Self-testing security sensor for monitoring closure of vault doors and the like

• US 5,633,626 A
• Filed: 08/29/1995
• Issued: 05/27/1997
• Est. Priority Date: 08/29/1995
• Status: Expired due to Fees

• Current Assignee: United States Department of Energy
• Original Assignee: United States Department of Energy
• Inventors: Cawthorne, Duane C.
• Primary Examiner(s): Mullen, Thomas
• Assistant Examiner(s): Lee, Benjamin C.
• Application Number:
  US08/520,634
• Time in Patent Office: 637 Days
• Field of Search: 340/545, 340/546, 340/547, 340/514, 340/515, 340/516, 340/541, 340/551, 335/206, 335/207, 335/205, 116/12, 116/25, 116/85, 116/86, 116/100, 49/13, 49/14, 200/61.62, 200/61.93
• US Class Current: 340/545.1
• CPC Class Codes: G08B 13/08 by opening, e.g. of door, of window, of drawer, of shutter, of curtain, of blind

Abstract

A self-testing device is provided for a monitoring system for monitoring whether a closure member such as a door or window is closed. The monitoring system includes a switch unit mounted on the frame of the closure member being monitored and including magnetically biased switches connected in one or more electrical monitoring circuits, and a door magnet unit mounted on the closure member being monitored. The door magnet includes one or more permanent magnets that produce a magnetic field which, when the closure member is closed, cause said switches to assume a first state. When the closure member is opened, the switches switch to a second, alarm state. The self-testing device is electrically controllable from a remote location and produces a canceling or diverting magnetic field which simulates the effect of movement of the closure member from the closed position thereof without any actual movement of the member.

Claims

1. A self-testing security device and monitoring system for closure monitoring, comprising:

a) a switch unit adapted to be mounted on a frame part for a moveable panel being monitored and comprising at least one magnetically biased switch connected to at least one electrical monitoring circuit, said switch unit switchable between first and second states;

b) a magnet means adapted to be mounted on the moveable panel being monitored, said magnet means comprising at least one magnet for enabling said switch unit to assume said first state when said moveable panel is closed with respect to said frame part and for causing said switch to assume said second state when said moveable panel is opened with respect to said frame part;

c) a self-testing means for magnetically simulating the effect of movement of the moveable panel from the closed position to the open position without any actual movement of said moveable panel so as to test the response of the system to movement of said moveable panel; and

d) an alarm indicating means which is activated when said moveable panel being monitored is actually or simulated to be moved from the closed state to the opened state.

2. The invention of claim 1 wherein said magnet means generates a magnetic flux for causing said switch to assume said first state and wherein said self-testing means comprises magnetic means for generating a magnetic flux which cancels or diverts the magnetic flux produced by said magnet means.

3. The invention of claim 1 wherein said self-testing means is controllable from a remote location.

4. The invention of claim 1 wherein said magnet means comprises at least one electromagnet and said self-testing means comprises a current reducing means connected to said at least one electromagnet for reducing the current flow thereto so as to simulate movement of said moveable member from a closed position with respect to said frame part.

5. The invention of claim 1 further comprising a tamper switch.

6. The invention of claim 1 wherein said magnet means comprises at least one permanent magnet for producing a first magnetic flux and said self-testing means comprises at least one electromagnet mounted within a door magnet unit for generating a second magnetic flux which reduces the effect of said first magnetic flux produced by said at least one permanent magnet.

7. The invention of claim 6 wherein said second magnetic flux produced by said at least one electromagnet substantially cancels said first magnetic flux produced by said at least one permanent magnet.

8. The invention of claim 6, wherein said second magnetic flux produced by said at least one electromagnet causes diversion of said first magnetic flux produced by said permanent magnet.

9. The invention of claim 6 further comprising a tamper switch mounted in an actuating unit and mounted on a vault door.

10. The invention of claim 6 wherein said at least one permanent magnet comprises a plurality of permanent magnets and wherein a said electromagnet is disposed adjacent each of said permanent magnets.

11. The invention of claim 6 wherein said at least one permanent magnet comprises a plurality of permanent magnets and wherein a said at least one electromagnet is disposed between said plurality of permanent magnets.

12. The invention of claim 1 wherein said magnet means comprises a magnet for producing a magnetic flux for retaining said switch in said first state and said self-testing means comprises a magnetic coil for producing a flux field which reduces the effect of the flux field produced by magnet to an extent that enables switching of said switch from said first state thereof to said second state thereof.

13. The invention of claim 12 wherein said switch unit comprises a reed switch and a biasing magnet for biasing said reed switch into said second state thereof.

14. The invention of claim 13 wherein said biasing magnet is disposed adjacent to said reed switch.

15. The invention of claim 13 wherein a magnetic coil is disposed around said biasing magnet.

16. A security device and monitoring system for monitoring the closed status of a door, comprising:

(a) a switch means adapted to be mounted on a door frame of a door being monitored, said switch means further comprising at least one magnetically biased switch connected to at least one electrical monitoring circuit including an alarm means wherein said switch means is switchable between first and second states;

(b) a magnet means to be mounted on the said door, said magnet means further comprising at least one magnet for causing said switch to assume said first state when said closure member is closed with respect to said door frame, and for causing said switch means to assume said second state when said door is opened with respect to said door frame;

(c) a self-testing means controllable from a remote location for magnetically simulating the effect of movement of said door from said door frame so as to test the response of said system to said opening of said door, wherein said at least one magnet further comprises at least one permanent magnet for producing a first magnetic flux and said self-testing means comprises at least one electromagnet mounted within said magnet means for generating a second magnetic flux which reduces the effect of the first magnetic flux produced by said at least one permanent magnet;

(d) a tamper means for detecting tampering to said security system; and

wherein the alarm means is activated when the door being monitored is actually or simulated to be opened or when said security system is being tampered with.

17. The invention of claim 16 wherein the magnetic flux produced by said at least one electromagnet substantially cancels the magnetic flux produced by said permanent magnet.

18. The invention of claim 16 wherein the magnetic flux produced by said at least one electromagnet causes diversion of the magnetic flux produced by said permanent magnet.

19. A testing device as claimed in claim 16 wherein said at least one permanent magnet comprises a plurality of permanent magnets and wherein a said electromagnet is disposed adjacent each of said permanent magnets.

20. A self-testing device and monitoring system for panel closure monitoring, comprising:

a) a switch unit adapted to be mounted on a frame part for a moveable panel being monitored, said switch unit further comprising at least one magnetically biased switch connected to at least one electrical monitoring circuit, said switch unit switchable between first and second states;

b) a magnet unit adapted to be mounted on a moveable panel being monitored by said security system, said magnet unit further comprising at least one magnet for enabling said switch unit to assume said first state when said moveable panel is closed with respect to said frame part and for causing said switch to assume said second state when said moveable panel is opened with respect to said frame part, wherein said at least one magnet generates a magnetic flux for causing said switch to assume said first state;

c) a self-testing means controllable from a remote location for magnetically simulating the effect of movement of the moveable panel from the closed position to the open position without any actual movement of said moveable panel so as to test the response of the system to movement of said moveable panel, wherein self-testing means comprises magnetic means for generating a magnetic flux which cancels or diverts the magnetic flux produced by said magnet means;

d) a tamper means for detecting tampering to said security system; and

e) an alarm indicating means which is activated when said moveable panel being monitored is actually or simulated to be moved from the closed state to the opened state or when said security system is being tampered with.