Method and apparatus for inhibiting article theft

Claim 1

A system for monitoring the unauthorized movement of articles along a prescribed path, said system comprising: a. transmitting means located proximate to said prescribed path, said means transmitting first and second signals of different frequencies; b. receiver means associated with an article the unauthorized movement of which is to be monitored, said receiver including: i. first means for receiving said first signal and providing a first output signal at the first output terminal thereof; ii. power supply means for energizing said first means and coupled to the first output terminal of said first means, said power supply means being responsive to the first output signal to provide power at its power supply output terminal upon receipt of said first output signal, said terminal being coupled to the receiver circuit elements; iii. second means for receiving said second signal and providing a second output signal at the second output terminal thereof; iv third means for receiving a third signal and providing a third output signal at the third output terminal thereof; v logic means coupled to said second and third output terminals, said logic means having a fourth output terminal coupled to said power supply means and providing a fourth output signal in response to said second signal, the receipt of said fourth output signal by said power supply means causing power to be provided at the power supply output terminal, said logic means being inhibited by the receipt of said third output signal to provide no output signal; and vi firing means including a firing device and coupled to the fourth output terminal of said logic means for receiving the fourth output signal and actuating said firing device to indicate the unauthorized movement of the monitored article.

Claim 2

A system for monitoring the unauthorized movement of articles along a prescribed path, said system comprising: a. transmitting means located proximate to said prescribed path, said means transmitting first and second signals of different frequencies; b. receiver means associated with an article the unauthorized movement of which is to be monitored, said receiver including: i. first means for receiving said first signal and providing a first output signal at the first output terminal thereof; ii. power supply means for energizing said first means and coupled to the first output terminal of said first means, said power supply means being responsive to the first output signal to provide power at its power supply output terminal upon receipt of said first output signal, said terminal being coupled to the receiver circuit elements; iii. second means for receiving said second signal and providing a second output signal at the second output terminal thereof; iv third means for receiving a third signal and providing a third output signal at the third output terminal thereof; v logic means coupled to said second and third output terminals, said logic means having a fourth output terminal coupled to said power supply means and providing a fourth output signal in response to said second signal, the receipt of said fourth output signal by said power supply means causing power to be provided at the power supply output terminal, said logic means being inhibited by the receipt of said third output signal to provide no output signal; and vi firing means including a firing device and coupled to the fourth output terminal of said logic means for receiving the fourth output signal and actuating said firing device to indicate the unauthorized movement of the monitored article.

Claim 17

A method for inhibiting the unauthorized movement of articles along a defined path which comprises the steps of: a. transmitting first frequency and second frequency signals across a portion of said defined path; b providing said article with receiver means responsive to the first and second signals when said article is moved within said portion of the defined path; c filtering said first and second signals; d detecting the presence of a third frequency signal in said receiver means and inhibiting circuit action in response thereto. e producing a firing signal in response to the receipt of said first and second signals and the absence of said third signal to thereby indicate the unauthorized movement of articles along said defined path.

Claim 18

A method for inhibiting the unauthorized movement of articles along a defined path which comprises the steps of: a. transmitting first frequency and second frequency signals across a portion of said defined path; b providing said article with receiver means responsive to the first and second signals when said article is moved within said portion of the defined path; c filtering said first and second signals; d detecting the presence of a third frequency signal in said receiver means and inhibiting circuit action in response thereto. e producing a firing signal in response to the receipt of said first and second signals and the absence of said third signal to thereby indicate the unauthorized movement of articles along said defined path.

Claim 19

A system for monitoring the unauthorized movement of articles along a prescribed path, said system comprising: a transmitting means located proximate to said prescribed path, said means transmitting first and second signals of different frequencies; b receiver means associated with an article the unauthorized movement of which is to be monitored, said receiver including: i first means for receiving said first signal and providing a first output signal at the first output terminal thereof; ii a power supply having an output terminal coupled to the first means for receiving said first signal; iii power switch means coupled to the power supply output terminal, said power switch means receiving the first output signal and causing receiver circuit elements to be energized in response thereto; iv second means for receiving said second signal and providing a second output signal at the second output terminal thereof; v circuit means coupled to said second output terminal and having a third output terminal coupled to said power switch means, said circuit means providing a third output signal in response to said second output signal, and vi firing means including a firing device and coupled to said circuit means for receiving the third output signal and actuating said firing device to indicate the unauthorized movement of the monitored article.

Claim 20

A system for monitoring the unauthorized movement of articles along a prescribed path, said system comprising: a transmitting means located proximate to said prescribed path, said means transmitting first and second signals of different frequencies; b receiver means associated with an article the unauthorized movement of which is to be monitored, said receiver including: i first means for receiving said first signal and providing a first output signal at the first output terminal thereof; ii a power supply having an output terminal coupled to the first means for receiving said first signal; iii power switch means coupled to the power supply output terminal, said power switch means receiving the first output signal and causing receiver circuit elements to be energized in response thereto; iv second means for receiving said second signal and providing a second output signal at the second output terminal thereof; v circuit means coupled to said second output terminal and having a third output terminal coupled to said power switch means, said circuit means providing a third output signal in response to said second output signal, and vi firing means including a firing device and coupled to said circuit means for receiving the third output signal and actuating said firing device to indicate the unauthorized movement of the monitored article.