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Safety device and method of establishing group communication

  • US 4,833,452 A
  • Filed: 05/04/1987
  • Issued: 05/23/1989
  • Est. Priority Date: 05/04/1987
  • Status: Expired due to Term
First Claim
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1. A personal electronic signaling apparatus used by each one of several persons moving about in a common area out of visual contact, each said apparatus comprising:

  • (a) a combined transmitter-receiver capable of transmitting a radio frequency signal over a short range and receiving radio frequency signals from transmitted radio frequency signals emanating from at least another one of said apparatus;

    (b) a combined pulse generator and a pulse interval timer cooperating together with said combined transmitter-receiver for allowing automatic transmission and reception of radio frequency signals; and

    (c) a mute pulse inverter cooperating with said transmitter-receiver for rendering said radio frequency signal receiver of said combined transmitter-receiver mute during times when transmission of radio frequency signal is active and returning said receiver to a radio frequency signal receiving mode between said active radio frequency signal transmissions.

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