ALARM APPARATUS FOR FACILITATING THE DETECTION OF AN UNAUTHORIZED REMOVAL OF PROPERTY

• US 3,828,341 A
• Filed: 01/20/1972
• Issued: 08/06/1974
• Est. Priority Date: 01/20/1972
• Status: Expired due to Term

• Current Assignee: Charles H. Carter Jr, Stewart M. Newfeld
• Original Assignee: Charles H. Carter Jr, Stewart M. Newfeld
• Inventors: Carter, Charles H. Jr., Newfeld, Stewart M.
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Wannisky, William M.
• Application Number:
  US05/219,349
• Time in Patent Office: 929 Days
• Field of Search: 340/280,421,224,258R,283,146.3 343/6,228 325/496,310 286/2,30
• US Class Current: 340/568.7
• CPC Class Codes: G08B 13/24 by interference with electromagnetic field distribution
• CPC Class Codes: G08B 13/2431 Tag circuit details
• CPC Class Codes: G08B 13/2445 Tag integrated into item to be protected, e.g. source tagging
• CPC Class Codes: G08B 15/00 Identifying, scaring or incapacitating burglars, thieves or intruders, e.g. by explosives

Abstract

An alarm packet of simulated paper currency contains alarm means and alarm-operating circuitry such that, when the packet is removed through an exit irradiated with a local field, the alarm means will thereby be automatically actuated to produce an alarm, as by the release of smoke, tear gas, or staining materials, or by producing alarm sounds, etc. Such a packet is placed with the currency given to a bank robber, and facilitates his apprehension and/or recovery of the loot. The electrical circuitry for actuating the alarm is constructed to prevent operation of the alarm until the packet has been taken into the local field and removed therefrom, so that it will not operate if the robber lingers in the exit area within the field. Preferably the removal of the packet from the local field initiates a timing cycle for further delaying actuation of the alarm means, and provision is made so that if the packet is returned to the local field at the exit before the timing cycle is completed the alarm means will not be actuated and the timing cycle will be reset. The field is preferably an alternating magnetic near-field radiation having a frequency of less than about 3,200 Hz, the preferred frequency range being about 400 to about 1,600 Hz.

Claims

1. In an alarm packet useful in impeding the successful robbery of paper currency from a bank having an exit irradiated with a local alternating electromagnetic field, said packet comprising a packet of simulated paper currency;

electrically operable alarm means concealed within said packet and responsive to an electrical alarm signal to produce an alarm; and

an alarm-signal generating circuit concealed within said packet for operating said alarm means;

the improvement wherein said alarm-signal generating circuit comprises;

receiver means for receiving, amplifying and rectifying said local alternating magnetic field to produce a direct-voltage input signal of greater than a first level only when said packet is within said field, a first SCR, a direct-voltage supply source for supplying anode-to-cathode voltage for said first SCR, means normally biasing the gate electrode of said first SCR at a level for which said SCR is non-conductive, means supplying said gate electrode with said input signal to render said SCR conductive when said input voltage exceeds said first level, a timing resistor and a timing capacitor connected in series across said supply source, timing-cycle start means connected in parallel with said capacitor and normally conductive to prevent said capacitor from charging to a predetermined voltage level, means responsive to the simultaneous occurrence of said conductive state in said SCR and to the absence of said first level of said input signal for reducing the conductivity of said timing-cycle start means sufficiently to allow said capacitor to charge to said predetermined voltage level, and threshold means responsive to the occurrence of said predetermined voltage level across said capacitor to actuate said alarm means, said timing-cycle start means being responsive to the presence of said level of said input signal to resume its conductive state and discharge said timing capacitor.

2. The alarm packet of claim 1, in which said timing-cycle start means comprises a normally on transistor and a normally off transistor in parallel with each other, a load element connecting said parallel combination across said supply source, means connecting the control electrode of said normally on transistor with said SCR to turn off said normally on transistor when SCR is turned on, means for supplying the control electrode of said normally off transistor with said input signal, and unilaterally conductive means connecting said parallel combination to said timing capacitor in the polarity to be blocked when both of said transistors are in their off condition.

3. The alarm packet of claim 2, in which said alarm means comprises an electric match and a heat-releasable material adjacent said electric match, whereby when current is Passed through said electric match said material is released to the exterior of said packet.

4. In apparatus for use in protecting against unauthorized removal of property from an area along a path extending through a localized field, said apparatus being adapted to be associated with said property so as to be removed from said area along with said property during an unauthorized removal thereof, said apparatus comprising an electrical alarm system responsive to removal of said apparatus from said area through said localized field to produce an alarm, said alarm system comprising means for preventing occurrence of said alarm until said apparatus has entered and then been removed from said localized field, means responsive to said removal from said field to enable said alarm, and means for delaying the occurrence of said alarm for a predetermined time interval after said removal from said field, the improvement comprising:

means responsive to return of said apparatus to a position within said localized field prior to the end of said time interval for preventing the occurrence of said alarm until said apparatus has again been removed from said field for longer than said time interval.

5. Apparatus in accordance with claim 4, in which said alarm apparatus comprises a packet of simulated paper currency and said alarm system is concealed within said packet.

6. In combination with the apparatus of claim 5, means for producing said localized detection field adjacent an exit from said area, said area comprising the public area of a bank.

7. In a robbery-protection alarm device adapted to be energized by the action thereon of an electrically produced local field located at an exit from the protected premises, and comprising a dummy packet of paper currency having secreted therein electrically-actuatable alarm means and electrical alarm-actuating means, the improvement wherein said alarm-actuating means comprises:

first means for sensing the presence of said alarm device in said local field and for producing a first output signal indicative thereof;

signal storage means having a normal deactuated state and an actuated state, and responsive to said first output signal to assume said actuated state and to remain in said actuated state after said first output signal disappears due to removal of said device from said field;

means responsive to said first output signal and to the state of said signal storage means for producing a second output signal only when said signal storage means is in said actuated state and said first output signal is simultaneously absent;

means responsive to said second output signal for operating said alarm means;

said signal storage means comprising a solid-state controlled rectifier having a control electrode supplied with said first output signal for turbing on said controlled rectifier when said first output signal occurs, said means for producing a second output signal co mprising a first nor mally on transistor and a second normally off transistor having their emitter-collector current paths in parallel with each other, means for maintaining said first transistor in its off state when said controlled rectifier is in its on state, and means for maintaining said second transistor in its on state only when said first output sitnal is present, whereby the parallel combination of said first and second transistor becomes non-conductive to produce said second output signal only after said first output signal has appeared and then disappeared;

said means for operating said alarm means comprising a timing circuit supplied with said second output signal to initiate a timing cycle for delaying operation of said alarm means for a predetermined interval of time following the occurrence of said second output signal;

said timing circuit comprising a timing capacitor effectively in parallel with said parallel combination of said first and second transistors so as to charge when said parallel combination is non-conDuctive and when said alarm device is returned to a position within said field said timing capacitor is discharged through said parallel combination and said timing circuit thereby reset.