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Emergency vehicle traffic controller

  • US 3,881,169 A
  • Filed: 06/01/1973
  • Issued: 04/29/1975
  • Est. Priority Date: 06/01/1973
  • Status: Expired due to Term
First Claim
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1. A traffic controller for regulating traffic flow through a traffic intersection equipped with a traffic signal comprising:

  • a. detector means responsive to an audible, transmitted audio frequency warning signal which has been transmitted through the atmosphere from an emergency vehicle;

    b. frequency selective means connected with said detector means for determining the presence of a plurality of selected audio frequencies in the transmitted signal;

    c. timing means connected with said frequency selective means for determining whether all of said plural selected signals occur within a selected time interval; and

    d. control means connected with said timing means and said frequency selective means and operable upon the occurrence of said plural selected signals within said selected time interval to operate said traffic signal in a non-normal, predetermined manner.

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