PREVENTION OF UNAUTHORIZED MOVEMENT OF ARTICLES BETWEEN PREDETERMINED AREAS

• US 3,609,741 A
• Filed: 03/21/1969
• Issued: 09/28/1971
• Est. Priority Date: 03/21/1969
• Status: Expired due to Term

• Current Assignee: Wendell S. Miller
• Original Assignee: Wendell S. Miller
• Inventors: Miller, Wendell S.
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Bobbitt, J. Michael
• Application Number:
  US04/809,259
• Time in Patent Office: 921 Days
• Field of Search: 340/152TR,312,258,280,276,224,420,421,171 325/8,16,21,29
• US Class Current: 340/568.1
• CPC Class Codes: G08B 13/14 by lifting or attempted removal of hand-portable articles

Abstract

A system for indicating an attempt to move an article, such as a piece of baggage or an article of merchandise, between predetermined areas, by providing a radio transmitter and radio receiver between the areas, and providing on the article a device having electrical circuitry adapted to receive from the transmitter a signal at a first frequency, and retransmit a radio signal of changed frequency, with the receiver being constructed to respond to and indicate the presence of the return signal. A person authorized to move the baggage or other article may have a key adapted to disable the circuitry against transmission of the changed frequency signal, or otherwise alter the signal, in a manner indicating to the receiver his authorization.

Claims

1. Apparatus for detecting an attempted unauthorized movement of an article between two areas, comprising means for transmitting a first radio signal at or near said areas, circuitry carried by said article responsive to said first signal and operable to transmit a second and different radio signal, means responsive to said second signal and operable to indicate whether an attempted movement of said article is authorized, and a control key device which is separable from said article and is adapted to alter the response of said circuitry to said first signal in a manner which may be sensed by said last mentioned means to indicate that a person having the key device is authorized to move the article.

2. Apparatus as recited in claim 1, in which said circuitry in a predetermined normal condition is responsive to said first signal to produce said second signal, said control key device being operable to disable the circuitry against transmission of said second signal.

3. Apparatus as recited in claim 1, in which said circuitry includes an antenna for receiving said first signal, a rectifier for producing said second signal from said first signal at a frequency which is a harmonic of the frequency of the first signal, and an antenna for emitting said second signal, said key device being movable to a predetermined position relative to said circuitry and operable to short circuit said circuitry in a relation preventing transmission of said second signal, there being means on said article defining a receptacle for removably retaining said key at said position.

4. Apparatus as recited in claim 1, in which said circuitry includes an antenna for receiving said first signal, a rectifier for rectifying the received first signal to produce an output of doubled frequency, and a transmitting antenna for transmitting said second signal at said doubled frequency.

5. Apparatus as recited in claim 1, including holder means for removably receiving and holding said key device at a predetermined active position in which its presence has an effect on said second signal.

6. A device for detecting an attempted unauthorized movement of an article between two areas, comprising a structure to be carried by the article and having circuitry adapted to receive a first radio signal from a transmitter at or near said areas, and responsive to said first signal to produce a second and different radio signal for indicating by said second signal whether an attempted movement of the article is authorized, and a control key device which is separable from said structure and adapted to be carried by an authorized person and is adapted to alter the response of said circuitry to said first signal in a relation indicating that the person is authorized.

7. A device as recited in claim 6, in which said circuitry is a transponder circuit utilizing the received power of said first signal to produce said second signal.

8. A device as recited in claim 6, including holder means for removably receiving and holding saId key device at a predetermined active position in which its presence has an effect on said second signal.

9. A device as recited in claim 6, in which said circuitry includes antenna means for receiving said first signal, rectifier means for rectifying said first signal and producing said second signal at a frequency which is a harmonic of the frequency of the first signal, and antenna means for emitting said second signal, there being a socket for removably receiving said key device, said key device being operable when in said socket to disable said circuitry against production of said second signal.

10. The combination comprising an article which may be removed from a predetermined area, and a device carried by said article for indicating an attempted unauthorized removal of the article from said area, said device including circuitry adapted to receive a first radio signal from a transmitter at or near said area, and responsive to said first signal to produce a second and different radio signal for indicating by said second signal whether an attempted removal of the article is authorized, and a control key which is separable from said device and is adapted to alter the response of said circuitry to said first signal in a relation indicating that a person having said key is authorized.

11. The combination as recited in claim 10, in which said article is an article of baggage.

12. The method of detecting an attempted unauthorized movement of an article between two areas, comprising requiring said article to be carried past a detection station if it is moved between said areas, transmitting a radio signal to said article as it passes said station, providing the article with circuitry responsive to said transmitted signal and operable to transmit a second radio signal, monitoring said second signal as an indication of whether an unauthorized movement of the article is being attempted, applying a key to said circuitry if movement of said article is authorized, changing the condition of said circuitry by use of said key, and detecting said change in condition of the circuitry through a change in said second signal.

13. Apparatus for detecting an attempted unauthorized movement of an article between two areas, comprising circuitry carried by said article and operable to transmit a radio signal which is to be monitored by a receiver and which indicates whether said movement of the article is authorized, and a key which is separable from said article and is adapted to alter the transmission of said radio signal in a manner which may be sensed by said receiver to indicate that a person having the key is authorized.

14. The method of detecting attempted unauthorized movement of any of a number of articles between two ares, comprising requiring said articles to be carried past a detection station upon such movement, monitoring radio signals received from circuitry carried by said articles as they are moved past said station, converting said circuitry of any article authorized for said movement to a condition different from that of any articles not authorized for said movement by means of keys carried by authorized persons and separable from said articles, and distinguishing between said authorized and unauthorized articles by differences in said monitored radio signals.

15. Apparatus for controlling movement of an article between two areas;

comprising means to be located at or near said areas and operable to transmit a first radio signal to circuitry carried by said article;

means for receiving a response signal from said circuitry and determining therefrom whether or not said movement of the article is authorized;

a turnstile or other movement controlling structure between said areas; and

means controlling operation of said turnstile or other movement controlling structure in correspondence with changes in said response signal.

16. The method of detecting an attempted unauthorized movement of an article between two areas, comprising requiring said article to be carrIed past a detection station if it is moved between said areas, transmitting a radio signal to said articles as it passes said station, providing the article with circuitry responsive to said transmitted signal and operable to transmit a second radio signal, monitoring said second signal as an indication of whether an unauthorized movement of the article is being attempted, and applying to said circuitry a third radio signal intense enough to purposely destroy its capacity to produce said second signal, if said movement of the article is to be authorized.