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Voice communication for elevator

  • US 5,345,046 A
  • Filed: 05/03/1993
  • Issued: 09/06/1994
  • Est. Priority Date: 07/23/1991
  • Status: Expired due to Term
First Claim
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1. Apparatus for ringing a telephone in a building having at least one elevator with a trapped passenger, comprising:

  • control means (18), responsive to a trapped passenger signal (30, 32,

         34) indicative of a trapped passenger in the elevator car, for providing a communications initiating signal (60);

    a ring voltage source (64), responsive to the initiating signal, for providing a ring voltage signal;

    a switch (62), responsive to the initiating signal, for providing the ring voltage signal for annunciating the telephone;

    a hook switch detector (66), responsive to a handset switch indicative of the telephone handset being picked up or the telephone being otherwise answered, for providing an off-hook signal; and

    an analog switch (54), responsive to the off-hook signal, for providing a voice communication signal path between the telephone and the car.

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