Alarm apparatus for handgun security

• US 5,196,827 A
• Filed: 05/13/1991
• Issued: 03/23/1993
• Est. Priority Date: 05/13/1991
• Status: Expired due to Fees

• Current Assignee: Leon A. Chavis, William J. Allen
• Original Assignee: Leon A. Chavis, William J. Allen
• Inventors: Allen, William J., Chavis, Leon A.
• Primary Examiner(s): Ng, Jin F.
• Assistant Examiner(s): Oda, Christine K.
• Application Number:
  US07/698,788
• Time in Patent Office: 680 Days
• Field of Search: 340/568, 340/540, 340/666, 340/665, 340/510, 340/595, 340/599
• US Class Current: 340/568.1
• CPC Class Codes: F41A 23/18 Rests for supporting smallarms in non-shooting position racks for storage A47B81/00; racks in vehicles B60R7/14
• CPC Class Codes: G08B 13/1472 with force or weight detection

Abstract

An alarm apparatus for detecting the removal of a handgun from a plate where the handgun is kept for quick accessibility. Embedded sensors detect the force exerted by the handgun on the plate. A handgun is placed on the plate and upper and lower threshold controls are adjusted to create a window encompassing the force exerted by the handgun. An alarm sounds if the force on the plate exceeds the window.

Claims

1. An alarm apparatus for sensing the removal of a handgun, comprising:

a lower base plate;

an upper base plate separate from said lower base plate and disposed above and adjacent to the lower base plate, the upper base plate having an upper surface for placement of said handgun on said surface;

at least one alarm means for producing an alarm signal in response to an alarm activation signal;

a symmetrical array of force sensors disposed directly between said lower base plate and said upper base plate and secured to one of said plates, said force sensors each comprising a thin membrane having an electrical property which varies in response tot he force applied to each of said force sensors by said upper and lower base plates;

a cushioning pad located directly between each of said force sensors and one of said plates for cushioning said sensors;

a sensor signal means for providing a voltage comprising a sensor signal proportional to said electrical property of each of said force sensors;

an upper threshold means for providing an upper sensor signal level, the upper threshold means including means for adjusting said upper sensor signal level in response to the force applied by said handgun on said upper base plate;

a lower threshold means for providing a lower sensor signal level, the lower threshold means including means for adjusting the lower sensor signal level in response to the force applied by said handgun on said upper plate;

the upper and lower sensor signal levels together defining a force threshold window encompassing the force exerted by the handgun weight on said upper plate;

a compressor means for detecting said sensor signal and generating an alarm activation signal in response to said sensor signal falling outside the force threshold window bounded by said upper and lower sensor signal levels; and

a reset means for resetting the alarm apparatus.

2. The alarm apparatus as in claim 1 wherein said electrical property of said force sensor is resistance.

3. The alarm apparatus as in claim 1 wherein said alarm means comprises an audible alarm means for providing an audible alarm signal.

4. The alarm apparatus as in claim 3 wherein said audible alarm means is a piezoelectric device.

5. The alarm apparatus as in claim 1 further comprising a sensitivity means for establishing the minimum duration of said alarm activation signal necessary to activate said alarm means.

6. The alarm apparatus as in claim 5 wherein said sensitivity means comprises a low pass filter.

7. The alarm apparatus as in claim 1 wherein said lower threshold means comprises a first variable resistor and said upper threshold means comprises a second variable resistor.

8. An alarm apparatus for sensing the removal of a handgun, comprising:

a lower base plate;

an upper base plate disposed above and adjacent to the lower base plate, the upper base plate having an upper surface for placement of said handgun on said surface;

alarm means for producing an alarm signal in response to an alarm activation signal;

at least one force sensor disposed between said lower base plate and said upper base plate, said force sensor having an electrical property which varies in response to the force applied to said force sensor by said upper and lower base plates;

a sensor signal means for providing a voltage comprising a sensor signal proportional to said electrical property of said force sensor;

an upper threshold means for providing an upper sensor signal level;

a lower threshold means for providing a lower sensor-signal level;

comparator means for detecting said sensor signal and generating an alarm activation signal in response to said sensor signal falling outside a signal range bounded by said upper and lower sensor signal levels;

said alarm means comprising a first audible alarm means for providing a first audible alarm signal in response to said alarm activation signal and a second audible alarm means for producing a second audible alarm signal with said first audible alarm signal;

said first and second audible alarm signals differing in at least one audible characteristic;

automatic reset means for deactivating said first audible alarm means in response to detection of said sensor signal within said signal range; and

reset means for deactivating said second audible alarm means and resetting the alarm apparatus.

9. The alarm apparatus in claim 8 wherein said first and second audible alarm means are piezoelectric devices.

10. An alarm apparatus for detecting unauthorized removal of a handgun, comprising:

a platform having an upper surface for placement of said handgun on the surface;

the platform comprising an upper base plate on which said handgun is placed, a lower base plate separate from said upper base plate, and a force sensing means located directly between the upper surface of said lower plate and the lower surface of said upper plate for detecting force applied on said sensing means and producing a sensor output signal proportional to the applied force, the force sensing means comprising a symmetrical array of thin membrane force sensing members;

a cushioning pad located between each one of said force sensing members and one of said plates for cushioning said member;

comparator means connected to said sensing means for comparing said sensor output signal to a predetermined signal range and for producing an alarm activation signal if said sensor output signal falls outside said range;

said comparator means including an upper and a lower signal level control means for controlling the upper and lower limits of said predetermined signal range to define a force threshold window encompassing the sensor output signal produced by the weight of the handgun on said platform; and

alarm means connected to said comparator means for producing an alarm signal in response to said alarm activation signal.

11. The apparatus as claimed in claim 10, wherein said upper and lower signal level control means comprise variable resistors.

12. A method of detecting unauthorized removal of a handgun, comprising the steps of:

placing the handgun on the upper surface of a sensor platform having upper and lower base plates and force sensing means located between the plates;

connecting the output signal of the force sensing means produced by the weight of the handgun to a comparator circuit;

connecting threshold setting inputs of the comparator circuit to a lower threshold setting circuit and an upper threshold setting circuit;

adjusting the threshold setting circuits to provide a lower threshold level which is a predetermined amount below said output signal and an upper threshold level which is a predetermined amount above said output signal;

the upper and lower threshold levels together defining a force threshold window encompassing the output signal produced by the weight of the handgun;

providing an alarm signal from the comparator circuit to activate an audible alarm if the output of the force sensing means is outside the force threshold window.

13. The method as claimed in claim 12, wherein the step of adjusting the threshold setting comprises adjusting each of the threshold setting circuits in turn with the handgun in place until the alarm is activated, and then adjusting the setting slightly away from the alarm activating position.