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Arrangement for preventing a motor vehicle from passing a specific place unauthorized

  • US 5,798,714 A
  • Filed: 09/24/1996
  • Issued: 08/25/1998
  • Est. Priority Date: 03/24/1994
  • Status: Expired due to Fees
First Claim
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1. A system for preventing unauthorized passage of a motor vehicle past a specific location, said system comprising:

  • a stationary transmitter mounted at the specific location for transmitting a first radio signal;

    a receiver mounted in the vehicle for receiving the first radio signal;

    check means mounted in the vehicle for checking whether the vehicle is authorized to pass the specific location and for activating at least one circuit in the vehicle to render the vehicle undrivable selectively, said receiver activating said check means upon receipt of the first radio signal, the system further comprising a vehicle-mounted transmitter for transmitting a second radio signal, wherein said stationary transmitter is a transponder that transmits the first radio signal in response to the second radio signal when said vehicle-mounted transmitter is in a range of the transponder, the first radio signal being a modulated reflected signal relative to the second radio signal.

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