Stolen equipment recovery device
First Claim
1. A device for detecting the unauthorized movement or asportation of a body which comprises:
- a check station having;
means for transmitting a first pulse-coded signal;
means for receiving a second pulse-coded signal;
means for comparing the first signal to the second signal;
means, responsive to said means for comparing, for signaling the reception of the second signal;
on the body, a code-repeating transceiver having;
means for receiving said first signal;
means, responsive to said first signal, for transmitting said second signal, said means for receiving comprising;
a shift register receiving said first signal on its serial input and delivering said second signal on its serial output;
switchable means for selectively enabling the operation of the code-repeating transceiver.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and necessary apparatus for detecting the unauthorized operation or asportation of mobile or portable equipment. The apparatus comprises a concealable transmitter designed to re-transmit a coded message received from a check station. The check station may be stationary such as at the exit gate of a garage or at a fixed checkpoint along a thoroughfare; or may be carried on a vehicle such as a police car or other type of security patrol. The concealed repeating transmitter is switched on or off by means of a pocket-sized short-range coded remote switch unit not unlike those used for the remote control of household television receivers.
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Citations
11 Claims
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1. A device for detecting the unauthorized movement or asportation of a body which comprises:
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a check station having; means for transmitting a first pulse-coded signal; means for receiving a second pulse-coded signal; means for comparing the first signal to the second signal; means, responsive to said means for comparing, for signaling the reception of the second signal; on the body, a code-repeating transceiver having; means for receiving said first signal; means, responsive to said first signal, for transmitting said second signal, said means for receiving comprising; a shift register receiving said first signal on its serial input and delivering said second signal on its serial output; switchable means for selectively enabling the operation of the code-repeating transceiver. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for detecting the unauthorized movement or asportation of a body which comprises the steps of:
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concealing upon said body a remotely energizable and remotely activable signal-emitting device; remotely energizing said signal-emitting device before it is left unattended; at a check station, emitting a stimulus signal capable of remotely activating said signal-emitting device when said device is in the proximity of said station, said stimulus comprising a carrier frequency modulated by a pulse-train which can be stored and transmitted back from the signal emitting device to the check station; listening for a return signal from said signal-emitting device responsive to said stimulus signal; interpreting said return signal; and in function of said interpretation, indicating the proximate presence of said body. - View Dependent Claims (11)
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Specification