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Automatic hangup apparatus for restoring service to off-hook telephones

  • US 4,922,529 A
  • Filed: 12/06/1988
  • Issued: 05/01/1990
  • Est. Priority Date: 12/06/1988
  • Status: Expired due to Term
First Claim
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1. An automatic telephone hangup apparatus for use with a telephone connected to the telephone lines of a telephone system of the type which provides an audible off-hook alert signal which is characterized by containing at least one prearranged identifying frequency to warn the user that his telephone has been left off-hook, wherein the telephone has a voice network and a hookswitch, and wherein the hookswitch is connected between the voice network and the telephone lines so as to connect the voice network to the telephone lines when the hookswitch is closed, and so as to disconnect the voice network from the telephone lines when the hookswitch is open, said automatic telephone hangup apparatus comprising:

  • frequency-discriminating off-hook alert signal detecting means for coupling to said telephone lines for detecting signals within a pass band including said identifying frequency and for generating in response thereto an automatic hangup signal;

    automatic hangup means for coupling to said telephone and to said alert signal detecting means, for responding to said automatic hangup signal by disconnecting said voice network from said lines.

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