signal is indicative of the armature separation distance, the controller being calibrate-able to provide a door alarm signal and door opening signal at any desired value of the armature separation distance.

Claims

1. A door lock system configured to cooperate with a door movable in a door frame, the system being configured for sensing when a person attempts to open said door in locked mode, and for allowing said door to become unlocked after a subsequent delay, the system comprising:

a) an electromagnet configured to be affixed to one of said door and said door frame for electromagnetically attracting an armature, said armature resiliently affixed to the other of said door and said door frame;

b) a sensor configured to be mounted to one of said door and said door frame for detecting movement of said door away from a closed position; and

c) a controller configured for receiving a signal from said sensor and for providing an output signal to occur as a function of said signal;

wherein said sensor includes an analog Hall Effect device.

2. A door lock system in accordance with claim 1 wherein said electromagnet is configured to be affixed to said door frame and said armature is resiliently affixed to said door.

3. A door lock system in accordance with claim 2 wherein an armature mounting device is affixed to said door and said armature is resiliently affixed to said armature mounting device.

4. A door lock system in accordance with claim 1 further comprising a permanent magnet configured for interacting with said sensor and mounted to the other of said door and said door frame.

5. A door lock system in accordance with claim 4 configured to provide a first sensor separation distance between said sensor and said permanent magnet when said door is in a closed position and a second sensor separation distance when said door is moved from said closed position wherein said sensor is configured to send a signal to said controller indicative of an instantaneous sensor separation distance over a range of separation distances between said first sensor separation distance and said second sensor separation distance, said sensor separation distances being proportional to distances between said door and said door frame as said door is moved from said closed position.

6. A door lock system in accordance with claim 5 wherein said output signal provided from said controller is an alarm signal calibrated to correlate to a predetermined sensor separation distance.

7. A door lock system in accordance with claim 1 wherein said signal from said sensor to said controller is continuous.

8. A door lock system in accordance with claim 5 wherein said controller output signal correlates said sensor signal to said sensor separation distance.

9. A door lock system in accordance with claim 5 wherein said output signal correlates said sensor signal to an instantaneous distance between said door and said door frame as said door is moved from said closed position.

10. A door lock system in accordance with claim 1 wherein said controller is further configured to deactivate said electromagnet at a predetermined time after said sensor senses door movement.

11. A door lock system in accordance with claim 10 wherein said door movement is indicative of a desired door/frame gap.

12. A door lock system in accordance with claim 11 wherein said desired door/frame gap is in the range of about 0.125 inch (0.32 cm) to about 1 inch (2.54 cm).

13. A door lock system in accordance with claim 1 wherein said controller is a micro-controller.