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Use of public subscriber telephone network; method and apparatus

  • US 3,947,641 A
  • Filed: 06/03/1974
  • Issued: 03/30/1976
  • Est. Priority Date: 06/07/1973
  • Status: Expired due to Term
First Claim
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1. The method of utilizing a public subscriber telephone network for door signalling and opening purposes by means of a telephone set connected to said telephone network, said set being arranged outside the entrance door of an apartment house or any other entrance door and intended for the purpose of communication between a visitor and a tenant inside said entrance door, when locked, said visitor thus being able to make a call from said telephone set, hereinafter called the "entrance set", to the subscriber telephone set, hereinafter called the "reply set", of any desired tenant, caretaker or other party authorized to release the entrance door lock of said entrance door, the communication thus established via said telephone network between the entrance set and the reply set enabling, apart from conversation, the called party to initiate the release of said entrance door lock, said method comprising the steps of,employing the common public subscriber telephone network, including common automatic exchanges, common telephone numbers and common subscriber telephone sets for all communication between the entrance set and the reply set,providing the entrance set with switching means by which it can be coupled onto a telephone line going out to the automatic exchanges of said telephone network, means for number selecting and means for verbal communication,providing the entrance set with means connected to said entrance door lock responsive to signals received via said telephone network and induced from a reply set after establishment of telephone contact between the entrance set and any reply set for thereupon releasing said door lock, andproviding the entrance set, when intended only for contact via the telephone network with an authorized party for release of the entrance door lock, with number discriminating means, programmable for desired telephone numbers or their equivalents, for securing that only said programmed numbers will be connected through said telephone network in a way that enables reply sets to actuate the release of said entrance door lock.

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