Patents by Inventor James J. Porter

James J. Porter has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4172967
    Abstract: This device enables apartment dwellers to communicate with and thereby identify persons desiring ingress to an apartment building through a controlled access vestibule. The convenience and security of a conventional intercom is provided by this device, but without substations and their associated dedicated wiring. Communication is initiated via residential telephones which effect a ringing signal (to be sent) from the central telephone office to the device. This device automatically answers the incoming call on the line, transmits an audible signal in the preferred embodiment, enables voice communication, and disconnects.
    Type: Grant
    Filed: June 14, 1978
    Date of Patent: October 30, 1979
    Assignee: James John Porter
    Inventors: James J. Porter, Robert G. Bresler